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11 * The above copyright notice and this permission notice (including the next
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24 #include "nir_builder.h"
26 /** @file nir_lower_point_size.c
28 * The OpenGL spec requires that implementations clamp gl_PointSize to an
29 * implementation-dependant point size range. The OpenGL ES 3.0 spec further
30 * requires that this range must match GL_ALIASED_POINT_SIZE_RANGE.
31 * Some hardware such as V3D don't clamp to a valid range automatically so
32 * the driver must clamp the point size written by the shader manually to a
37 lower_point_size_instr(nir_builder
*b
, nir_instr
*psiz_instr
,
40 b
->cursor
= nir_before_instr(psiz_instr
);
42 nir_intrinsic_instr
*instr
= nir_instr_as_intrinsic(psiz_instr
);
44 assert(instr
->src
[1].is_ssa
);
45 assert(instr
->src
[1].ssa
->num_components
== 1);
46 nir_ssa_def
*psiz
= instr
->src
[1].ssa
;
49 psiz
= nir_fmax(b
, psiz
, nir_imm_float(b
, min
));
52 psiz
= nir_fmin(b
, psiz
, nir_imm_float(b
, max
));
54 nir_instr_rewrite_src(&instr
->instr
, &instr
->src
[1], nir_src_for_ssa(psiz
));
58 instr_is_point_size(const nir_instr
*instr
)
60 if (instr
->type
!= nir_instr_type_intrinsic
)
63 nir_intrinsic_instr
*intr
= nir_instr_as_intrinsic(instr
);
64 if (intr
->intrinsic
!= nir_intrinsic_store_deref
)
67 nir_deref_instr
*deref
= nir_src_as_deref(intr
->src
[0]);
68 nir_variable
*var
= nir_deref_instr_get_variable(deref
);
69 if (var
->data
.location
!= VARYING_SLOT_PSIZ
)
76 * Clamps gl_PointSize to the range [min, max]. If either min or max are not
77 * greater than 0 then no clamping is done for that side of the range.
80 nir_lower_point_size(nir_shader
*s
, float min
, float max
)
82 assert(s
->info
.stage
!= MESA_SHADER_FRAGMENT
&&
83 s
->info
.stage
!= MESA_SHADER_COMPUTE
);
85 assert(min
> 0.0f
|| max
> 0.0f
);
86 assert(min
<= 0.0f
|| max
<= 0.0f
|| min
<= max
);
88 bool progress
= false;
89 nir_foreach_function(function
, s
) {
94 nir_builder_init(&b
, function
->impl
);
96 nir_foreach_block(block
, function
->impl
) {
97 nir_foreach_instr_safe(instr
, block
) {
98 if (instr_is_point_size(instr
)) {
99 lower_point_size_instr(&b
, instr
, min
, max
);
106 nir_metadata_preserve(function
->impl
,
107 nir_metadata_block_index
|
108 nir_metadata_dominance
);