src/gallium/drivers/r300/r300_vs_draw.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2009 Marek Olšák <maraeo@gmail.com>
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sub license, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject to
  11  * the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the
  14  * next paragraph) shall be included in all copies or substantial portions
  15  * of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  20  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  21  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  22  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  23  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  *
  25  **************************************************************************/
  26
  27 /* This file contains the vertex shader tranformations for SW TCL needed
  28  * to overcome the limitations of the r300 rasterizer.
  29  *
  30  * Transformations:
  31  * 1) If the secondary color output is present, the primary color must be
  32  *    present too.
  33  * 2) If any back-face color output is present, there must be all 4 color
  34  *    outputs and missing ones must be inserted.
  35  * 3) Insert a trailing texcoord output containing a copy of POS, for WPOS.
  36  *
  37  * I know this code is cumbersome, but I don't know of any nicer way
  38  * of transforming TGSI shaders. ~ M.
  39  */
  40
  41 #include "r300_vs.h"
  42
  43 #include <stdio.h>
  44
  45 #include "tgsi/tgsi_transform.h"
  46 #include "tgsi/tgsi_dump.h"
  47
  48 #include "draw/draw_context.h"
  49
  50 struct vs_transform_context {
  51     struct tgsi_transform_context base;
  52
  53     boolean color_used[2];
  54     boolean bcolor_used[2];
  55
  56     /* Index of the pos output, typically 0. */
  57     unsigned pos_output;
  58     /* Index of the pos temp where all writes of pos are redirected to. */
  59     unsigned pos_temp;
  60     /* The index of the last generic output, after which we insert a new
  61      * output for WPOS. */
  62     int last_generic;
  63
  64     unsigned num_outputs;
  65     /* Used to shift output decl. indices when inserting new ones. */
  66     unsigned decl_shift;
  67     /* Used to remap writes to output decls if their indices changed. */
  68     unsigned out_remap[32];
  69
  70     /* First instruction processed? */
  71     boolean first_instruction;
  72     /* End instruction processed? */
  73     boolean end_instruction;
  74
  75     boolean temp_used[1024];
  76 };
  77
  78 static void emit_temp(struct tgsi_transform_context *ctx, unsigned reg)
  79 {
  80     struct tgsi_full_declaration decl;
  81
  82     decl = tgsi_default_full_declaration();
  83     decl.Declaration.File = TGSI_FILE_TEMPORARY;
  84     decl.Range.First = decl.Range.Last = reg;
  85     ctx->emit_declaration(ctx, &decl);
  86 }
  87
  88 static void emit_output(struct tgsi_transform_context *ctx,
  89                         unsigned name, unsigned index, unsigned interp,
  90                         unsigned reg)
  91 {
  92     struct vs_transform_context *vsctx = (struct vs_transform_context *)ctx;
  93     struct tgsi_full_declaration decl;
  94
  95     decl = tgsi_default_full_declaration();
  96     decl.Declaration.File = TGSI_FILE_OUTPUT;
  97     decl.Declaration.Interpolate = 1;
  98     decl.Declaration.Semantic = TRUE;
  99     decl.Semantic.Name = name;
 100     decl.Semantic.Index = index;
 101     decl.Range.First = decl.Range.Last = reg;
 102     decl.Interp.Interpolate = interp;
 103     ctx->emit_declaration(ctx, &decl);
 104     ++vsctx->num_outputs;
 105 }
 106
 107 static void insert_output_before(struct tgsi_transform_context *ctx,
 108                                  struct tgsi_full_declaration *before,
 109                                  unsigned name, unsigned index, unsigned interp)
 110 {
 111     struct vs_transform_context *vsctx = (struct vs_transform_context *)ctx;
 112     unsigned i;
 113
 114     /* Make a place for the new output. */
 115     for (i = before->Range.First; i < Elements(vsctx->out_remap); i++) {
 116         ++vsctx->out_remap[i];
 117     }
 118
 119     /* Insert the new output. */
 120     emit_output(ctx, name, index, interp,
 121                 before->Range.First + vsctx->decl_shift);
 122
 123     ++vsctx->decl_shift;
 124 }
 125
 126 static void insert_output_after(struct tgsi_transform_context *ctx,
 127                                 struct tgsi_full_declaration *after,
 128                                 unsigned name, unsigned index, unsigned interp)
 129 {
 130     struct vs_transform_context *vsctx = (struct vs_transform_context *)ctx;
 131     unsigned i;
 132
 133     /* Make a place for the new output. */
 134     for (i = after->Range.First+1; i < Elements(vsctx->out_remap); i++) {
 135         ++vsctx->out_remap[i];
 136     }
 137
 138     /* Insert the new output. */
 139     emit_output(ctx, name, index, interp,
 140                 after->Range.First + 1);
 141
 142     ++vsctx->decl_shift;
 143 }
 144
 145 static void transform_decl(struct tgsi_transform_context *ctx,
 146                            struct tgsi_full_declaration *decl)
 147 {
 148     struct vs_transform_context *vsctx = (struct vs_transform_context *)ctx;
 149     unsigned i;
 150
 151     if (decl->Declaration.File == TGSI_FILE_OUTPUT) {
 152         switch (decl->Semantic.Name) {
 153             case TGSI_SEMANTIC_POSITION:
 154                 vsctx->pos_output = decl->Range.First;
 155                 break;
 156
 157             case TGSI_SEMANTIC_COLOR:
 158                 assert(decl->Semantic.Index < 2);
 159
 160                 /* We must rasterize the first color if the second one is
 161                  * used, otherwise the rasterizer doesn't do the color
 162                  * selection correctly. Declare it, but don't write to it. */
 163                 if (decl->Semantic.Index == 1 && !vsctx->color_used[0]) {
 164                     insert_output_before(ctx, decl, TGSI_SEMANTIC_COLOR, 0,
 165                                          TGSI_INTERPOLATE_LINEAR);
 166                     vsctx->color_used[0] = TRUE;
 167                 }
 168                 break;
 169
 170             case TGSI_SEMANTIC_BCOLOR:
 171                 assert(decl->Semantic.Index < 2);
 172
 173                 /* We must rasterize all 4 colors if back-face colors are
 174                  * used, otherwise the rasterizer doesn't do the color
 175                  * selection correctly. Declare it, but don't write to it. */
 176                 if (!vsctx->color_used[0]) {
 177                     insert_output_before(ctx, decl, TGSI_SEMANTIC_COLOR, 0,
 178                                          TGSI_INTERPOLATE_LINEAR);
 179                     vsctx->color_used[0] = TRUE;
 180                 }
 181                 if (!vsctx->color_used[1]) {
 182                     insert_output_before(ctx, decl, TGSI_SEMANTIC_COLOR, 1,
 183                                          TGSI_INTERPOLATE_LINEAR);
 184                     vsctx->color_used[1] = TRUE;
 185                 }
 186                 if (decl->Semantic.Index == 1 && !vsctx->bcolor_used[0]) {
 187                     insert_output_before(ctx, decl, TGSI_SEMANTIC_BCOLOR, 0,
 188                                          TGSI_INTERPOLATE_LINEAR);
 189                     vsctx->bcolor_used[0] = TRUE;
 190                 }
 191                 break;
 192
 193             case TGSI_SEMANTIC_GENERIC:
 194                 vsctx->last_generic = MAX2(vsctx->last_generic, decl->Semantic.Index);
 195                 break;
 196         }
 197
 198         /* Since we're inserting new outputs in between, the following outputs
 199          * should be moved to the right so that they don't overlap with
 200          * the newly added ones. */
 201         decl->Range.First += vsctx->decl_shift;
 202         decl->Range.Last += vsctx->decl_shift;
 203
 204         ++vsctx->num_outputs;
 205     } else if (decl->Declaration.File == TGSI_FILE_TEMPORARY) {
 206         for (i = decl->Range.First; i <= decl->Range.Last; i++) {
 207            vsctx->temp_used[i] = TRUE;
 208         }
 209     }
 210
 211     ctx->emit_declaration(ctx, decl);
 212
 213     /* Insert BCOLOR1 if needed. */
 214     if (decl->Declaration.File == TGSI_FILE_OUTPUT &&
 215         decl->Semantic.Name == TGSI_SEMANTIC_BCOLOR &&
 216         !vsctx->bcolor_used[1]) {
 217         insert_output_after(ctx, decl, TGSI_SEMANTIC_BCOLOR, 1,
 218                             TGSI_INTERPOLATE_LINEAR);
 219     }
 220 }
 221
 222 static void transform_inst(struct tgsi_transform_context *ctx,
 223                            struct tgsi_full_instruction *inst)
 224 {
 225     struct vs_transform_context *vsctx = (struct vs_transform_context *) ctx;
 226     struct tgsi_full_instruction new_inst;
 227     unsigned i;
 228
 229     if (!vsctx->first_instruction) {
 230         vsctx->first_instruction = TRUE;
 231
 232         /* Insert the generic output for WPOS. */
 233         emit_output(ctx, TGSI_SEMANTIC_GENERIC, vsctx->last_generic + 1,
 234                     TGSI_INTERPOLATE_PERSPECTIVE, vsctx->num_outputs);
 235
 236         /* Find a free temp for POSITION. */
 237         for (i = 0; i < Elements(vsctx->temp_used); i++) {
 238             if (!vsctx->temp_used[i]) {
 239                 emit_temp(ctx, i);
 240                 vsctx->pos_temp = i;
 241                 break;
 242             }
 243         }
 244     }
 245
 246     if (inst->Instruction.Opcode == TGSI_OPCODE_END) {
 247         /* MOV OUT[pos_output], TEMP[pos_temp]; */
 248         new_inst = tgsi_default_full_instruction();
 249         new_inst.Instruction.Opcode = TGSI_OPCODE_MOV;
 250         new_inst.Instruction.NumDstRegs = 1;
 251         new_inst.Dst[0].Register.File = TGSI_FILE_OUTPUT;
 252         new_inst.Dst[0].Register.Index = vsctx->pos_output;
 253         new_inst.Dst[0].Register.WriteMask = TGSI_WRITEMASK_XYZW;
 254         new_inst.Instruction.NumSrcRegs = 1;
 255         new_inst.Src[0].Register.File = TGSI_FILE_TEMPORARY;
 256         new_inst.Src[0].Register.Index = vsctx->pos_temp;
 257         ctx->emit_instruction(ctx, &new_inst);
 258
 259         /* MOV OUT[n-1], TEMP[pos_temp]; */
 260         new_inst = tgsi_default_full_instruction();
 261         new_inst.Instruction.Opcode = TGSI_OPCODE_MOV;
 262         new_inst.Instruction.NumDstRegs = 1;
 263         new_inst.Dst[0].Register.File = TGSI_FILE_OUTPUT;
 264         new_inst.Dst[0].Register.Index = vsctx->num_outputs - 1;
 265         new_inst.Dst[0].Register.WriteMask = TGSI_WRITEMASK_XYZW;
 266         new_inst.Instruction.NumSrcRegs = 1;
 267         new_inst.Src[0].Register.File = TGSI_FILE_TEMPORARY;
 268         new_inst.Src[0].Register.Index = vsctx->pos_temp;
 269         ctx->emit_instruction(ctx, &new_inst);
 270
 271         vsctx->end_instruction = TRUE;
 272     } else {
 273         /* Not an END instruction. */
 274         /* Fix writes to outputs. */
 275         for (i = 0; i < inst->Instruction.NumDstRegs; i++) {
 276             struct tgsi_full_dst_register *dst = &inst->Dst[i];
 277             if (dst->Register.File == TGSI_FILE_OUTPUT) {
 278                 if (dst->Register.Index == vsctx->pos_output) {
 279                     /* Replace writes to OUT[pos_output] with TEMP[pos_temp]. */
 280                     dst->Register.File = TGSI_FILE_TEMPORARY;
 281                     dst->Register.Index = vsctx->pos_temp;
 282                 } else {
 283                     /* Not a position, good...
 284                      * Since we were changing the indices of output decls,
 285                      * we must redirect writes into them too. */
 286                     dst->Register.Index = vsctx->out_remap[dst->Register.Index];
 287                 }
 288             }
 289         }
 290
 291         /* Inserting 2 instructions before the END opcode moves all following
 292          * labels by 2. Subroutines are always after the END opcode so
 293          * they're always moved. */
 294         if (inst->Instruction.Opcode == TGSI_OPCODE_CAL) {
 295             inst->Label.Label += 2;
 296         }
 297         /* The labels of the following opcodes are moved only after
 298          * the END opcode. */
 299         if (vsctx->end_instruction &&
 300             (inst->Instruction.Opcode == TGSI_OPCODE_IF ||
 301              inst->Instruction.Opcode == TGSI_OPCODE_ELSE ||
 302              inst->Instruction.Opcode == TGSI_OPCODE_BGNLOOP ||
 303              inst->Instruction.Opcode == TGSI_OPCODE_ENDLOOP)) {
 304             inst->Label.Label += 2;
 305         }
 306     }
 307
 308     ctx->emit_instruction(ctx, inst);
 309 }
 310
 311 void r300_draw_init_vertex_shader(struct r300_context *r300,
 312                                   struct r300_vertex_shader *vs)
 313 {
 314     struct draw_context *draw = r300->draw;
 315     struct pipe_shader_state new_vs;
 316     struct tgsi_shader_info info;
 317     struct vs_transform_context transform;
 318     const uint newLen = tgsi_num_tokens(vs->state.tokens) + 100 /* XXX */;
 319     unsigned i;
 320
 321     tgsi_scan_shader(vs->state.tokens, &info);
 322
 323     new_vs.tokens = tgsi_alloc_tokens(newLen);
 324     if (new_vs.tokens == NULL)
 325         return;
 326
 327     memset(&transform, 0, sizeof(transform));
 328     for (i = 0; i < Elements(transform.out_remap); i++) {
 329         transform.out_remap[i] = i;
 330     }
 331     transform.last_generic = -1;
 332     transform.base.transform_instruction = transform_inst;
 333     transform.base.transform_declaration = transform_decl;
 334
 335     for (i = 0; i < info.num_outputs; i++) {
 336         unsigned index = info.output_semantic_index[i];
 337
 338         switch (info.output_semantic_name[i]) {
 339             case TGSI_SEMANTIC_COLOR:
 340                 assert(index < 2);
 341                 transform.color_used[index] = TRUE;
 342                 break;
 343
 344             case TGSI_SEMANTIC_BCOLOR:
 345                 assert(index < 2);
 346                 transform.bcolor_used[index] = TRUE;
 347                 break;
 348         }
 349     }
 350
 351     tgsi_transform_shader(vs->state.tokens,
 352                           (struct tgsi_token*)new_vs.tokens,
 353                           newLen, &transform.base);
 354
 355 #if 0
 356     printf("----------------------------------------------\norig shader:\n");
 357     tgsi_dump(vs->state.tokens, 0);
 358     printf("----------------------------------------------\nnew shader:\n");
 359     tgsi_dump(new_vs.tokens, 0);
 360     printf("----------------------------------------------\n");
 361 #endif
 362
 363     /* Free old tokens. */
 364     FREE((void*)vs->state.tokens);
 365
 366     vs->draw_vs = draw_create_vertex_shader(draw, &new_vs);
 367
 368     /* Instead of duplicating and freeing the tokens, copy the pointer directly. */
 369     vs->state.tokens = new_vs.tokens;
 370
 371     /* Init the VS output table for the rasterizer. */
 372     r300_init_vs_outputs(r300, vs);
 373
 374     /* Make the last generic be WPOS. */
 375     vs->outputs.wpos = vs->outputs.generic[transform.last_generic + 1];
 376     vs->outputs.generic[transform.last_generic + 1] = ATTR_UNUSED;
 377 }