src/mesa/state_tracker/st_cb_bitmap.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   * Authors:
  30   *   Brian Paul
  31   */
  32
  33 #include "main/imports.h"
  34 #include "main/image.h"
  35 #include "main/bufferobj.h"
  36 #include "main/macros.h"
  37 #include "main/texformat.h"
  38 #include "shader/program.h"
  39 #include "shader/prog_parameter.h"
  40 #include "shader/prog_print.h"
  41
  42 #include "st_context.h"
  43 #include "st_atom.h"
  44 #include "st_atom_constbuf.h"
  45 #include "st_program.h"
  46 #include "st_cb_bitmap.h"
  47 #include "st_cb_program.h"
  48 #include "st_mesa_to_tgsi.h"
  49 #include "st_texture.h"
  50 #include "pipe/p_context.h"
  51 #include "pipe/p_defines.h"
  52 #include "pipe/p_inlines.h"
  53 #include "util/p_tile.h"
  54 #include "util/u_draw_quad.h"
  55 #include "util/u_simple_shaders.h"
  56 #include "shader/prog_instruction.h"
  57 #include "cso_cache/cso_context.h"
  58
  59
  60
  61 /**
  62  * glBitmaps are drawn as textured quads.  The user's bitmap pattern
  63  * is stored in a texture image.  An alpha8 texture format is used.
  64  * The fragment shader samples a bit (texel) from the texture, then
  65  * discards the fragment if the bit is off.
  66  *
  67  * Note that we actually store the inverse image of the bitmap to
  68  * simplify the fragment program.  An "on" bit gets stored as texel=0x0
  69  * and an "off" bit is stored as texel=0xff.  Then we kill the
  70  * fragment if the negated texel value is less than zero.
  71  */
  72
  73
  74 /**
  75  * The bitmap cache attempts to accumulate multiple glBitmap calls in a
  76  * buffer which is then rendered en mass upon a flush, state change, etc.
  77  * A wide, short buffer is used to target the common case of a series
  78  * of glBitmap calls being used to draw text.
  79  */
  80 static GLboolean UseBitmapCache = GL_TRUE;
  81
  82
  83 #define BITMAP_CACHE_WIDTH  512
  84 #define BITMAP_CACHE_HEIGHT 32
  85
  86 struct bitmap_cache
  87 {
  88    /** Window pos to render the cached image */
  89    GLint xpos, ypos;
  90    /** Bounds of region used in window coords */
  91    GLint xmin, ymin, xmax, ymax;
  92
  93    struct pipe_texture *texture;
  94    struct pipe_surface *surf;
  95
  96    GLboolean empty;
  97
  98    /** An I8 texture image: */
  99    ubyte *buffer;
 100 };
 101
 102
 103
 104
 105 /**
 106  * Make fragment program for glBitmap:
 107  *   Sample the texture and kill the fragment if the bit is 0.
 108  * This program will be combined with the user's fragment program.
 109  */
 110 static struct st_fragment_program *
 111 make_bitmap_fragment_program(GLcontext *ctx, GLuint samplerIndex)
 112 {
 113    struct st_fragment_program *stfp;
 114    struct gl_program *p;
 115    GLuint ic = 0;
 116
 117    p = ctx->Driver.NewProgram(ctx, GL_FRAGMENT_PROGRAM_ARB, 0);
 118    if (!p)
 119       return NULL;
 120
 121    p->NumInstructions = 3;
 122
 123    p->Instructions = _mesa_alloc_instructions(p->NumInstructions);
 124    if (!p->Instructions) {
 125       ctx->Driver.DeleteProgram(ctx, p);
 126       return NULL;
 127    }
 128    _mesa_init_instructions(p->Instructions, p->NumInstructions);
 129
 130    /* TEX tmp0, fragment.texcoord[0], texture[0], 2D; */
 131    p->Instructions[ic].Opcode = OPCODE_TEX;
 132    p->Instructions[ic].DstReg.File = PROGRAM_TEMPORARY;
 133    p->Instructions[ic].DstReg.Index = 0;
 134    p->Instructions[ic].SrcReg[0].File = PROGRAM_INPUT;
 135    p->Instructions[ic].SrcReg[0].Index = FRAG_ATTRIB_TEX0;
 136    p->Instructions[ic].TexSrcUnit = samplerIndex;
 137    p->Instructions[ic].TexSrcTarget = TEXTURE_2D_INDEX;
 138    ic++;
 139
 140    /* KIL if -tmp0 < 0 # texel=0 -> keep / texel=0 -> discard */
 141    p->Instructions[ic].Opcode = OPCODE_KIL;
 142    p->Instructions[ic].SrcReg[0].File = PROGRAM_TEMPORARY;
 143    p->Instructions[ic].SrcReg[0].Index = 0;
 144    p->Instructions[ic].SrcReg[0].NegateBase = NEGATE_XYZW;
 145    ic++;
 146
 147    /* END; */
 148    p->Instructions[ic++].Opcode = OPCODE_END;
 149
 150    assert(ic == p->NumInstructions);
 151
 152    p->InputsRead = FRAG_BIT_TEX0;
 153    p->OutputsWritten = 0x0;
 154    p->SamplersUsed = (1 << samplerIndex);
 155
 156    stfp = (struct st_fragment_program *) p;
 157    stfp->Base.UsesKill = GL_TRUE;
 158    st_translate_fragment_program(ctx->st, stfp, NULL);
 159
 160    return stfp;
 161 }
 162
 163
 164 static int
 165 find_free_bit(uint bitfield)
 166 {
 167    int i;
 168    for (i = 0; i < 32; i++) {
 169       if ((bitfield & (1 << i)) == 0) {
 170          return i;
 171       }
 172    }
 173    return -1;
 174 }
 175
 176
 177 /**
 178  * Combine basic bitmap fragment program with the user-defined program.
 179  */
 180 static struct st_fragment_program *
 181 combined_bitmap_fragment_program(GLcontext *ctx)
 182 {
 183    struct st_context *st = ctx->st;
 184    struct st_fragment_program *stfp = st->fp;
 185
 186    if (!stfp->bitmap_program) {
 187       /*
 188        * Generate new program which is the user-defined program prefixed
 189        * with the bitmap sampler/kill instructions.
 190        */
 191       struct st_fragment_program *bitmap_prog;
 192       uint sampler;
 193
 194       sampler = find_free_bit(st->fp->Base.Base.SamplersUsed);
 195       bitmap_prog = make_bitmap_fragment_program(ctx, sampler);
 196
 197       stfp->bitmap_program = (struct st_fragment_program *)
 198          _mesa_combine_programs(ctx,
 199                                 &bitmap_prog->Base.Base, &stfp->Base.Base);
 200       stfp->bitmap_program->bitmap_sampler = sampler;
 201 #if 0
 202       {
 203          struct gl_program *p = &stfp->bitmap_program->Base.Base;
 204          printf("Combined bitmap program:\n");
 205          _mesa_print_program(p);
 206          printf("InputsRead: 0x%x\n", p->InputsRead);
 207          printf("OutputsWritten: 0x%x\n", p->OutputsWritten);
 208          _mesa_print_parameter_list(p->Parameters);
 209       }
 210 #endif
 211
 212       /* translate to TGSI tokens */
 213       st_translate_fragment_program(st, stfp->bitmap_program, NULL);
 214    }
 215
 216    /* Ideally we'd have updated the pipe constants during the normal
 217     * st/atom mechanism.  But we can't since this is specific to glBitmap.
 218     */
 219    st_upload_constants(st, stfp->Base.Base.Parameters, PIPE_SHADER_FRAGMENT);
 220
 221    return stfp->bitmap_program;
 222 }
 223
 224
 225 /**
 226  * Copy user-provide bitmap bits into texture buffer, expanding
 227  * bits into texels.
 228  * "On" bits will set texels to 0xff.
 229  * "Off" bits will not modify texels.
 230  * Note that the image is actually going to be upside down in
 231  * the texture.  We deal with that with texcoords.
 232  */
 233 static void
 234 unpack_bitmap(struct st_context *st,
 235               GLint px, GLint py, GLsizei width, GLsizei height,
 236               const struct gl_pixelstore_attrib *unpack,
 237               const GLubyte *bitmap,
 238               ubyte *destBuffer, uint destStride)
 239 {
 240    GLint row, col;
 241
 242 #define SET_PIXEL(COL, ROW) \
 243    destBuffer[(py + (ROW)) * destStride + px + (COL)] = 0x0;
 244
 245    for (row = 0; row < height; row++) {
 246       const GLubyte *src = (const GLubyte *) _mesa_image_address2d(unpack,
 247                  bitmap, width, height, GL_COLOR_INDEX, GL_BITMAP, row, 0);
 248
 249       if (unpack->LsbFirst) {
 250          /* Lsb first */
 251          GLubyte mask = 1U << (unpack->SkipPixels & 0x7);
 252          for (col = 0; col < width; col++) {
 253
 254             if (*src & mask) {
 255                SET_PIXEL(col, row);
 256             }
 257
 258             if (mask == 128U) {
 259                src++;
 260                mask = 1U;
 261             }
 262             else {
 263                mask = mask << 1;
 264             }
 265          }
 266
 267          /* get ready for next row */
 268          if (mask != 1)
 269             src++;
 270       }
 271       else {
 272          /* Msb first */
 273          GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
 274          for (col = 0; col < width; col++) {
 275
 276             if (*src & mask) {
 277                SET_PIXEL(col, row);
 278             }
 279
 280             if (mask == 1U) {
 281                src++;
 282                mask = 128U;
 283             }
 284             else {
 285                mask = mask >> 1;
 286             }
 287          }
 288
 289          /* get ready for next row */
 290          if (mask != 128)
 291             src++;
 292       }
 293
 294    } /* row */
 295
 296 #undef SET_PIXEL
 297 }
 298
 299
 300 /**
 301  * Create a texture which represents a bitmap image.
 302  */
 303 static struct pipe_texture *
 304 make_bitmap_texture(GLcontext *ctx, GLsizei width, GLsizei height,
 305                     const struct gl_pixelstore_attrib *unpack,
 306                     const GLubyte *bitmap)
 307 {
 308    struct pipe_context *pipe = ctx->st->pipe;
 309    struct pipe_screen *screen = pipe->screen;
 310    struct pipe_surface *surface;
 311    ubyte *dest;
 312    struct pipe_texture *pt;
 313
 314    /* PBO source... */
 315    bitmap = _mesa_map_bitmap_pbo(ctx, unpack, bitmap);
 316    if (!bitmap) {
 317       return NULL;
 318    }
 319
 320    /**
 321     * Create texture to hold bitmap pattern.
 322     */
 323    pt = st_texture_create(ctx->st, PIPE_TEXTURE_2D, ctx->st->bitmap.tex_format,
 324                           0, width, height, 1, 0,
 325                           PIPE_TEXTURE_USAGE_SAMPLER);
 326    if (!pt) {
 327       _mesa_unmap_bitmap_pbo(ctx, unpack);
 328       return NULL;
 329    }
 330
 331    surface = screen->get_tex_surface(screen, pt, 0, 0, 0,
 332                                      PIPE_BUFFER_USAGE_CPU_WRITE);
 333
 334    /* map texture surface */
 335    dest = screen->surface_map(screen, surface, PIPE_BUFFER_USAGE_CPU_WRITE);
 336
 337    /* Put image into texture surface */
 338    memset(dest, 0xff, height * surface->pitch);
 339    unpack_bitmap(ctx->st, 0, 0, width, height, unpack, bitmap,
 340                  dest, surface->pitch);
 341
 342    _mesa_unmap_bitmap_pbo(ctx, unpack);
 343
 344    /* Release surface */
 345    screen->surface_unmap(screen, surface);
 346    pipe_surface_reference(&surface, NULL);
 347
 348    return pt;
 349 }
 350
 351
 352 static void
 353 setup_bitmap_vertex_data(struct st_context *st,
 354                          int x, int y, int width, int height,
 355                          float z, const float color[4])
 356 {
 357    struct pipe_context *pipe = st->pipe;
 358    const struct gl_framebuffer *fb = st->ctx->DrawBuffer;
 359    const GLfloat fb_width = fb->Width;
 360    const GLfloat fb_height = fb->Height;
 361    const GLfloat x0 = x;
 362    const GLfloat x1 = x + width;
 363    const GLfloat y0 = y;
 364    const GLfloat y1 = y + height;
 365    const GLfloat sLeft = 0.0F, sRight = 1.0F;
 366    const GLfloat tTop = 0.0, tBot = 1.0 - tTop;
 367    const GLfloat clip_x0 = x0 / fb_width * 2.0 - 1.0;
 368    const GLfloat clip_y0 = y0 / fb_height * 2.0 - 1.0;
 369    const GLfloat clip_x1 = x1 / fb_width * 2.0 - 1.0;
 370    const GLfloat clip_y1 = y1 / fb_height * 2.0 - 1.0;
 371    GLuint i;
 372    void *buf;
 373
 374    if (!st->bitmap.vbuf) {
 375       st->bitmap.vbuf = pipe_buffer_create(pipe, 32, PIPE_BUFFER_USAGE_VERTEX,
 376                                            sizeof(st->bitmap.vertices));
 377    }
 378
 379    /* Positions are in clip coords since we need to do clipping in case
 380     * the bitmap quad goes beyond the window bounds.
 381     */
 382    st->bitmap.vertices[0][0][0] = clip_x0;
 383    st->bitmap.vertices[0][0][1] = clip_y0;
 384    st->bitmap.vertices[0][2][0] = sLeft;
 385    st->bitmap.vertices[0][2][1] = tTop;
 386
 387    st->bitmap.vertices[1][0][0] = clip_x1;
 388    st->bitmap.vertices[1][0][1] = clip_y0;
 389    st->bitmap.vertices[1][2][0] = sRight;
 390    st->bitmap.vertices[1][2][1] = tTop;
 391
 392    st->bitmap.vertices[2][0][0] = clip_x1;
 393    st->bitmap.vertices[2][0][1] = clip_y1;
 394    st->bitmap.vertices[2][2][0] = sRight;
 395    st->bitmap.vertices[2][2][1] = tBot;
 396
 397    st->bitmap.vertices[3][0][0] = clip_x0;
 398    st->bitmap.vertices[3][0][1] = clip_y1;
 399    st->bitmap.vertices[3][2][0] = sLeft;
 400    st->bitmap.vertices[3][2][1] = tBot;
 401
 402    /* same for all verts: */
 403    for (i = 0; i < 4; i++) {
 404       st->bitmap.vertices[i][0][2] = z;
 405       st->bitmap.vertices[i][0][3] = 1.0;
 406       st->bitmap.vertices[i][1][0] = color[0];
 407       st->bitmap.vertices[i][1][1] = color[1];
 408       st->bitmap.vertices[i][1][2] = color[2];
 409       st->bitmap.vertices[i][1][3] = color[3];
 410       st->bitmap.vertices[i][2][2] = 0.0; /*R*/
 411       st->bitmap.vertices[i][2][3] = 1.0; /*Q*/
 412    }
 413
 414    /* put vertex data into vbuf */
 415    buf = pipe_buffer_map(pipe, st->bitmap.vbuf, PIPE_BUFFER_USAGE_CPU_WRITE);
 416    memcpy(buf, st->bitmap.vertices, sizeof(st->bitmap.vertices));
 417    pipe_buffer_unmap(pipe, st->bitmap.vbuf);
 418 }
 419
 420
 421
 422 /**
 423  * Render a glBitmap by drawing a textured quad
 424  */
 425 static void
 426 draw_bitmap_quad(GLcontext *ctx, GLint x, GLint y, GLfloat z,
 427                  GLsizei width, GLsizei height,
 428                  struct pipe_texture *pt)
 429 {
 430    struct st_context *st = ctx->st;
 431    struct pipe_context *pipe = ctx->st->pipe;
 432    struct cso_context *cso = ctx->st->cso_context;
 433    struct st_fragment_program *stfp;
 434    GLuint maxSize;
 435
 436    stfp = combined_bitmap_fragment_program(ctx);
 437
 438    /* limit checks */
 439    /* XXX if the bitmap is larger than the max texture size, break
 440     * it up into chunks.
 441     */
 442    maxSize = 1 << (pipe->screen->get_param(pipe->screen, PIPE_CAP_MAX_TEXTURE_2D_LEVELS) - 1);
 443    assert(width <= maxSize);
 444    assert(height <= maxSize);
 445
 446    cso_save_rasterizer(cso);
 447    cso_save_samplers(cso);
 448    cso_save_sampler_textures(cso);
 449    cso_save_viewport(cso);
 450    cso_save_fragment_shader(cso);
 451    cso_save_vertex_shader(cso);
 452
 453    /* rasterizer state: just scissor */
 454    st->bitmap.rasterizer.scissor = ctx->Scissor.Enabled;
 455    cso_set_rasterizer(cso, &st->bitmap.rasterizer);
 456
 457    /* fragment shader state: TEX lookup program */
 458    cso_set_fragment_shader_handle(cso, stfp->driver_shader);
 459
 460    /* vertex shader state: position + texcoord pass-through */
 461    cso_set_vertex_shader_handle(cso, st->bitmap.vs);
 462
 463    /* user samplers, plus our bitmap sampler */
 464    {
 465       struct pipe_sampler_state *samplers[PIPE_MAX_SAMPLERS];
 466       uint num = MAX2(stfp->bitmap_sampler + 1, st->state.num_samplers);
 467       uint i;
 468       for (i = 0; i < st->state.num_samplers; i++) {
 469          samplers[i] = &st->state.samplers[i];
 470       }
 471       samplers[stfp->bitmap_sampler] = &st->bitmap.sampler;
 472       cso_set_samplers(cso, num, (const struct pipe_sampler_state **) samplers);   }
 473
 474    /* user textures, plus the bitmap texture */
 475    {
 476       struct pipe_texture *textures[PIPE_MAX_SAMPLERS];
 477       uint num = MAX2(stfp->bitmap_sampler + 1, st->state.num_textures);
 478       memcpy(textures, st->state.sampler_texture, sizeof(textures));
 479       textures[stfp->bitmap_sampler] = pt;
 480       cso_set_sampler_textures(cso, num, textures);
 481    }
 482
 483    /* viewport state: viewport matching window dims */
 484    {
 485       const struct gl_framebuffer *fb = st->ctx->DrawBuffer;
 486       const GLboolean invert = (st_fb_orientation(fb) == Y_0_TOP);
 487       const float width = fb->Width;
 488       const float height = fb->Height;
 489       struct pipe_viewport_state vp;
 490       vp.scale[0] =  0.5 * width;
 491       vp.scale[1] = height * (invert ? -0.5 : 0.5);
 492       vp.scale[2] = 1.0;
 493       vp.scale[3] = 1.0;
 494       vp.translate[0] = 0.5 * width;
 495       vp.translate[1] = 0.5 * height;
 496       vp.translate[2] = 0.0;
 497       vp.translate[3] = 0.0;
 498       cso_set_viewport(cso, &vp);
 499    }
 500
 501    /* draw textured quad */
 502    setup_bitmap_vertex_data(st, x, y, width, height,
 503                             ctx->Current.RasterPos[2],
 504                             ctx->Current.RasterColor);
 505
 506    util_draw_vertex_buffer(pipe, st->bitmap.vbuf,
 507                            PIPE_PRIM_TRIANGLE_FAN,
 508                            4,  /* verts */
 509                            3); /* attribs/vert */
 510
 511
 512    /* restore state */
 513    cso_restore_rasterizer(cso);
 514    cso_restore_samplers(cso);
 515    cso_restore_sampler_textures(cso);
 516    cso_restore_viewport(cso);
 517    cso_restore_fragment_shader(cso);
 518    cso_restore_vertex_shader(cso);
 519 }
 520
 521
 522 static void
 523 reset_cache(struct st_context *st)
 524 {
 525    struct pipe_context *pipe = st->pipe;
 526    struct pipe_screen *screen = pipe->screen;
 527    struct bitmap_cache *cache = st->bitmap.cache;
 528
 529    //memset(cache->buffer, 0xff, sizeof(cache->buffer));
 530    cache->empty = GL_TRUE;
 531
 532    cache->xmin = 1000000;
 533    cache->xmax = -1000000;
 534    cache->ymin = 1000000;
 535    cache->ymax = -1000000;
 536
 537    assert(!cache->texture);
 538
 539    /* allocate a new texture */
 540    cache->texture = st_texture_create(st, PIPE_TEXTURE_2D,
 541                                       st->bitmap.tex_format, 0,
 542                                       BITMAP_CACHE_WIDTH, BITMAP_CACHE_HEIGHT,
 543                                       1, 0,
 544                                       PIPE_TEXTURE_USAGE_SAMPLER);
 545
 546    /* Map the texture surface.
 547     * Subsequent glBitmap calls will write into the texture image.
 548     */
 549    cache->surf = screen->get_tex_surface(screen, cache->texture, 0, 0, 0,
 550                                          PIPE_BUFFER_USAGE_CPU_WRITE);
 551    cache->buffer = screen->surface_map(screen, cache->surf,
 552                                        PIPE_BUFFER_USAGE_CPU_WRITE);
 553
 554    /* init image to all 0xff */
 555    memset(cache->buffer, 0xff, BITMAP_CACHE_WIDTH * BITMAP_CACHE_HEIGHT);
 556 }
 557
 558
 559 /**
 560  * If there's anything in the bitmap cache, draw/flush it now.
 561  */
 562 void
 563 st_flush_bitmap_cache(struct st_context *st)
 564 {
 565    if (!st->bitmap.cache->empty) {
 566       if (st->ctx->DrawBuffer) {
 567          struct bitmap_cache *cache = st->bitmap.cache;
 568          struct pipe_context *pipe = st->pipe;
 569          struct pipe_screen *screen = pipe->screen;
 570
 571          assert(cache->xmin <= cache->xmax);
 572          /*
 573          printf("flush size %d x %d  at %d, %d\n",
 574                 cache->xmax - cache->xmin,
 575                 cache->ymax - cache->ymin,
 576                 cache->xpos, cache->ypos);
 577          */
 578
 579          /* The texture surface has been mapped until now.
 580           * So unmap and release the texture surface before drawing.
 581           */
 582          screen->surface_unmap(screen, cache->surf);
 583          screen->tex_surface_release(screen, &cache->surf);
 584
 585          draw_bitmap_quad(st->ctx,
 586                           cache->xpos,
 587                           cache->ypos,
 588                           st->ctx->Current.RasterPos[2],
 589                           BITMAP_CACHE_WIDTH, BITMAP_CACHE_HEIGHT,
 590                           cache->texture);
 591
 592          /* release/free the texture */
 593          pipe_texture_reference(&cache->texture, NULL);
 594       }
 595       reset_cache(st);
 596    }
 597 }
 598
 599
 600 /**
 601  * Try to accumulate this glBitmap call in the bitmap cache.
 602  * \return  GL_TRUE for success, GL_FALSE if bitmap is too large, etc.
 603  */
 604 static GLboolean
 605 accum_bitmap(struct st_context *st,
 606              GLint x, GLint y, GLsizei width, GLsizei height,
 607              const struct gl_pixelstore_attrib *unpack,
 608              const GLubyte *bitmap )
 609 {
 610    struct bitmap_cache *cache = st->bitmap.cache;
 611    int px = -999, py;
 612
 613    if (width > BITMAP_CACHE_WIDTH ||
 614        height > BITMAP_CACHE_HEIGHT)
 615       return GL_FALSE; /* too big to cache */
 616
 617    if (!cache->empty) {
 618       px = x - cache->xpos;  /* pos in buffer */
 619       py = y - cache->ypos;
 620       if (px < 0 || px + width > BITMAP_CACHE_WIDTH ||
 621           py < 0 || py + height > BITMAP_CACHE_HEIGHT) {
 622          /* This bitmap would extend beyond cache bounds,
 623           * so flush and continue.
 624           */
 625          st_flush_bitmap_cache(st);
 626       }
 627    }
 628
 629    if (cache->empty) {
 630       /* Initialize.  Center bitmap vertically in the buffer. */
 631       px = 0;
 632       py = (BITMAP_CACHE_HEIGHT - height) / 2;
 633       cache->xpos = x;
 634       cache->ypos = y - py;
 635       cache->empty = GL_FALSE;
 636    }
 637
 638    assert(px != -999);
 639
 640    if (x < cache->xmin)
 641       cache->xmin = x;
 642    if (y < cache->ymin)
 643       cache->ymin = y;
 644    if (x + width > cache->xmax)
 645       cache->xmax = x + width;
 646    if (y + height > cache->ymax)
 647       cache->ymax = y + height;
 648
 649    unpack_bitmap(st, px, py, width, height, unpack, bitmap,
 650                  cache->buffer, BITMAP_CACHE_WIDTH);
 651
 652    return GL_TRUE; /* accumulated */
 653 }
 654
 655
 656
 657 /**
 658  * Called via ctx->Driver.Bitmap()
 659  */
 660 static void
 661 st_Bitmap(GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height,
 662           const struct gl_pixelstore_attrib *unpack, const GLubyte *bitmap )
 663 {
 664    struct st_context *st = ctx->st;
 665    struct pipe_texture *pt;
 666
 667    if (width == 0 || height == 0)
 668       return;
 669
 670    st_validate_state(st);
 671
 672    if (!st->bitmap.vs) {
 673       /* create pass-through vertex shader now */
 674       const uint semantic_names[] = { TGSI_SEMANTIC_POSITION,
 675                                       TGSI_SEMANTIC_COLOR,
 676                                       TGSI_SEMANTIC_GENERIC };
 677       const uint semantic_indexes[] = { 0, 0, 0 };
 678       st->bitmap.vs = util_make_vertex_passthrough_shader(st->pipe, 3,
 679                                                           semantic_names,
 680                                                           semantic_indexes,
 681                                                           &st->bitmap.vert_shader);
 682    }
 683
 684    if (UseBitmapCache && accum_bitmap(st, x, y, width, height, unpack, bitmap))
 685       return;
 686
 687    pt = make_bitmap_texture(ctx, width, height, unpack, bitmap);
 688    if (pt) {
 689       assert(pt->target == PIPE_TEXTURE_2D);
 690       draw_bitmap_quad(ctx, x, y, ctx->Current.RasterPos[2],
 691                        width, height, pt);
 692       /* release/free the texture */
 693       pipe_texture_reference(&pt, NULL);
 694    }
 695 }
 696
 697
 698 /** Per-context init */
 699 void
 700 st_init_bitmap_functions(struct dd_function_table *functions)
 701 {
 702    functions->Bitmap = st_Bitmap;
 703 }
 704
 705
 706 /** Per-context init */
 707 void
 708 st_init_bitmap(struct st_context *st)
 709 {
 710    struct pipe_sampler_state *sampler = &st->bitmap.sampler;
 711    struct pipe_context *pipe = st->pipe;
 712    struct pipe_screen *screen = pipe->screen;
 713
 714    /* init sampler state once */
 715    memset(sampler, 0, sizeof(*sampler));
 716    sampler->wrap_s = PIPE_TEX_WRAP_CLAMP;
 717    sampler->wrap_t = PIPE_TEX_WRAP_CLAMP;
 718    sampler->wrap_r = PIPE_TEX_WRAP_CLAMP;
 719    sampler->min_img_filter = PIPE_TEX_FILTER_NEAREST;
 720    sampler->min_mip_filter = PIPE_TEX_MIPFILTER_NONE;
 721    sampler->mag_img_filter = PIPE_TEX_FILTER_NEAREST;
 722    sampler->normalized_coords = 1;
 723
 724    /* init baseline rasterizer state once */
 725    memset(&st->bitmap.rasterizer, 0, sizeof(st->bitmap.rasterizer));
 726    st->bitmap.rasterizer.gl_rasterization_rules = 1;
 727    st->bitmap.rasterizer.bypass_vs = 1;
 728
 729    /* find a usable texture format */
 730    if (screen->is_format_supported(screen, PIPE_FORMAT_I8_UNORM, PIPE_TEXTURE)) {
 731       st->bitmap.tex_format = PIPE_FORMAT_I8_UNORM;
 732    }
 733    else {
 734       /* XXX support more formats */
 735       assert(0);
 736    }
 737
 738    /* alloc bitmap cache object */
 739    st->bitmap.cache = CALLOC_STRUCT(bitmap_cache);
 740
 741    reset_cache(st);
 742 }
 743
 744
 745 /** Per-context tear-down */
 746 void
 747 st_destroy_bitmap(struct st_context *st)
 748 {
 749    struct pipe_context *pipe = st->pipe;
 750    struct pipe_screen *screen = pipe->screen;
 751    struct bitmap_cache *cache = st->bitmap.cache;
 752
 753    screen->surface_unmap(screen, cache->surf);
 754    screen->tex_surface_release(screen, &cache->surf);
 755
 756    if (st->bitmap.vs) {
 757       cso_delete_vertex_shader(st->cso_context, st->bitmap.vs);
 758       st->bitmap.vs = NULL;
 759    }
 760
 761    if (st->bitmap.vbuf) {
 762       pipe_buffer_destroy(pipe, st->bitmap.vbuf);
 763       st->bitmap.vbuf = NULL;
 764    }
 765
 766    if (st->bitmap.cache) {
 767       pipe_texture_release(&st->bitmap.cache->texture);
 768       FREE(st->bitmap.cache);
 769       st->bitmap.cache = NULL;
 770    }
 771 }