1/*
2 * Copyright © Microsoft Corporation
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 * on the rights to use, copy, modify, merge, publish, distribute, sub
8 * license, and/or sell copies of the Software, and to permit persons to whom
9 * the 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 NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
21 * USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24#include "d3d12_nir_lower_texcmp.h"
25#include "nir_builder.h"
26#include "nir_builtin_builder.h"
27
28static bool
29lower_sample_tex_compare_filter(const nir_instr *instr,
30                                UNUSED const void *_options)
31{
32   if (instr->type != nir_instr_type_tex)
33      return false;
34
35   /* To be consistent we also want to lower tex when we lower anything,
36    * otherwise the differences in evaluating the shadow value might lead
37    * to artifacts. */
38   nir_tex_instr *tex = nir_instr_as_tex(instr);
39   if (tex->op != nir_texop_txb &&
40       tex->op != nir_texop_txl &&
41       tex->op != nir_texop_txd &&
42       tex->op != nir_texop_tex)
43      return false;
44
45   return tex->is_shadow;
46}
47
48static const struct glsl_type *
49strip_shadow(const struct glsl_type *type)
50{
51   const struct glsl_type *new_type =
52         glsl_sampler_type(
53            glsl_get_sampler_dim(type),
54            false, glsl_sampler_type_is_array(type),
55            GLSL_TYPE_FLOAT);
56   return new_type;
57}
58
59
60static const struct glsl_type *
61strip_shadow_with_array(const struct glsl_type *type)
62{
63   if (glsl_type_is_array(type))
64      return glsl_array_type(strip_shadow(glsl_without_array(type)),
65                             glsl_get_length(type), 0);
66   return strip_shadow(type);
67}
68
69typedef struct {
70   unsigned n_states;
71   enum compare_func *compare_func;
72   dxil_texture_swizzle_state *tex_swizzles;
73} sampler_state;
74
75static nir_ssa_def *
76lower_sample_tex_compare_impl(nir_builder *b, nir_instr *instr,
77                              void *options)
78
79{
80   nir_tex_instr *tex = nir_instr_as_tex(instr);
81
82   sampler_state *state = (sampler_state *)options;
83   unsigned num_components = nir_tex_instr_result_size(tex);
84
85   b->cursor = nir_after_instr(instr);
86   tex->is_shadow = false;
87
88   int comp_index = nir_tex_instr_src_index(tex, nir_tex_src_comparator);
89
90   nir_deref_instr *sampler_deref = NULL;
91   nir_variable *sampler = NULL;
92
93   int sampler_index = nir_tex_instr_src_index(tex, nir_tex_src_sampler_deref);
94   assert(sampler_index >= 0);
95
96   sampler_deref = nir_instr_as_deref(tex->src[sampler_index].src.ssa->parent_instr);
97   sampler = nir_deref_instr_get_variable(sampler_deref);
98
99   /* NIR expects a vec4 result from the above texture instructions */
100   nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
101
102   nir_ssa_def *tex_r = nir_channel(b, &tex->dest.ssa, 0);
103   nir_ssa_def *cmp = tex->src[comp_index].src.ssa;
104
105   int proj_index = nir_tex_instr_src_index(tex, nir_tex_src_projector);
106   if (proj_index >= 0)
107      cmp = nir_fmul(b, cmp, nir_frcp(b, tex->src[proj_index].src.ssa));
108
109   nir_ssa_def * result =
110         nir_compare_func(b,
111                          sampler->data.binding < state->n_states ?
112                             state->compare_func[sampler->data.binding] : COMPARE_FUNC_ALWAYS,
113                          cmp, tex_r);
114
115   result = nir_b2f32(b, result);
116   nir_ssa_def *one = nir_imm_float(b, 1.0);
117   nir_ssa_def *zero = nir_imm_float(b, 0.0);
118
119   nir_ssa_def *lookup[6] = {result, NULL, NULL, NULL, zero, one};
120   nir_ssa_def *r[4] = {lookup[state->tex_swizzles[sampler->data.binding].swizzle_r],
121                        lookup[state->tex_swizzles[sampler->data.binding].swizzle_g],
122                        lookup[state->tex_swizzles[sampler->data.binding].swizzle_b],
123                        lookup[state->tex_swizzles[sampler->data.binding].swizzle_a]
124                       };
125
126   result = nir_vec(b, r, num_components);
127
128   sampler->type = strip_shadow_with_array(sampler->type);
129   sampler_deref->type = sampler->type;
130
131   tex->is_shadow = false;
132   nir_tex_instr_remove_src(tex, comp_index);
133
134   return result;
135}
136
137bool
138d3d12_lower_sample_tex_compare(nir_shader *s,
139                               unsigned n_states,
140                               enum compare_func *compare_func,
141                               dxil_texture_swizzle_state *tex_swizzles)
142{
143   sampler_state state = {n_states, compare_func, tex_swizzles};
144
145   bool result =
146         nir_shader_lower_instructions(s,
147                                       lower_sample_tex_compare_filter,
148                                       lower_sample_tex_compare_impl,
149                                       &state);
150   return result;
151}
152