1/*
2 * Copyright 2008 Corbin Simpson <MostAwesomeDude@gmail.com>
3 *                Joakim Sindholt <opensource@zhasha.com>
4 * Copyright 2009 Marek Olšák <maraeo@gmail.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * on the rights to use, copy, modify, merge, publish, distribute, sub
10 * license, and/or sell copies of the Software, and to permit persons to whom
11 * the Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
21 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
22 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
23 * USE OR OTHER DEALINGS IN THE SOFTWARE. */
24
25#include "util/u_format.h"
26#include "util/u_math.h"
27#include "util/u_memory.h"
28
29#include "tgsi/tgsi_dump.h"
30#include "tgsi/tgsi_ureg.h"
31
32#include "r300_cb.h"
33#include "r300_context.h"
34#include "r300_emit.h"
35#include "r300_screen.h"
36#include "r300_fs.h"
37#include "r300_reg.h"
38#include "r300_texture.h"
39#include "r300_tgsi_to_rc.h"
40
41#include "compiler/radeon_compiler.h"
42
43/* Convert info about FS input semantics to r300_shader_semantics. */
44void r300_shader_read_fs_inputs(struct tgsi_shader_info* info,
45                                struct r300_shader_semantics* fs_inputs)
46{
47    int i;
48    unsigned index;
49
50    r300_shader_semantics_reset(fs_inputs);
51
52    for (i = 0; i < info->num_inputs; i++) {
53        index = info->input_semantic_index[i];
54
55        switch (info->input_semantic_name[i]) {
56            case TGSI_SEMANTIC_COLOR:
57                assert(index < ATTR_COLOR_COUNT);
58                fs_inputs->color[index] = i;
59                break;
60
61            case TGSI_SEMANTIC_GENERIC:
62                assert(index < ATTR_GENERIC_COUNT);
63                fs_inputs->generic[index] = i;
64                break;
65
66            case TGSI_SEMANTIC_FOG:
67                assert(index == 0);
68                fs_inputs->fog = i;
69                break;
70
71            case TGSI_SEMANTIC_POSITION:
72                assert(index == 0);
73                fs_inputs->wpos = i;
74                break;
75
76            case TGSI_SEMANTIC_FACE:
77                assert(index == 0);
78                fs_inputs->face = i;
79                break;
80
81            default:
82                fprintf(stderr, "r300: FP: Unknown input semantic: %i\n",
83                        info->input_semantic_name[i]);
84        }
85    }
86}
87
88static void find_output_registers(struct r300_fragment_program_compiler * compiler,
89                                  struct r300_fragment_shader_code *shader)
90{
91    unsigned i, colorbuf_count = 0;
92
93    /* Mark the outputs as not present initially */
94    compiler->OutputColor[0] = shader->info.num_outputs;
95    compiler->OutputColor[1] = shader->info.num_outputs;
96    compiler->OutputColor[2] = shader->info.num_outputs;
97    compiler->OutputColor[3] = shader->info.num_outputs;
98    compiler->OutputDepth = shader->info.num_outputs;
99
100    /* Now see where they really are. */
101    for(i = 0; i < shader->info.num_outputs; ++i) {
102        switch(shader->info.output_semantic_name[i]) {
103            case TGSI_SEMANTIC_COLOR:
104                compiler->OutputColor[colorbuf_count] = i;
105                colorbuf_count++;
106                break;
107            case TGSI_SEMANTIC_POSITION:
108                compiler->OutputDepth = i;
109                break;
110        }
111    }
112}
113
114static void allocate_hardware_inputs(
115    struct r300_fragment_program_compiler * c,
116    void (*allocate)(void * data, unsigned input, unsigned hwreg),
117    void * mydata)
118{
119    struct r300_shader_semantics* inputs =
120        (struct r300_shader_semantics*)c->UserData;
121    int i, reg = 0;
122
123    /* Allocate input registers. */
124    for (i = 0; i < ATTR_COLOR_COUNT; i++) {
125        if (inputs->color[i] != ATTR_UNUSED) {
126            allocate(mydata, inputs->color[i], reg++);
127        }
128    }
129    if (inputs->face != ATTR_UNUSED) {
130        allocate(mydata, inputs->face, reg++);
131    }
132    for (i = 0; i < ATTR_GENERIC_COUNT; i++) {
133        if (inputs->generic[i] != ATTR_UNUSED) {
134            allocate(mydata, inputs->generic[i], reg++);
135        }
136    }
137    if (inputs->fog != ATTR_UNUSED) {
138        allocate(mydata, inputs->fog, reg++);
139    }
140    if (inputs->wpos != ATTR_UNUSED) {
141        allocate(mydata, inputs->wpos, reg++);
142    }
143}
144
145static void get_external_state(
146    struct r300_context* r300,
147    struct r300_fragment_program_external_state* state)
148{
149    struct r300_textures_state *texstate = r300->textures_state.state;
150    unsigned i;
151
152    for (i = 0; i < texstate->sampler_state_count; i++) {
153        struct r300_sampler_state *s = texstate->sampler_states[i];
154        struct r300_sampler_view *v = texstate->sampler_views[i];
155        struct r300_resource *t;
156
157        if (!s || !v) {
158            continue;
159        }
160
161        t = r300_resource(v->base.texture);
162
163        if (s->state.compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE) {
164            state->unit[i].compare_mode_enabled = 1;
165
166            /* Fortunately, no need to translate this. */
167            state->unit[i].texture_compare_func = s->state.compare_func;
168        }
169
170        state->unit[i].non_normalized_coords = !s->state.normalized_coords;
171        state->unit[i].convert_unorm_to_snorm =
172                v->base.format == PIPE_FORMAT_RGTC1_SNORM ||
173                v->base.format == PIPE_FORMAT_LATC1_SNORM;
174
175        /* Pass texture swizzling to the compiler, some lowering passes need it. */
176        if (v->base.format == PIPE_FORMAT_RGTC1_SNORM ||
177            v->base.format == PIPE_FORMAT_LATC1_SNORM) {
178            unsigned char swizzle[4];
179
180            util_format_compose_swizzles(
181                            util_format_description(v->base.format)->swizzle,
182                            v->swizzle,
183                            swizzle);
184
185            state->unit[i].texture_swizzle =
186                    RC_MAKE_SWIZZLE(swizzle[0], swizzle[1],
187                                    swizzle[2], swizzle[3]);
188        } else if (state->unit[i].compare_mode_enabled) {
189            state->unit[i].texture_swizzle =
190                RC_MAKE_SWIZZLE(v->swizzle[0], v->swizzle[1],
191                                v->swizzle[2], v->swizzle[3]);
192        }
193
194        /* XXX this should probably take into account STR, not just S. */
195        if (t->tex.is_npot) {
196            switch (s->state.wrap_s) {
197            case PIPE_TEX_WRAP_REPEAT:
198                state->unit[i].wrap_mode = RC_WRAP_REPEAT;
199                break;
200
201            case PIPE_TEX_WRAP_MIRROR_REPEAT:
202                state->unit[i].wrap_mode = RC_WRAP_MIRRORED_REPEAT;
203                break;
204
205            case PIPE_TEX_WRAP_MIRROR_CLAMP:
206            case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
207            case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
208                state->unit[i].wrap_mode = RC_WRAP_MIRRORED_CLAMP;
209                break;
210
211            default:
212                state->unit[i].wrap_mode = RC_WRAP_NONE;
213            }
214
215            if (t->b.b.target == PIPE_TEXTURE_3D)
216                state->unit[i].clamp_and_scale_before_fetch = TRUE;
217        }
218    }
219}
220
221static void r300_translate_fragment_shader(
222    struct r300_context* r300,
223    struct r300_fragment_shader_code* shader,
224    const struct tgsi_token *tokens);
225
226static void r300_dummy_fragment_shader(
227    struct r300_context* r300,
228    struct r300_fragment_shader_code* shader)
229{
230    struct pipe_shader_state state;
231    struct ureg_program *ureg;
232    struct ureg_dst out;
233    struct ureg_src imm;
234
235    /* Make a simple fragment shader which outputs (0, 0, 0, 1) */
236    ureg = ureg_create(TGSI_PROCESSOR_FRAGMENT);
237    out = ureg_DECL_output(ureg, TGSI_SEMANTIC_COLOR, 0);
238    imm = ureg_imm4f(ureg, 0, 0, 0, 1);
239
240    ureg_MOV(ureg, out, imm);
241    ureg_END(ureg);
242
243    state.tokens = ureg_finalize(ureg);
244
245    shader->dummy = TRUE;
246    r300_translate_fragment_shader(r300, shader, state.tokens);
247
248    ureg_destroy(ureg);
249}
250
251static void r300_emit_fs_code_to_buffer(
252    struct r300_context *r300,
253    struct r300_fragment_shader_code *shader)
254{
255    struct rX00_fragment_program_code *generic_code = &shader->code;
256    unsigned imm_count = shader->immediates_count;
257    unsigned imm_first = shader->externals_count;
258    unsigned imm_end = generic_code->constants.Count;
259    struct rc_constant *constants = generic_code->constants.Constants;
260    unsigned i;
261    CB_LOCALS;
262
263    if (r300->screen->caps.is_r500) {
264        struct r500_fragment_program_code *code = &generic_code->code.r500;
265
266        shader->cb_code_size = 19 +
267                               ((code->inst_end + 1) * 6) +
268                               imm_count * 7 +
269                               code->int_constant_count * 2;
270
271        NEW_CB(shader->cb_code, shader->cb_code_size);
272        OUT_CB_REG(R500_US_CONFIG, R500_ZERO_TIMES_ANYTHING_EQUALS_ZERO);
273        OUT_CB_REG(R500_US_PIXSIZE, code->max_temp_idx);
274        OUT_CB_REG(R500_US_FC_CTRL, code->us_fc_ctrl);
275        for(i = 0; i < code->int_constant_count; i++){
276                OUT_CB_REG(R500_US_FC_INT_CONST_0 + (i * 4),
277                                                code->int_constants[i]);
278        }
279        OUT_CB_REG(R500_US_CODE_RANGE,
280                   R500_US_CODE_RANGE_ADDR(0) | R500_US_CODE_RANGE_SIZE(code->inst_end));
281        OUT_CB_REG(R500_US_CODE_OFFSET, 0);
282        OUT_CB_REG(R500_US_CODE_ADDR,
283                   R500_US_CODE_START_ADDR(0) | R500_US_CODE_END_ADDR(code->inst_end));
284
285        OUT_CB_REG(R500_GA_US_VECTOR_INDEX, R500_GA_US_VECTOR_INDEX_TYPE_INSTR);
286        OUT_CB_ONE_REG(R500_GA_US_VECTOR_DATA, (code->inst_end + 1) * 6);
287        for (i = 0; i <= code->inst_end; i++) {
288            OUT_CB(code->inst[i].inst0);
289            OUT_CB(code->inst[i].inst1);
290            OUT_CB(code->inst[i].inst2);
291            OUT_CB(code->inst[i].inst3);
292            OUT_CB(code->inst[i].inst4);
293            OUT_CB(code->inst[i].inst5);
294        }
295
296        /* Emit immediates. */
297        if (imm_count) {
298            for(i = imm_first; i < imm_end; ++i) {
299                if (constants[i].Type == RC_CONSTANT_IMMEDIATE) {
300                    const float *data = constants[i].u.Immediate;
301
302                    OUT_CB_REG(R500_GA_US_VECTOR_INDEX,
303                               R500_GA_US_VECTOR_INDEX_TYPE_CONST |
304                               (i & R500_GA_US_VECTOR_INDEX_MASK));
305                    OUT_CB_ONE_REG(R500_GA_US_VECTOR_DATA, 4);
306                    OUT_CB_TABLE(data, 4);
307                }
308            }
309        }
310    } else { /* r300 */
311        struct r300_fragment_program_code *code = &generic_code->code.r300;
312        unsigned int alu_length = code->alu.length;
313        unsigned int alu_iterations = ((alu_length - 1) / 64) + 1;
314        unsigned int tex_length = code->tex.length;
315        unsigned int tex_iterations =
316            tex_length > 0 ? ((tex_length - 1) / 32) + 1 : 0;
317        unsigned int iterations =
318            alu_iterations > tex_iterations ? alu_iterations : tex_iterations;
319        unsigned int bank = 0;
320
321        shader->cb_code_size = 15 +
322            /* R400_US_CODE_BANK */
323            (r300->screen->caps.is_r400 ? 2 * (iterations + 1): 0) +
324            /* R400_US_CODE_EXT */
325            (r300->screen->caps.is_r400 ? 2 : 0) +
326            /* R300_US_ALU_{RGB,ALPHA}_{INST,ADDR}_0, R400_US_ALU_EXT_ADDR_0 */
327            (code->r390_mode ? (5 * alu_iterations) : 4) +
328            /* R400_US_ALU_EXT_ADDR_[0-63] */
329            (code->r390_mode ? (code->alu.length) : 0) +
330            /* R300_US_ALU_{RGB,ALPHA}_{INST,ADDR}_0 */
331            code->alu.length * 4 +
332            /* R300_US_TEX_INST_0, R300_US_TEX_INST_[0-31] */
333            (code->tex.length > 0 ? code->tex.length + tex_iterations : 0) +
334            imm_count * 5;
335
336        NEW_CB(shader->cb_code, shader->cb_code_size);
337
338        OUT_CB_REG(R300_US_CONFIG, code->config);
339        OUT_CB_REG(R300_US_PIXSIZE, code->pixsize);
340        OUT_CB_REG(R300_US_CODE_OFFSET, code->code_offset);
341
342        if (code->r390_mode) {
343            OUT_CB_REG(R400_US_CODE_EXT, code->r400_code_offset_ext);
344        } else if (r300->screen->caps.is_r400) {
345            /* This register appears to affect shaders even if r390_mode is
346             * disabled, so it needs to be set to 0 for shaders that
347             * don't use r390_mode. */
348            OUT_CB_REG(R400_US_CODE_EXT, 0);
349        }
350
351        OUT_CB_REG_SEQ(R300_US_CODE_ADDR_0, 4);
352        OUT_CB_TABLE(code->code_addr, 4);
353
354        do {
355            unsigned int bank_alu_length = (alu_length < 64 ? alu_length : 64);
356            unsigned int bank_alu_offset = bank * 64;
357            unsigned int bank_tex_length = (tex_length < 32 ? tex_length : 32);
358            unsigned int bank_tex_offset = bank * 32;
359
360            if (r300->screen->caps.is_r400) {
361                OUT_CB_REG(R400_US_CODE_BANK, code->r390_mode ?
362                                (bank << R400_BANK_SHIFT) | R400_R390_MODE_ENABLE : 0);//2
363            }
364
365            if (bank_alu_length > 0) {
366                OUT_CB_REG_SEQ(R300_US_ALU_RGB_INST_0, bank_alu_length);
367                for (i = 0; i < bank_alu_length; i++)
368                    OUT_CB(code->alu.inst[i + bank_alu_offset].rgb_inst);
369
370                OUT_CB_REG_SEQ(R300_US_ALU_RGB_ADDR_0, bank_alu_length);
371                for (i = 0; i < bank_alu_length; i++)
372                    OUT_CB(code->alu.inst[i + bank_alu_offset].rgb_addr);
373
374                OUT_CB_REG_SEQ(R300_US_ALU_ALPHA_INST_0, bank_alu_length);
375                for (i = 0; i < bank_alu_length; i++)
376                    OUT_CB(code->alu.inst[i + bank_alu_offset].alpha_inst);
377
378                OUT_CB_REG_SEQ(R300_US_ALU_ALPHA_ADDR_0, bank_alu_length);
379                for (i = 0; i < bank_alu_length; i++)
380                    OUT_CB(code->alu.inst[i + bank_alu_offset].alpha_addr);
381
382                if (code->r390_mode) {
383                    OUT_CB_REG_SEQ(R400_US_ALU_EXT_ADDR_0, bank_alu_length);
384                    for (i = 0; i < bank_alu_length; i++)
385                        OUT_CB(code->alu.inst[i + bank_alu_offset].r400_ext_addr);
386                }
387            }
388
389            if (bank_tex_length > 0) {
390                OUT_CB_REG_SEQ(R300_US_TEX_INST_0, bank_tex_length);
391                OUT_CB_TABLE(code->tex.inst + bank_tex_offset, bank_tex_length);
392            }
393
394            alu_length -= bank_alu_length;
395            tex_length -= bank_tex_length;
396            bank++;
397        } while(code->r390_mode && (alu_length > 0 || tex_length > 0));
398
399        /* R400_US_CODE_BANK needs to be reset to 0, otherwise some shaders
400         * will be rendered incorrectly. */
401        if (r300->screen->caps.is_r400) {
402            OUT_CB_REG(R400_US_CODE_BANK,
403                code->r390_mode ? R400_R390_MODE_ENABLE : 0);
404        }
405
406        /* Emit immediates. */
407        if (imm_count) {
408            for(i = imm_first; i < imm_end; ++i) {
409                if (constants[i].Type == RC_CONSTANT_IMMEDIATE) {
410                    const float *data = constants[i].u.Immediate;
411
412                    OUT_CB_REG_SEQ(R300_PFS_PARAM_0_X + i * 16, 4);
413                    OUT_CB(pack_float24(data[0]));
414                    OUT_CB(pack_float24(data[1]));
415                    OUT_CB(pack_float24(data[2]));
416                    OUT_CB(pack_float24(data[3]));
417                }
418            }
419        }
420    }
421
422    OUT_CB_REG(R300_FG_DEPTH_SRC, shader->fg_depth_src);
423    OUT_CB_REG(R300_US_W_FMT, shader->us_out_w);
424    END_CB;
425}
426
427static void r300_translate_fragment_shader(
428    struct r300_context* r300,
429    struct r300_fragment_shader_code* shader,
430    const struct tgsi_token *tokens)
431{
432    struct r300_fragment_program_compiler compiler;
433    struct tgsi_to_rc ttr;
434    int wpos, face;
435    unsigned i;
436
437    tgsi_scan_shader(tokens, &shader->info);
438    r300_shader_read_fs_inputs(&shader->info, &shader->inputs);
439
440    wpos = shader->inputs.wpos;
441    face = shader->inputs.face;
442
443    /* Setup the compiler. */
444    memset(&compiler, 0, sizeof(compiler));
445    rc_init(&compiler.Base);
446    DBG_ON(r300, DBG_FP) ? compiler.Base.Debug |= RC_DBG_LOG : 0;
447    DBG_ON(r300, DBG_P_STAT) ? compiler.Base.Debug |= RC_DBG_STATS : 0;
448
449    compiler.code = &shader->code;
450    compiler.state = shader->compare_state;
451    compiler.Base.is_r500 = r300->screen->caps.is_r500;
452    compiler.Base.is_r400 = r300->screen->caps.is_r400;
453    compiler.Base.disable_optimizations = DBG_ON(r300, DBG_NO_OPT);
454    compiler.Base.has_half_swizzles = TRUE;
455    compiler.Base.has_presub = TRUE;
456    compiler.Base.has_omod = TRUE;
457    compiler.Base.max_temp_regs =
458        compiler.Base.is_r500 ? 128 : (compiler.Base.is_r400 ? 64 : 32);
459    compiler.Base.max_constants = compiler.Base.is_r500 ? 256 : 32;
460    compiler.Base.max_alu_insts =
461        (compiler.Base.is_r500 || compiler.Base.is_r400) ? 512 : 64;
462    compiler.Base.max_tex_insts =
463        (compiler.Base.is_r500 || compiler.Base.is_r400) ? 512 : 32;
464    compiler.AllocateHwInputs = &allocate_hardware_inputs;
465    compiler.UserData = &shader->inputs;
466
467    find_output_registers(&compiler, shader);
468
469    shader->write_all = FALSE;
470    for (i = 0; i < shader->info.num_properties; i++) {
471        if (shader->info.properties[i].name == TGSI_PROPERTY_FS_COLOR0_WRITES_ALL_CBUFS) {
472            shader->write_all = TRUE;
473        }
474    }
475
476    if (compiler.Base.Debug & RC_DBG_LOG) {
477        DBG(r300, DBG_FP, "r300: Initial fragment program\n");
478        tgsi_dump(tokens, 0);
479    }
480
481    /* Translate TGSI to our internal representation */
482    ttr.compiler = &compiler.Base;
483    ttr.info = &shader->info;
484    ttr.use_half_swizzles = TRUE;
485
486    r300_tgsi_to_rc(&ttr, tokens);
487
488    if (ttr.error) {
489        fprintf(stderr, "r300 FP: Cannot translate a shader. "
490                "Using a dummy shader instead.\n");
491        r300_dummy_fragment_shader(r300, shader);
492        return;
493    }
494
495    if (!r300->screen->caps.is_r500 ||
496        compiler.Base.Program.Constants.Count > 200) {
497        compiler.Base.remove_unused_constants = TRUE;
498    }
499
500    /**
501     * Transform the program to support WPOS.
502     *
503     * Introduce a small fragment at the start of the program that will be
504     * the only code that directly reads the WPOS input.
505     * All other code pieces that reference that input will be rewritten
506     * to read from a newly allocated temporary. */
507    if (wpos != ATTR_UNUSED) {
508        /* Moving the input to some other reg is not really necessary. */
509        rc_transform_fragment_wpos(&compiler.Base, wpos, wpos, TRUE);
510    }
511
512    if (face != ATTR_UNUSED) {
513        rc_transform_fragment_face(&compiler.Base, face);
514    }
515
516    /* Invoke the compiler */
517    r3xx_compile_fragment_program(&compiler);
518
519    if (compiler.Base.Error) {
520        fprintf(stderr, "r300 FP: Compiler Error:\n%sUsing a dummy shader"
521                " instead.\n", compiler.Base.ErrorMsg);
522
523        if (shader->dummy) {
524            fprintf(stderr, "r300 FP: Cannot compile the dummy shader! "
525                    "Giving up...\n");
526            abort();
527        }
528
529        rc_destroy(&compiler.Base);
530        r300_dummy_fragment_shader(r300, shader);
531        return;
532    }
533
534    /* Shaders with zero instructions are invalid,
535     * use the dummy shader instead. */
536    if (shader->code.code.r500.inst_end == -1) {
537        rc_destroy(&compiler.Base);
538        r300_dummy_fragment_shader(r300, shader);
539        return;
540    }
541
542    /* Initialize numbers of constants for each type. */
543    shader->externals_count = 0;
544    for (i = 0;
545         i < shader->code.constants.Count &&
546         shader->code.constants.Constants[i].Type == RC_CONSTANT_EXTERNAL; i++) {
547        shader->externals_count = i+1;
548    }
549    shader->immediates_count = 0;
550    shader->rc_state_count = 0;
551
552    for (i = shader->externals_count; i < shader->code.constants.Count; i++) {
553        switch (shader->code.constants.Constants[i].Type) {
554            case RC_CONSTANT_IMMEDIATE:
555                ++shader->immediates_count;
556                break;
557            case RC_CONSTANT_STATE:
558                ++shader->rc_state_count;
559                break;
560            default:
561                assert(0);
562        }
563    }
564
565    /* Setup shader depth output. */
566    if (shader->code.writes_depth) {
567        shader->fg_depth_src = R300_FG_DEPTH_SRC_SHADER;
568        shader->us_out_w = R300_W_FMT_W24 | R300_W_SRC_US;
569    } else {
570        shader->fg_depth_src = R300_FG_DEPTH_SRC_SCAN;
571        shader->us_out_w = R300_W_FMT_W0 | R300_W_SRC_US;
572    }
573
574    /* And, finally... */
575    rc_destroy(&compiler.Base);
576
577    /* Build the command buffer. */
578    r300_emit_fs_code_to_buffer(r300, shader);
579}
580
581boolean r300_pick_fragment_shader(struct r300_context* r300)
582{
583    struct r300_fragment_shader* fs = r300_fs(r300);
584    struct r300_fragment_program_external_state state = {{{ 0 }}};
585    struct r300_fragment_shader_code* ptr;
586
587    get_external_state(r300, &state);
588
589    if (!fs->first) {
590        /* Build the fragment shader for the first time. */
591        fs->first = fs->shader = CALLOC_STRUCT(r300_fragment_shader_code);
592
593        memcpy(&fs->shader->compare_state, &state,
594            sizeof(struct r300_fragment_program_external_state));
595        r300_translate_fragment_shader(r300, fs->shader, fs->state.tokens);
596        return TRUE;
597
598    } else {
599        /* Check if the currently-bound shader has been compiled
600         * with the texture-compare state we need. */
601        if (memcmp(&fs->shader->compare_state, &state, sizeof(state)) != 0) {
602            /* Search for the right shader. */
603            ptr = fs->first;
604            while (ptr) {
605                if (memcmp(&ptr->compare_state, &state, sizeof(state)) == 0) {
606                    if (fs->shader != ptr) {
607                        fs->shader = ptr;
608                        return TRUE;
609                    }
610                    /* The currently-bound one is OK. */
611                    return FALSE;
612                }
613                ptr = ptr->next;
614            }
615
616            /* Not found, gotta compile a new one. */
617            ptr = CALLOC_STRUCT(r300_fragment_shader_code);
618            ptr->next = fs->first;
619            fs->first = fs->shader = ptr;
620
621            ptr->compare_state = state;
622            r300_translate_fragment_shader(r300, ptr, fs->state.tokens);
623            return TRUE;
624        }
625    }
626
627    return FALSE;
628}
629