4 TGSI, Tungsten Graphics Shader Infrastructure, is an intermediate language
5 for describing shaders. Since Gallium is inherently shaderful, shaders are
6 an important part of the API. TGSI is the only intermediate representation
12 All TGSI instructions, known as *opcodes*, operate on arbitrary-precision
13 floating-point four-component vectors. An opcode may have up to one
14 destination register, known as *dst*, and between zero and three source
15 registers, called *src0* through *src2*, or simply *src* if there is only
18 Some instructions, like :opcode:`I2F`, permit re-interpretation of vector
19 components as integers. Other instructions permit using registers as
20 two-component vectors with double precision; see :ref:`doubleopcodes`.
22 When an instruction has a scalar result, the result is usually copied into
23 each of the components of *dst*. When this happens, the result is said to be
24 *replicated* to *dst*. :opcode:`RCP` is one such instruction.
29 TGSI supports modifiers on inputs (as well as saturate and precise modifier
32 For arithmetic instruction having a precise modifier certain optimizations
33 which may alter the result are disallowed. Example: *add(mul(a,b),c)* can't be
34 optimized to TGSI_OPCODE_MAD, because some hardware only supports the fused
37 For inputs which have a floating point type, both absolute value and
38 negation modifiers are supported (with absolute value being applied
39 first). The only source of TGSI_OPCODE_MOV and the second and third
40 sources of TGSI_OPCODE_UCMP are considered to have float type for
43 For inputs which have signed or unsigned type only the negate modifier is
50 ^^^^^^^^^^^^^^^^^^^^^^^^^
52 These opcodes are guaranteed to be available regardless of the driver being
55 .. opcode:: ARL - Address Register Load
59 dst.x = (int) \lfloor src.x\rfloor
61 dst.y = (int) \lfloor src.y\rfloor
63 dst.z = (int) \lfloor src.z\rfloor
65 dst.w = (int) \lfloor src.w\rfloor
68 .. opcode:: MOV - Move
81 .. opcode:: LIT - Light Coefficients
86 dst.y &= max(src.x, 0) \\
87 dst.z &= (src.x > 0) ? max(src.y, 0)^{clamp(src.w, -128, 128))} : 0 \\
91 .. opcode:: RCP - Reciprocal
93 This instruction replicates its result.
100 .. opcode:: RSQ - Reciprocal Square Root
102 This instruction replicates its result. The results are undefined for src <= 0.
106 dst = \frac{1}{\sqrt{src.x}}
109 .. opcode:: SQRT - Square Root
111 This instruction replicates its result. The results are undefined for src < 0.
118 .. opcode:: EXP - Approximate Exponential Base 2
122 dst.x &= 2^{\lfloor src.x\rfloor} \\
123 dst.y &= src.x - \lfloor src.x\rfloor \\
124 dst.z &= 2^{src.x} \\
128 .. opcode:: LOG - Approximate Logarithm Base 2
132 dst.x &= \lfloor\log_2{|src.x|}\rfloor \\
133 dst.y &= \frac{|src.x|}{2^{\lfloor\log_2{|src.x|}\rfloor}} \\
134 dst.z &= \log_2{|src.x|} \\
138 .. opcode:: MUL - Multiply
142 dst.x = src0.x \times src1.x
144 dst.y = src0.y \times src1.y
146 dst.z = src0.z \times src1.z
148 dst.w = src0.w \times src1.w
151 .. opcode:: ADD - Add
155 dst.x = src0.x + src1.x
157 dst.y = src0.y + src1.y
159 dst.z = src0.z + src1.z
161 dst.w = src0.w + src1.w
164 .. opcode:: DP3 - 3-component Dot Product
166 This instruction replicates its result.
170 dst = src0.x \times src1.x + src0.y \times src1.y + src0.z \times src1.z
173 .. opcode:: DP4 - 4-component Dot Product
175 This instruction replicates its result.
179 dst = src0.x \times src1.x + src0.y \times src1.y + src0.z \times src1.z + src0.w \times src1.w
182 .. opcode:: DST - Distance Vector
187 dst.y &= src0.y \times src1.y\\
192 .. opcode:: MIN - Minimum
196 dst.x = min(src0.x, src1.x)
198 dst.y = min(src0.y, src1.y)
200 dst.z = min(src0.z, src1.z)
202 dst.w = min(src0.w, src1.w)
205 .. opcode:: MAX - Maximum
209 dst.x = max(src0.x, src1.x)
211 dst.y = max(src0.y, src1.y)
213 dst.z = max(src0.z, src1.z)
215 dst.w = max(src0.w, src1.w)
218 .. opcode:: SLT - Set On Less Than
222 dst.x = (src0.x < src1.x) ? 1.0F : 0.0F
224 dst.y = (src0.y < src1.y) ? 1.0F : 0.0F
226 dst.z = (src0.z < src1.z) ? 1.0F : 0.0F
228 dst.w = (src0.w < src1.w) ? 1.0F : 0.0F
231 .. opcode:: SGE - Set On Greater Equal Than
235 dst.x = (src0.x >= src1.x) ? 1.0F : 0.0F
237 dst.y = (src0.y >= src1.y) ? 1.0F : 0.0F
239 dst.z = (src0.z >= src1.z) ? 1.0F : 0.0F
241 dst.w = (src0.w >= src1.w) ? 1.0F : 0.0F
244 .. opcode:: MAD - Multiply And Add
246 Perform a * b + c. The implementation is free to decide whether there is an
247 intermediate rounding step or not.
251 dst.x = src0.x \times src1.x + src2.x
253 dst.y = src0.y \times src1.y + src2.y
255 dst.z = src0.z \times src1.z + src2.z
257 dst.w = src0.w \times src1.w + src2.w
260 .. opcode:: LRP - Linear Interpolate
264 dst.x = src0.x \times src1.x + (1 - src0.x) \times src2.x
266 dst.y = src0.y \times src1.y + (1 - src0.y) \times src2.y
268 dst.z = src0.z \times src1.z + (1 - src0.z) \times src2.z
270 dst.w = src0.w \times src1.w + (1 - src0.w) \times src2.w
273 .. opcode:: FMA - Fused Multiply-Add
275 Perform a * b + c with no intermediate rounding step.
279 dst.x = src0.x \times src1.x + src2.x
281 dst.y = src0.y \times src1.y + src2.y
283 dst.z = src0.z \times src1.z + src2.z
285 dst.w = src0.w \times src1.w + src2.w
288 .. opcode:: FRC - Fraction
292 dst.x = src.x - \lfloor src.x\rfloor
294 dst.y = src.y - \lfloor src.y\rfloor
296 dst.z = src.z - \lfloor src.z\rfloor
298 dst.w = src.w - \lfloor src.w\rfloor
301 .. opcode:: FLR - Floor
305 dst.x = \lfloor src.x\rfloor
307 dst.y = \lfloor src.y\rfloor
309 dst.z = \lfloor src.z\rfloor
311 dst.w = \lfloor src.w\rfloor
314 .. opcode:: ROUND - Round
327 .. opcode:: EX2 - Exponential Base 2
329 This instruction replicates its result.
336 .. opcode:: LG2 - Logarithm Base 2
338 This instruction replicates its result.
345 .. opcode:: POW - Power
347 This instruction replicates its result.
351 dst = src0.x^{src1.x}
354 .. opcode:: COS - Cosine
356 This instruction replicates its result.
363 .. opcode:: DDX, DDX_FINE - Derivative Relative To X
365 The fine variant is only used when ``PIPE_CAP_TGSI_FS_FINE_DERIVATIVE`` is
366 advertised. When it is, the fine version guarantees one derivative per row
367 while DDX is allowed to be the same for the entire 2x2 quad.
371 dst.x = partialx(src.x)
373 dst.y = partialx(src.y)
375 dst.z = partialx(src.z)
377 dst.w = partialx(src.w)
380 .. opcode:: DDY, DDY_FINE - Derivative Relative To Y
382 The fine variant is only used when ``PIPE_CAP_TGSI_FS_FINE_DERIVATIVE`` is
383 advertised. When it is, the fine version guarantees one derivative per column
384 while DDY is allowed to be the same for the entire 2x2 quad.
388 dst.x = partialy(src.x)
390 dst.y = partialy(src.y)
392 dst.z = partialy(src.z)
394 dst.w = partialy(src.w)
397 .. opcode:: PK2H - Pack Two 16-bit Floats
399 This instruction replicates its result.
403 dst = f32\_to\_f16(src.x) | f32\_to\_f16(src.y) << 16
406 .. opcode:: PK2US - Pack Two Unsigned 16-bit Scalars
411 .. opcode:: PK4B - Pack Four Signed 8-bit Scalars
416 .. opcode:: PK4UB - Pack Four Unsigned 8-bit Scalars
421 .. opcode:: SEQ - Set On Equal
425 dst.x = (src0.x == src1.x) ? 1.0F : 0.0F
427 dst.y = (src0.y == src1.y) ? 1.0F : 0.0F
429 dst.z = (src0.z == src1.z) ? 1.0F : 0.0F
431 dst.w = (src0.w == src1.w) ? 1.0F : 0.0F
434 .. opcode:: SGT - Set On Greater Than
438 dst.x = (src0.x > src1.x) ? 1.0F : 0.0F
440 dst.y = (src0.y > src1.y) ? 1.0F : 0.0F
442 dst.z = (src0.z > src1.z) ? 1.0F : 0.0F
444 dst.w = (src0.w > src1.w) ? 1.0F : 0.0F
447 .. opcode:: SIN - Sine
449 This instruction replicates its result.
456 .. opcode:: SLE - Set On Less Equal Than
460 dst.x = (src0.x <= src1.x) ? 1.0F : 0.0F
462 dst.y = (src0.y <= src1.y) ? 1.0F : 0.0F
464 dst.z = (src0.z <= src1.z) ? 1.0F : 0.0F
466 dst.w = (src0.w <= src1.w) ? 1.0F : 0.0F
469 .. opcode:: SNE - Set On Not Equal
473 dst.x = (src0.x != src1.x) ? 1.0F : 0.0F
475 dst.y = (src0.y != src1.y) ? 1.0F : 0.0F
477 dst.z = (src0.z != src1.z) ? 1.0F : 0.0F
479 dst.w = (src0.w != src1.w) ? 1.0F : 0.0F
482 .. opcode:: TEX - Texture Lookup
484 for array textures src0.y contains the slice for 1D,
485 and src0.z contain the slice for 2D.
487 for shadow textures with no arrays (and not cube map),
488 src0.z contains the reference value.
490 for shadow textures with arrays, src0.z contains
491 the reference value for 1D arrays, and src0.w contains
492 the reference value for 2D arrays and cube maps.
494 for cube map array shadow textures, the reference value
495 cannot be passed in src0.w, and TEX2 must be used instead.
501 shadow_ref = src0.z or src0.w (optional)
505 dst = texture\_sample(unit, coord, shadow_ref)
508 .. opcode:: TEX2 - Texture Lookup (for shadow cube map arrays only)
510 this is the same as TEX, but uses another reg to encode the
521 dst = texture\_sample(unit, coord, shadow_ref)
526 .. opcode:: TXD - Texture Lookup with Derivatives
538 dst = texture\_sample\_deriv(unit, coord, ddx, ddy)
541 .. opcode:: TXP - Projective Texture Lookup
545 coord.x = src0.x / src0.w
547 coord.y = src0.y / src0.w
549 coord.z = src0.z / src0.w
555 dst = texture\_sample(unit, coord)
558 .. opcode:: UP2H - Unpack Two 16-Bit Floats
562 dst.x = f16\_to\_f32(src0.x \& 0xffff)
564 dst.y = f16\_to\_f32(src0.x >> 16)
566 dst.z = f16\_to\_f32(src0.x \& 0xffff)
568 dst.w = f16\_to\_f32(src0.x >> 16)
572 Considered for removal.
574 .. opcode:: UP2US - Unpack Two Unsigned 16-Bit Scalars
580 Considered for removal.
582 .. opcode:: UP4B - Unpack Four Signed 8-Bit Values
588 Considered for removal.
590 .. opcode:: UP4UB - Unpack Four Unsigned 8-Bit Scalars
596 Considered for removal.
599 .. opcode:: ARR - Address Register Load With Round
603 dst.x = (int) round(src.x)
605 dst.y = (int) round(src.y)
607 dst.z = (int) round(src.z)
609 dst.w = (int) round(src.w)
612 .. opcode:: SSG - Set Sign
616 dst.x = (src.x > 0) ? 1 : (src.x < 0) ? -1 : 0
618 dst.y = (src.y > 0) ? 1 : (src.y < 0) ? -1 : 0
620 dst.z = (src.z > 0) ? 1 : (src.z < 0) ? -1 : 0
622 dst.w = (src.w > 0) ? 1 : (src.w < 0) ? -1 : 0
625 .. opcode:: CMP - Compare
629 dst.x = (src0.x < 0) ? src1.x : src2.x
631 dst.y = (src0.y < 0) ? src1.y : src2.y
633 dst.z = (src0.z < 0) ? src1.z : src2.z
635 dst.w = (src0.w < 0) ? src1.w : src2.w
638 .. opcode:: KILL_IF - Conditional Discard
640 Conditional discard. Allowed in fragment shaders only.
644 if (src.x < 0 || src.y < 0 || src.z < 0 || src.w < 0)
649 .. opcode:: KILL - Discard
651 Unconditional discard. Allowed in fragment shaders only.
654 .. opcode:: TXB - Texture Lookup With Bias
656 for cube map array textures and shadow cube maps, the bias value
657 cannot be passed in src0.w, and TXB2 must be used instead.
659 if the target is a shadow texture, the reference value is always
660 in src.z (this prevents shadow 3d and shadow 2d arrays from
661 using this instruction, but this is not needed).
677 dst = texture\_sample(unit, coord, bias)
680 .. opcode:: TXB2 - Texture Lookup With Bias (some cube maps only)
682 this is the same as TXB, but uses another reg to encode the
683 lod bias value for cube map arrays and shadow cube maps.
684 Presumably shadow 2d arrays and shadow 3d targets could use
685 this encoding too, but this is not legal.
687 shadow cube map arrays are neither possible nor required.
697 dst = texture\_sample(unit, coord, bias)
700 .. opcode:: DIV - Divide
704 dst.x = \frac{src0.x}{src1.x}
706 dst.y = \frac{src0.y}{src1.y}
708 dst.z = \frac{src0.z}{src1.z}
710 dst.w = \frac{src0.w}{src1.w}
713 .. opcode:: DP2 - 2-component Dot Product
715 This instruction replicates its result.
719 dst = src0.x \times src1.x + src0.y \times src1.y
722 .. opcode:: TEX_LZ - Texture Lookup With LOD = 0
724 This is the same as TXL with LOD = 0. Like every texture opcode, it obeys
725 pipe_sampler_view::u.tex.first_level and pipe_sampler_state::min_lod.
726 There is no way to override those two in shaders.
742 dst = texture\_sample(unit, coord, lod)
745 .. opcode:: TXL - Texture Lookup With explicit LOD
747 for cube map array textures, the explicit lod value
748 cannot be passed in src0.w, and TXL2 must be used instead.
750 if the target is a shadow texture, the reference value is always
751 in src.z (this prevents shadow 3d / 2d array / cube targets from
752 using this instruction, but this is not needed).
768 dst = texture\_sample(unit, coord, lod)
771 .. opcode:: TXL2 - Texture Lookup With explicit LOD (for cube map arrays only)
773 this is the same as TXL, but uses another reg to encode the
775 Presumably shadow 3d / 2d array / cube targets could use
776 this encoding too, but this is not legal.
778 shadow cube map arrays are neither possible nor required.
788 dst = texture\_sample(unit, coord, lod)
792 ^^^^^^^^^^^^^^^^^^^^^^^^
794 These opcodes are primarily provided for special-use computational shaders.
795 Support for these opcodes indicated by a special pipe capability bit (TBD).
797 XXX doesn't look like most of the opcodes really belong here.
799 .. opcode:: CEIL - Ceiling
803 dst.x = \lceil src.x\rceil
805 dst.y = \lceil src.y\rceil
807 dst.z = \lceil src.z\rceil
809 dst.w = \lceil src.w\rceil
812 .. opcode:: TRUNC - Truncate
825 .. opcode:: MOD - Modulus
829 dst.x = src0.x \bmod src1.x
831 dst.y = src0.y \bmod src1.y
833 dst.z = src0.z \bmod src1.z
835 dst.w = src0.w \bmod src1.w
838 .. opcode:: UARL - Integer Address Register Load
840 Moves the contents of the source register, assumed to be an integer, into the
841 destination register, which is assumed to be an address (ADDR) register.
844 .. opcode:: TXF - Texel Fetch
846 As per NV_gpu_shader4, extract a single texel from a specified texture
847 image or PIPE_BUFFER resource. The source sampler may not be a CUBE or
849 four-component signed integer vector used to identify the single texel
850 accessed. 3 components + level. If the texture is multisampled, then
851 the fourth component indicates the sample, not the mipmap level.
852 Just like texture instructions, an optional
853 offset vector is provided, which is subject to various driver restrictions
854 (regarding range, source of offsets). This instruction ignores the sampler
857 TXF(uint_vec coord, int_vec offset).
860 .. opcode:: TXQ - Texture Size Query
862 As per NV_gpu_program4, retrieve the dimensions of the texture depending on
863 the target. For 1D (width), 2D/RECT/CUBE (width, height), 3D (width, height,
864 depth), 1D array (width, layers), 2D array (width, height, layers).
865 Also return the number of accessible levels (last_level - first_level + 1)
868 For components which don't return a resource dimension, their value
875 dst.x = texture\_width(unit, lod)
877 dst.y = texture\_height(unit, lod)
879 dst.z = texture\_depth(unit, lod)
881 dst.w = texture\_levels(unit)
884 .. opcode:: TXQS - Texture Samples Query
886 This retrieves the number of samples in the texture, and stores it
887 into the x component as an unsigned integer. The other components are
888 undefined. If the texture is not multisampled, this function returns
889 (1, undef, undef, undef).
893 dst.x = texture\_samples(unit)
896 .. opcode:: TG4 - Texture Gather
898 As per ARB_texture_gather, gathers the four texels to be used in a bi-linear
899 filtering operation and packs them into a single register. Only works with
900 2D, 2D array, cubemaps, and cubemaps arrays. For 2D textures, only the
901 addressing modes of the sampler and the top level of any mip pyramid are
902 used. Set W to zero. It behaves like the TEX instruction, but a filtered
903 sample is not generated. The four samples that contribute to filtering are
904 placed into xyzw in clockwise order, starting with the (u,v) texture
905 coordinate delta at the following locations (-, +), (+, +), (+, -), (-, -),
906 where the magnitude of the deltas are half a texel.
908 PIPE_CAP_TEXTURE_SM5 enhances this instruction to support shadow per-sample
909 depth compares, single component selection, and a non-constant offset. It
910 doesn't allow support for the GL independent offset to get i0,j0. This would
911 require another CAP is hw can do it natively. For now we lower that before
920 dst = texture\_gather4 (unit, coord, component)
922 (with SM5 - cube array shadow)
930 dst = texture\_gather (uint, coord, compare)
932 .. opcode:: LODQ - level of detail query
934 Compute the LOD information that the texture pipe would use to access the
935 texture. The Y component contains the computed LOD lambda_prime. The X
936 component contains the LOD that will be accessed, based on min/max lod's
943 dst.xy = lodq(uint, coord);
945 .. opcode:: CLOCK - retrieve the current shader time
947 Invoking this instruction multiple times in the same shader should
948 cause monotonically increasing values to be returned. The values
949 are implicitly 64-bit, so if fewer than 64 bits of precision are
950 available, to provide expected wraparound semantics, the value
951 should be shifted up so that the most significant bit of the time
952 is the most significant bit of the 64-bit value.
960 ^^^^^^^^^^^^^^^^^^^^^^^^
961 These opcodes are used for integer operations.
962 Support for these opcodes indicated by PIPE_SHADER_CAP_INTEGERS (all of them?)
965 .. opcode:: I2F - Signed Integer To Float
967 Rounding is unspecified (round to nearest even suggested).
971 dst.x = (float) src.x
973 dst.y = (float) src.y
975 dst.z = (float) src.z
977 dst.w = (float) src.w
980 .. opcode:: U2F - Unsigned Integer To Float
982 Rounding is unspecified (round to nearest even suggested).
986 dst.x = (float) src.x
988 dst.y = (float) src.y
990 dst.z = (float) src.z
992 dst.w = (float) src.w
995 .. opcode:: F2I - Float to Signed Integer
997 Rounding is towards zero (truncate).
998 Values outside signed range (including NaNs) produce undefined results.
1011 .. opcode:: F2U - Float to Unsigned Integer
1013 Rounding is towards zero (truncate).
1014 Values outside unsigned range (including NaNs) produce undefined results.
1018 dst.x = (unsigned) src.x
1020 dst.y = (unsigned) src.y
1022 dst.z = (unsigned) src.z
1024 dst.w = (unsigned) src.w
1027 .. opcode:: UADD - Integer Add
1029 This instruction works the same for signed and unsigned integers.
1030 The low 32bit of the result is returned.
1034 dst.x = src0.x + src1.x
1036 dst.y = src0.y + src1.y
1038 dst.z = src0.z + src1.z
1040 dst.w = src0.w + src1.w
1043 .. opcode:: UMAD - Integer Multiply And Add
1045 This instruction works the same for signed and unsigned integers.
1046 The multiplication returns the low 32bit (as does the result itself).
1050 dst.x = src0.x \times src1.x + src2.x
1052 dst.y = src0.y \times src1.y + src2.y
1054 dst.z = src0.z \times src1.z + src2.z
1056 dst.w = src0.w \times src1.w + src2.w
1059 .. opcode:: UMUL - Integer Multiply
1061 This instruction works the same for signed and unsigned integers.
1062 The low 32bit of the result is returned.
1066 dst.x = src0.x \times src1.x
1068 dst.y = src0.y \times src1.y
1070 dst.z = src0.z \times src1.z
1072 dst.w = src0.w \times src1.w
1075 .. opcode:: IMUL_HI - Signed Integer Multiply High Bits
1077 The high 32bits of the multiplication of 2 signed integers are returned.
1081 dst.x = (src0.x \times src1.x) >> 32
1083 dst.y = (src0.y \times src1.y) >> 32
1085 dst.z = (src0.z \times src1.z) >> 32
1087 dst.w = (src0.w \times src1.w) >> 32
1090 .. opcode:: UMUL_HI - Unsigned Integer Multiply High Bits
1092 The high 32bits of the multiplication of 2 unsigned integers are returned.
1096 dst.x = (src0.x \times src1.x) >> 32
1098 dst.y = (src0.y \times src1.y) >> 32
1100 dst.z = (src0.z \times src1.z) >> 32
1102 dst.w = (src0.w \times src1.w) >> 32
1105 .. opcode:: IDIV - Signed Integer Division
1107 TBD: behavior for division by zero.
1111 dst.x = \frac{src0.x}{src1.x}
1113 dst.y = \frac{src0.y}{src1.y}
1115 dst.z = \frac{src0.z}{src1.z}
1117 dst.w = \frac{src0.w}{src1.w}
1120 .. opcode:: UDIV - Unsigned Integer Division
1122 For division by zero, 0xffffffff is returned.
1126 dst.x = \frac{src0.x}{src1.x}
1128 dst.y = \frac{src0.y}{src1.y}
1130 dst.z = \frac{src0.z}{src1.z}
1132 dst.w = \frac{src0.w}{src1.w}
1135 .. opcode:: UMOD - Unsigned Integer Remainder
1137 If second arg is zero, 0xffffffff is returned.
1141 dst.x = src0.x \bmod src1.x
1143 dst.y = src0.y \bmod src1.y
1145 dst.z = src0.z \bmod src1.z
1147 dst.w = src0.w \bmod src1.w
1150 .. opcode:: NOT - Bitwise Not
1163 .. opcode:: AND - Bitwise And
1167 dst.x = src0.x \& src1.x
1169 dst.y = src0.y \& src1.y
1171 dst.z = src0.z \& src1.z
1173 dst.w = src0.w \& src1.w
1176 .. opcode:: OR - Bitwise Or
1180 dst.x = src0.x | src1.x
1182 dst.y = src0.y | src1.y
1184 dst.z = src0.z | src1.z
1186 dst.w = src0.w | src1.w
1189 .. opcode:: XOR - Bitwise Xor
1193 dst.x = src0.x \oplus src1.x
1195 dst.y = src0.y \oplus src1.y
1197 dst.z = src0.z \oplus src1.z
1199 dst.w = src0.w \oplus src1.w
1202 .. opcode:: IMAX - Maximum of Signed Integers
1206 dst.x = max(src0.x, src1.x)
1208 dst.y = max(src0.y, src1.y)
1210 dst.z = max(src0.z, src1.z)
1212 dst.w = max(src0.w, src1.w)
1215 .. opcode:: UMAX - Maximum of Unsigned Integers
1219 dst.x = max(src0.x, src1.x)
1221 dst.y = max(src0.y, src1.y)
1223 dst.z = max(src0.z, src1.z)
1225 dst.w = max(src0.w, src1.w)
1228 .. opcode:: IMIN - Minimum of Signed Integers
1232 dst.x = min(src0.x, src1.x)
1234 dst.y = min(src0.y, src1.y)
1236 dst.z = min(src0.z, src1.z)
1238 dst.w = min(src0.w, src1.w)
1241 .. opcode:: UMIN - Minimum of Unsigned Integers
1245 dst.x = min(src0.x, src1.x)
1247 dst.y = min(src0.y, src1.y)
1249 dst.z = min(src0.z, src1.z)
1251 dst.w = min(src0.w, src1.w)
1254 .. opcode:: SHL - Shift Left
1256 The shift count is masked with 0x1f before the shift is applied.
1260 dst.x = src0.x << (0x1f \& src1.x)
1262 dst.y = src0.y << (0x1f \& src1.y)
1264 dst.z = src0.z << (0x1f \& src1.z)
1266 dst.w = src0.w << (0x1f \& src1.w)
1269 .. opcode:: ISHR - Arithmetic Shift Right (of Signed Integer)
1271 The shift count is masked with 0x1f before the shift is applied.
1275 dst.x = src0.x >> (0x1f \& src1.x)
1277 dst.y = src0.y >> (0x1f \& src1.y)
1279 dst.z = src0.z >> (0x1f \& src1.z)
1281 dst.w = src0.w >> (0x1f \& src1.w)
1284 .. opcode:: USHR - Logical Shift Right
1286 The shift count is masked with 0x1f before the shift is applied.
1290 dst.x = src0.x >> (unsigned) (0x1f \& src1.x)
1292 dst.y = src0.y >> (unsigned) (0x1f \& src1.y)
1294 dst.z = src0.z >> (unsigned) (0x1f \& src1.z)
1296 dst.w = src0.w >> (unsigned) (0x1f \& src1.w)
1299 .. opcode:: UCMP - Integer Conditional Move
1303 dst.x = src0.x ? src1.x : src2.x
1305 dst.y = src0.y ? src1.y : src2.y
1307 dst.z = src0.z ? src1.z : src2.z
1309 dst.w = src0.w ? src1.w : src2.w
1313 .. opcode:: ISSG - Integer Set Sign
1317 dst.x = (src0.x < 0) ? -1 : (src0.x > 0) ? 1 : 0
1319 dst.y = (src0.y < 0) ? -1 : (src0.y > 0) ? 1 : 0
1321 dst.z = (src0.z < 0) ? -1 : (src0.z > 0) ? 1 : 0
1323 dst.w = (src0.w < 0) ? -1 : (src0.w > 0) ? 1 : 0
1327 .. opcode:: FSLT - Float Set On Less Than (ordered)
1329 Same comparison as SLT but returns integer instead of 1.0/0.0 float
1333 dst.x = (src0.x < src1.x) ? \sim 0 : 0
1335 dst.y = (src0.y < src1.y) ? \sim 0 : 0
1337 dst.z = (src0.z < src1.z) ? \sim 0 : 0
1339 dst.w = (src0.w < src1.w) ? \sim 0 : 0
1342 .. opcode:: ISLT - Signed Integer Set On Less Than
1346 dst.x = (src0.x < src1.x) ? \sim 0 : 0
1348 dst.y = (src0.y < src1.y) ? \sim 0 : 0
1350 dst.z = (src0.z < src1.z) ? \sim 0 : 0
1352 dst.w = (src0.w < src1.w) ? \sim 0 : 0
1355 .. opcode:: USLT - Unsigned Integer Set On Less Than
1359 dst.x = (src0.x < src1.x) ? \sim 0 : 0
1361 dst.y = (src0.y < src1.y) ? \sim 0 : 0
1363 dst.z = (src0.z < src1.z) ? \sim 0 : 0
1365 dst.w = (src0.w < src1.w) ? \sim 0 : 0
1368 .. opcode:: FSGE - Float Set On Greater Equal Than (ordered)
1370 Same comparison as SGE but returns integer instead of 1.0/0.0 float
1374 dst.x = (src0.x >= src1.x) ? \sim 0 : 0
1376 dst.y = (src0.y >= src1.y) ? \sim 0 : 0
1378 dst.z = (src0.z >= src1.z) ? \sim 0 : 0
1380 dst.w = (src0.w >= src1.w) ? \sim 0 : 0
1383 .. opcode:: ISGE - Signed Integer Set On Greater Equal Than
1387 dst.x = (src0.x >= src1.x) ? \sim 0 : 0
1389 dst.y = (src0.y >= src1.y) ? \sim 0 : 0
1391 dst.z = (src0.z >= src1.z) ? \sim 0 : 0
1393 dst.w = (src0.w >= src1.w) ? \sim 0 : 0
1396 .. opcode:: USGE - Unsigned Integer Set On Greater Equal Than
1400 dst.x = (src0.x >= src1.x) ? \sim 0 : 0
1402 dst.y = (src0.y >= src1.y) ? \sim 0 : 0
1404 dst.z = (src0.z >= src1.z) ? \sim 0 : 0
1406 dst.w = (src0.w >= src1.w) ? \sim 0 : 0
1409 .. opcode:: FSEQ - Float Set On Equal (ordered)
1411 Same comparison as SEQ but returns integer instead of 1.0/0.0 float
1415 dst.x = (src0.x == src1.x) ? \sim 0 : 0
1417 dst.y = (src0.y == src1.y) ? \sim 0 : 0
1419 dst.z = (src0.z == src1.z) ? \sim 0 : 0
1421 dst.w = (src0.w == src1.w) ? \sim 0 : 0
1424 .. opcode:: USEQ - Integer Set On Equal
1428 dst.x = (src0.x == src1.x) ? \sim 0 : 0
1430 dst.y = (src0.y == src1.y) ? \sim 0 : 0
1432 dst.z = (src0.z == src1.z) ? \sim 0 : 0
1434 dst.w = (src0.w == src1.w) ? \sim 0 : 0
1437 .. opcode:: FSNE - Float Set On Not Equal (unordered)
1439 Same comparison as SNE but returns integer instead of 1.0/0.0 float
1443 dst.x = (src0.x != src1.x) ? \sim 0 : 0
1445 dst.y = (src0.y != src1.y) ? \sim 0 : 0
1447 dst.z = (src0.z != src1.z) ? \sim 0 : 0
1449 dst.w = (src0.w != src1.w) ? \sim 0 : 0
1452 .. opcode:: USNE - Integer Set On Not Equal
1456 dst.x = (src0.x != src1.x) ? \sim 0 : 0
1458 dst.y = (src0.y != src1.y) ? \sim 0 : 0
1460 dst.z = (src0.z != src1.z) ? \sim 0 : 0
1462 dst.w = (src0.w != src1.w) ? \sim 0 : 0
1465 .. opcode:: INEG - Integer Negate
1480 .. opcode:: IABS - Integer Absolute Value
1494 These opcodes are used for bit-level manipulation of integers.
1496 .. opcode:: IBFE - Signed Bitfield Extract
1498 Like GLSL bitfieldExtract. Extracts a set of bits from the input, and
1499 sign-extends them if the high bit of the extracted window is set.
1503 def ibfe(value, offset, bits):
1504 if offset < 0 or bits < 0 or offset + bits > 32:
1506 if bits == 0: return 0
1507 # Note: >> sign-extends
1508 return (value << (32 - offset - bits)) >> (32 - bits)
1510 .. opcode:: UBFE - Unsigned Bitfield Extract
1512 Like GLSL bitfieldExtract. Extracts a set of bits from the input, without
1517 def ubfe(value, offset, bits):
1518 if offset < 0 or bits < 0 or offset + bits > 32:
1520 if bits == 0: return 0
1521 # Note: >> does not sign-extend
1522 return (value << (32 - offset - bits)) >> (32 - bits)
1524 .. opcode:: BFI - Bitfield Insert
1526 Like GLSL bitfieldInsert. Replaces a bit region of 'base' with the low bits
1531 def bfi(base, insert, offset, bits):
1532 if offset < 0 or bits < 0 or offset + bits > 32:
1534 # << defined such that mask == ~0 when bits == 32, offset == 0
1535 mask = ((1 << bits) - 1) << offset
1536 return ((insert << offset) & mask) | (base & ~mask)
1538 .. opcode:: BREV - Bitfield Reverse
1540 See SM5 instruction BFREV. Reverses the bits of the argument.
1542 .. opcode:: POPC - Population Count
1544 See SM5 instruction COUNTBITS. Counts the number of set bits in the argument.
1546 .. opcode:: LSB - Index of lowest set bit
1548 See SM5 instruction FIRSTBIT_LO. Computes the 0-based index of the first set
1549 bit of the argument. Returns -1 if none are set.
1551 .. opcode:: IMSB - Index of highest non-sign bit
1553 See SM5 instruction FIRSTBIT_SHI. Computes the 0-based index of the highest
1554 non-sign bit of the argument (i.e. highest 0 bit for negative numbers,
1555 highest 1 bit for positive numbers). Returns -1 if all bits are the same
1556 (i.e. for inputs 0 and -1).
1558 .. opcode:: UMSB - Index of highest set bit
1560 See SM5 instruction FIRSTBIT_HI. Computes the 0-based index of the highest
1561 set bit of the argument. Returns -1 if none are set.
1564 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1566 These opcodes are only supported in geometry shaders; they have no meaning
1567 in any other type of shader.
1569 .. opcode:: EMIT - Emit
1571 Generate a new vertex for the current primitive into the specified vertex
1572 stream using the values in the output registers.
1575 .. opcode:: ENDPRIM - End Primitive
1577 Complete the current primitive in the specified vertex stream (consisting of
1578 the emitted vertices), and start a new one.
1584 These opcodes are part of :term:`GLSL`'s opcode set. Support for these
1585 opcodes is determined by a special capability bit, ``GLSL``.
1586 Some require glsl version 1.30 (UIF/SWITCH/CASE/DEFAULT/ENDSWITCH).
1588 .. opcode:: CAL - Subroutine Call
1594 .. opcode:: RET - Subroutine Call Return
1599 .. opcode:: CONT - Continue
1601 Unconditionally moves the point of execution to the instruction after the
1602 last bgnloop. The instruction must appear within a bgnloop/endloop.
1606 Support for CONT is determined by a special capability bit,
1607 ``TGSI_CONT_SUPPORTED``. See :ref:`Screen` for more information.
1610 .. opcode:: BGNLOOP - Begin a Loop
1612 Start a loop. Must have a matching endloop.
1615 .. opcode:: BGNSUB - Begin Subroutine
1617 Starts definition of a subroutine. Must have a matching endsub.
1620 .. opcode:: ENDLOOP - End a Loop
1622 End a loop started with bgnloop.
1625 .. opcode:: ENDSUB - End Subroutine
1627 Ends definition of a subroutine.
1630 .. opcode:: NOP - No Operation
1635 .. opcode:: BRK - Break
1637 Unconditionally moves the point of execution to the instruction after the
1638 next endloop or endswitch. The instruction must appear within a loop/endloop
1639 or switch/endswitch.
1642 .. opcode:: IF - Float If
1644 Start an IF ... ELSE .. ENDIF block. Condition evaluates to true if
1648 where src0.x is interpreted as a floating point register.
1651 .. opcode:: UIF - Bitwise If
1653 Start an UIF ... ELSE .. ENDIF block. Condition evaluates to true if
1657 where src0.x is interpreted as an integer register.
1660 .. opcode:: ELSE - Else
1662 Starts an else block, after an IF or UIF statement.
1665 .. opcode:: ENDIF - End If
1667 Ends an IF or UIF block.
1670 .. opcode:: SWITCH - Switch
1672 Starts a C-style switch expression. The switch consists of one or multiple
1673 CASE statements, and at most one DEFAULT statement. Execution of a statement
1674 ends when a BRK is hit, but just like in C falling through to other cases
1675 without a break is allowed. Similarly, DEFAULT label is allowed anywhere not
1676 just as last statement, and fallthrough is allowed into/from it.
1677 CASE src arguments are evaluated at bit level against the SWITCH src argument.
1683 (some instructions here)
1686 (some instructions here)
1689 (some instructions here)
1694 .. opcode:: CASE - Switch case
1696 This represents a switch case label. The src arg must be an integer immediate.
1699 .. opcode:: DEFAULT - Switch default
1701 This represents the default case in the switch, which is taken if no other
1705 .. opcode:: ENDSWITCH - End of switch
1707 Ends a switch expression.
1713 The interpolation instructions allow an input to be interpolated in a
1714 different way than its declaration. This corresponds to the GLSL 4.00
1715 interpolateAt* functions. The first argument of each of these must come from
1716 ``TGSI_FILE_INPUT``.
1718 .. opcode:: INTERP_CENTROID - Interpolate at the centroid
1720 Interpolates the varying specified by src0 at the centroid
1722 .. opcode:: INTERP_SAMPLE - Interpolate at the specified sample
1724 Interpolates the varying specified by src0 at the sample id specified by
1725 src1.x (interpreted as an integer)
1727 .. opcode:: INTERP_OFFSET - Interpolate at the specified offset
1729 Interpolates the varying specified by src0 at the offset src1.xy from the
1730 pixel center (interpreted as floats)
1738 The double-precision opcodes reinterpret four-component vectors into
1739 two-component vectors with doubled precision in each component.
1741 .. opcode:: DABS - Absolute
1749 .. opcode:: DADD - Add
1753 dst.xy = src0.xy + src1.xy
1755 dst.zw = src0.zw + src1.zw
1757 .. opcode:: DSEQ - Set on Equal
1761 dst.x = src0.xy == src1.xy ? \sim 0 : 0
1763 dst.z = src0.zw == src1.zw ? \sim 0 : 0
1765 .. opcode:: DSNE - Set on Not Equal
1769 dst.x = src0.xy != src1.xy ? \sim 0 : 0
1771 dst.z = src0.zw != src1.zw ? \sim 0 : 0
1773 .. opcode:: DSLT - Set on Less than
1777 dst.x = src0.xy < src1.xy ? \sim 0 : 0
1779 dst.z = src0.zw < src1.zw ? \sim 0 : 0
1781 .. opcode:: DSGE - Set on Greater equal
1785 dst.x = src0.xy >= src1.xy ? \sim 0 : 0
1787 dst.z = src0.zw >= src1.zw ? \sim 0 : 0
1789 .. opcode:: DFRAC - Fraction
1793 dst.xy = src.xy - \lfloor src.xy\rfloor
1795 dst.zw = src.zw - \lfloor src.zw\rfloor
1797 .. opcode:: DTRUNC - Truncate
1801 dst.xy = trunc(src.xy)
1803 dst.zw = trunc(src.zw)
1805 .. opcode:: DCEIL - Ceiling
1809 dst.xy = \lceil src.xy\rceil
1811 dst.zw = \lceil src.zw\rceil
1813 .. opcode:: DFLR - Floor
1817 dst.xy = \lfloor src.xy\rfloor
1819 dst.zw = \lfloor src.zw\rfloor
1821 .. opcode:: DROUND - Fraction
1825 dst.xy = round(src.xy)
1827 dst.zw = round(src.zw)
1829 .. opcode:: DSSG - Set Sign
1833 dst.xy = (src.xy > 0) ? 1.0 : (src.xy < 0) ? -1.0 : 0.0
1835 dst.zw = (src.zw > 0) ? 1.0 : (src.zw < 0) ? -1.0 : 0.0
1837 .. opcode:: DFRACEXP - Convert Number to Fractional and Integral Components
1839 Like the ``frexp()`` routine in many math libraries, this opcode stores the
1840 exponent of its source to ``dst0``, and the significand to ``dst1``, such that
1841 :math:`dst1 \times 2^{dst0} = src` .
1845 dst0.xy = exp(src.xy)
1847 dst1.xy = frac(src.xy)
1849 dst0.zw = exp(src.zw)
1851 dst1.zw = frac(src.zw)
1853 .. opcode:: DLDEXP - Multiply Number by Integral Power of 2
1855 This opcode is the inverse of :opcode:`DFRACEXP`. The second
1856 source is an integer.
1860 dst.xy = src0.xy \times 2^{src1.x}
1862 dst.zw = src0.zw \times 2^{src1.y}
1864 .. opcode:: DMIN - Minimum
1868 dst.xy = min(src0.xy, src1.xy)
1870 dst.zw = min(src0.zw, src1.zw)
1872 .. opcode:: DMAX - Maximum
1876 dst.xy = max(src0.xy, src1.xy)
1878 dst.zw = max(src0.zw, src1.zw)
1880 .. opcode:: DMUL - Multiply
1884 dst.xy = src0.xy \times src1.xy
1886 dst.zw = src0.zw \times src1.zw
1889 .. opcode:: DMAD - Multiply And Add
1893 dst.xy = src0.xy \times src1.xy + src2.xy
1895 dst.zw = src0.zw \times src1.zw + src2.zw
1898 .. opcode:: DFMA - Fused Multiply-Add
1900 Perform a * b + c with no intermediate rounding step.
1904 dst.xy = src0.xy \times src1.xy + src2.xy
1906 dst.zw = src0.zw \times src1.zw + src2.zw
1909 .. opcode:: DDIV - Divide
1913 dst.xy = \frac{src0.xy}{src1.xy}
1915 dst.zw = \frac{src0.zw}{src1.zw}
1918 .. opcode:: DRCP - Reciprocal
1922 dst.xy = \frac{1}{src.xy}
1924 dst.zw = \frac{1}{src.zw}
1926 .. opcode:: DSQRT - Square Root
1930 dst.xy = \sqrt{src.xy}
1932 dst.zw = \sqrt{src.zw}
1934 .. opcode:: DRSQ - Reciprocal Square Root
1938 dst.xy = \frac{1}{\sqrt{src.xy}}
1940 dst.zw = \frac{1}{\sqrt{src.zw}}
1942 .. opcode:: F2D - Float to Double
1946 dst.xy = double(src0.x)
1948 dst.zw = double(src0.y)
1950 .. opcode:: D2F - Double to Float
1954 dst.x = float(src0.xy)
1956 dst.y = float(src0.zw)
1958 .. opcode:: I2D - Int to Double
1962 dst.xy = double(src0.x)
1964 dst.zw = double(src0.y)
1966 .. opcode:: D2I - Double to Int
1970 dst.x = int(src0.xy)
1972 dst.y = int(src0.zw)
1974 .. opcode:: U2D - Unsigned Int to Double
1978 dst.xy = double(src0.x)
1980 dst.zw = double(src0.y)
1982 .. opcode:: D2U - Double to Unsigned Int
1986 dst.x = unsigned(src0.xy)
1988 dst.y = unsigned(src0.zw)
1993 The 64-bit integer opcodes reinterpret four-component vectors into
1994 two-component vectors with 64-bits in each component.
1996 .. opcode:: I64ABS - 64-bit Integer Absolute Value
2004 .. opcode:: I64NEG - 64-bit Integer Negate
2014 .. opcode:: I64SSG - 64-bit Integer Set Sign
2018 dst.xy = (src0.xy < 0) ? -1 : (src0.xy > 0) ? 1 : 0
2020 dst.zw = (src0.zw < 0) ? -1 : (src0.zw > 0) ? 1 : 0
2022 .. opcode:: U64ADD - 64-bit Integer Add
2026 dst.xy = src0.xy + src1.xy
2028 dst.zw = src0.zw + src1.zw
2030 .. opcode:: U64MUL - 64-bit Integer Multiply
2034 dst.xy = src0.xy * src1.xy
2036 dst.zw = src0.zw * src1.zw
2038 .. opcode:: U64SEQ - 64-bit Integer Set on Equal
2042 dst.x = src0.xy == src1.xy ? \sim 0 : 0
2044 dst.z = src0.zw == src1.zw ? \sim 0 : 0
2046 .. opcode:: U64SNE - 64-bit Integer Set on Not Equal
2050 dst.x = src0.xy != src1.xy ? \sim 0 : 0
2052 dst.z = src0.zw != src1.zw ? \sim 0 : 0
2054 .. opcode:: U64SLT - 64-bit Unsigned Integer Set on Less Than
2058 dst.x = src0.xy < src1.xy ? \sim 0 : 0
2060 dst.z = src0.zw < src1.zw ? \sim 0 : 0
2062 .. opcode:: U64SGE - 64-bit Unsigned Integer Set on Greater Equal
2066 dst.x = src0.xy >= src1.xy ? \sim 0 : 0
2068 dst.z = src0.zw >= src1.zw ? \sim 0 : 0
2070 .. opcode:: I64SLT - 64-bit Signed Integer Set on Less Than
2074 dst.x = src0.xy < src1.xy ? \sim 0 : 0
2076 dst.z = src0.zw < src1.zw ? \sim 0 : 0
2078 .. opcode:: I64SGE - 64-bit Signed Integer Set on Greater Equal
2082 dst.x = src0.xy >= src1.xy ? \sim 0 : 0
2084 dst.z = src0.zw >= src1.zw ? \sim 0 : 0
2086 .. opcode:: I64MIN - Minimum of 64-bit Signed Integers
2090 dst.xy = min(src0.xy, src1.xy)
2092 dst.zw = min(src0.zw, src1.zw)
2094 .. opcode:: U64MIN - Minimum of 64-bit Unsigned Integers
2098 dst.xy = min(src0.xy, src1.xy)
2100 dst.zw = min(src0.zw, src1.zw)
2102 .. opcode:: I64MAX - Maximum of 64-bit Signed Integers
2106 dst.xy = max(src0.xy, src1.xy)
2108 dst.zw = max(src0.zw, src1.zw)
2110 .. opcode:: U64MAX - Maximum of 64-bit Unsigned Integers
2114 dst.xy = max(src0.xy, src1.xy)
2116 dst.zw = max(src0.zw, src1.zw)
2118 .. opcode:: U64SHL - Shift Left 64-bit Unsigned Integer
2120 The shift count is masked with 0x3f before the shift is applied.
2124 dst.xy = src0.xy << (0x3f \& src1.x)
2126 dst.zw = src0.zw << (0x3f \& src1.y)
2128 .. opcode:: I64SHR - Arithmetic Shift Right (of 64-bit Signed Integer)
2130 The shift count is masked with 0x3f before the shift is applied.
2134 dst.xy = src0.xy >> (0x3f \& src1.x)
2136 dst.zw = src0.zw >> (0x3f \& src1.y)
2138 .. opcode:: U64SHR - Logical Shift Right (of 64-bit Unsigned Integer)
2140 The shift count is masked with 0x3f before the shift is applied.
2144 dst.xy = src0.xy >> (unsigned) (0x3f \& src1.x)
2146 dst.zw = src0.zw >> (unsigned) (0x3f \& src1.y)
2148 .. opcode:: I64DIV - 64-bit Signed Integer Division
2152 dst.xy = \frac{src0.xy}{src1.xy}
2154 dst.zw = \frac{src0.zw}{src1.zw}
2156 .. opcode:: U64DIV - 64-bit Unsigned Integer Division
2160 dst.xy = \frac{src0.xy}{src1.xy}
2162 dst.zw = \frac{src0.zw}{src1.zw}
2164 .. opcode:: U64MOD - 64-bit Unsigned Integer Remainder
2168 dst.xy = src0.xy \bmod src1.xy
2170 dst.zw = src0.zw \bmod src1.zw
2172 .. opcode:: I64MOD - 64-bit Signed Integer Remainder
2176 dst.xy = src0.xy \bmod src1.xy
2178 dst.zw = src0.zw \bmod src1.zw
2180 .. opcode:: F2U64 - Float to 64-bit Unsigned Int
2184 dst.xy = (uint64_t) src0.x
2186 dst.zw = (uint64_t) src0.y
2188 .. opcode:: F2I64 - Float to 64-bit Int
2192 dst.xy = (int64_t) src0.x
2194 dst.zw = (int64_t) src0.y
2196 .. opcode:: U2I64 - Unsigned Integer to 64-bit Integer
2198 This is a zero extension.
2202 dst.xy = (int64_t) src0.x
2204 dst.zw = (int64_t) src0.y
2206 .. opcode:: I2I64 - Signed Integer to 64-bit Integer
2208 This is a sign extension.
2212 dst.xy = (int64_t) src0.x
2214 dst.zw = (int64_t) src0.y
2216 .. opcode:: D2U64 - Double to 64-bit Unsigned Int
2220 dst.xy = (uint64_t) src0.xy
2222 dst.zw = (uint64_t) src0.zw
2224 .. opcode:: D2I64 - Double to 64-bit Int
2228 dst.xy = (int64_t) src0.xy
2230 dst.zw = (int64_t) src0.zw
2232 .. opcode:: U642F - 64-bit unsigned integer to float
2236 dst.x = (float) src0.xy
2238 dst.y = (float) src0.zw
2240 .. opcode:: I642F - 64-bit Int to Float
2244 dst.x = (float) src0.xy
2246 dst.y = (float) src0.zw
2248 .. opcode:: U642D - 64-bit unsigned integer to double
2252 dst.xy = (double) src0.xy
2254 dst.zw = (double) src0.zw
2256 .. opcode:: I642D - 64-bit Int to double
2260 dst.xy = (double) src0.xy
2262 dst.zw = (double) src0.zw
2264 .. _samplingopcodes:
2266 Resource Sampling Opcodes
2267 ^^^^^^^^^^^^^^^^^^^^^^^^^
2269 Those opcodes follow very closely semantics of the respective Direct3D
2270 instructions. If in doubt double check Direct3D documentation.
2271 Note that the swizzle on SVIEW (src1) determines texel swizzling
2276 Using provided address, sample data from the specified texture using the
2277 filtering mode identified by the given sampler. The source data may come from
2278 any resource type other than buffers.
2280 Syntax: ``SAMPLE dst, address, sampler_view, sampler``
2282 Example: ``SAMPLE TEMP[0], TEMP[1], SVIEW[0], SAMP[0]``
2284 .. opcode:: SAMPLE_I
2286 Simplified alternative to the SAMPLE instruction. Using the provided
2287 integer address, SAMPLE_I fetches data from the specified sampler view
2288 without any filtering. The source data may come from any resource type
2291 Syntax: ``SAMPLE_I dst, address, sampler_view``
2293 Example: ``SAMPLE_I TEMP[0], TEMP[1], SVIEW[0]``
2295 The 'address' is specified as unsigned integers. If the 'address' is out of
2296 range [0...(# texels - 1)] the result of the fetch is always 0 in all
2297 components. As such the instruction doesn't honor address wrap modes, in
2298 cases where that behavior is desirable 'SAMPLE' instruction should be used.
2299 address.w always provides an unsigned integer mipmap level. If the value is
2300 out of the range then the instruction always returns 0 in all components.
2301 address.yz are ignored for buffers and 1d textures. address.z is ignored
2302 for 1d texture arrays and 2d textures.
2304 For 1D texture arrays address.y provides the array index (also as unsigned
2305 integer). If the value is out of the range of available array indices
2306 [0... (array size - 1)] then the opcode always returns 0 in all components.
2307 For 2D texture arrays address.z provides the array index, otherwise it
2308 exhibits the same behavior as in the case for 1D texture arrays. The exact
2309 semantics of the source address are presented in the table below:
2311 +---------------------------+----+-----+-----+---------+
2312 | resource type | X | Y | Z | W |
2313 +===========================+====+=====+=====+=========+
2314 | ``PIPE_BUFFER`` | x | | | ignored |
2315 +---------------------------+----+-----+-----+---------+
2316 | ``PIPE_TEXTURE_1D`` | x | | | mpl |
2317 +---------------------------+----+-----+-----+---------+
2318 | ``PIPE_TEXTURE_2D`` | x | y | | mpl |
2319 +---------------------------+----+-----+-----+---------+
2320 | ``PIPE_TEXTURE_3D`` | x | y | z | mpl |
2321 +---------------------------+----+-----+-----+---------+
2322 | ``PIPE_TEXTURE_RECT`` | x | y | | mpl |
2323 +---------------------------+----+-----+-----+---------+
2324 | ``PIPE_TEXTURE_CUBE`` | not allowed as source |
2325 +---------------------------+----+-----+-----+---------+
2326 | ``PIPE_TEXTURE_1D_ARRAY`` | x | idx | | mpl |
2327 +---------------------------+----+-----+-----+---------+
2328 | ``PIPE_TEXTURE_2D_ARRAY`` | x | y | idx | mpl |
2329 +---------------------------+----+-----+-----+---------+
2331 Where 'mpl' is a mipmap level and 'idx' is the array index.
2333 .. opcode:: SAMPLE_I_MS
2335 Just like SAMPLE_I but allows fetch data from multi-sampled surfaces.
2337 Syntax: ``SAMPLE_I_MS dst, address, sampler_view, sample``
2339 .. opcode:: SAMPLE_B
2341 Just like the SAMPLE instruction with the exception that an additional bias
2342 is applied to the level of detail computed as part of the instruction
2345 Syntax: ``SAMPLE_B dst, address, sampler_view, sampler, lod_bias``
2347 Example: ``SAMPLE_B TEMP[0], TEMP[1], SVIEW[0], SAMP[0], TEMP[2].x``
2349 .. opcode:: SAMPLE_C
2351 Similar to the SAMPLE instruction but it performs a comparison filter. The
2352 operands to SAMPLE_C are identical to SAMPLE, except that there is an
2353 additional float32 operand, reference value, which must be a register with
2354 single-component, or a scalar literal. SAMPLE_C makes the hardware use the
2355 current samplers compare_func (in pipe_sampler_state) to compare reference
2356 value against the red component value for the surce resource at each texel
2357 that the currently configured texture filter covers based on the provided
2360 Syntax: ``SAMPLE_C dst, address, sampler_view.r, sampler, ref_value``
2362 Example: ``SAMPLE_C TEMP[0], TEMP[1], SVIEW[0].r, SAMP[0], TEMP[2].x``
2364 .. opcode:: SAMPLE_C_LZ
2366 Same as SAMPLE_C, but LOD is 0 and derivatives are ignored. The LZ stands
2369 Syntax: ``SAMPLE_C_LZ dst, address, sampler_view.r, sampler, ref_value``
2371 Example: ``SAMPLE_C_LZ TEMP[0], TEMP[1], SVIEW[0].r, SAMP[0], TEMP[2].x``
2374 .. opcode:: SAMPLE_D
2376 SAMPLE_D is identical to the SAMPLE opcode except that the derivatives for
2377 the source address in the x direction and the y direction are provided by
2380 Syntax: ``SAMPLE_D dst, address, sampler_view, sampler, der_x, der_y``
2382 Example: ``SAMPLE_D TEMP[0], TEMP[1], SVIEW[0], SAMP[0], TEMP[2], TEMP[3]``
2384 .. opcode:: SAMPLE_L
2386 SAMPLE_L is identical to the SAMPLE opcode except that the LOD is provided
2387 directly as a scalar value, representing no anisotropy.
2389 Syntax: ``SAMPLE_L dst, address, sampler_view, sampler, explicit_lod``
2391 Example: ``SAMPLE_L TEMP[0], TEMP[1], SVIEW[0], SAMP[0], TEMP[2].x``
2395 Gathers the four texels to be used in a bi-linear filtering operation and
2396 packs them into a single register. Only works with 2D, 2D array, cubemaps,
2397 and cubemaps arrays. For 2D textures, only the addressing modes of the
2398 sampler and the top level of any mip pyramid are used. Set W to zero. It
2399 behaves like the SAMPLE instruction, but a filtered sample is not
2400 generated. The four samples that contribute to filtering are placed into
2401 xyzw in counter-clockwise order, starting with the (u,v) texture coordinate
2402 delta at the following locations (-, +), (+, +), (+, -), (-, -), where the
2403 magnitude of the deltas are half a texel.
2406 .. opcode:: SVIEWINFO
2408 Query the dimensions of a given sampler view. dst receives width, height,
2409 depth or array size and number of mipmap levels as int4. The dst can have a
2410 writemask which will specify what info is the caller interested in.
2412 Syntax: ``SVIEWINFO dst, src_mip_level, sampler_view``
2414 Example: ``SVIEWINFO TEMP[0], TEMP[1].x, SVIEW[0]``
2416 src_mip_level is an unsigned integer scalar. If it's out of range then
2417 returns 0 for width, height and depth/array size but the total number of
2418 mipmap is still returned correctly for the given sampler view. The returned
2419 width, height and depth values are for the mipmap level selected by the
2420 src_mip_level and are in the number of texels. For 1d texture array width
2421 is in dst.x, array size is in dst.y and dst.z is 0. The number of mipmaps is
2422 still in dst.w. In contrast to d3d10 resinfo, there's no way in the tgsi
2423 instruction encoding to specify the return type (float/rcpfloat/uint), hence
2424 always using uint. Also, unlike the SAMPLE instructions, the swizzle on src1
2425 resinfo allowing swizzling dst values is ignored (due to the interaction
2426 with rcpfloat modifier which requires some swizzle handling in the state
2429 .. opcode:: SAMPLE_POS
2431 Query the position of a sample in the given resource or render target
2432 when per-sample fragment shading is in effect.
2434 Syntax: ``SAMPLE_POS dst, source, sample_index``
2436 dst receives float4 (x, y, undef, undef) indicated where the sample is
2437 located. Sample locations are in the range [0, 1] where 0.5 is the center
2440 source is either a sampler view (to indicate a shader resource) or temp
2441 register (to indicate the render target). The source register may have
2442 an optional swizzle to apply to the returned result
2444 sample_index is an integer scalar indicating which sample position is to
2447 If per-sample shading is not in effect or the source resource or render
2448 target is not multisampled, the result is (0.5, 0.5, undef, undef).
2450 NOTE: no driver has implemented this opcode yet (and no state tracker
2451 emits it). This information is subject to change.
2453 .. opcode:: SAMPLE_INFO
2455 Query the number of samples in a multisampled resource or render target.
2457 Syntax: ``SAMPLE_INFO dst, source``
2459 dst receives int4 (n, 0, 0, 0) where n is the number of samples in a
2460 resource or the render target.
2462 source is either a sampler view (to indicate a shader resource) or temp
2463 register (to indicate the render target). The source register may have
2464 an optional swizzle to apply to the returned result
2466 If per-sample shading is not in effect or the source resource or render
2467 target is not multisampled, the result is (1, 0, 0, 0).
2469 NOTE: no driver has implemented this opcode yet (and no state tracker
2470 emits it). This information is subject to change.
2472 .. _resourceopcodes:
2474 Resource Access Opcodes
2475 ^^^^^^^^^^^^^^^^^^^^^^^
2477 For these opcodes, the resource can be a BUFFER, IMAGE, or MEMORY.
2479 .. opcode:: LOAD - Fetch data from a shader buffer or image
2481 Syntax: ``LOAD dst, resource, address``
2483 Example: ``LOAD TEMP[0], BUFFER[0], TEMP[1]``
2485 Using the provided integer address, LOAD fetches data
2486 from the specified buffer or texture without any
2489 The 'address' is specified as a vector of unsigned
2490 integers. If the 'address' is out of range the result
2493 Only the first mipmap level of a resource can be read
2494 from using this instruction.
2496 For 1D or 2D texture arrays, the array index is
2497 provided as an unsigned integer in address.y or
2498 address.z, respectively. address.yz are ignored for
2499 buffers and 1D textures. address.z is ignored for 1D
2500 texture arrays and 2D textures. address.w is always
2503 A swizzle suffix may be added to the resource argument
2504 this will cause the resource data to be swizzled accordingly.
2506 .. opcode:: STORE - Write data to a shader resource
2508 Syntax: ``STORE resource, address, src``
2510 Example: ``STORE BUFFER[0], TEMP[0], TEMP[1]``
2512 Using the provided integer address, STORE writes data
2513 to the specified buffer or texture.
2515 The 'address' is specified as a vector of unsigned
2516 integers. If the 'address' is out of range the result
2519 Only the first mipmap level of a resource can be
2520 written to using this instruction.
2522 For 1D or 2D texture arrays, the array index is
2523 provided as an unsigned integer in address.y or
2524 address.z, respectively. address.yz are ignored for
2525 buffers and 1D textures. address.z is ignored for 1D
2526 texture arrays and 2D textures. address.w is always
2529 .. opcode:: RESQ - Query information about a resource
2531 Syntax: ``RESQ dst, resource``
2533 Example: ``RESQ TEMP[0], BUFFER[0]``
2535 Returns information about the buffer or image resource. For buffer
2536 resources, the size (in bytes) is returned in the x component. For
2537 image resources, .xyz will contain the width/height/layers of the
2538 image, while .w will contain the number of samples for multi-sampled
2541 .. opcode:: FBFETCH - Load data from framebuffer
2543 Syntax: ``FBFETCH dst, output``
2545 Example: ``FBFETCH TEMP[0], OUT[0]``
2547 This is only valid on ``COLOR`` semantic outputs. Returns the color
2548 of the current position in the framebuffer from before this fragment
2549 shader invocation. May return the same value from multiple calls for
2550 a particular output within a single invocation. Note that result may
2551 be undefined if a fragment is drawn multiple times without a blend
2555 .. _threadsyncopcodes:
2557 Inter-thread synchronization opcodes
2558 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2560 These opcodes are intended for communication between threads running
2561 within the same compute grid. For now they're only valid in compute
2564 .. opcode:: BARRIER - Thread group barrier
2568 This opcode suspends the execution of the current thread until all
2569 the remaining threads in the working group reach the same point of
2570 the program. Results are unspecified if any of the remaining
2571 threads terminates or never reaches an executed BARRIER instruction.
2573 .. opcode:: MEMBAR - Memory barrier
2577 This opcode waits for the completion of all memory accesses based on
2578 the type passed in. The type is an immediate bitfield with the following
2581 Bit 0: Shader storage buffers
2582 Bit 1: Atomic buffers
2584 Bit 3: Shared memory
2587 These may be passed in in any combination. An implementation is free to not
2588 distinguish between these as it sees fit. However these map to all the
2589 possibilities made available by GLSL.
2596 These opcodes provide atomic variants of some common arithmetic and
2597 logical operations. In this context atomicity means that another
2598 concurrent memory access operation that affects the same memory
2599 location is guaranteed to be performed strictly before or after the
2600 entire execution of the atomic operation. The resource may be a BUFFER,
2601 IMAGE, or MEMORY. In the case of an image, the offset works the same as for
2602 ``LOAD`` and ``STORE``, specified above. These atomic operations may
2603 only be used with 32-bit integer image formats.
2605 .. opcode:: ATOMUADD - Atomic integer addition
2607 Syntax: ``ATOMUADD dst, resource, offset, src``
2609 Example: ``ATOMUADD TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
2611 The following operation is performed atomically:
2615 dst_x = resource[offset]
2617 resource[offset] = dst_x + src_x
2620 .. opcode:: ATOMXCHG - Atomic exchange
2622 Syntax: ``ATOMXCHG dst, resource, offset, src``
2624 Example: ``ATOMXCHG TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
2626 The following operation is performed atomically:
2630 dst_x = resource[offset]
2632 resource[offset] = src_x
2635 .. opcode:: ATOMCAS - Atomic compare-and-exchange
2637 Syntax: ``ATOMCAS dst, resource, offset, cmp, src``
2639 Example: ``ATOMCAS TEMP[0], BUFFER[0], TEMP[1], TEMP[2], TEMP[3]``
2641 The following operation is performed atomically:
2645 dst_x = resource[offset]
2647 resource[offset] = (dst_x == cmp_x ? src_x : dst_x)
2650 .. opcode:: ATOMAND - Atomic bitwise And
2652 Syntax: ``ATOMAND dst, resource, offset, src``
2654 Example: ``ATOMAND TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
2656 The following operation is performed atomically:
2660 dst_x = resource[offset]
2662 resource[offset] = dst_x \& src_x
2665 .. opcode:: ATOMOR - Atomic bitwise Or
2667 Syntax: ``ATOMOR dst, resource, offset, src``
2669 Example: ``ATOMOR TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
2671 The following operation is performed atomically:
2675 dst_x = resource[offset]
2677 resource[offset] = dst_x | src_x
2680 .. opcode:: ATOMXOR - Atomic bitwise Xor
2682 Syntax: ``ATOMXOR dst, resource, offset, src``
2684 Example: ``ATOMXOR TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
2686 The following operation is performed atomically:
2690 dst_x = resource[offset]
2692 resource[offset] = dst_x \oplus src_x
2695 .. opcode:: ATOMUMIN - Atomic unsigned minimum
2697 Syntax: ``ATOMUMIN dst, resource, offset, src``
2699 Example: ``ATOMUMIN TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
2701 The following operation is performed atomically:
2705 dst_x = resource[offset]
2707 resource[offset] = (dst_x < src_x ? dst_x : src_x)
2710 .. opcode:: ATOMUMAX - Atomic unsigned maximum
2712 Syntax: ``ATOMUMAX dst, resource, offset, src``
2714 Example: ``ATOMUMAX TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
2716 The following operation is performed atomically:
2720 dst_x = resource[offset]
2722 resource[offset] = (dst_x > src_x ? dst_x : src_x)
2725 .. opcode:: ATOMIMIN - Atomic signed minimum
2727 Syntax: ``ATOMIMIN dst, resource, offset, src``
2729 Example: ``ATOMIMIN TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
2731 The following operation is performed atomically:
2735 dst_x = resource[offset]
2737 resource[offset] = (dst_x < src_x ? dst_x : src_x)
2740 .. opcode:: ATOMIMAX - Atomic signed maximum
2742 Syntax: ``ATOMIMAX dst, resource, offset, src``
2744 Example: ``ATOMIMAX TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
2746 The following operation is performed atomically:
2750 dst_x = resource[offset]
2752 resource[offset] = (dst_x > src_x ? dst_x : src_x)
2755 .. _interlaneopcodes:
2760 These opcodes reduce the given value across the shader invocations
2761 running in the current SIMD group. Every thread in the subgroup will receive
2762 the same result. The BALLOT operations accept a single-channel argument that
2763 is treated as a boolean and produce a 64-bit value.
2765 .. opcode:: VOTE_ANY - Value is set in any of the active invocations
2767 Syntax: ``VOTE_ANY dst, value``
2769 Example: ``VOTE_ANY TEMP[0].x, TEMP[1].x``
2772 .. opcode:: VOTE_ALL - Value is set in all of the active invocations
2774 Syntax: ``VOTE_ALL dst, value``
2776 Example: ``VOTE_ALL TEMP[0].x, TEMP[1].x``
2779 .. opcode:: VOTE_EQ - Value is the same in all of the active invocations
2781 Syntax: ``VOTE_EQ dst, value``
2783 Example: ``VOTE_EQ TEMP[0].x, TEMP[1].x``
2786 .. opcode:: BALLOT - Lanemask of whether the value is set in each active
2789 Syntax: ``BALLOT dst, value``
2791 Example: ``BALLOT TEMP[0].xy, TEMP[1].x``
2793 When the argument is a constant true, this produces a bitmask of active
2794 invocations. In fragment shaders, this can include helper invocations
2795 (invocations whose outputs and writes to memory are discarded, but which
2796 are used to compute derivatives).
2799 .. opcode:: READ_FIRST - Broadcast the value from the first active
2800 invocation to all active lanes
2802 Syntax: ``READ_FIRST dst, value``
2804 Example: ``READ_FIRST TEMP[0], TEMP[1]``
2807 .. opcode:: READ_INVOC - Retrieve the value from the given invocation
2808 (need not be uniform)
2810 Syntax: ``READ_INVOC dst, value, invocation``
2812 Example: ``READ_INVOC TEMP[0].xy, TEMP[1].xy, TEMP[2].x``
2814 invocation.x controls the invocation number to read from for all channels.
2815 The invocation number must be the same across all active invocations in a
2816 sub-group; otherwise, the results are undefined.
2819 Explanation of symbols used
2820 ------------------------------
2827 :math:`|x|` Absolute value of `x`.
2829 :math:`\lceil x \rceil` Ceiling of `x`.
2831 clamp(x,y,z) Clamp x between y and z.
2832 (x < y) ? y : (x > z) ? z : x
2834 :math:`\lfloor x\rfloor` Floor of `x`.
2836 :math:`\log_2{x}` Logarithm of `x`, base 2.
2838 max(x,y) Maximum of x and y.
2841 min(x,y) Minimum of x and y.
2844 partialx(x) Derivative of x relative to fragment's X.
2846 partialy(x) Derivative of x relative to fragment's Y.
2848 pop() Pop from stack.
2850 :math:`x^y` `x` to the power `y`.
2852 push(x) Push x on stack.
2856 trunc(x) Truncate x, i.e. drop the fraction bits.
2863 discard Discard fragment.
2867 target Label of target instruction.
2878 Declares a register that is will be referenced as an operand in Instruction
2881 File field contains register file that is being declared and is one
2884 UsageMask field specifies which of the register components can be accessed
2885 and is one of TGSI_WRITEMASK.
2887 The Local flag specifies that a given value isn't intended for
2888 subroutine parameter passing and, as a result, the implementation
2889 isn't required to give any guarantees of it being preserved across
2890 subroutine boundaries. As it's merely a compiler hint, the
2891 implementation is free to ignore it.
2893 If Dimension flag is set to 1, a Declaration Dimension token follows.
2895 If Semantic flag is set to 1, a Declaration Semantic token follows.
2897 If Interpolate flag is set to 1, a Declaration Interpolate token follows.
2899 If file is TGSI_FILE_RESOURCE, a Declaration Resource token follows.
2901 If Array flag is set to 1, a Declaration Array token follows.
2904 ^^^^^^^^^^^^^^^^^^^^^^^^
2906 Declarations can optional have an ArrayID attribute which can be referred by
2907 indirect addressing operands. An ArrayID of zero is reserved and treated as
2908 if no ArrayID is specified.
2910 If an indirect addressing operand refers to a specific declaration by using
2911 an ArrayID only the registers in this declaration are guaranteed to be
2912 accessed, accessing any register outside this declaration results in undefined
2913 behavior. Note that for compatibility the effective index is zero-based and
2914 not relative to the specified declaration
2916 If no ArrayID is specified with an indirect addressing operand the whole
2917 register file might be accessed by this operand. This is strongly discouraged
2918 and will prevent packing of scalar/vec2 arrays and effective alias analysis.
2919 This is only legal for TEMP and CONST register files.
2921 Declaration Semantic
2922 ^^^^^^^^^^^^^^^^^^^^^^^^
2924 Vertex and fragment shader input and output registers may be labeled
2925 with semantic information consisting of a name and index.
2927 Follows Declaration token if Semantic bit is set.
2929 Since its purpose is to link a shader with other stages of the pipeline,
2930 it is valid to follow only those Declaration tokens that declare a register
2931 either in INPUT or OUTPUT file.
2933 SemanticName field contains the semantic name of the register being declared.
2934 There is no default value.
2936 SemanticIndex is an optional subscript that can be used to distinguish
2937 different register declarations with the same semantic name. The default value
2940 The meanings of the individual semantic names are explained in the following
2943 TGSI_SEMANTIC_POSITION
2944 """"""""""""""""""""""
2946 For vertex shaders, TGSI_SEMANTIC_POSITION indicates the vertex shader
2947 output register which contains the homogeneous vertex position in the clip
2948 space coordinate system. After clipping, the X, Y and Z components of the
2949 vertex will be divided by the W value to get normalized device coordinates.
2951 For fragment shaders, TGSI_SEMANTIC_POSITION is used to indicate that
2952 fragment shader input (or system value, depending on which one is
2953 supported by the driver) contains the fragment's window position. The X
2954 component starts at zero and always increases from left to right.
2955 The Y component starts at zero and always increases but Y=0 may either
2956 indicate the top of the window or the bottom depending on the fragment
2957 coordinate origin convention (see TGSI_PROPERTY_FS_COORD_ORIGIN).
2958 The Z coordinate ranges from 0 to 1 to represent depth from the front
2959 to the back of the Z buffer. The W component contains the interpolated
2960 reciprocal of the vertex position W component (corresponding to gl_Fragcoord,
2961 but unlike d3d10 which interpolates the same 1/w but then gives back
2962 the reciprocal of the interpolated value).
2964 Fragment shaders may also declare an output register with
2965 TGSI_SEMANTIC_POSITION. Only the Z component is writable. This allows
2966 the fragment shader to change the fragment's Z position.
2973 For vertex shader outputs or fragment shader inputs/outputs, this
2974 label indicates that the register contains an R,G,B,A color.
2976 Several shader inputs/outputs may contain colors so the semantic index
2977 is used to distinguish them. For example, color[0] may be the diffuse
2978 color while color[1] may be the specular color.
2980 This label is needed so that the flat/smooth shading can be applied
2981 to the right interpolants during rasterization.
2985 TGSI_SEMANTIC_BCOLOR
2986 """"""""""""""""""""
2988 Back-facing colors are only used for back-facing polygons, and are only valid
2989 in vertex shader outputs. After rasterization, all polygons are front-facing
2990 and COLOR and BCOLOR end up occupying the same slots in the fragment shader,
2991 so all BCOLORs effectively become regular COLORs in the fragment shader.
2997 Vertex shader inputs and outputs and fragment shader inputs may be
2998 labeled with TGSI_SEMANTIC_FOG to indicate that the register contains
2999 a fog coordinate. Typically, the fragment shader will use the fog coordinate
3000 to compute a fog blend factor which is used to blend the normal fragment color
3001 with a constant fog color. But fog coord really is just an ordinary vec4
3002 register like regular semantics.
3008 Vertex shader input and output registers may be labeled with
3009 TGIS_SEMANTIC_PSIZE to indicate that the register contains a point size
3010 in the form (S, 0, 0, 1). The point size controls the width or diameter
3011 of points for rasterization. This label cannot be used in fragment
3014 When using this semantic, be sure to set the appropriate state in the
3015 :ref:`rasterizer` first.
3018 TGSI_SEMANTIC_TEXCOORD
3019 """"""""""""""""""""""
3021 Only available if PIPE_CAP_TGSI_TEXCOORD is exposed !
3023 Vertex shader outputs and fragment shader inputs may be labeled with
3024 this semantic to make them replaceable by sprite coordinates via the
3025 sprite_coord_enable state in the :ref:`rasterizer`.
3026 The semantic index permitted with this semantic is limited to <= 7.
3028 If the driver does not support TEXCOORD, sprite coordinate replacement
3029 applies to inputs with the GENERIC semantic instead.
3031 The intended use case for this semantic is gl_TexCoord.
3034 TGSI_SEMANTIC_PCOORD
3035 """"""""""""""""""""
3037 Only available if PIPE_CAP_TGSI_TEXCOORD is exposed !
3039 Fragment shader inputs may be labeled with TGSI_SEMANTIC_PCOORD to indicate
3040 that the register contains sprite coordinates in the form (x, y, 0, 1), if
3041 the current primitive is a point and point sprites are enabled. Otherwise,
3042 the contents of the register are undefined.
3044 The intended use case for this semantic is gl_PointCoord.
3047 TGSI_SEMANTIC_GENERIC
3048 """""""""""""""""""""
3050 All vertex/fragment shader inputs/outputs not labeled with any other
3051 semantic label can be considered to be generic attributes. Typical
3052 uses of generic inputs/outputs are texcoords and user-defined values.
3055 TGSI_SEMANTIC_NORMAL
3056 """"""""""""""""""""
3058 Indicates that a vertex shader input is a normal vector. This is
3059 typically only used for legacy graphics APIs.
3065 This label applies to fragment shader inputs (or system values,
3066 depending on which one is supported by the driver) and indicates that
3067 the register contains front/back-face information.
3069 If it is an input, it will be a floating-point vector in the form (F, 0, 0, 1),
3070 where F will be positive when the fragment belongs to a front-facing polygon,
3071 and negative when the fragment belongs to a back-facing polygon.
3073 If it is a system value, it will be an integer vector in the form (F, 0, 0, 1),
3074 where F is 0xffffffff when the fragment belongs to a front-facing polygon and
3075 0 when the fragment belongs to a back-facing polygon.
3078 TGSI_SEMANTIC_EDGEFLAG
3079 """"""""""""""""""""""
3081 For vertex shaders, this sematic label indicates that an input or
3082 output is a boolean edge flag. The register layout is [F, x, x, x]
3083 where F is 0.0 or 1.0 and x = don't care. Normally, the vertex shader
3084 simply copies the edge flag input to the edgeflag output.
3086 Edge flags are used to control which lines or points are actually
3087 drawn when the polygon mode converts triangles/quads/polygons into
3091 TGSI_SEMANTIC_STENCIL
3092 """""""""""""""""""""
3094 For fragment shaders, this semantic label indicates that an output
3095 is a writable stencil reference value. Only the Y component is writable.
3096 This allows the fragment shader to change the fragments stencilref value.
3099 TGSI_SEMANTIC_VIEWPORT_INDEX
3100 """"""""""""""""""""""""""""
3102 For geometry shaders, this semantic label indicates that an output
3103 contains the index of the viewport (and scissor) to use.
3104 This is an integer value, and only the X component is used.
3106 If PIPE_CAP_TGSI_VS_LAYER_VIEWPORT or PIPE_CAP_TGSI_TES_LAYER_VIEWPORT is
3107 supported, then this semantic label can also be used in vertex or
3108 tessellation evaluation shaders, respectively. Only the value written in the
3109 last vertex processing stage is used.
3115 For geometry shaders, this semantic label indicates that an output
3116 contains the layer value to use for the color and depth/stencil surfaces.
3117 This is an integer value, and only the X component is used.
3118 (Also known as rendertarget array index.)
3120 If PIPE_CAP_TGSI_VS_LAYER_VIEWPORT or PIPE_CAP_TGSI_TES_LAYER_VIEWPORT is
3121 supported, then this semantic label can also be used in vertex or
3122 tessellation evaluation shaders, respectively. Only the value written in the
3123 last vertex processing stage is used.
3126 TGSI_SEMANTIC_CULLDIST
3127 """"""""""""""""""""""
3129 Used as distance to plane for performing application-defined culling
3130 of individual primitives against a plane. When components of vertex
3131 elements are given this label, these values are assumed to be a
3132 float32 signed distance to a plane. Primitives will be completely
3133 discarded if the plane distance for all of the vertices in the
3134 primitive are < 0. If a vertex has a cull distance of NaN, that
3135 vertex counts as "out" (as if its < 0);
3136 The limits on both clip and cull distances are bound
3137 by the PIPE_MAX_CLIP_OR_CULL_DISTANCE_COUNT define which defines
3138 the maximum number of components that can be used to hold the
3139 distances and by the PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT
3140 which specifies the maximum number of registers which can be
3141 annotated with those semantics.
3144 TGSI_SEMANTIC_CLIPDIST
3145 """"""""""""""""""""""
3147 Note this covers clipping and culling distances.
3149 When components of vertex elements are identified this way, these
3150 values are each assumed to be a float32 signed distance to a plane.
3153 Primitive setup only invokes rasterization on pixels for which
3154 the interpolated plane distances are >= 0.
3157 Primitives will be completely discarded if the plane distance
3158 for all of the vertices in the primitive are < 0.
3159 If a vertex has a cull distance of NaN, that vertex counts as "out"
3162 Multiple clip/cull planes can be implemented simultaneously, by
3163 annotating multiple components of one or more vertex elements with
3164 the above specified semantic.
3165 The limits on both clip and cull distances are bound
3166 by the PIPE_MAX_CLIP_OR_CULL_DISTANCE_COUNT define which defines
3167 the maximum number of components that can be used to hold the
3168 distances and by the PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT
3169 which specifies the maximum number of registers which can be
3170 annotated with those semantics.
3171 The properties NUM_CLIPDIST_ENABLED and NUM_CULLDIST_ENABLED
3172 are used to divide up the 2 x vec4 space between clipping and culling.
3174 TGSI_SEMANTIC_SAMPLEID
3175 """"""""""""""""""""""
3177 For fragment shaders, this semantic label indicates that a system value
3178 contains the current sample id (i.e. gl_SampleID) as an unsigned int.
3179 Only the X component is used. If per-sample shading is not enabled,
3180 the result is (0, undef, undef, undef).
3182 Note that if the fragment shader uses this system value, the fragment
3183 shader is automatically executed at per sample frequency.
3185 TGSI_SEMANTIC_SAMPLEPOS
3186 """""""""""""""""""""""
3188 For fragment shaders, this semantic label indicates that a system
3189 value contains the current sample's position as float4(x, y, undef, undef)
3190 in the render target (i.e. gl_SamplePosition) when per-fragment shading
3191 is in effect. Position values are in the range [0, 1] where 0.5 is
3192 the center of the fragment.
3194 Note that if the fragment shader uses this system value, the fragment
3195 shader is automatically executed at per sample frequency.
3197 TGSI_SEMANTIC_SAMPLEMASK
3198 """"""""""""""""""""""""
3200 For fragment shaders, this semantic label can be applied to either a
3201 shader system value input or output.
3203 For a system value, the sample mask indicates the set of samples covered by
3204 the current primitive. If MSAA is not enabled, the value is (1, 0, 0, 0).
3206 For an output, the sample mask is used to disable further sample processing.
3208 For both, the register type is uint[4] but only the X component is used
3209 (i.e. gl_SampleMask[0]). Each bit corresponds to one sample position (up
3210 to 32x MSAA is supported).
3212 TGSI_SEMANTIC_INVOCATIONID
3213 """"""""""""""""""""""""""
3215 For geometry shaders, this semantic label indicates that a system value
3216 contains the current invocation id (i.e. gl_InvocationID).
3217 This is an integer value, and only the X component is used.
3219 TGSI_SEMANTIC_INSTANCEID
3220 """"""""""""""""""""""""
3222 For vertex shaders, this semantic label indicates that a system value contains
3223 the current instance id (i.e. gl_InstanceID). It does not include the base
3224 instance. This is an integer value, and only the X component is used.
3226 TGSI_SEMANTIC_VERTEXID
3227 """"""""""""""""""""""
3229 For vertex shaders, this semantic label indicates that a system value contains
3230 the current vertex id (i.e. gl_VertexID). It does (unlike in d3d10) include the
3231 base vertex. This is an integer value, and only the X component is used.
3233 TGSI_SEMANTIC_VERTEXID_NOBASE
3234 """""""""""""""""""""""""""""""
3236 For vertex shaders, this semantic label indicates that a system value contains
3237 the current vertex id without including the base vertex (this corresponds to
3238 d3d10 vertex id, so TGSI_SEMANTIC_VERTEXID_NOBASE + TGSI_SEMANTIC_BASEVERTEX
3239 == TGSI_SEMANTIC_VERTEXID). This is an integer value, and only the X component
3242 TGSI_SEMANTIC_BASEVERTEX
3243 """"""""""""""""""""""""
3245 For vertex shaders, this semantic label indicates that a system value contains
3246 the base vertex (i.e. gl_BaseVertex). Note that for non-indexed draw calls,
3247 this contains the first (or start) value instead.
3248 This is an integer value, and only the X component is used.
3250 TGSI_SEMANTIC_PRIMID
3251 """"""""""""""""""""
3253 For geometry and fragment shaders, this semantic label indicates the value
3254 contains the primitive id (i.e. gl_PrimitiveID). This is an integer value,
3255 and only the X component is used.
3256 FIXME: This right now can be either a ordinary input or a system value...
3262 For tessellation evaluation/control shaders, this semantic label indicates a
3263 generic per-patch attribute. Such semantics will not implicitly be per-vertex
3266 TGSI_SEMANTIC_TESSCOORD
3267 """""""""""""""""""""""
3269 For tessellation evaluation shaders, this semantic label indicates the
3270 coordinates of the vertex being processed. This is available in XYZ; W is
3273 TGSI_SEMANTIC_TESSOUTER
3274 """""""""""""""""""""""
3276 For tessellation evaluation/control shaders, this semantic label indicates the
3277 outer tessellation levels of the patch. Isoline tessellation will only have XY
3278 defined, triangle will have XYZ and quads will have XYZW defined. This
3279 corresponds to gl_TessLevelOuter.
3281 TGSI_SEMANTIC_TESSINNER
3282 """""""""""""""""""""""
3284 For tessellation evaluation/control shaders, this semantic label indicates the
3285 inner tessellation levels of the patch. The X value is only defined for
3286 triangle tessellation, while quads will have XY defined. This is entirely
3287 undefined for isoline tessellation.
3289 TGSI_SEMANTIC_VERTICESIN
3290 """"""""""""""""""""""""
3292 For tessellation evaluation/control shaders, this semantic label indicates the
3293 number of vertices provided in the input patch. Only the X value is defined.
3295 TGSI_SEMANTIC_HELPER_INVOCATION
3296 """""""""""""""""""""""""""""""
3298 For fragment shaders, this semantic indicates whether the current
3299 invocation is covered or not. Helper invocations are created in order
3300 to properly compute derivatives, however it may be desirable to skip
3301 some of the logic in those cases. See ``gl_HelperInvocation`` documentation.
3303 TGSI_SEMANTIC_BASEINSTANCE
3304 """"""""""""""""""""""""""
3306 For vertex shaders, the base instance argument supplied for this
3307 draw. This is an integer value, and only the X component is used.
3309 TGSI_SEMANTIC_DRAWID
3310 """"""""""""""""""""
3312 For vertex shaders, the zero-based index of the current draw in a
3313 ``glMultiDraw*`` invocation. This is an integer value, and only the X
3317 TGSI_SEMANTIC_WORK_DIM
3318 """"""""""""""""""""""
3320 For compute shaders started via opencl this retrieves the work_dim
3321 parameter to the clEnqueueNDRangeKernel call with which the shader
3325 TGSI_SEMANTIC_GRID_SIZE
3326 """""""""""""""""""""""
3328 For compute shaders, this semantic indicates the maximum (x, y, z) dimensions
3329 of a grid of thread blocks.
3332 TGSI_SEMANTIC_BLOCK_ID
3333 """"""""""""""""""""""
3335 For compute shaders, this semantic indicates the (x, y, z) coordinates of the
3336 current block inside of the grid.
3339 TGSI_SEMANTIC_BLOCK_SIZE
3340 """"""""""""""""""""""""
3342 For compute shaders, this semantic indicates the maximum (x, y, z) dimensions
3343 of a block in threads.
3346 TGSI_SEMANTIC_THREAD_ID
3347 """""""""""""""""""""""
3349 For compute shaders, this semantic indicates the (x, y, z) coordinates of the
3350 current thread inside of the block.
3353 TGSI_SEMANTIC_SUBGROUP_SIZE
3354 """""""""""""""""""""""""""
3356 This semantic indicates the subgroup size for the current invocation. This is
3357 an integer of at most 64, as it indicates the width of lanemasks. It does not
3358 depend on the number of invocations that are active.
3361 TGSI_SEMANTIC_SUBGROUP_INVOCATION
3362 """""""""""""""""""""""""""""""""
3364 The index of the current invocation within its subgroup.
3367 TGSI_SEMANTIC_SUBGROUP_EQ_MASK
3368 """"""""""""""""""""""""""""""
3370 A bit mask of ``bit index == TGSI_SEMANTIC_SUBGROUP_INVOCATION``, i.e.
3371 ``1 << subgroup_invocation`` in arbitrary precision arithmetic.
3374 TGSI_SEMANTIC_SUBGROUP_GE_MASK
3375 """"""""""""""""""""""""""""""
3377 A bit mask of ``bit index >= TGSI_SEMANTIC_SUBGROUP_INVOCATION``, i.e.
3378 ``((1 << (subgroup_size - subgroup_invocation)) - 1) << subgroup_invocation``
3379 in arbitrary precision arithmetic.
3382 TGSI_SEMANTIC_SUBGROUP_GT_MASK
3383 """"""""""""""""""""""""""""""
3385 A bit mask of ``bit index > TGSI_SEMANTIC_SUBGROUP_INVOCATION``, i.e.
3386 ``((1 << (subgroup_size - subgroup_invocation - 1)) - 1) << (subgroup_invocation + 1)``
3387 in arbitrary precision arithmetic.
3390 TGSI_SEMANTIC_SUBGROUP_LE_MASK
3391 """"""""""""""""""""""""""""""
3393 A bit mask of ``bit index <= TGSI_SEMANTIC_SUBGROUP_INVOCATION``, i.e.
3394 ``(1 << (subgroup_invocation + 1)) - 1`` in arbitrary precision arithmetic.
3397 TGSI_SEMANTIC_SUBGROUP_LT_MASK
3398 """"""""""""""""""""""""""""""
3400 A bit mask of ``bit index > TGSI_SEMANTIC_SUBGROUP_INVOCATION``, i.e.
3401 ``(1 << subgroup_invocation) - 1`` in arbitrary precision arithmetic.
3404 Declaration Interpolate
3405 ^^^^^^^^^^^^^^^^^^^^^^^
3407 This token is only valid for fragment shader INPUT declarations.
3409 The Interpolate field specifes the way input is being interpolated by
3410 the rasteriser and is one of TGSI_INTERPOLATE_*.
3412 The Location field specifies the location inside the pixel that the
3413 interpolation should be done at, one of ``TGSI_INTERPOLATE_LOC_*``. Note that
3414 when per-sample shading is enabled, the implementation may choose to
3415 interpolate at the sample irrespective of the Location field.
3417 The CylindricalWrap bitfield specifies which register components
3418 should be subject to cylindrical wrapping when interpolating by the
3419 rasteriser. If TGSI_CYLINDRICAL_WRAP_X is set to 1, the X component
3420 should be interpolated according to cylindrical wrapping rules.
3423 Declaration Sampler View
3424 ^^^^^^^^^^^^^^^^^^^^^^^^
3426 Follows Declaration token if file is TGSI_FILE_SAMPLER_VIEW.
3428 DCL SVIEW[#], resource, type(s)
3430 Declares a shader input sampler view and assigns it to a SVIEW[#]
3433 resource can be one of BUFFER, 1D, 2D, 3D, 1DArray and 2DArray.
3435 type must be 1 or 4 entries (if specifying on a per-component
3436 level) out of UNORM, SNORM, SINT, UINT and FLOAT.
3438 For TEX\* style texture sample opcodes (as opposed to SAMPLE\* opcodes
3439 which take an explicit SVIEW[#] source register), there may be optionally
3440 SVIEW[#] declarations. In this case, the SVIEW index is implied by the
3441 SAMP index, and there must be a corresponding SVIEW[#] declaration for
3442 each SAMP[#] declaration. Drivers are free to ignore this if they wish.
3443 But note in particular that some drivers need to know the sampler type
3444 (float/int/unsigned) in order to generate the correct code, so cases
3445 where integer textures are sampled, SVIEW[#] declarations should be
3448 NOTE: It is NOT legal to mix SAMPLE\* style opcodes and TEX\* opcodes
3451 Declaration Resource
3452 ^^^^^^^^^^^^^^^^^^^^
3454 Follows Declaration token if file is TGSI_FILE_RESOURCE.
3456 DCL RES[#], resource [, WR] [, RAW]
3458 Declares a shader input resource and assigns it to a RES[#]
3461 resource can be one of BUFFER, 1D, 2D, 3D, CUBE, 1DArray and
3464 If the RAW keyword is not specified, the texture data will be
3465 subject to conversion, swizzling and scaling as required to yield
3466 the specified data type from the physical data format of the bound
3469 If the RAW keyword is specified, no channel conversion will be
3470 performed: the values read for each of the channels (X,Y,Z,W) will
3471 correspond to consecutive words in the same order and format
3472 they're found in memory. No element-to-address conversion will be
3473 performed either: the value of the provided X coordinate will be
3474 interpreted in byte units instead of texel units. The result of
3475 accessing a misaligned address is undefined.
3477 Usage of the STORE opcode is only allowed if the WR (writable) flag
3482 ^^^^^^^^^^^^^^^^^^^^^^^^
3484 Properties are general directives that apply to the whole TGSI program.
3489 Specifies the fragment shader TGSI_SEMANTIC_POSITION coordinate origin.
3490 The default value is UPPER_LEFT.
3492 If UPPER_LEFT, the position will be (0,0) at the upper left corner and
3493 increase downward and rightward.
3494 If LOWER_LEFT, the position will be (0,0) at the lower left corner and
3495 increase upward and rightward.
3497 OpenGL defaults to LOWER_LEFT, and is configurable with the
3498 GL_ARB_fragment_coord_conventions extension.
3500 DirectX 9/10 use UPPER_LEFT.
3502 FS_COORD_PIXEL_CENTER
3503 """""""""""""""""""""
3505 Specifies the fragment shader TGSI_SEMANTIC_POSITION pixel center convention.
3506 The default value is HALF_INTEGER.
3508 If HALF_INTEGER, the fractionary part of the position will be 0.5
3509 If INTEGER, the fractionary part of the position will be 0.0
3511 Note that this does not affect the set of fragments generated by
3512 rasterization, which is instead controlled by half_pixel_center in the
3515 OpenGL defaults to HALF_INTEGER, and is configurable with the
3516 GL_ARB_fragment_coord_conventions extension.
3518 DirectX 9 uses INTEGER.
3519 DirectX 10 uses HALF_INTEGER.
3521 FS_COLOR0_WRITES_ALL_CBUFS
3522 """"""""""""""""""""""""""
3523 Specifies that writes to the fragment shader color 0 are replicated to all
3524 bound cbufs. This facilitates OpenGL's fragColor output vs fragData[0] where
3525 fragData is directed to a single color buffer, but fragColor is broadcast.
3528 """"""""""""""""""""""""""
3529 If this property is set on the program bound to the shader stage before the
3530 fragment shader, user clip planes should have no effect (be disabled) even if
3531 that shader does not write to any clip distance outputs and the rasterizer's
3532 clip_plane_enable is non-zero.
3533 This property is only supported by drivers that also support shader clip
3535 This is useful for APIs that don't have UCPs and where clip distances written
3536 by a shader cannot be disabled.
3541 Specifies the number of times a geometry shader should be executed for each
3542 input primitive. Each invocation will have a different
3543 TGSI_SEMANTIC_INVOCATIONID system value set. If not specified, assumed to
3546 VS_WINDOW_SPACE_POSITION
3547 """"""""""""""""""""""""""
3548 If this property is set on the vertex shader, the TGSI_SEMANTIC_POSITION output
3549 is assumed to contain window space coordinates.
3550 Division of X,Y,Z by W and the viewport transformation are disabled, and 1/W is
3551 directly taken from the 4-th component of the shader output.
3552 Naturally, clipping is not performed on window coordinates either.
3553 The effect of this property is undefined if a geometry or tessellation shader
3559 The number of vertices written by the tessellation control shader. This
3560 effectively defines the patch input size of the tessellation evaluation shader
3566 This sets the tessellation primitive mode, one of ``PIPE_PRIM_TRIANGLES``,
3567 ``PIPE_PRIM_QUADS``, or ``PIPE_PRIM_LINES``. (Unlike in GL, there is no
3568 separate isolines settings, the regular lines is assumed to mean isolines.)
3573 This sets the spacing mode of the tessellation generator, one of
3574 ``PIPE_TESS_SPACING_*``.
3579 This sets the vertex order to be clockwise if the value is 1, or
3580 counter-clockwise if set to 0.
3585 If set to a non-zero value, this turns on point mode for the tessellator,
3586 which means that points will be generated instead of primitives.
3588 NUM_CLIPDIST_ENABLED
3589 """"""""""""""""""""
3591 How many clip distance scalar outputs are enabled.
3593 NUM_CULLDIST_ENABLED
3594 """"""""""""""""""""
3596 How many cull distance scalar outputs are enabled.
3598 FS_EARLY_DEPTH_STENCIL
3599 """"""""""""""""""""""
3601 Whether depth test, stencil test, and occlusion query should run before
3602 the fragment shader (regardless of fragment shader side effects). Corresponds
3603 to GLSL early_fragment_tests.
3608 Which shader stage will MOST LIKELY follow after this shader when the shader
3609 is bound. This is only a hint to the driver and doesn't have to be precise.
3610 Only set for VS and TES.
3612 CS_FIXED_BLOCK_WIDTH / HEIGHT / DEPTH
3613 """""""""""""""""""""""""""""""""""""
3615 Threads per block in each dimension, if known at compile time. If the block size
3616 is known all three should be at least 1. If it is unknown they should all be set
3622 The MUL TGSI operation (FP32 multiplication) will return 0 if either
3623 of the operands are equal to 0. That means that 0 * Inf = 0. This
3624 should be set the same way for an entire pipeline. Note that this
3625 applies not only to the literal MUL TGSI opcode, but all FP32
3626 multiplications implied by other operations, such as MAD, FMA, DP2,
3627 DP3, DP4, DST, LOG, LRP, and possibly others. If there is a
3628 mismatch between shaders, then it is unspecified whether this behavior
3631 FS_POST_DEPTH_COVERAGE
3632 """"""""""""""""""""""
3634 When enabled, the input for TGSI_SEMANTIC_SAMPLEMASK will exclude samples
3635 that have failed the depth/stencil tests. This is only valid when
3636 FS_EARLY_DEPTH_STENCIL is also specified.
3639 Texture Sampling and Texture Formats
3640 ------------------------------------
3642 This table shows how texture image components are returned as (x,y,z,w) tuples
3643 by TGSI texture instructions, such as :opcode:`TEX`, :opcode:`TXD`, and
3644 :opcode:`TXP`. For reference, OpenGL and Direct3D conventions are shown as
3647 +--------------------+--------------+--------------------+--------------+
3648 | Texture Components | Gallium | OpenGL | Direct3D 9 |
3649 +====================+==============+====================+==============+
3650 | R | (r, 0, 0, 1) | (r, 0, 0, 1) | (r, 1, 1, 1) |
3651 +--------------------+--------------+--------------------+--------------+
3652 | RG | (r, g, 0, 1) | (r, g, 0, 1) | (r, g, 1, 1) |
3653 +--------------------+--------------+--------------------+--------------+
3654 | RGB | (r, g, b, 1) | (r, g, b, 1) | (r, g, b, 1) |
3655 +--------------------+--------------+--------------------+--------------+
3656 | RGBA | (r, g, b, a) | (r, g, b, a) | (r, g, b, a) |
3657 +--------------------+--------------+--------------------+--------------+
3658 | A | (0, 0, 0, a) | (0, 0, 0, a) | (0, 0, 0, a) |
3659 +--------------------+--------------+--------------------+--------------+
3660 | L | (l, l, l, 1) | (l, l, l, 1) | (l, l, l, 1) |
3661 +--------------------+--------------+--------------------+--------------+
3662 | LA | (l, l, l, a) | (l, l, l, a) | (l, l, l, a) |
3663 +--------------------+--------------+--------------------+--------------+
3664 | I | (i, i, i, i) | (i, i, i, i) | N/A |
3665 +--------------------+--------------+--------------------+--------------+
3666 | UV | XXX TBD | (0, 0, 0, 1) | (u, v, 1, 1) |
3667 | | | [#envmap-bumpmap]_ | |
3668 +--------------------+--------------+--------------------+--------------+
3669 | Z | XXX TBD | (z, z, z, 1) | (0, z, 0, 1) |
3670 | | | [#depth-tex-mode]_ | |
3671 +--------------------+--------------+--------------------+--------------+
3672 | S | (s, s, s, s) | unknown | unknown |
3673 +--------------------+--------------+--------------------+--------------+
3675 .. [#envmap-bumpmap] http://www.opengl.org/registry/specs/ATI/envmap_bumpmap.txt
3676 .. [#depth-tex-mode] the default is (z, z, z, 1) but may also be (0, 0, 0, z)
3677 or (z, z, z, z) depending on the value of GL_DEPTH_TEXTURE_MODE.