src/compiler/shader_enums.h

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   5  * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 #ifndef SHADER_ENUMS_H
  27 #define SHADER_ENUMS_H
  28
  29 #ifdef __cplusplus
  30 extern "C" {
  31 #endif
  32
  33 /**
  34  * Shader stages.
  35  *
  36  * The order must match how shaders are ordered in the pipeline.
  37  * The GLSL linker assumes that if i<j, then the j-th shader is
  38  * executed later than the i-th shader.
  39  */
  40 typedef enum
  41 {
  42    MESA_SHADER_NONE = -1,
  43    MESA_SHADER_VERTEX = 0,
  44    MESA_SHADER_TESS_CTRL = 1,
  45    MESA_SHADER_TESS_EVAL = 2,
  46    MESA_SHADER_GEOMETRY = 3,
  47    MESA_SHADER_FRAGMENT = 4,
  48    MESA_SHADER_COMPUTE = 5,
  49 } gl_shader_stage;
  50
  51 const char *gl_shader_stage_name(gl_shader_stage stage);
  52
  53 /**
  54  * Translate a gl_shader_stage to a short shader stage name for debug
  55  * printouts and error messages.
  56  */
  57 const char *_mesa_shader_stage_to_string(unsigned stage);
  58
  59 /**
  60  * Translate a gl_shader_stage to a shader stage abbreviation (VS, GS, FS)
  61  * for debug printouts and error messages.
  62  */
  63 const char *_mesa_shader_stage_to_abbrev(unsigned stage);
  64
  65 #define MESA_SHADER_STAGES (MESA_SHADER_COMPUTE + 1)
  66
  67
  68 /**
  69  * Indexes for vertex program attributes.
  70  * GL_NV_vertex_program aliases generic attributes over the conventional
  71  * attributes.  In GL_ARB_vertex_program shader the aliasing is optional.
  72  * In GL_ARB_vertex_shader / OpenGL 2.0 the aliasing is disallowed (the
  73  * generic attributes are distinct/separate).
  74  */
  75 typedef enum
  76 {
  77    VERT_ATTRIB_POS,
  78    VERT_ATTRIB_NORMAL,
  79    VERT_ATTRIB_COLOR0,
  80    VERT_ATTRIB_COLOR1,
  81    VERT_ATTRIB_FOG,
  82    VERT_ATTRIB_COLOR_INDEX,
  83    VERT_ATTRIB_EDGEFLAG,
  84    VERT_ATTRIB_TEX0,
  85    VERT_ATTRIB_TEX1,
  86    VERT_ATTRIB_TEX2,
  87    VERT_ATTRIB_TEX3,
  88    VERT_ATTRIB_TEX4,
  89    VERT_ATTRIB_TEX5,
  90    VERT_ATTRIB_TEX6,
  91    VERT_ATTRIB_TEX7,
  92    VERT_ATTRIB_POINT_SIZE,
  93    VERT_ATTRIB_GENERIC0,
  94    VERT_ATTRIB_GENERIC1,
  95    VERT_ATTRIB_GENERIC2,
  96    VERT_ATTRIB_GENERIC3,
  97    VERT_ATTRIB_GENERIC4,
  98    VERT_ATTRIB_GENERIC5,
  99    VERT_ATTRIB_GENERIC6,
 100    VERT_ATTRIB_GENERIC7,
 101    VERT_ATTRIB_GENERIC8,
 102    VERT_ATTRIB_GENERIC9,
 103    VERT_ATTRIB_GENERIC10,
 104    VERT_ATTRIB_GENERIC11,
 105    VERT_ATTRIB_GENERIC12,
 106    VERT_ATTRIB_GENERIC13,
 107    VERT_ATTRIB_GENERIC14,
 108    VERT_ATTRIB_GENERIC15,
 109    VERT_ATTRIB_MAX
 110 } gl_vert_attrib;
 111
 112 const char *gl_vert_attrib_name(gl_vert_attrib attrib);
 113
 114 /**
 115  * Symbolic constats to help iterating over
 116  * specific blocks of vertex attributes.
 117  *
 118  * VERT_ATTRIB_FF
 119  *   includes all fixed function attributes as well as
 120  *   the aliased GL_NV_vertex_program shader attributes.
 121  * VERT_ATTRIB_TEX
 122  *   include the classic texture coordinate attributes.
 123  *   Is a subset of VERT_ATTRIB_FF.
 124  * VERT_ATTRIB_GENERIC
 125  *   include the OpenGL 2.0+ GLSL generic shader attributes.
 126  *   These alias the generic GL_ARB_vertex_shader attributes.
 127  */
 128 #define VERT_ATTRIB_FF(i)           (VERT_ATTRIB_POS + (i))
 129 #define VERT_ATTRIB_FF_MAX          VERT_ATTRIB_GENERIC0
 130
 131 #define VERT_ATTRIB_TEX(i)          (VERT_ATTRIB_TEX0 + (i))
 132 #define VERT_ATTRIB_TEX_MAX         MAX_TEXTURE_COORD_UNITS
 133
 134 #define VERT_ATTRIB_GENERIC(i)      (VERT_ATTRIB_GENERIC0 + (i))
 135 #define VERT_ATTRIB_GENERIC_MAX     MAX_VERTEX_GENERIC_ATTRIBS
 136
 137 /**
 138  * Bitflags for vertex attributes.
 139  * These are used in bitfields in many places.
 140  */
 141 /*@{*/
 142 #define VERT_BIT_POS             BITFIELD_BIT(VERT_ATTRIB_POS)
 143 #define VERT_BIT_NORMAL          BITFIELD_BIT(VERT_ATTRIB_NORMAL)
 144 #define VERT_BIT_COLOR0          BITFIELD_BIT(VERT_ATTRIB_COLOR0)
 145 #define VERT_BIT_COLOR1          BITFIELD_BIT(VERT_ATTRIB_COLOR1)
 146 #define VERT_BIT_FOG             BITFIELD_BIT(VERT_ATTRIB_FOG)
 147 #define VERT_BIT_COLOR_INDEX     BITFIELD_BIT(VERT_ATTRIB_COLOR_INDEX)
 148 #define VERT_BIT_EDGEFLAG        BITFIELD_BIT(VERT_ATTRIB_EDGEFLAG)
 149 #define VERT_BIT_TEX0            BITFIELD_BIT(VERT_ATTRIB_TEX0)
 150 #define VERT_BIT_TEX1            BITFIELD_BIT(VERT_ATTRIB_TEX1)
 151 #define VERT_BIT_TEX2            BITFIELD_BIT(VERT_ATTRIB_TEX2)
 152 #define VERT_BIT_TEX3            BITFIELD_BIT(VERT_ATTRIB_TEX3)
 153 #define VERT_BIT_TEX4            BITFIELD_BIT(VERT_ATTRIB_TEX4)
 154 #define VERT_BIT_TEX5            BITFIELD_BIT(VERT_ATTRIB_TEX5)
 155 #define VERT_BIT_TEX6            BITFIELD_BIT(VERT_ATTRIB_TEX6)
 156 #define VERT_BIT_TEX7            BITFIELD_BIT(VERT_ATTRIB_TEX7)
 157 #define VERT_BIT_POINT_SIZE      BITFIELD_BIT(VERT_ATTRIB_POINT_SIZE)
 158 #define VERT_BIT_GENERIC0        BITFIELD_BIT(VERT_ATTRIB_GENERIC0)
 159
 160 #define VERT_BIT(i)              BITFIELD_BIT(i)
 161 #define VERT_BIT_ALL             BITFIELD_RANGE(0, VERT_ATTRIB_MAX)
 162
 163 #define VERT_BIT_FF(i)           VERT_BIT(i)
 164 #define VERT_BIT_FF_ALL          BITFIELD_RANGE(0, VERT_ATTRIB_FF_MAX)
 165 #define VERT_BIT_TEX(i)          VERT_BIT(VERT_ATTRIB_TEX(i))
 166 #define VERT_BIT_TEX_ALL         \
 167    BITFIELD_RANGE(VERT_ATTRIB_TEX(0), VERT_ATTRIB_TEX_MAX)
 168
 169 #define VERT_BIT_GENERIC(i)      VERT_BIT(VERT_ATTRIB_GENERIC(i))
 170 #define VERT_BIT_GENERIC_ALL     \
 171    BITFIELD_RANGE(VERT_ATTRIB_GENERIC(0), VERT_ATTRIB_GENERIC_MAX)
 172 /*@}*/
 173
 174 #define MAX_VARYING 32 /**< number of float[4] vectors */
 175
 176 /**
 177  * Indexes for vertex shader outputs, geometry shader inputs/outputs, and
 178  * fragment shader inputs.
 179  *
 180  * Note that some of these values are not available to all pipeline stages.
 181  *
 182  * When this enum is updated, the following code must be updated too:
 183  * - vertResults (in prog_print.c's arb_output_attrib_string())
 184  * - fragAttribs (in prog_print.c's arb_input_attrib_string())
 185  * - _mesa_varying_slot_in_fs()
 186  */
 187 typedef enum
 188 {
 189    VARYING_SLOT_POS,
 190    VARYING_SLOT_COL0, /* COL0 and COL1 must be contiguous */
 191    VARYING_SLOT_COL1,
 192    VARYING_SLOT_FOGC,
 193    VARYING_SLOT_TEX0, /* TEX0-TEX7 must be contiguous */
 194    VARYING_SLOT_TEX1,
 195    VARYING_SLOT_TEX2,
 196    VARYING_SLOT_TEX3,
 197    VARYING_SLOT_TEX4,
 198    VARYING_SLOT_TEX5,
 199    VARYING_SLOT_TEX6,
 200    VARYING_SLOT_TEX7,
 201    VARYING_SLOT_PSIZ, /* Does not appear in FS */
 202    VARYING_SLOT_BFC0, /* Does not appear in FS */
 203    VARYING_SLOT_BFC1, /* Does not appear in FS */
 204    VARYING_SLOT_EDGE, /* Does not appear in FS */
 205    VARYING_SLOT_CLIP_VERTEX, /* Does not appear in FS */
 206    VARYING_SLOT_CLIP_DIST0,
 207    VARYING_SLOT_CLIP_DIST1,
 208    VARYING_SLOT_CULL_DIST0,
 209    VARYING_SLOT_CULL_DIST1,
 210    VARYING_SLOT_PRIMITIVE_ID, /* Does not appear in VS */
 211    VARYING_SLOT_LAYER, /* Appears as VS or GS output */
 212    VARYING_SLOT_VIEWPORT, /* Appears as VS or GS output */
 213    VARYING_SLOT_FACE, /* FS only */
 214    VARYING_SLOT_PNTC, /* FS only */
 215    VARYING_SLOT_TESS_LEVEL_OUTER, /* Only appears as TCS output. */
 216    VARYING_SLOT_TESS_LEVEL_INNER, /* Only appears as TCS output. */
 217    VARYING_SLOT_BOUNDING_BOX0, /* Only appears as TCS output. */
 218    VARYING_SLOT_BOUNDING_BOX1, /* Only appears as TCS output. */
 219    VARYING_SLOT_VIEW_INDEX,
 220    VARYING_SLOT_VAR0, /* First generic varying slot */
 221    /* the remaining are simply for the benefit of gl_varying_slot_name()
 222     * and not to be construed as an upper bound:
 223     */
 224    VARYING_SLOT_VAR1,
 225    VARYING_SLOT_VAR2,
 226    VARYING_SLOT_VAR3,
 227    VARYING_SLOT_VAR4,
 228    VARYING_SLOT_VAR5,
 229    VARYING_SLOT_VAR6,
 230    VARYING_SLOT_VAR7,
 231    VARYING_SLOT_VAR8,
 232    VARYING_SLOT_VAR9,
 233    VARYING_SLOT_VAR10,
 234    VARYING_SLOT_VAR11,
 235    VARYING_SLOT_VAR12,
 236    VARYING_SLOT_VAR13,
 237    VARYING_SLOT_VAR14,
 238    VARYING_SLOT_VAR15,
 239    VARYING_SLOT_VAR16,
 240    VARYING_SLOT_VAR17,
 241    VARYING_SLOT_VAR18,
 242    VARYING_SLOT_VAR19,
 243    VARYING_SLOT_VAR20,
 244    VARYING_SLOT_VAR21,
 245    VARYING_SLOT_VAR22,
 246    VARYING_SLOT_VAR23,
 247    VARYING_SLOT_VAR24,
 248    VARYING_SLOT_VAR25,
 249    VARYING_SLOT_VAR26,
 250    VARYING_SLOT_VAR27,
 251    VARYING_SLOT_VAR28,
 252    VARYING_SLOT_VAR29,
 253    VARYING_SLOT_VAR30,
 254    VARYING_SLOT_VAR31,
 255 } gl_varying_slot;
 256
 257
 258 #define VARYING_SLOT_MAX        (VARYING_SLOT_VAR0 + MAX_VARYING)
 259 #define VARYING_SLOT_PATCH0     (VARYING_SLOT_MAX)
 260 #define VARYING_SLOT_TESS_MAX   (VARYING_SLOT_PATCH0 + MAX_VARYING)
 261 #define MAX_VARYINGS_INCL_PATCH (VARYING_SLOT_TESS_MAX - VARYING_SLOT_VAR0)
 262
 263 const char *gl_varying_slot_name(gl_varying_slot slot);
 264
 265 /**
 266  * Bitflags for varying slots.
 267  */
 268 /*@{*/
 269 #define VARYING_BIT_POS BITFIELD64_BIT(VARYING_SLOT_POS)
 270 #define VARYING_BIT_COL0 BITFIELD64_BIT(VARYING_SLOT_COL0)
 271 #define VARYING_BIT_COL1 BITFIELD64_BIT(VARYING_SLOT_COL1)
 272 #define VARYING_BIT_FOGC BITFIELD64_BIT(VARYING_SLOT_FOGC)
 273 #define VARYING_BIT_TEX0 BITFIELD64_BIT(VARYING_SLOT_TEX0)
 274 #define VARYING_BIT_TEX1 BITFIELD64_BIT(VARYING_SLOT_TEX1)
 275 #define VARYING_BIT_TEX2 BITFIELD64_BIT(VARYING_SLOT_TEX2)
 276 #define VARYING_BIT_TEX3 BITFIELD64_BIT(VARYING_SLOT_TEX3)
 277 #define VARYING_BIT_TEX4 BITFIELD64_BIT(VARYING_SLOT_TEX4)
 278 #define VARYING_BIT_TEX5 BITFIELD64_BIT(VARYING_SLOT_TEX5)
 279 #define VARYING_BIT_TEX6 BITFIELD64_BIT(VARYING_SLOT_TEX6)
 280 #define VARYING_BIT_TEX7 BITFIELD64_BIT(VARYING_SLOT_TEX7)
 281 #define VARYING_BIT_TEX(U) BITFIELD64_BIT(VARYING_SLOT_TEX0 + (U))
 282 #define VARYING_BITS_TEX_ANY BITFIELD64_RANGE(VARYING_SLOT_TEX0, \
 283                                               MAX_TEXTURE_COORD_UNITS)
 284 #define VARYING_BIT_PSIZ BITFIELD64_BIT(VARYING_SLOT_PSIZ)
 285 #define VARYING_BIT_BFC0 BITFIELD64_BIT(VARYING_SLOT_BFC0)
 286 #define VARYING_BIT_BFC1 BITFIELD64_BIT(VARYING_SLOT_BFC1)
 287 #define VARYING_BIT_EDGE BITFIELD64_BIT(VARYING_SLOT_EDGE)
 288 #define VARYING_BIT_CLIP_VERTEX BITFIELD64_BIT(VARYING_SLOT_CLIP_VERTEX)
 289 #define VARYING_BIT_CLIP_DIST0 BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST0)
 290 #define VARYING_BIT_CLIP_DIST1 BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST1)
 291 #define VARYING_BIT_CULL_DIST0 BITFIELD64_BIT(VARYING_SLOT_CULL_DIST0)
 292 #define VARYING_BIT_CULL_DIST1 BITFIELD64_BIT(VARYING_SLOT_CULL_DIST1)
 293 #define VARYING_BIT_PRIMITIVE_ID BITFIELD64_BIT(VARYING_SLOT_PRIMITIVE_ID)
 294 #define VARYING_BIT_LAYER BITFIELD64_BIT(VARYING_SLOT_LAYER)
 295 #define VARYING_BIT_VIEWPORT BITFIELD64_BIT(VARYING_SLOT_VIEWPORT)
 296 #define VARYING_BIT_FACE BITFIELD64_BIT(VARYING_SLOT_FACE)
 297 #define VARYING_BIT_PNTC BITFIELD64_BIT(VARYING_SLOT_PNTC)
 298 #define VARYING_BIT_TESS_LEVEL_OUTER BITFIELD64_BIT(VARYING_SLOT_TESS_LEVEL_OUTER)
 299 #define VARYING_BIT_TESS_LEVEL_INNER BITFIELD64_BIT(VARYING_SLOT_TESS_LEVEL_INNER)
 300 #define VARYING_BIT_BOUNDING_BOX0 BITFIELD64_BIT(VARYING_SLOT_BOUNDING_BOX0)
 301 #define VARYING_BIT_BOUNDING_BOX1 BITFIELD64_BIT(VARYING_SLOT_BOUNDING_BOX1)
 302 #define VARYING_BIT_VAR(V) BITFIELD64_BIT(VARYING_SLOT_VAR0 + (V))
 303 /*@}*/
 304
 305 /**
 306  * Bitflags for system values.
 307  */
 308 #define SYSTEM_BIT_SAMPLE_ID ((uint64_t)1 << SYSTEM_VALUE_SAMPLE_ID)
 309 #define SYSTEM_BIT_SAMPLE_POS ((uint64_t)1 << SYSTEM_VALUE_SAMPLE_POS)
 310 #define SYSTEM_BIT_SAMPLE_MASK_IN ((uint64_t)1 << SYSTEM_VALUE_SAMPLE_MASK_IN)
 311 #define SYSTEM_BIT_LOCAL_INVOCATION_ID ((uint64_t)1 << SYSTEM_VALUE_LOCAL_INVOCATION_ID)
 312
 313 /**
 314  * If the gl_register_file is PROGRAM_SYSTEM_VALUE, the register index will be
 315  * one of these values.  If a NIR variable's mode is nir_var_system_value, it
 316  * will be one of these values.
 317  */
 318 typedef enum
 319 {
 320    /**
 321     * \name System values applicable to all shaders
 322     */
 323    /*@{*/
 324
 325    /**
 326     * Builtin variables added by GL_ARB_shader_ballot.
 327     */
 328    /*@{*/
 329
 330    /**
 331     * From the GL_ARB_shader-ballot spec:
 332     *
 333     *    "A sub-group is a collection of invocations which execute in lockstep.
 334     *     The variable <gl_SubGroupSizeARB> is the maximum number of
 335     *     invocations in a sub-group. The maximum <gl_SubGroupSizeARB>
 336     *     supported in this extension is 64."
 337     *
 338     * The spec defines this as a uniform. However, it's highly unlikely that
 339     * implementations actually treat it as a uniform (which is loaded from a
 340     * constant buffer). Most likely, this is an implementation-wide constant,
 341     * or perhaps something that depends on the shader stage.
 342     */
 343    SYSTEM_VALUE_SUBGROUP_SIZE,
 344
 345    /**
 346     * From the GL_ARB_shader_ballot spec:
 347     *
 348     *    "The variable <gl_SubGroupInvocationARB> holds the index of the
 349     *     invocation within sub-group. This variable is in the range 0 to
 350     *     <gl_SubGroupSizeARB>-1, where <gl_SubGroupSizeARB> is the total
 351     *     number of invocations in a sub-group."
 352     */
 353    SYSTEM_VALUE_SUBGROUP_INVOCATION,
 354
 355    /**
 356     * From the GL_ARB_shader_ballot spec:
 357     *
 358     *    "The <gl_SubGroup??MaskARB> variables provide a bitmask for all
 359     *     invocations, with one bit per invocation starting with the least
 360     *     significant bit, according to the following table,
 361     *
 362     *       variable               equation for bit values
 363     *       --------------------   ------------------------------------
 364     *       gl_SubGroupEqMaskARB   bit index == gl_SubGroupInvocationARB
 365     *       gl_SubGroupGeMaskARB   bit index >= gl_SubGroupInvocationARB
 366     *       gl_SubGroupGtMaskARB   bit index >  gl_SubGroupInvocationARB
 367     *       gl_SubGroupLeMaskARB   bit index <= gl_SubGroupInvocationARB
 368     *       gl_SubGroupLtMaskARB   bit index <  gl_SubGroupInvocationARB
 369     */
 370    SYSTEM_VALUE_SUBGROUP_EQ_MASK,
 371    SYSTEM_VALUE_SUBGROUP_GE_MASK,
 372    SYSTEM_VALUE_SUBGROUP_GT_MASK,
 373    SYSTEM_VALUE_SUBGROUP_LE_MASK,
 374    SYSTEM_VALUE_SUBGROUP_LT_MASK,
 375    /*@}*/
 376
 377    /*@}*/
 378
 379    /**
 380     * \name Vertex shader system values
 381     */
 382    /*@{*/
 383    /**
 384     * OpenGL-style vertex ID.
 385     *
 386     * Section 2.11.7 (Shader Execution), subsection Shader Inputs, of the
 387     * OpenGL 3.3 core profile spec says:
 388     *
 389     *     "gl_VertexID holds the integer index i implicitly passed by
 390     *     DrawArrays or one of the other drawing commands defined in section
 391     *     2.8.3."
 392     *
 393     * Section 2.8.3 (Drawing Commands) of the same spec says:
 394     *
 395     *     "The commands....are equivalent to the commands with the same base
 396     *     name (without the BaseVertex suffix), except that the ith element
 397     *     transferred by the corresponding draw call will be taken from
 398     *     element indices[i] + basevertex of each enabled array."
 399     *
 400     * Additionally, the overview in the GL_ARB_shader_draw_parameters spec
 401     * says:
 402     *
 403     *     "In unextended GL, vertex shaders have inputs named gl_VertexID and
 404     *     gl_InstanceID, which contain, respectively the index of the vertex
 405     *     and instance. The value of gl_VertexID is the implicitly passed
 406     *     index of the vertex being processed, which includes the value of
 407     *     baseVertex, for those commands that accept it."
 408     *
 409     * gl_VertexID gets basevertex added in.  This differs from DirectX where
 410     * SV_VertexID does \b not get basevertex added in.
 411     *
 412     * \note
 413     * If all system values are available, \c SYSTEM_VALUE_VERTEX_ID will be
 414     * equal to \c SYSTEM_VALUE_VERTEX_ID_ZERO_BASE plus
 415     * \c SYSTEM_VALUE_BASE_VERTEX.
 416     *
 417     * \sa SYSTEM_VALUE_VERTEX_ID_ZERO_BASE, SYSTEM_VALUE_BASE_VERTEX
 418     */
 419    SYSTEM_VALUE_VERTEX_ID,
 420
 421    /**
 422     * Instanced ID as supplied to gl_InstanceID
 423     *
 424     * Values assigned to gl_InstanceID always begin with zero, regardless of
 425     * the value of baseinstance.
 426     *
 427     * Section 11.1.3.9 (Shader Inputs) of the OpenGL 4.4 core profile spec
 428     * says:
 429     *
 430     *     "gl_InstanceID holds the integer instance number of the current
 431     *     primitive in an instanced draw call (see section 10.5)."
 432     *
 433     * Through a big chain of pseudocode, section 10.5 describes that
 434     * baseinstance is not counted by gl_InstanceID.  In that section, notice
 435     *
 436     *     "If an enabled vertex attribute array is instanced (it has a
 437     *     non-zero divisor as specified by VertexAttribDivisor), the element
 438     *     index that is transferred to the GL, for all vertices, is given by
 439     *
 440     *         floor(instance/divisor) + baseinstance
 441     *
 442     *     If an array corresponding to an attribute required by a vertex
 443     *     shader is not enabled, then the corresponding element is taken from
 444     *     the current attribute state (see section 10.2)."
 445     *
 446     * Note that baseinstance is \b not included in the value of instance.
 447     */
 448    SYSTEM_VALUE_INSTANCE_ID,
 449
 450    /**
 451     * Vulkan InstanceIndex.
 452     *
 453     * InstanceIndex = gl_InstanceID + gl_BaseInstance
 454     */
 455    SYSTEM_VALUE_INSTANCE_INDEX,
 456
 457    /**
 458     * DirectX-style vertex ID.
 459     *
 460     * Unlike \c SYSTEM_VALUE_VERTEX_ID, this system value does \b not include
 461     * the value of basevertex.
 462     *
 463     * \sa SYSTEM_VALUE_VERTEX_ID, SYSTEM_VALUE_BASE_VERTEX
 464     */
 465    SYSTEM_VALUE_VERTEX_ID_ZERO_BASE,
 466
 467    /**
 468     * Value of \c basevertex passed to \c glDrawElementsBaseVertex and similar
 469     * functions.
 470     *
 471     * \sa SYSTEM_VALUE_VERTEX_ID, SYSTEM_VALUE_VERTEX_ID_ZERO_BASE
 472     */
 473    SYSTEM_VALUE_BASE_VERTEX,
 474
 475    /**
 476     * Value of \c baseinstance passed to instanced draw entry points
 477     *
 478     * \sa SYSTEM_VALUE_INSTANCE_ID
 479     */
 480    SYSTEM_VALUE_BASE_INSTANCE,
 481
 482    /**
 483     * From _ARB_shader_draw_parameters:
 484     *
 485     *   "Additionally, this extension adds a further built-in variable,
 486     *    gl_DrawID to the shading language. This variable contains the index
 487     *    of the draw currently being processed by a Multi* variant of a
 488     *    drawing command (such as MultiDrawElements or
 489     *    MultiDrawArraysIndirect)."
 490     *
 491     * If GL_ARB_multi_draw_indirect is not supported, this is always 0.
 492     */
 493    SYSTEM_VALUE_DRAW_ID,
 494    /*@}*/
 495
 496    /**
 497     * \name Geometry shader system values
 498     */
 499    /*@{*/
 500    SYSTEM_VALUE_INVOCATION_ID,  /**< (Also in Tessellation Control shader) */
 501    /*@}*/
 502
 503    /**
 504     * \name Fragment shader system values
 505     */
 506    /*@{*/
 507    SYSTEM_VALUE_FRAG_COORD,
 508    SYSTEM_VALUE_FRONT_FACE,
 509    SYSTEM_VALUE_SAMPLE_ID,
 510    SYSTEM_VALUE_SAMPLE_POS,
 511    SYSTEM_VALUE_SAMPLE_MASK_IN,
 512    SYSTEM_VALUE_HELPER_INVOCATION,
 513    /*@}*/
 514
 515    /**
 516     * \name Tessellation Evaluation shader system values
 517     */
 518    /*@{*/
 519    SYSTEM_VALUE_TESS_COORD,
 520    SYSTEM_VALUE_VERTICES_IN,    /**< Tessellation vertices in input patch */
 521    SYSTEM_VALUE_PRIMITIVE_ID,
 522    SYSTEM_VALUE_TESS_LEVEL_OUTER, /**< TES input */
 523    SYSTEM_VALUE_TESS_LEVEL_INNER, /**< TES input */
 524    /*@}*/
 525
 526    /**
 527     * \name Compute shader system values
 528     */
 529    /*@{*/
 530    SYSTEM_VALUE_LOCAL_INVOCATION_ID,
 531    SYSTEM_VALUE_LOCAL_INVOCATION_INDEX,
 532    SYSTEM_VALUE_GLOBAL_INVOCATION_ID,
 533    SYSTEM_VALUE_WORK_GROUP_ID,
 534    SYSTEM_VALUE_NUM_WORK_GROUPS,
 535    SYSTEM_VALUE_LOCAL_GROUP_SIZE,
 536    /*@}*/
 537
 538    /** Required for VK_KHX_multiview */
 539    SYSTEM_VALUE_VIEW_INDEX,
 540
 541    /**
 542     * Driver internal vertex-count, used (for example) for drivers to
 543     * calculate stride for stream-out outputs.  Not externally visible.
 544     */
 545    SYSTEM_VALUE_VERTEX_CNT,
 546
 547    SYSTEM_VALUE_MAX             /**< Number of values */
 548 } gl_system_value;
 549
 550 const char *gl_system_value_name(gl_system_value sysval);
 551
 552 /**
 553  * The possible interpolation qualifiers that can be applied to a fragment
 554  * shader input in GLSL.
 555  *
 556  * Note: INTERP_MODE_NONE must be 0 so that memsetting the
 557  * ir_variable data structure to 0 causes the default behavior.
 558  */
 559 enum glsl_interp_mode
 560 {
 561    INTERP_MODE_NONE = 0,
 562    INTERP_MODE_SMOOTH,
 563    INTERP_MODE_FLAT,
 564    INTERP_MODE_NOPERSPECTIVE,
 565    INTERP_MODE_COUNT /**< Number of interpolation qualifiers */
 566 };
 567
 568 enum glsl_interface_packing {
 569    GLSL_INTERFACE_PACKING_STD140,
 570    GLSL_INTERFACE_PACKING_SHARED,
 571    GLSL_INTERFACE_PACKING_PACKED,
 572    GLSL_INTERFACE_PACKING_STD430
 573 };
 574
 575 const char *glsl_interp_mode_name(enum glsl_interp_mode qual);
 576
 577 /**
 578  * Fragment program results
 579  */
 580 typedef enum
 581 {
 582    FRAG_RESULT_DEPTH = 0,
 583    FRAG_RESULT_STENCIL = 1,
 584    /* If a single color should be written to all render targets, this
 585     * register is written.  No FRAG_RESULT_DATAn will be written.
 586     */
 587    FRAG_RESULT_COLOR = 2,
 588    FRAG_RESULT_SAMPLE_MASK = 3,
 589
 590    /* FRAG_RESULT_DATAn are the per-render-target (GLSL gl_FragData[n]
 591     * or ARB_fragment_program fragment.color[n]) color results.  If
 592     * any are written, FRAG_RESULT_COLOR will not be written.
 593     * FRAG_RESULT_DATA1 and up are simply for the benefit of
 594     * gl_frag_result_name() and not to be construed as an upper bound
 595     */
 596    FRAG_RESULT_DATA0 = 4,
 597    FRAG_RESULT_DATA1,
 598    FRAG_RESULT_DATA2,
 599    FRAG_RESULT_DATA3,
 600    FRAG_RESULT_DATA4,
 601    FRAG_RESULT_DATA5,
 602    FRAG_RESULT_DATA6,
 603    FRAG_RESULT_DATA7,
 604 } gl_frag_result;
 605
 606 const char *gl_frag_result_name(gl_frag_result result);
 607
 608 #define FRAG_RESULT_MAX         (FRAG_RESULT_DATA0 + MAX_DRAW_BUFFERS)
 609
 610 /**
 611  * \brief Layout qualifiers for gl_FragDepth.
 612  *
 613  * Extension AMD_conservative_depth allows gl_FragDepth to be redeclared with
 614  * a layout qualifier.
 615  *
 616  * \see enum ir_depth_layout
 617  */
 618 enum gl_frag_depth_layout
 619 {
 620    FRAG_DEPTH_LAYOUT_NONE, /**< No layout is specified. */
 621    FRAG_DEPTH_LAYOUT_ANY,
 622    FRAG_DEPTH_LAYOUT_GREATER,
 623    FRAG_DEPTH_LAYOUT_LESS,
 624    FRAG_DEPTH_LAYOUT_UNCHANGED
 625 };
 626
 627 /**
 628  * \brief Buffer access qualifiers
 629  */
 630 enum gl_buffer_access_qualifier
 631 {
 632    ACCESS_COHERENT = 1,
 633    ACCESS_RESTRICT = 2,
 634    ACCESS_VOLATILE = 4,
 635 };
 636
 637 /**
 638  * \brief Blend support qualifiers
 639  */
 640 enum gl_advanced_blend_mode
 641 {
 642    BLEND_NONE           = 0x0000,
 643
 644    BLEND_MULTIPLY       = 0x0001,
 645    BLEND_SCREEN         = 0x0002,
 646    BLEND_OVERLAY        = 0x0004,
 647    BLEND_DARKEN         = 0x0008,
 648    BLEND_LIGHTEN        = 0x0010,
 649    BLEND_COLORDODGE     = 0x0020,
 650    BLEND_COLORBURN      = 0x0040,
 651    BLEND_HARDLIGHT      = 0x0080,
 652    BLEND_SOFTLIGHT      = 0x0100,
 653    BLEND_DIFFERENCE     = 0x0200,
 654    BLEND_EXCLUSION      = 0x0400,
 655    BLEND_HSL_HUE        = 0x0800,
 656    BLEND_HSL_SATURATION = 0x1000,
 657    BLEND_HSL_COLOR      = 0x2000,
 658    BLEND_HSL_LUMINOSITY = 0x4000,
 659
 660    BLEND_ALL            = 0x7fff,
 661 };
 662
 663 enum gl_tess_spacing
 664 {
 665    TESS_SPACING_UNSPECIFIED,
 666    TESS_SPACING_EQUAL,
 667    TESS_SPACING_FRACTIONAL_ODD,
 668    TESS_SPACING_FRACTIONAL_EVEN,
 669 };
 670
 671 /**
 672  * A compare function enum for use in compiler lowering passes.  This is in
 673  * the same order as GL's compare functions (shifted down by GL_NEVER), and is
 674  * exactly the same as gallium's PIPE_FUNC_*.
 675  */
 676 enum compare_func
 677 {
 678    COMPARE_FUNC_NEVER,
 679    COMPARE_FUNC_LESS,
 680    COMPARE_FUNC_EQUAL,
 681    COMPARE_FUNC_LEQUAL,
 682    COMPARE_FUNC_GREATER,
 683    COMPARE_FUNC_NOTEQUAL,
 684    COMPARE_FUNC_GEQUAL,
 685    COMPARE_FUNC_ALWAYS,
 686 };
 687
 688 #ifdef __cplusplus
 689 } /* extern "C" */
 690 #endif
 691
 692 #endif /* SHADER_ENUMS_H */