src/mesa/swrast/s_blit.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  *
   5  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions 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 MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 #include "main/glheader.h"
  27 #include "main/condrender.h"
  28 #include "main/image.h"
  29 #include "main/macros.h"
  30 #include "main/format_unpack.h"
  31 #include "main/format_pack.h"
  32 #include "s_context.h"
  33
  34
  35 #define ABS(X)   ((X) < 0 ? -(X) : (X))
  36
  37
  38 /**
  39  * Generate a row resampler function for GL_NEAREST mode.
  40  */
  41 #define RESAMPLE(NAME, PIXELTYPE, SIZE)                 \
  42 static void                                             \
  43 NAME(GLint srcWidth, GLint dstWidth,                    \
  44      const GLvoid *srcBuffer, GLvoid *dstBuffer,        \
  45      GLboolean flip)                                    \
  46 {                                                       \
  47    const PIXELTYPE *src = (const PIXELTYPE *) srcBuffer;\
  48    PIXELTYPE *dst = (PIXELTYPE *) dstBuffer;            \
  49    GLint dstCol;                                        \
  50                                                         \
  51    if (flip) {                                          \
  52       for (dstCol = 0; dstCol < dstWidth; dstCol++) {   \
  53          GLint srcCol = (dstCol * srcWidth) / dstWidth; \
  54          ASSERT(srcCol >= 0);                           \
  55          ASSERT(srcCol < srcWidth);                     \
  56          srcCol = srcWidth - 1 - srcCol; /* flip */     \
  57          if (SIZE == 1) {                               \
  58             dst[dstCol] = src[srcCol];                  \
  59          }                                              \
  60          else if (SIZE == 2) {                          \
  61             dst[dstCol*2+0] = src[srcCol*2+0];          \
  62             dst[dstCol*2+1] = src[srcCol*2+1];          \
  63          }                                              \
  64          else if (SIZE == 4) {                          \
  65             dst[dstCol*4+0] = src[srcCol*4+0];          \
  66             dst[dstCol*4+1] = src[srcCol*4+1];          \
  67             dst[dstCol*4+2] = src[srcCol*4+2];          \
  68             dst[dstCol*4+3] = src[srcCol*4+3];          \
  69          }                                              \
  70       }                                                 \
  71    }                                                    \
  72    else {                                               \
  73       for (dstCol = 0; dstCol < dstWidth; dstCol++) {   \
  74          GLint srcCol = (dstCol * srcWidth) / dstWidth; \
  75          ASSERT(srcCol >= 0);                           \
  76          ASSERT(srcCol < srcWidth);                     \
  77          if (SIZE == 1) {                               \
  78             dst[dstCol] = src[srcCol];                  \
  79          }                                              \
  80          else if (SIZE == 2) {                          \
  81             dst[dstCol*2+0] = src[srcCol*2+0];          \
  82             dst[dstCol*2+1] = src[srcCol*2+1];          \
  83          }                                              \
  84          else if (SIZE == 4) {                          \
  85             dst[dstCol*4+0] = src[srcCol*4+0];          \
  86             dst[dstCol*4+1] = src[srcCol*4+1];          \
  87             dst[dstCol*4+2] = src[srcCol*4+2];          \
  88             dst[dstCol*4+3] = src[srcCol*4+3];          \
  89          }                                              \
  90       }                                                 \
  91    }                                                    \
  92 }
  93
  94 /**
  95  * Resamplers for 1, 2, 4, 8 and 16-byte pixels.
  96  */
  97 RESAMPLE(resample_row_1, GLubyte, 1)
  98 RESAMPLE(resample_row_2, GLushort, 1)
  99 RESAMPLE(resample_row_4, GLuint, 1)
 100 RESAMPLE(resample_row_8, GLuint, 2)
 101 RESAMPLE(resample_row_16, GLuint, 4)
 102
 103
 104 /**
 105  * Blit color, depth or stencil with GL_NEAREST filtering.
 106  */
 107 static void
 108 blit_nearest(struct gl_context *ctx,
 109              GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
 110              GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
 111              GLbitfield buffer)
 112 {
 113    struct gl_renderbuffer *readRb, *drawRb = NULL;
 114    struct gl_renderbuffer_attachment *readAtt = NULL, *drawAtt = NULL;
 115    struct gl_framebuffer *readFb = ctx->ReadBuffer;
 116    struct gl_framebuffer *drawFb = ctx->DrawBuffer;
 117    GLuint numDrawBuffers = 0;
 118    GLuint i;
 119
 120    const GLint srcWidth = ABS(srcX1 - srcX0);
 121    const GLint dstWidth = ABS(dstX1 - dstX0);
 122    const GLint srcHeight = ABS(srcY1 - srcY0);
 123    const GLint dstHeight = ABS(dstY1 - dstY0);
 124
 125    const GLint srcXpos = MIN2(srcX0, srcX1);
 126    const GLint srcYpos = MIN2(srcY0, srcY1);
 127    const GLint dstXpos = MIN2(dstX0, dstX1);
 128    const GLint dstYpos = MIN2(dstY0, dstY1);
 129
 130    const GLboolean invertX = (srcX1 < srcX0) ^ (dstX1 < dstX0);
 131    const GLboolean invertY = (srcY1 < srcY0) ^ (dstY1 < dstY0);
 132    enum mode {
 133       DIRECT,
 134       UNPACK_RGBA_FLOAT,
 135       UNPACK_Z_FLOAT,
 136       UNPACK_Z_INT,
 137       UNPACK_S,
 138    } mode = DIRECT;
 139    GLubyte *srcMap, *dstMap;
 140    GLint srcRowStride, dstRowStride;
 141    GLint dstRow;
 142
 143    GLint pixelSize = 0;
 144    GLvoid *srcBuffer, *dstBuffer;
 145    GLint prevY = -1;
 146
 147    typedef void (*resample_func)(GLint srcWidth, GLint dstWidth,
 148                                  const GLvoid *srcBuffer, GLvoid *dstBuffer,
 149                                  GLboolean flip);
 150    resample_func resampleRow;
 151
 152    switch (buffer) {
 153    case GL_COLOR_BUFFER_BIT:
 154       readAtt = &readFb->Attachment[readFb->_ColorReadBufferIndex];
 155       readRb = readFb->_ColorReadBuffer;
 156       numDrawBuffers = drawFb->_NumColorDrawBuffers;
 157       break;
 158    case GL_DEPTH_BUFFER_BIT:
 159       readAtt = &readFb->Attachment[BUFFER_DEPTH];
 160       drawAtt = &drawFb->Attachment[BUFFER_DEPTH];
 161       readRb = readAtt->Renderbuffer;
 162       drawRb = drawAtt->Renderbuffer;
 163       numDrawBuffers = 1;
 164
 165       /* Note that for depth/stencil, the formats of src/dst must match.  By
 166        * using the core helpers for pack/unpack, we avoid needing to handle
 167        * masking for things like DEPTH copies of Z24S8.
 168        */
 169       if (readRb->Format == MESA_FORMAT_Z32_FLOAT ||
 170           readRb->Format == MESA_FORMAT_Z32_FLOAT_X24S8) {
 171          mode = UNPACK_Z_FLOAT;
 172       } else {
 173          mode = UNPACK_Z_INT;
 174       }
 175       pixelSize = 4;
 176       break;
 177    case GL_STENCIL_BUFFER_BIT:
 178       readAtt = &readFb->Attachment[BUFFER_STENCIL];
 179       drawAtt = &drawFb->Attachment[BUFFER_STENCIL];
 180       readRb = readAtt->Renderbuffer;
 181       drawRb = drawAtt->Renderbuffer;
 182       numDrawBuffers = 1;
 183       mode = UNPACK_S;
 184       pixelSize = 1;
 185       break;
 186    default:
 187       _mesa_problem(ctx, "unexpected buffer in blit_nearest()");
 188       return;
 189    }
 190
 191    /* allocate the src/dst row buffers */
 192    srcBuffer = malloc(MAX_PIXEL_BYTES * srcWidth);
 193    dstBuffer = malloc(MAX_PIXEL_BYTES * dstWidth);
 194    if (!srcBuffer || !dstBuffer)
 195       goto fail_no_memory;
 196
 197    /* Blit to all the draw buffers */
 198    for (i = 0; i < numDrawBuffers; i++) {
 199       if (buffer == GL_COLOR_BUFFER_BIT) {
 200          int idx = drawFb->_ColorDrawBufferIndexes[i];
 201          if (idx == -1)
 202             continue;
 203          drawAtt = &drawFb->Attachment[idx];
 204          drawRb = drawAtt->Renderbuffer;
 205
 206          if (!drawRb)
 207             continue;
 208
 209          if (readRb->Format == drawRb->Format) {
 210             mode = DIRECT;
 211             pixelSize = _mesa_get_format_bytes(readRb->Format);
 212          } else {
 213             mode = UNPACK_RGBA_FLOAT;
 214             pixelSize = 16;
 215          }
 216       }
 217
 218       /* choose row resampler */
 219       switch (pixelSize) {
 220       case 1:
 221          resampleRow = resample_row_1;
 222          break;
 223       case 2:
 224          resampleRow = resample_row_2;
 225          break;
 226       case 4:
 227          resampleRow = resample_row_4;
 228          break;
 229       case 8:
 230          resampleRow = resample_row_8;
 231          break;
 232       case 16:
 233          resampleRow = resample_row_16;
 234          break;
 235       default:
 236          _mesa_problem(ctx, "unexpected pixel size (%d) in blit_nearest",
 237                        pixelSize);
 238          goto fail;
 239       }
 240
 241       if ((readRb == drawRb) ||
 242           (readAtt->Texture && drawAtt->Texture &&
 243            (readAtt->Texture == drawAtt->Texture))) {
 244          /* map whole buffer for read/write */
 245          /* XXX we could be clever and just map the union region of the
 246           * source and dest rects.
 247           */
 248          GLubyte *map;
 249          GLint rowStride;
 250          GLint formatSize = _mesa_get_format_bytes(readRb->Format);
 251
 252          ctx->Driver.MapRenderbuffer(ctx, readRb, 0, 0,
 253                                      readRb->Width, readRb->Height,
 254                                      GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
 255                                      &map, &rowStride);
 256          if (!map) {
 257             goto fail_no_memory;
 258          }
 259
 260          srcMap = map + srcYpos * rowStride + srcXpos * formatSize;
 261          dstMap = map + dstYpos * rowStride + dstXpos * formatSize;
 262
 263          /* this handles overlapping copies */
 264          if (srcY0 < dstY0) {
 265             /* copy in reverse (top->down) order */
 266             srcMap += rowStride * (readRb->Height - 1);
 267             dstMap += rowStride * (readRb->Height - 1);
 268             srcRowStride = -rowStride;
 269             dstRowStride = -rowStride;
 270          }
 271          else {
 272             /* copy in normal (bottom->up) order */
 273             srcRowStride = rowStride;
 274             dstRowStride = rowStride;
 275          }
 276       }
 277       else {
 278          /* different src/dst buffers */
 279          ctx->Driver.MapRenderbuffer(ctx, readRb,
 280                                      srcXpos, srcYpos,
 281                                      srcWidth, srcHeight,
 282                                      GL_MAP_READ_BIT, &srcMap, &srcRowStride);
 283          if (!srcMap) {
 284             goto fail_no_memory;
 285          }
 286          ctx->Driver.MapRenderbuffer(ctx, drawRb,
 287                                      dstXpos, dstYpos,
 288                                      dstWidth, dstHeight,
 289                                      GL_MAP_WRITE_BIT, &dstMap, &dstRowStride);
 290          if (!dstMap) {
 291             ctx->Driver.UnmapRenderbuffer(ctx, readRb);
 292             goto fail_no_memory;
 293          }
 294       }
 295
 296       for (dstRow = 0; dstRow < dstHeight; dstRow++) {
 297          GLfloat srcRowF = (dstRow + 0.5F) / dstHeight * srcHeight - 0.5F;
 298          GLint srcRow = IROUND(srcRowF);
 299          GLubyte *dstRowStart = dstMap + dstRowStride * dstRow;
 300
 301          ASSERT(srcRow >= 0);
 302          ASSERT(srcRow < srcHeight);
 303
 304          if (invertY) {
 305             srcRow = srcHeight - 1 - srcRow;
 306          }
 307
 308          /* get pixel row from source and resample to match dest width */
 309          if (prevY != srcRow) {
 310             GLubyte *srcRowStart = srcMap + srcRowStride * srcRow;
 311
 312             switch (mode) {
 313             case DIRECT:
 314                memcpy(srcBuffer, srcRowStart, pixelSize * srcWidth);
 315                break;
 316             case UNPACK_RGBA_FLOAT:
 317                _mesa_unpack_rgba_row(readRb->Format, srcWidth, srcRowStart,
 318                                      srcBuffer);
 319                break;
 320             case UNPACK_Z_FLOAT:
 321                _mesa_unpack_float_z_row(readRb->Format, srcWidth, srcRowStart,
 322                                         srcBuffer);
 323                break;
 324             case UNPACK_Z_INT:
 325                _mesa_unpack_uint_z_row(readRb->Format, srcWidth, srcRowStart,
 326                                        srcBuffer);
 327                break;
 328             case UNPACK_S:
 329                _mesa_unpack_ubyte_stencil_row(readRb->Format, srcWidth,
 330                                               srcRowStart, srcBuffer);
 331                break;
 332             }
 333
 334             (*resampleRow)(srcWidth, dstWidth, srcBuffer, dstBuffer, invertX);
 335             prevY = srcRow;
 336          }
 337
 338          /* store pixel row in destination */
 339          switch (mode) {
 340          case DIRECT:
 341             memcpy(dstRowStart, dstBuffer, pixelSize * dstWidth);
 342             break;
 343          case UNPACK_RGBA_FLOAT:
 344             _mesa_pack_float_rgba_row(drawRb->Format, dstWidth, dstBuffer,
 345                                       dstRowStart);
 346             break;
 347          case UNPACK_Z_FLOAT:
 348             _mesa_pack_float_z_row(drawRb->Format, dstWidth, dstBuffer,
 349                                    dstRowStart);
 350             break;
 351          case UNPACK_Z_INT:
 352             _mesa_pack_uint_z_row(drawRb->Format, dstWidth, dstBuffer,
 353                                   dstRowStart);
 354             break;
 355          case UNPACK_S:
 356             _mesa_pack_ubyte_stencil_row(drawRb->Format, dstWidth, dstBuffer,
 357                                          dstRowStart);
 358             break;
 359          }
 360       }
 361
 362       ctx->Driver.UnmapRenderbuffer(ctx, readRb);
 363       if (drawRb != readRb) {
 364          ctx->Driver.UnmapRenderbuffer(ctx, drawRb);
 365       }
 366    }
 367
 368 fail:
 369    free(srcBuffer);
 370    free(dstBuffer);
 371    return;
 372
 373 fail_no_memory:
 374    free(srcBuffer);
 375    free(dstBuffer);
 376    _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBuffer");
 377 }
 378
 379
 380
 381 #define LERP(T, A, B)  ( (A) + (T) * ((B) - (A)) )
 382
 383 static inline GLfloat
 384 lerp_2d(GLfloat a, GLfloat b,
 385         GLfloat v00, GLfloat v10, GLfloat v01, GLfloat v11)
 386 {
 387    const GLfloat temp0 = LERP(a, v00, v10);
 388    const GLfloat temp1 = LERP(a, v01, v11);
 389    return LERP(b, temp0, temp1);
 390 }
 391
 392
 393 /**
 394  * Bilinear interpolation of two source rows.
 395  * GLubyte pixels.
 396  */
 397 static void
 398 resample_linear_row_ub(GLint srcWidth, GLint dstWidth,
 399                        const GLvoid *srcBuffer0, const GLvoid *srcBuffer1,
 400                        GLvoid *dstBuffer, GLboolean flip, GLfloat rowWeight)
 401 {
 402    const GLubyte (*srcColor0)[4] = (const GLubyte (*)[4]) srcBuffer0;
 403    const GLubyte (*srcColor1)[4] = (const GLubyte (*)[4]) srcBuffer1;
 404    GLubyte (*dstColor)[4] = (GLubyte (*)[4]) dstBuffer;
 405    GLint dstCol;
 406
 407    for (dstCol = 0; dstCol < dstWidth; dstCol++) {
 408       const GLfloat srcCol = (dstCol + 0.5F) / dstWidth * srcWidth - 0.5F;
 409       GLint srcCol0 = MAX2(0, IFLOOR(srcCol));
 410       GLint srcCol1 = srcCol0 + 1;
 411       GLfloat colWeight = srcCol - srcCol0; /* fractional part of srcCol */
 412       GLfloat red, green, blue, alpha;
 413
 414       ASSERT(srcCol0 < srcWidth);
 415       ASSERT(srcCol1 <= srcWidth);
 416
 417       if (srcCol1 == srcWidth) {
 418          /* last column fudge */
 419          srcCol1--;
 420          colWeight = 0.0;
 421       }
 422
 423       if (flip) {
 424          srcCol0 = srcWidth - 1 - srcCol0;
 425          srcCol1 = srcWidth - 1 - srcCol1;
 426       }
 427
 428       red = lerp_2d(colWeight, rowWeight,
 429                     srcColor0[srcCol0][RCOMP], srcColor0[srcCol1][RCOMP],
 430                     srcColor1[srcCol0][RCOMP], srcColor1[srcCol1][RCOMP]);
 431       green = lerp_2d(colWeight, rowWeight,
 432                     srcColor0[srcCol0][GCOMP], srcColor0[srcCol1][GCOMP],
 433                     srcColor1[srcCol0][GCOMP], srcColor1[srcCol1][GCOMP]);
 434       blue = lerp_2d(colWeight, rowWeight,
 435                     srcColor0[srcCol0][BCOMP], srcColor0[srcCol1][BCOMP],
 436                     srcColor1[srcCol0][BCOMP], srcColor1[srcCol1][BCOMP]);
 437       alpha = lerp_2d(colWeight, rowWeight,
 438                     srcColor0[srcCol0][ACOMP], srcColor0[srcCol1][ACOMP],
 439                     srcColor1[srcCol0][ACOMP], srcColor1[srcCol1][ACOMP]);
 440
 441       dstColor[dstCol][RCOMP] = IFLOOR(red);
 442       dstColor[dstCol][GCOMP] = IFLOOR(green);
 443       dstColor[dstCol][BCOMP] = IFLOOR(blue);
 444       dstColor[dstCol][ACOMP] = IFLOOR(alpha);
 445    }
 446 }
 447
 448
 449 /**
 450  * Bilinear interpolation of two source rows.  floating point pixels.
 451  */
 452 static void
 453 resample_linear_row_float(GLint srcWidth, GLint dstWidth,
 454                           const GLvoid *srcBuffer0, const GLvoid *srcBuffer1,
 455                           GLvoid *dstBuffer, GLboolean flip, GLfloat rowWeight)
 456 {
 457    const GLfloat (*srcColor0)[4] = (const GLfloat (*)[4]) srcBuffer0;
 458    const GLfloat (*srcColor1)[4] = (const GLfloat (*)[4]) srcBuffer1;
 459    GLfloat (*dstColor)[4] = (GLfloat (*)[4]) dstBuffer;
 460    GLint dstCol;
 461
 462    for (dstCol = 0; dstCol < dstWidth; dstCol++) {
 463       const GLfloat srcCol = (dstCol + 0.5F) / dstWidth * srcWidth - 0.5F;
 464       GLint srcCol0 = MAX2(0, IFLOOR(srcCol));
 465       GLint srcCol1 = srcCol0 + 1;
 466       GLfloat colWeight = srcCol - srcCol0; /* fractional part of srcCol */
 467       GLfloat red, green, blue, alpha;
 468
 469       ASSERT(srcCol0 < srcWidth);
 470       ASSERT(srcCol1 <= srcWidth);
 471
 472       if (srcCol1 == srcWidth) {
 473          /* last column fudge */
 474          srcCol1--;
 475          colWeight = 0.0;
 476       }
 477
 478       if (flip) {
 479          srcCol0 = srcWidth - 1 - srcCol0;
 480          srcCol1 = srcWidth - 1 - srcCol1;
 481       }
 482
 483       red = lerp_2d(colWeight, rowWeight,
 484                     srcColor0[srcCol0][RCOMP], srcColor0[srcCol1][RCOMP],
 485                     srcColor1[srcCol0][RCOMP], srcColor1[srcCol1][RCOMP]);
 486       green = lerp_2d(colWeight, rowWeight,
 487                     srcColor0[srcCol0][GCOMP], srcColor0[srcCol1][GCOMP],
 488                     srcColor1[srcCol0][GCOMP], srcColor1[srcCol1][GCOMP]);
 489       blue = lerp_2d(colWeight, rowWeight,
 490                     srcColor0[srcCol0][BCOMP], srcColor0[srcCol1][BCOMP],
 491                     srcColor1[srcCol0][BCOMP], srcColor1[srcCol1][BCOMP]);
 492       alpha = lerp_2d(colWeight, rowWeight,
 493                     srcColor0[srcCol0][ACOMP], srcColor0[srcCol1][ACOMP],
 494                     srcColor1[srcCol0][ACOMP], srcColor1[srcCol1][ACOMP]);
 495
 496       dstColor[dstCol][RCOMP] = red;
 497       dstColor[dstCol][GCOMP] = green;
 498       dstColor[dstCol][BCOMP] = blue;
 499       dstColor[dstCol][ACOMP] = alpha;
 500    }
 501 }
 502
 503
 504
 505 /**
 506  * Bilinear filtered blit (color only, non-integer values).
 507  */
 508 static void
 509 blit_linear(struct gl_context *ctx,
 510             GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
 511             GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1)
 512 {
 513    struct gl_framebuffer *drawFb = ctx->DrawBuffer;
 514    struct gl_framebuffer *readFb = ctx->ReadBuffer;
 515    struct gl_renderbuffer *readRb = readFb->_ColorReadBuffer;
 516    struct gl_renderbuffer_attachment *readAtt =
 517       &readFb->Attachment[readFb->_ColorReadBufferIndex];
 518
 519    const GLint srcWidth = ABS(srcX1 - srcX0);
 520    const GLint dstWidth = ABS(dstX1 - dstX0);
 521    const GLint srcHeight = ABS(srcY1 - srcY0);
 522    const GLint dstHeight = ABS(dstY1 - dstY0);
 523
 524    const GLint srcXpos = MIN2(srcX0, srcX1);
 525    const GLint srcYpos = MIN2(srcY0, srcY1);
 526    const GLint dstXpos = MIN2(dstX0, dstX1);
 527    const GLint dstYpos = MIN2(dstY0, dstY1);
 528
 529    const GLboolean invertX = (srcX1 < srcX0) ^ (dstX1 < dstX0);
 530    const GLboolean invertY = (srcY1 < srcY0) ^ (dstY1 < dstY0);
 531
 532    GLint dstRow;
 533
 534    GLint pixelSize;
 535    GLvoid *srcBuffer0, *srcBuffer1;
 536    GLint srcBufferY0 = -1, srcBufferY1 = -1;
 537    GLvoid *dstBuffer;
 538
 539    gl_format readFormat = _mesa_get_srgb_format_linear(readRb->Format);
 540    GLuint bpp = _mesa_get_format_bytes(readFormat);
 541
 542    GLenum pixelType;
 543
 544    GLubyte *srcMap, *dstMap;
 545    GLint srcRowStride, dstRowStride;
 546    GLuint i;
 547
 548
 549    /* Determine datatype for resampling */
 550    if (_mesa_get_format_max_bits(readFormat) == 8 &&
 551        _mesa_get_format_datatype(readFormat) == GL_UNSIGNED_NORMALIZED) {
 552       pixelType = GL_UNSIGNED_BYTE;
 553       pixelSize = 4 * sizeof(GLubyte);
 554    }
 555    else {
 556       pixelType = GL_FLOAT;
 557       pixelSize = 4 * sizeof(GLfloat);
 558    }
 559
 560    /* Allocate the src/dst row buffers.
 561     * Keep two adjacent src rows around for bilinear sampling.
 562     */
 563    srcBuffer0 = malloc(pixelSize * srcWidth);
 564    srcBuffer1 = malloc(pixelSize * srcWidth);
 565    dstBuffer = malloc(pixelSize * dstWidth);
 566    if (!srcBuffer0 || !srcBuffer1 || !dstBuffer) {
 567       goto fail_no_memory;
 568    }
 569
 570    for (i = 0; i < drawFb->_NumColorDrawBuffers; i++) {
 571       GLint idx = drawFb->_ColorDrawBufferIndexes[i];
 572       struct gl_renderbuffer_attachment *drawAtt;
 573       struct gl_renderbuffer *drawRb;
 574       gl_format drawFormat;
 575
 576       if (idx == -1)
 577          continue;
 578
 579       drawAtt = &drawFb->Attachment[idx];
 580       drawRb = drawAtt->Renderbuffer;
 581       if (!drawRb)
 582          continue;
 583
 584       drawFormat = _mesa_get_srgb_format_linear(drawRb->Format);
 585
 586       /*
 587        * Map src / dst renderbuffers
 588        */
 589       if ((readRb == drawRb) ||
 590           (readAtt->Texture && drawAtt->Texture &&
 591            (readAtt->Texture == drawAtt->Texture))) {
 592          /* map whole buffer for read/write */
 593          ctx->Driver.MapRenderbuffer(ctx, readRb,
 594                                      0, 0, readRb->Width, readRb->Height,
 595                                      GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
 596                                      &srcMap, &srcRowStride);
 597          if (!srcMap) {
 598             goto fail_no_memory;
 599          }
 600
 601          dstMap = srcMap;
 602          dstRowStride = srcRowStride;
 603       }
 604       else {
 605          /* different src/dst buffers */
 606          /* XXX with a bit of work we could just map the regions to be
 607           * read/written instead of the whole buffers.
 608           */
 609          ctx->Driver.MapRenderbuffer(ctx, readRb,
 610                                      0, 0, readRb->Width, readRb->Height,
 611                                      GL_MAP_READ_BIT, &srcMap, &srcRowStride);
 612          if (!srcMap) {
 613             goto fail_no_memory;
 614          }
 615          ctx->Driver.MapRenderbuffer(ctx, drawRb,
 616                                      0, 0, drawRb->Width, drawRb->Height,
 617                                      GL_MAP_WRITE_BIT, &dstMap, &dstRowStride);
 618          if (!dstMap) {
 619             ctx->Driver.UnmapRenderbuffer(ctx, readRb);
 620             goto fail_no_memory;
 621          }
 622       }
 623
 624       for (dstRow = 0; dstRow < dstHeight; dstRow++) {
 625          const GLint dstY = dstYpos + dstRow;
 626          GLfloat srcRow = (dstRow + 0.5F) / dstHeight * srcHeight - 0.5F;
 627          GLint srcRow0 = MAX2(0, IFLOOR(srcRow));
 628          GLint srcRow1 = srcRow0 + 1;
 629          GLfloat rowWeight = srcRow - srcRow0; /* fractional part of srcRow */
 630
 631          if (srcRow1 == srcHeight) {
 632             /* last row fudge */
 633             srcRow1 = srcRow0;
 634             rowWeight = 0.0;
 635          }
 636
 637          if (invertY) {
 638             srcRow0 = srcHeight - 1 - srcRow0;
 639             srcRow1 = srcHeight - 1 - srcRow1;
 640          }
 641
 642          srcY0 = srcYpos + srcRow0;
 643          srcY1 = srcYpos + srcRow1;
 644
 645          /* get the two source rows */
 646          if (srcY0 == srcBufferY0 && srcY1 == srcBufferY1) {
 647             /* use same source row buffers again */
 648          }
 649          else if (srcY0 == srcBufferY1) {
 650             /* move buffer1 into buffer0 by swapping pointers */
 651             GLvoid *tmp = srcBuffer0;
 652             srcBuffer0 = srcBuffer1;
 653             srcBuffer1 = tmp;
 654             /* get y1 row */
 655             {
 656                GLubyte *src = srcMap + srcY1 * srcRowStride + srcXpos * bpp;
 657                if (pixelType == GL_UNSIGNED_BYTE) {
 658                   _mesa_unpack_ubyte_rgba_row(readFormat, srcWidth,
 659                                               src, srcBuffer1);
 660                }
 661                else {
 662                   _mesa_unpack_rgba_row(readFormat, srcWidth,
 663                                         src, srcBuffer1);
 664                }
 665             }
 666             srcBufferY0 = srcY0;
 667             srcBufferY1 = srcY1;
 668          }
 669          else {
 670             /* get both new rows */
 671             {
 672                GLubyte *src0 = srcMap + srcY0 * srcRowStride + srcXpos * bpp;
 673                GLubyte *src1 = srcMap + srcY1 * srcRowStride + srcXpos * bpp;
 674                if (pixelType == GL_UNSIGNED_BYTE) {
 675                   _mesa_unpack_ubyte_rgba_row(readFormat, srcWidth,
 676                                               src0, srcBuffer0);
 677                   _mesa_unpack_ubyte_rgba_row(readFormat, srcWidth,
 678                                               src1, srcBuffer1);
 679                }
 680                else {
 681                   _mesa_unpack_rgba_row(readFormat, srcWidth, src0, srcBuffer0);
 682                   _mesa_unpack_rgba_row(readFormat, srcWidth, src1, srcBuffer1);
 683                }
 684             }
 685             srcBufferY0 = srcY0;
 686             srcBufferY1 = srcY1;
 687          }
 688
 689          if (pixelType == GL_UNSIGNED_BYTE) {
 690             resample_linear_row_ub(srcWidth, dstWidth, srcBuffer0, srcBuffer1,
 691                                    dstBuffer, invertX, rowWeight);
 692          }
 693          else {
 694             resample_linear_row_float(srcWidth, dstWidth, srcBuffer0, srcBuffer1,
 695                                       dstBuffer, invertX, rowWeight);
 696          }
 697
 698          /* store pixel row in destination */
 699          {
 700             GLubyte *dst = dstMap + dstY * dstRowStride + dstXpos * bpp;
 701             if (pixelType == GL_UNSIGNED_BYTE) {
 702                _mesa_pack_ubyte_rgba_row(drawFormat, dstWidth, dstBuffer, dst);
 703             }
 704             else {
 705                _mesa_pack_float_rgba_row(drawFormat, dstWidth, dstBuffer, dst);
 706             }
 707          }
 708       }
 709
 710       ctx->Driver.UnmapRenderbuffer(ctx, readRb);
 711       if (drawRb != readRb) {
 712          ctx->Driver.UnmapRenderbuffer(ctx, drawRb);
 713       }
 714    }
 715
 716    free(srcBuffer0);
 717    free(srcBuffer1);
 718    free(dstBuffer);
 719    return;
 720
 721 fail_no_memory:
 722    free(srcBuffer0);
 723    free(srcBuffer1);
 724    free(dstBuffer);
 725    _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFramebuffer");
 726 }
 727
 728
 729
 730 /**
 731  * Software fallback for glBlitFramebufferEXT().
 732  */
 733 void
 734 _swrast_BlitFramebuffer(struct gl_context *ctx,
 735                         GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
 736                         GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
 737                         GLbitfield mask, GLenum filter)
 738 {
 739    static const GLbitfield buffers[3] = {
 740       GL_COLOR_BUFFER_BIT,
 741       GL_DEPTH_BUFFER_BIT,
 742       GL_STENCIL_BUFFER_BIT
 743    };
 744    static const GLenum buffer_enums[3] = {
 745       GL_COLOR,
 746       GL_DEPTH,
 747       GL_STENCIL,
 748    };
 749    GLint i;
 750
 751    if (!_mesa_clip_blit(ctx, &srcX0, &srcY0, &srcX1, &srcY1,
 752                         &dstX0, &dstY0, &dstX1, &dstY1)) {
 753       return;
 754    }
 755
 756    if (SWRAST_CONTEXT(ctx)->NewState)
 757       _swrast_validate_derived(ctx);
 758
 759    /* First, try covering whatever buffers possible using the fast 1:1 copy
 760     * path.
 761     */
 762    if (srcX1 - srcX0 == dstX1 - dstX0 &&
 763        srcY1 - srcY0 == dstY1 - dstY0 &&
 764        srcX0 < srcX1 &&
 765        srcY0 < srcY1 &&
 766        dstX0 < dstX1 &&
 767        dstY0 < dstY1) {
 768       for (i = 0; i < 3; i++) {
 769          if (mask & buffers[i]) {
 770             if (swrast_fast_copy_pixels(ctx,
 771                                         srcX0, srcY0,
 772                                         srcX1 - srcX0, srcY1 - srcY0,
 773                                         dstX0, dstY0,
 774                                         buffer_enums[i])) {
 775                mask &= ~buffers[i];
 776             }
 777          }
 778       }
 779
 780       if (!mask)
 781          return;
 782    }
 783
 784    if (filter == GL_NEAREST) {
 785       for (i = 0; i < 3; i++) {
 786          if (mask & buffers[i]) {
 787             blit_nearest(ctx,  srcX0, srcY0, srcX1, srcY1,
 788                          dstX0, dstY0, dstX1, dstY1, buffers[i]);
 789          }
 790       }
 791    }
 792    else {
 793       ASSERT(filter == GL_LINEAR);
 794       if (mask & GL_COLOR_BUFFER_BIT) {  /* depth/stencil not allowed */
 795          blit_linear(ctx,  srcX0, srcY0, srcX1, srcY1,
 796                      dstX0, dstY0, dstX1, dstY1);
 797       }
 798    }
 799
 800 }