src/gallium/auxiliary/draw/draw_aaline.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 /**
  29  * AA line stage:  AA lines are converted to texture mapped triangles.
  30  *
  31  * Authors:  Brian Paul
  32  */
  33
  34
  35 #include "pipe/p_util.h"
  36 #include "pipe/p_inlines.h"
  37 #include "pipe/p_context.h"
  38 #include "pipe/p_defines.h"
  39 #include "pipe/p_shader_tokens.h"
  40
  41 #include "tgsi/util/tgsi_transform.h"
  42 #include "tgsi/util/tgsi_dump.h"
  43
  44 #include "draw_context.h"
  45 #include "draw_private.h"
  46
  47
  48 /**
  49  * Max texture level for the alpha texture used for antialiasing
  50  */
  51 #define MAX_TEXTURE_LEVEL  5   /* 32 x 32 */
  52
  53
  54 /**
  55  * Subclass of pipe_shader_state to carry extra fragment shader info.
  56  */
  57 struct aaline_fragment_shader
  58 {
  59    struct pipe_shader_state state;
  60    void *driver_fs;
  61    void *aaline_fs;
  62    void *aapoint_fs; /* not yet */
  63    void *sprite_fs; /* not yet */
  64 };
  65
  66
  67 /**
  68  * Subclass of draw_stage
  69  */
  70 struct aaline_stage
  71 {
  72    struct draw_stage stage;
  73
  74    float half_line_width;
  75
  76    /** For AA lines, this is the vertex attrib slot for the new texcoords */
  77    uint tex_slot;
  78
  79    void *sampler_cso;
  80    struct pipe_texture *texture;
  81    uint sampler_unit;
  82
  83
  84    /*
  85     * Currently bound state
  86     */
  87    struct aaline_fragment_shader *fs;
  88    struct {
  89       void *sampler[PIPE_MAX_SAMPLERS];
  90       struct pipe_texture *texture[PIPE_MAX_SAMPLERS];
  91    } state;
  92
  93    /*
  94     * Driver interface/override functions
  95     */
  96    void * (*driver_create_fs_state)(struct pipe_context *,
  97                                     const struct pipe_shader_state *);
  98    void (*driver_bind_fs_state)(struct pipe_context *, void *);
  99    void (*driver_delete_fs_state)(struct pipe_context *, void *);
 100
 101    void (*driver_bind_sampler_state)(struct pipe_context *, unsigned, void *);
 102
 103    void (*driver_set_sampler_texture)(struct pipe_context *,
 104                                       unsigned sampler,
 105                                       struct pipe_texture *);
 106
 107    struct pipe_context *pipe;
 108 };
 109
 110
 111
 112 /**
 113  * Subclass of tgsi_transform_context, used for transforming the
 114  * user's fragment shader to add the special AA instructions.
 115  */
 116 struct aa_transform_context {
 117    struct tgsi_transform_context base;
 118    uint tempsUsed;  /**< bitmask */
 119    int colorOutput; /**< which output is the primary color */
 120    int maxSampler;  /**< max sampler index found */
 121    int maxInput, maxGeneric;  /**< max input index found */
 122    int colorTemp, texTemp;  /**< temp registers */
 123    boolean firstInstruction;
 124 };
 125
 126
 127 /**
 128  * TGSI declaration transform callback.
 129  * Look for a free sampler, a free input attrib, and two free temp regs.
 130  */
 131 static void
 132 aa_transform_decl(struct tgsi_transform_context *ctx,
 133                   struct tgsi_full_declaration *decl)
 134 {
 135    struct aa_transform_context *aactx = (struct aa_transform_context *) ctx;
 136
 137    if (decl->Declaration.File == TGSI_FILE_OUTPUT &&
 138        decl->Semantic.SemanticName == TGSI_SEMANTIC_COLOR &&
 139        decl->Semantic.SemanticIndex == 0) {
 140       aactx->colorOutput = decl->u.DeclarationRange.First;
 141    }
 142    else if (decl->Declaration.File == TGSI_FILE_SAMPLER) {
 143       if ((int) decl->u.DeclarationRange.Last > aactx->maxSampler)
 144          aactx->maxSampler = decl->u.DeclarationRange.Last + 1;
 145    }
 146    else if (decl->Declaration.File == TGSI_FILE_INPUT) {
 147       if ((int) decl->u.DeclarationRange.Last > aactx->maxInput)
 148          aactx->maxInput = decl->u.DeclarationRange.Last;
 149       if (decl->Semantic.SemanticName == TGSI_SEMANTIC_GENERIC &&
 150            (int) decl->Semantic.SemanticIndex > aactx->maxGeneric) {
 151          aactx->maxGeneric = decl->Semantic.SemanticIndex;
 152       }
 153    }
 154    else if (decl->Declaration.File == TGSI_FILE_TEMPORARY) {
 155       uint i;
 156       for (i = decl->u.DeclarationRange.First;
 157            i <= decl->u.DeclarationRange.Last; i++) {
 158          aactx->tempsUsed |= (1 << i);
 159       }
 160    }
 161
 162    ctx->emit_declaration(ctx, decl);
 163 }
 164
 165
 166 /**
 167  * TGSI instruction transform callback.
 168  * Replace writes to result.color w/ a temp reg.
 169  * Upon END instruction, insert texture sampling code for antialiasing.
 170  */
 171 static void
 172 aa_transform_inst(struct tgsi_transform_context *ctx,
 173                   struct tgsi_full_instruction *inst)
 174 {
 175    struct aa_transform_context *aactx = (struct aa_transform_context *) ctx;
 176
 177    if (aactx->firstInstruction) {
 178       /* emit our new declarations before the first instruction */
 179
 180       struct tgsi_full_declaration decl;
 181       uint i;
 182
 183       /* find two free temp regs */
 184       for (i = 0; i < 32; i++) {
 185          if ((aactx->tempsUsed & (1 << i)) == 0) {
 186             /* found a free temp */
 187             if (aactx->colorTemp < 0)
 188                aactx->colorTemp  = i;
 189             else if (aactx->texTemp < 0)
 190                aactx->texTemp  = i;
 191             else
 192                break;
 193          }
 194       }
 195       assert(aactx->colorTemp >= 0);
 196       assert(aactx->texTemp >= 0);
 197
 198       /* declare new generic input/texcoord */
 199       decl = tgsi_default_full_declaration();
 200       decl.Declaration.File = TGSI_FILE_INPUT;
 201       decl.Declaration.Semantic = 1;
 202       decl.Semantic.SemanticName = TGSI_SEMANTIC_GENERIC;
 203       decl.Semantic.SemanticIndex = aactx->maxGeneric + 1;
 204       decl.Declaration.Interpolate = 1;
 205       /* XXX this could be linear... */
 206       decl.Interpolation.Interpolate = TGSI_INTERPOLATE_PERSPECTIVE;
 207       decl.u.DeclarationRange.First =
 208       decl.u.DeclarationRange.Last = aactx->maxInput + 1;
 209       ctx->emit_declaration(ctx, &decl);
 210
 211       /* declare new sampler */
 212       decl = tgsi_default_full_declaration();
 213       decl.Declaration.File = TGSI_FILE_SAMPLER;
 214       decl.u.DeclarationRange.First =
 215       decl.u.DeclarationRange.Last = aactx->maxSampler + 1;
 216       ctx->emit_declaration(ctx, &decl);
 217
 218       /* declare new temp regs */
 219       decl = tgsi_default_full_declaration();
 220       decl.Declaration.File = TGSI_FILE_TEMPORARY;
 221       decl.u.DeclarationRange.First =
 222       decl.u.DeclarationRange.Last = aactx->texTemp;
 223       ctx->emit_declaration(ctx, &decl);
 224
 225       decl = tgsi_default_full_declaration();
 226       decl.Declaration.File = TGSI_FILE_TEMPORARY;
 227       decl.u.DeclarationRange.First =
 228       decl.u.DeclarationRange.Last = aactx->colorTemp;
 229       ctx->emit_declaration(ctx, &decl);
 230
 231       aactx->firstInstruction = FALSE;
 232    }
 233
 234    if (inst->Instruction.Opcode == TGSI_OPCODE_END &&
 235        aactx->colorOutput != -1) {
 236       struct tgsi_full_instruction newInst;
 237
 238       /* TEX */
 239       newInst = tgsi_default_full_instruction();
 240       newInst.Instruction.Opcode = TGSI_OPCODE_TEX;
 241       newInst.Instruction.NumDstRegs = 1;
 242       newInst.FullDstRegisters[0].DstRegister.File = TGSI_FILE_TEMPORARY;
 243       newInst.FullDstRegisters[0].DstRegister.Index = aactx->texTemp;
 244       newInst.Instruction.NumSrcRegs = 2;
 245       newInst.InstructionExtTexture.Texture = TGSI_TEXTURE_2D;
 246       newInst.FullSrcRegisters[0].SrcRegister.File = TGSI_FILE_INPUT;
 247       newInst.FullSrcRegisters[0].SrcRegister.Index = aactx->maxInput + 1;
 248       newInst.FullSrcRegisters[1].SrcRegister.File = TGSI_FILE_SAMPLER;
 249       newInst.FullSrcRegisters[1].SrcRegister.Index = aactx->maxSampler + 1;
 250
 251       ctx->emit_instruction(ctx, &newInst);
 252
 253       /* MOV rgb */
 254       newInst = tgsi_default_full_instruction();
 255       newInst.Instruction.Opcode = TGSI_OPCODE_MOV;
 256       newInst.Instruction.NumDstRegs = 1;
 257       newInst.FullDstRegisters[0].DstRegister.File = TGSI_FILE_OUTPUT;
 258       newInst.FullDstRegisters[0].DstRegister.Index = aactx->colorOutput;
 259       newInst.FullDstRegisters[0].DstRegister.WriteMask = TGSI_WRITEMASK_XYZ;
 260       newInst.Instruction.NumSrcRegs = 1;
 261       newInst.FullSrcRegisters[0].SrcRegister.File = TGSI_FILE_TEMPORARY;
 262       newInst.FullSrcRegisters[0].SrcRegister.Index = aactx->colorTemp;
 263       ctx->emit_instruction(ctx, &newInst);
 264
 265       /* MUL alpha */
 266       newInst = tgsi_default_full_instruction();
 267       newInst.Instruction.Opcode = TGSI_OPCODE_MUL;
 268       newInst.Instruction.NumDstRegs = 1;
 269       newInst.FullDstRegisters[0].DstRegister.File = TGSI_FILE_OUTPUT;
 270       newInst.FullDstRegisters[0].DstRegister.Index = aactx->colorOutput;
 271       newInst.FullDstRegisters[0].DstRegister.WriteMask = TGSI_WRITEMASK_W;
 272       newInst.Instruction.NumSrcRegs = 2;
 273       newInst.FullSrcRegisters[0].SrcRegister.File = TGSI_FILE_TEMPORARY;
 274       newInst.FullSrcRegisters[0].SrcRegister.Index = aactx->colorTemp;
 275       newInst.FullSrcRegisters[1].SrcRegister.File = TGSI_FILE_TEMPORARY;
 276       newInst.FullSrcRegisters[1].SrcRegister.Index = aactx->texTemp;
 277       ctx->emit_instruction(ctx, &newInst);
 278
 279       /* END */
 280       newInst = tgsi_default_full_instruction();
 281       newInst.Instruction.Opcode = TGSI_OPCODE_END;
 282       newInst.Instruction.NumDstRegs = 0;
 283       newInst.Instruction.NumSrcRegs = 0;
 284       ctx->emit_instruction(ctx, &newInst);
 285    }
 286    else {
 287       /* Not an END instruction.
 288        * Look for writes to result.color and replace with colorTemp reg.
 289        */
 290       uint i;
 291
 292       for (i = 0; i < inst->Instruction.NumDstRegs; i++) {
 293          struct tgsi_full_dst_register *dst = &inst->FullDstRegisters[i];
 294          if (dst->DstRegister.File == TGSI_FILE_OUTPUT &&
 295              dst->DstRegister.Index == aactx->colorOutput) {
 296             dst->DstRegister.File = TGSI_FILE_TEMPORARY;
 297             dst->DstRegister.Index = aactx->colorTemp;
 298          }
 299       }
 300
 301       ctx->emit_instruction(ctx, inst);
 302    }
 303 }
 304
 305
 306 /**
 307  * Generate the frag shader we'll use for drawing AA lines.
 308  * This will be the user's shader plus some texture/modulate instructions.
 309  */
 310 static void
 311 generate_aaline_fs(struct aaline_stage *aaline)
 312 {
 313    const struct pipe_shader_state *orig_fs = &aaline->fs->state;
 314    struct draw_context *draw = aaline->stage.draw;
 315    struct pipe_shader_state aaline_fs;
 316    struct aa_transform_context transform;
 317
 318 #define MAX 1000
 319
 320    aaline_fs = *orig_fs; /* copy to init */
 321    aaline_fs.tokens = MALLOC(sizeof(struct tgsi_token) * MAX);
 322
 323    memset(&transform, 0, sizeof(transform));
 324    transform.colorOutput = -1;
 325    transform.maxSampler = -1;
 326    transform.maxInput = -1;
 327    transform.maxGeneric = -1;
 328    transform.colorTemp = -1;
 329    transform.texTemp = -1;
 330    transform.firstInstruction = TRUE;
 331    transform.base.transform_instruction = aa_transform_inst;
 332    transform.base.transform_declaration = aa_transform_decl;
 333
 334    tgsi_transform_shader(orig_fs->tokens,
 335                          (struct tgsi_token *) aaline_fs.tokens,
 336                          MAX, &transform.base);
 337
 338 #if 0 /* DEBUG */
 339    tgsi_dump(orig_fs->tokens, 0);
 340    tgsi_dump(aaline_fs.tokens, 0);
 341 #endif
 342
 343    aaline_fs.input_semantic_name[aaline_fs.num_inputs] = TGSI_SEMANTIC_GENERIC;
 344    aaline_fs.input_semantic_index[aaline_fs.num_inputs] = transform.maxGeneric + 1;
 345    aaline_fs.num_inputs++;
 346
 347    aaline->fs->aaline_fs
 348       = aaline->driver_create_fs_state(aaline->pipe, &aaline_fs);
 349
 350    /* advertise the extra post-transform vertex attributes which will have
 351     * the texcoords.
 352     */
 353    draw->extra_vp_outputs.semantic_name = TGSI_SEMANTIC_GENERIC;
 354    draw->extra_vp_outputs.semantic_index = transform.maxGeneric + 1;
 355 }
 356
 357
 358 /**
 359  * Create the texture map we'll use for antialiasing the lines.
 360  */
 361 static void
 362 aaline_create_texture(struct aaline_stage *aaline)
 363 {
 364    struct pipe_context *pipe = aaline->pipe;
 365    struct pipe_texture texTemp;
 366    uint level;
 367
 368    memset(&texTemp, 0, sizeof(texTemp));
 369    texTemp.target = PIPE_TEXTURE_2D;
 370    texTemp.format = PIPE_FORMAT_U_A8; /* XXX verify supported by driver! */
 371    texTemp.last_level = MAX_TEXTURE_LEVEL;
 372    texTemp.width[0] = 1 << MAX_TEXTURE_LEVEL;
 373    texTemp.height[0] = 1 << MAX_TEXTURE_LEVEL;
 374    texTemp.depth[0] = 1;
 375    texTemp.cpp = 1;
 376
 377    aaline->texture = pipe->texture_create(pipe, &texTemp);
 378
 379    /* Fill in mipmap images.
 380     * Basically each level is solid opaque, except for the outermost
 381     * texels which are zero.  Special case the 1x1 and 2x2 levels.
 382     */
 383    for (level = 0; level <= MAX_TEXTURE_LEVEL; level++) {
 384       struct pipe_surface *surface;
 385       const uint size = aaline->texture->width[level];
 386       ubyte *data;
 387       uint i, j;
 388
 389       assert(aaline->texture->width[level] == aaline->texture->height[level]);
 390
 391       surface = pipe->get_tex_surface(pipe, aaline->texture, 0, level, 0);
 392       data = pipe_surface_map(surface);
 393
 394       for (i = 0; i < size; i++) {
 395          for (j = 0; j < size; j++) {
 396             ubyte d;
 397             if (size == 1) {
 398                d = 255;
 399             }
 400             else if (size == 2) {
 401                d = 200; /* tuneable */
 402             }
 403             else if (i == 0 || j == 0 || i == size - 1 || j == size - 1) {
 404                d = 0;
 405             }
 406             else {
 407                d = 255;
 408             }
 409             data[i * surface->pitch + j] = d;
 410          }
 411       }
 412
 413       /* unmap */
 414       pipe_surface_unmap(surface);
 415       pipe_surface_reference(&surface, NULL);
 416    }
 417 }
 418
 419
 420 /**
 421  * Create the sampler CSO that'll be used for antialiasing.
 422  * By using a mipmapped texture, we don't have to generate a different
 423  * texture image for each line size.
 424  */
 425 static void
 426 aaline_create_sampler(struct aaline_stage *aaline)
 427 {
 428    struct pipe_sampler_state sampler;
 429    struct pipe_context *pipe = aaline->pipe;
 430
 431    memset(&sampler, 0, sizeof(sampler));
 432    sampler.wrap_s = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
 433    sampler.wrap_t = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
 434    sampler.wrap_r = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
 435    sampler.min_mip_filter = PIPE_TEX_MIPFILTER_LINEAR;
 436    sampler.min_img_filter = PIPE_TEX_FILTER_LINEAR;
 437    sampler.mag_img_filter = PIPE_TEX_FILTER_LINEAR;
 438    sampler.normalized_coords = 1;
 439    sampler.min_lod = 0.0f;
 440    sampler.max_lod = MAX_TEXTURE_LEVEL;
 441
 442    aaline->sampler_cso = pipe->create_sampler_state(pipe, &sampler);
 443 }
 444
 445
 446 /**
 447  * When we're about to draw our first AA line in a batch, this function is
 448  * called to tell the driver to bind our modified fragment shader.
 449  */
 450 static void
 451 bind_aaline_fragment_shader(struct aaline_stage *aaline)
 452 {
 453    if (!aaline->fs->aaline_fs) {
 454       generate_aaline_fs(aaline);
 455    }
 456    aaline->driver_bind_fs_state(aaline->pipe, aaline->fs->aaline_fs);
 457 }
 458
 459
 460
 461 static INLINE struct aaline_stage *
 462 aaline_stage( struct draw_stage *stage )
 463 {
 464    return (struct aaline_stage *) stage;
 465 }
 466
 467
 468 static void
 469 passthrough_point(struct draw_stage *stage, struct prim_header *header)
 470 {
 471    stage->next->point(stage->next, header);
 472 }
 473
 474
 475 static void
 476 passthrough_tri(struct draw_stage *stage, struct prim_header *header)
 477 {
 478    stage->next->tri(stage->next, header);
 479 }
 480
 481
 482 /**
 483  * Draw a wide line by drawing a quad, using geometry which will
 484  * fullfill GL's antialiased line requirements.
 485  */
 486 static void
 487 aaline_line(struct draw_stage *stage, struct prim_header *header)
 488 {
 489    const struct aaline_stage *aaline = aaline_stage(stage);
 490    const float half_width = aaline->half_line_width;
 491    struct prim_header tri;
 492    struct vertex_header *v[8];
 493    uint texPos = aaline->tex_slot;
 494    float *pos, *tex;
 495    float dx = header->v[1]->data[0][0] - header->v[0]->data[0][0];
 496    float dy = header->v[1]->data[0][1] - header->v[0]->data[0][1];
 497    double a = atan2(dy, dx);
 498    float c_a = (float) cos(a), s_a = (float) sin(a);
 499    uint i;
 500
 501    /* XXX the ends of lines aren't quite perfect yet, but probably passable */
 502    dx = 0.5F * half_width;
 503    dy = half_width;
 504
 505    /* allocate/dup new verts */
 506    for (i = 0; i < 8; i++) {
 507       v[i] = dup_vert(stage, header->v[i/4], i);
 508    }
 509
 510    /*
 511     * Quad strip for line from v0 to v1 (*=endpoints):
 512     *
 513     *  1   3                     5   7
 514     *  +---+---------------------+---+
 515     *  |                             |
 516     *  | *v0                     v1* |
 517     *  |                             |
 518     *  +---+---------------------+---+
 519     *  0   2                     4   6
 520     */
 521
 522    /* new verts */
 523    pos = v[0]->data[0];
 524    pos[0] += (-dx * c_a -  dy * s_a);
 525    pos[1] += (-dx * s_a +  dy * c_a);
 526
 527    pos = v[1]->data[0];
 528    pos[0] += (-dx * c_a - -dy * s_a);
 529    pos[1] += (-dx * s_a + -dy * c_a);
 530
 531    pos = v[2]->data[0];
 532    pos[0] += ( dx * c_a -  dy * s_a);
 533    pos[1] += ( dx * s_a +  dy * c_a);
 534
 535    pos = v[3]->data[0];
 536    pos[0] += ( dx * c_a - -dy * s_a);
 537    pos[1] += ( dx * s_a + -dy * c_a);
 538
 539    pos = v[4]->data[0];
 540    pos[0] += (-dx * c_a -  dy * s_a);
 541    pos[1] += (-dx * s_a +  dy * c_a);
 542
 543    pos = v[5]->data[0];
 544    pos[0] += (-dx * c_a - -dy * s_a);
 545    pos[1] += (-dx * s_a + -dy * c_a);
 546
 547    pos = v[6]->data[0];
 548    pos[0] += ( dx * c_a -  dy * s_a);
 549    pos[1] += ( dx * s_a +  dy * c_a);
 550
 551    pos = v[7]->data[0];
 552    pos[0] += ( dx * c_a - -dy * s_a);
 553    pos[1] += ( dx * s_a + -dy * c_a);
 554
 555    /* new texcoords */
 556    tex = v[0]->data[texPos];
 557    ASSIGN_4V(tex, 0, 0, 0, 1);
 558
 559    tex = v[1]->data[texPos];
 560    ASSIGN_4V(tex, 0, 1, 0, 1);
 561
 562    tex = v[2]->data[texPos];
 563    ASSIGN_4V(tex, .5, 0, 0, 1);
 564
 565    tex = v[3]->data[texPos];
 566    ASSIGN_4V(tex, .5, 1, 0, 1);
 567
 568    tex = v[4]->data[texPos];
 569    ASSIGN_4V(tex, .5, 0, 0, 1);
 570
 571    tex = v[5]->data[texPos];
 572    ASSIGN_4V(tex, .5, 1, 0, 1);
 573
 574    tex = v[6]->data[texPos];
 575    ASSIGN_4V(tex, 1, 0, 0, 1);
 576
 577    tex = v[7]->data[texPos];
 578    ASSIGN_4V(tex, 1, 1, 0, 1);
 579
 580    /* emit 6 tris for the quad strip */
 581    tri.v[0] = v[2];  tri.v[1] = v[1];  tri.v[2] = v[0];
 582    stage->next->tri( stage->next, &tri );
 583
 584    tri.v[0] = v[3];  tri.v[1] = v[1];  tri.v[2] = v[2];
 585    stage->next->tri( stage->next, &tri );
 586
 587    tri.v[0] = v[4];  tri.v[1] = v[3];  tri.v[2] = v[2];
 588    stage->next->tri( stage->next, &tri );
 589
 590    tri.v[0] = v[5];  tri.v[1] = v[3];  tri.v[2] = v[4];
 591    stage->next->tri( stage->next, &tri );
 592
 593    tri.v[0] = v[6];  tri.v[1] = v[5];  tri.v[2] = v[4];
 594    stage->next->tri( stage->next, &tri );
 595
 596    tri.v[0] = v[7];  tri.v[1] = v[5];  tri.v[2] = v[6];
 597    stage->next->tri( stage->next, &tri );
 598 }
 599
 600
 601 static void
 602 aaline_first_line(struct draw_stage *stage, struct prim_header *header)
 603 {
 604    auto struct aaline_stage *aaline = aaline_stage(stage);
 605    struct draw_context *draw = stage->draw;
 606    struct pipe_context *pipe = aaline->pipe;
 607
 608    assert(draw->rasterizer->line_smooth);
 609
 610    if (draw->rasterizer->line_width <= 3.0)
 611       aaline->half_line_width = 1.5f;
 612    else
 613       aaline->half_line_width = 0.5f * draw->rasterizer->line_width;
 614
 615    aaline->tex_slot = draw->num_vs_outputs;
 616    assert(aaline->tex_slot > 0); /* output[0] is vertex pos */
 617    draw->extra_vp_outputs.slot = aaline->tex_slot;
 618
 619    /*
 620     * Bind our fragprog, sampler and texture
 621     */
 622    bind_aaline_fragment_shader(aaline);
 623
 624    aaline->driver_bind_sampler_state(pipe, aaline->sampler_unit, aaline->sampler_cso);
 625    aaline->driver_set_sampler_texture(pipe, aaline->sampler_unit, aaline->texture);
 626
 627    /* now really draw first line */
 628    stage->line = aaline_line;
 629    stage->line(stage, header);
 630 }
 631
 632
 633 static void
 634 aaline_flush(struct draw_stage *stage, unsigned flags)
 635 {
 636    struct draw_context *draw = stage->draw;
 637    struct aaline_stage *aaline = aaline_stage(stage);
 638    struct pipe_context *pipe = aaline->pipe;
 639
 640    stage->line = aaline_first_line;
 641    stage->next->flush( stage->next, flags );
 642
 643    /* restore original frag shader */
 644    aaline->driver_bind_fs_state(pipe, aaline->fs->driver_fs);
 645
 646    /* XXX restore original texture, sampler state */
 647    aaline->driver_bind_sampler_state(pipe, aaline->sampler_unit,
 648                                  aaline->state.sampler[aaline->sampler_unit]);
 649    aaline->driver_set_sampler_texture(pipe, aaline->sampler_unit,
 650                                  aaline->state.texture[aaline->sampler_unit]);
 651
 652    draw->extra_vp_outputs.slot = 0;
 653 }
 654
 655
 656 static void
 657 aaline_reset_stipple_counter(struct draw_stage *stage)
 658 {
 659    stage->next->reset_stipple_counter( stage->next );
 660 }
 661
 662
 663 static void
 664 aaline_destroy(struct draw_stage *stage)
 665 {
 666    draw_free_temp_verts( stage );
 667    FREE( stage );
 668 }
 669
 670
 671 static struct aaline_stage *
 672 draw_aaline_stage(struct draw_context *draw)
 673 {
 674    struct aaline_stage *aaline = CALLOC_STRUCT(aaline_stage);
 675
 676    draw_alloc_temp_verts( &aaline->stage, 8 );
 677
 678    aaline->stage.draw = draw;
 679    aaline->stage.next = NULL;
 680    aaline->stage.point = passthrough_point;
 681    aaline->stage.line = aaline_first_line;
 682    aaline->stage.tri = passthrough_tri;
 683    aaline->stage.flush = aaline_flush;
 684    aaline->stage.reset_stipple_counter = aaline_reset_stipple_counter;
 685    aaline->stage.destroy = aaline_destroy;
 686
 687    return aaline;
 688 }
 689
 690
 691 /*
 692  * XXX temporary? solution to mapping a pipe_context to a aaline_stage.
 693  */
 694
 695 #define MAX_CONTEXTS 10
 696
 697 static struct pipe_context *Pipe[MAX_CONTEXTS];
 698 static struct aaline_stage *Stage[MAX_CONTEXTS];
 699 static uint NumContexts;
 700
 701 static void
 702 add_aa_pipe_context(struct pipe_context *pipe, struct aaline_stage *aa)
 703 {
 704    assert(NumContexts < MAX_CONTEXTS);
 705    Pipe[NumContexts] = pipe;
 706    Stage[NumContexts] = aa;
 707    NumContexts++;
 708 }
 709
 710 static struct aaline_stage *
 711 aaline_stage_from_pipe(struct pipe_context *pipe)
 712 {
 713    uint i;
 714    for (i = 0; i < NumContexts; i++) {
 715       if (Pipe[i] == pipe)
 716          return Stage[i];
 717    }
 718    assert(0);
 719    return NULL;
 720 }
 721
 722
 723 /**
 724  * This function overrides the driver's create_fs_state() function and
 725  * will typically be called by the state tracker.
 726  */
 727 static void *
 728 aaline_create_fs_state(struct pipe_context *pipe,
 729                        const struct pipe_shader_state *fs)
 730 {
 731    struct aaline_stage *aaline = aaline_stage_from_pipe(pipe);
 732    struct aaline_fragment_shader *aafs = CALLOC_STRUCT(aaline_fragment_shader);
 733
 734    if (aafs) {
 735       aafs->state = *fs;
 736
 737       /* pass-through */
 738       aafs->driver_fs = aaline->driver_create_fs_state(aaline->pipe, fs);
 739    }
 740
 741    return aafs;
 742 }
 743
 744
 745 static void
 746 aaline_bind_fs_state(struct pipe_context *pipe, void *fs)
 747 {
 748    struct aaline_stage *aaline = aaline_stage_from_pipe(pipe);
 749    struct aaline_fragment_shader *aafs = (struct aaline_fragment_shader *) fs;
 750    /* save current */
 751    aaline->fs = aafs;
 752    /* pass-through */
 753    aaline->driver_bind_fs_state(aaline->pipe, aafs->driver_fs);
 754 }
 755
 756
 757 static void
 758 aaline_delete_fs_state(struct pipe_context *pipe, void *fs)
 759 {
 760    struct aaline_stage *aaline = aaline_stage_from_pipe(pipe);
 761    struct aaline_fragment_shader *aafs = (struct aaline_fragment_shader *) fs;
 762    /* pass-through */
 763    aaline->driver_delete_fs_state(aaline->pipe, aafs->driver_fs);
 764    FREE(aafs);
 765 }
 766
 767
 768 static void
 769 aaline_bind_sampler_state(struct pipe_context *pipe,
 770                           unsigned unit, void *sampler)
 771 {
 772    struct aaline_stage *aaline = aaline_stage_from_pipe(pipe);
 773    /* save current */
 774    aaline->state.sampler[unit] = sampler;
 775    /* pass-through */
 776    aaline->driver_bind_sampler_state(aaline->pipe, unit, sampler);
 777 }
 778
 779
 780 static void
 781 aaline_set_sampler_texture(struct pipe_context *pipe,
 782                            unsigned sampler, struct pipe_texture *texture)
 783 {
 784    struct aaline_stage *aaline = aaline_stage_from_pipe(pipe);
 785    /* save current */
 786    aaline->state.texture[sampler] = texture;
 787    /* pass-through */
 788    aaline->driver_set_sampler_texture(aaline->pipe, sampler, texture);
 789 }
 790
 791
 792 /**
 793  * Called by drivers that want to install this AA line prim stage
 794  * into the draw module's pipeline.  This will not be used if the
 795  * hardware has native support for AA lines.
 796  */
 797 void
 798 draw_install_aaline_stage(struct draw_context *draw, struct pipe_context *pipe)
 799 {
 800    struct aaline_stage *aaline;
 801
 802    /*
 803     * Create / install AA line drawing / prim stage
 804     */
 805    aaline = draw_aaline_stage( draw );
 806    assert(aaline);
 807    draw->pipeline.aaline = &aaline->stage;
 808
 809    aaline->pipe = pipe;
 810
 811    /* create special texture, sampler state */
 812    aaline_create_texture(aaline);
 813    aaline_create_sampler(aaline);
 814
 815    /* save original driver functions */
 816    aaline->driver_create_fs_state = pipe->create_fs_state;
 817    aaline->driver_bind_fs_state = pipe->bind_fs_state;
 818    aaline->driver_delete_fs_state = pipe->delete_fs_state;
 819
 820    aaline->driver_bind_sampler_state = pipe->bind_sampler_state;
 821    aaline->driver_set_sampler_texture = pipe->set_sampler_texture;
 822
 823    /* override the driver's functions */
 824    pipe->create_fs_state = aaline_create_fs_state;
 825    pipe->bind_fs_state = aaline_bind_fs_state;
 826    pipe->delete_fs_state = aaline_delete_fs_state;
 827
 828    pipe->bind_sampler_state = aaline_bind_sampler_state;
 829    pipe->set_sampler_texture = aaline_set_sampler_texture;
 830
 831    add_aa_pipe_context(pipe, aaline);
 832 }