1 /*
2 * Copyright © 2015 Red Hat
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 FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 */
23
24 #include "nir.h"
25 #include "nir_builder.h"
26
27 /* Lower glDrawPixels().
28 *
29 * This is based on the logic in st_get_drawpix_shader() in TGSI compiler.
30 *
31 * Run before nir_lower_io.
32 */
33
34 typedef struct {
35 const nir_lower_drawpixels_options *options;
36 nir_shader *shader;
37 nir_builder b;
38 nir_variable *texcoord, *texcoord_const, *scale, *bias, *tex, *pixelmap;
39 } lower_drawpixels_state;
40
41 static nir_ssa_def *
get_texcoord(lower_drawpixels_state * state)42 get_texcoord(lower_drawpixels_state *state)
43 {
44 if (state->texcoord == NULL) {
45 nir_variable *texcoord = NULL;
46
47 /* find gl_TexCoord, if it exists: */
48 nir_foreach_shader_in_variable(var, state->shader) {
49 if (var->data.location == VARYING_SLOT_TEX0) {
50 texcoord = var;
51 break;
52 }
53 }
54
55 /* otherwise create it: */
56 if (texcoord == NULL) {
57 texcoord = nir_variable_create(state->shader,
58 nir_var_shader_in,
59 glsl_vec4_type(),
60 "gl_TexCoord");
61 texcoord->data.location = VARYING_SLOT_TEX0;
62 }
63
64 state->texcoord = texcoord;
65 }
66 return nir_load_var(&state->b, state->texcoord);
67 }
68
69 static nir_variable *
create_uniform(nir_shader * shader,const char * name,const gl_state_index16 state_tokens[STATE_LENGTH])70 create_uniform(nir_shader *shader, const char *name,
71 const gl_state_index16 state_tokens[STATE_LENGTH])
72 {
73 nir_variable *var = nir_variable_create(shader,
74 nir_var_uniform,
75 glsl_vec4_type(),
76 name);
77 var->num_state_slots = 1;
78 var->state_slots = ralloc_array(var, nir_state_slot, 1);
79 memcpy(var->state_slots[0].tokens, state_tokens,
80 sizeof(var->state_slots[0].tokens));
81 return var;
82 }
83
84 static nir_ssa_def *
get_scale(lower_drawpixels_state * state)85 get_scale(lower_drawpixels_state *state)
86 {
87 if (state->scale == NULL) {
88 state->scale = create_uniform(state->shader, "gl_PTscale",
89 state->options->scale_state_tokens);
90 }
91 return nir_load_var(&state->b, state->scale);
92 }
93
94 static nir_ssa_def *
get_bias(lower_drawpixels_state * state)95 get_bias(lower_drawpixels_state *state)
96 {
97 if (state->bias == NULL) {
98 state->bias = create_uniform(state->shader, "gl_PTbias",
99 state->options->bias_state_tokens);
100 }
101 return nir_load_var(&state->b, state->bias);
102 }
103
104 static nir_ssa_def *
get_texcoord_const(lower_drawpixels_state * state)105 get_texcoord_const(lower_drawpixels_state *state)
106 {
107 if (state->texcoord_const == NULL) {
108 state->texcoord_const = create_uniform(state->shader,
109 "gl_MultiTexCoord0",
110 state->options->texcoord_state_tokens);
111 }
112 return nir_load_var(&state->b, state->texcoord_const);
113 }
114
115 static void
lower_color(lower_drawpixels_state * state,nir_intrinsic_instr * intr)116 lower_color(lower_drawpixels_state *state, nir_intrinsic_instr *intr)
117 {
118 nir_builder *b = &state->b;
119 nir_ssa_def *texcoord;
120 nir_tex_instr *tex;
121 nir_ssa_def *def;
122
123 assert(intr->dest.is_ssa);
124
125 b->cursor = nir_before_instr(&intr->instr);
126
127 texcoord = get_texcoord(state);
128
129 const struct glsl_type *sampler2D =
130 glsl_sampler_type(GLSL_SAMPLER_DIM_2D, false, false, GLSL_TYPE_FLOAT);
131
132 if (!state->tex) {
133 state->tex =
134 nir_variable_create(b->shader, nir_var_uniform, sampler2D, "drawpix");
135 state->tex->data.binding = state->options->drawpix_sampler;
136 state->tex->data.explicit_binding = true;
137 state->tex->data.how_declared = nir_var_hidden;
138 }
139
140 nir_deref_instr *tex_deref = nir_build_deref_var(b, state->tex);
141
142 /* replace load_var(gl_Color) w/ texture sample:
143 * TEX def, texcoord, drawpix_sampler, 2D
144 */
145 tex = nir_tex_instr_create(state->shader, 3);
146 tex->op = nir_texop_tex;
147 tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
148 tex->coord_components = 2;
149 tex->dest_type = nir_type_float32;
150 tex->src[0].src_type = nir_tex_src_texture_deref;
151 tex->src[0].src = nir_src_for_ssa(&tex_deref->dest.ssa);
152 tex->src[1].src_type = nir_tex_src_sampler_deref;
153 tex->src[1].src = nir_src_for_ssa(&tex_deref->dest.ssa);
154 tex->src[2].src_type = nir_tex_src_coord;
155 tex->src[2].src =
156 nir_src_for_ssa(nir_channels(b, texcoord,
157 (1 << tex->coord_components) - 1));
158
159 nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
160 nir_builder_instr_insert(b, &tex->instr);
161 def = &tex->dest.ssa;
162
163 /* Apply the scale and bias. */
164 if (state->options->scale_and_bias) {
165 /* MAD def, def, scale, bias; */
166 def = nir_ffma(b, def, get_scale(state), get_bias(state));
167 }
168
169 if (state->options->pixel_maps) {
170 if (!state->pixelmap) {
171 state->pixelmap = nir_variable_create(b->shader, nir_var_uniform,
172 sampler2D, "pixelmap");
173 state->pixelmap->data.binding = state->options->pixelmap_sampler;
174 state->pixelmap->data.explicit_binding = true;
175 state->pixelmap->data.how_declared = nir_var_hidden;
176 }
177
178 nir_deref_instr *pixelmap_deref =
179 nir_build_deref_var(b, state->pixelmap);
180
181 /* do four pixel map look-ups with two TEX instructions: */
182 nir_ssa_def *def_xy, *def_zw;
183
184 /* TEX def.xy, def.xyyy, pixelmap_sampler, 2D; */
185 tex = nir_tex_instr_create(state->shader, 3);
186 tex->op = nir_texop_tex;
187 tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
188 tex->coord_components = 2;
189 tex->sampler_index = state->options->pixelmap_sampler;
190 tex->texture_index = state->options->pixelmap_sampler;
191 tex->dest_type = nir_type_float32;
192 tex->src[0].src_type = nir_tex_src_texture_deref;
193 tex->src[0].src = nir_src_for_ssa(&pixelmap_deref->dest.ssa);
194 tex->src[1].src_type = nir_tex_src_sampler_deref;
195 tex->src[1].src = nir_src_for_ssa(&pixelmap_deref->dest.ssa);
196 tex->src[2].src_type = nir_tex_src_coord;
197 tex->src[2].src = nir_src_for_ssa(nir_channels(b, def, 0x3));
198
199 nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
200 nir_builder_instr_insert(b, &tex->instr);
201 def_xy = &tex->dest.ssa;
202
203 /* TEX def.zw, def.zwww, pixelmap_sampler, 2D; */
204 tex = nir_tex_instr_create(state->shader, 1);
205 tex->op = nir_texop_tex;
206 tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
207 tex->coord_components = 2;
208 tex->sampler_index = state->options->pixelmap_sampler;
209 tex->dest_type = nir_type_float32;
210 tex->src[0].src_type = nir_tex_src_coord;
211 tex->src[0].src = nir_src_for_ssa(nir_channels(b, def, 0xc));
212
213 nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
214 nir_builder_instr_insert(b, &tex->instr);
215 def_zw = &tex->dest.ssa;
216
217 /* def = vec4(def.xy, def.zw); */
218 def = nir_vec4(b,
219 nir_channel(b, def_xy, 0),
220 nir_channel(b, def_xy, 1),
221 nir_channel(b, def_zw, 0),
222 nir_channel(b, def_zw, 1));
223 }
224
225 nir_ssa_def_rewrite_uses(&intr->dest.ssa, def);
226 }
227
228 static void
lower_texcoord(lower_drawpixels_state * state,nir_intrinsic_instr * intr)229 lower_texcoord(lower_drawpixels_state *state, nir_intrinsic_instr *intr)
230 {
231 state->b.cursor = nir_before_instr(&intr->instr);
232
233 nir_ssa_def *texcoord_const = get_texcoord_const(state);
234 nir_ssa_def_rewrite_uses(&intr->dest.ssa, texcoord_const);
235 }
236
237 static bool
lower_drawpixels_block(lower_drawpixels_state * state,nir_block * block)238 lower_drawpixels_block(lower_drawpixels_state *state, nir_block *block)
239 {
240 nir_foreach_instr_safe(instr, block) {
241 if (instr->type == nir_instr_type_intrinsic) {
242 nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
243
244 switch (intr->intrinsic) {
245 case nir_intrinsic_load_deref: {
246 nir_deref_instr *deref = nir_src_as_deref(intr->src[0]);
247 nir_variable *var = nir_deref_instr_get_variable(deref);
248
249 if (var->data.location == VARYING_SLOT_COL0) {
250 /* gl_Color should not have array/struct derefs: */
251 assert(deref->deref_type == nir_deref_type_var);
252 lower_color(state, intr);
253 } else if (var->data.location == VARYING_SLOT_TEX0) {
254 /* gl_TexCoord should not have array/struct derefs: */
255 assert(deref->deref_type == nir_deref_type_var);
256 lower_texcoord(state, intr);
257 }
258 break;
259 }
260
261 case nir_intrinsic_load_color0:
262 lower_color(state, intr);
263 break;
264
265 case nir_intrinsic_load_interpolated_input:
266 case nir_intrinsic_load_input: {
267 if (nir_intrinsic_io_semantics(intr).location == VARYING_SLOT_TEX0)
268 lower_texcoord(state, intr);
269 break;
270 }
271 default:
272 break;
273 }
274 }
275 }
276
277 return true;
278 }
279
280 static void
lower_drawpixels_impl(lower_drawpixels_state * state,nir_function_impl * impl)281 lower_drawpixels_impl(lower_drawpixels_state *state, nir_function_impl *impl)
282 {
283 nir_builder_init(&state->b, impl);
284
285 nir_foreach_block(block, impl) {
286 lower_drawpixels_block(state, block);
287 }
288 nir_metadata_preserve(impl, nir_metadata_block_index |
289 nir_metadata_dominance);
290 }
291
292 void
nir_lower_drawpixels(nir_shader * shader,const nir_lower_drawpixels_options * options)293 nir_lower_drawpixels(nir_shader *shader,
294 const nir_lower_drawpixels_options *options)
295 {
296 lower_drawpixels_state state = {
297 .options = options,
298 .shader = shader,
299 };
300
301 assert(shader->info.stage == MESA_SHADER_FRAGMENT);
302
303 nir_foreach_function(function, shader) {
304 if (function->impl)
305 lower_drawpixels_impl(&state, function->impl);
306 }
307 }
308