1 /*
2 * Copyright © 2019 Collabora Ltd
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24 #include "nir.h"
25 #include "nir_builder.h"
26
27 /** nir_lower_point_size_mov.c
28 *
29 * This pass lowers glPointSize into gl_PointSize, by adding a uniform
30 * and a move from that uniform to VARYING_SLOT_PSIZ. This is useful for
31 * OpenGL ES level hardware that lack constant point-size hardware state.
32 */
33
34 static bool
lower_impl(nir_function_impl * impl,const gl_state_index16 * pointsize_state_tokens,nir_variable * out)35 lower_impl(nir_function_impl *impl,
36 const gl_state_index16 *pointsize_state_tokens,
37 nir_variable *out)
38 {
39 nir_shader *shader = impl->function->shader;
40 nir_builder b;
41 nir_variable *in;
42
43 nir_builder_init(&b, impl);
44 b.cursor = nir_before_cf_list(&impl->body);
45
46 in = nir_variable_create(shader, nir_var_uniform,
47 glsl_float_type(), "gl_PointSizeClampedMESA");
48 in->num_state_slots = 1;
49 in->state_slots = ralloc_array(in, nir_state_slot, 1);
50 memcpy(in->state_slots[0].tokens,
51 pointsize_state_tokens,
52 sizeof(in->state_slots[0].tokens));
53
54 if (!out) {
55 out = nir_variable_create(shader, nir_var_shader_out,
56 glsl_float_type(), "gl_PointSize");
57 out->data.location = VARYING_SLOT_PSIZ;
58 }
59
60 nir_copy_var(&b, out, in);
61
62 nir_metadata_preserve(impl, nir_metadata_block_index |
63 nir_metadata_dominance);
64 return true;
65 }
66
67 void
nir_lower_point_size_mov(nir_shader * shader,const gl_state_index16 * pointsize_state_tokens)68 nir_lower_point_size_mov(nir_shader *shader,
69 const gl_state_index16 *pointsize_state_tokens)
70 {
71 assert(shader->info.stage != MESA_SHADER_FRAGMENT &&
72 shader->info.stage != MESA_SHADER_COMPUTE);
73
74 nir_variable *out =
75 nir_find_variable_with_location(shader, nir_var_shader_out,
76 VARYING_SLOT_PSIZ);
77
78 lower_impl(nir_shader_get_entrypoint(shader), pointsize_state_tokens,
79 out);
80 }
81