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  * BRIAN PAUL 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;
 114    struct gl_renderbuffer_attachment *readAtt, *drawAtt;
 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;
 139    GLubyte *srcMap, *dstMap;
 140    GLint srcRowStride, dstRowStride;
 141    GLint dstRow;
 142
 143    GLint pixelSize;
 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    /* Blit to all the draw buffers */
 192    for (i = 0; i < numDrawBuffers; i++) {
 193       if (buffer == GL_COLOR_BUFFER_BIT) {
 194          int idx = drawFb->_ColorDrawBufferIndexes[i];
 195          if (idx == -1)
 196             continue;
 197          drawAtt = &drawFb->Attachment[idx];
 198          drawRb = drawAtt->Renderbuffer;
 199
 200          if (!drawRb)
 201             continue;
 202
 203          if (readRb->Format == drawRb->Format) {
 204             mode = DIRECT;
 205             pixelSize = _mesa_get_format_bytes(readRb->Format);
 206          } else {
 207             mode = UNPACK_RGBA_FLOAT;
 208             pixelSize = 16;
 209          }
 210       }
 211
 212       /* choose row resampler */
 213       switch (pixelSize) {
 214       case 1:
 215          resampleRow = resample_row_1;
 216          break;
 217       case 2:
 218          resampleRow = resample_row_2;
 219          break;
 220       case 4:
 221          resampleRow = resample_row_4;
 222          break;
 223       case 8:
 224          resampleRow = resample_row_8;
 225          break;
 226       case 16:
 227          resampleRow = resample_row_16;
 228          break;
 229       default:
 230          _mesa_problem(ctx, "unexpected pixel size (%d) in blit_nearest",
 231                        pixelSize);
 232          return;
 233       }
 234
 235       if ((readRb == drawRb) ||
 236           (readAtt->Texture && drawAtt->Texture &&
 237            (readAtt->Texture == drawAtt->Texture))) {
 238          /* map whole buffer for read/write */
 239          /* XXX we could be clever and just map the union region of the
 240           * source and dest rects.
 241           */
 242          GLubyte *map;
 243          GLint rowStride;
 244          GLint formatSize = _mesa_get_format_bytes(readRb->Format);
 245
 246          ctx->Driver.MapRenderbuffer(ctx, readRb, 0, 0,
 247                                      readRb->Width, readRb->Height,
 248                                      GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
 249                                      &map, &rowStride);
 250          if (!map) {
 251             _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFramebuffer");
 252             return;
 253          }
 254
 255          srcMap = map + srcYpos * rowStride + srcXpos * formatSize;
 256          dstMap = map + dstYpos * rowStride + dstXpos * formatSize;
 257
 258          /* this handles overlapping copies */
 259          if (srcY0 < dstY0) {
 260             /* copy in reverse (top->down) order */
 261             srcMap += rowStride * (readRb->Height - 1);
 262             dstMap += rowStride * (readRb->Height - 1);
 263             srcRowStride = -rowStride;
 264             dstRowStride = -rowStride;
 265          }
 266          else {
 267             /* copy in normal (bottom->up) order */
 268             srcRowStride = rowStride;
 269             dstRowStride = rowStride;
 270          }
 271       }
 272       else {
 273          /* different src/dst buffers */
 274          ctx->Driver.MapRenderbuffer(ctx, readRb,
 275                                      srcXpos, srcYpos,
 276                                      srcWidth, srcHeight,
 277                                      GL_MAP_READ_BIT, &srcMap, &srcRowStride);
 278          if (!srcMap) {
 279             _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFramebuffer");
 280             return;
 281          }
 282          ctx->Driver.MapRenderbuffer(ctx, drawRb,
 283                                      dstXpos, dstYpos,
 284                                      dstWidth, dstHeight,
 285                                      GL_MAP_WRITE_BIT, &dstMap, &dstRowStride);
 286          if (!dstMap) {
 287             ctx->Driver.UnmapRenderbuffer(ctx, readRb);
 288             _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFramebuffer");
 289             return;
 290          }
 291       }
 292
 293       /* allocate the src/dst row buffers */
 294       srcBuffer = malloc(pixelSize * srcWidth);
 295       if (!srcBuffer) {
 296          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBufferEXT");
 297          return;
 298       }
 299       dstBuffer = malloc(pixelSize * dstWidth);
 300       if (!dstBuffer) {
 301          free(srcBuffer);
 302          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBufferEXT");
 303          return;
 304       }
 305
 306       for (dstRow = 0; dstRow < dstHeight; dstRow++) {
 307          GLfloat srcRowF = (dstRow + 0.5F) / dstHeight * srcHeight - 0.5F;
 308          GLint srcRow = IROUND(srcRowF);
 309          GLubyte *dstRowStart = dstMap + dstRowStride * dstRow;
 310
 311          ASSERT(srcRow >= 0);
 312          ASSERT(srcRow < srcHeight);
 313
 314          if (invertY) {
 315             srcRow = srcHeight - 1 - srcRow;
 316          }
 317
 318          /* get pixel row from source and resample to match dest width */
 319          if (prevY != srcRow) {
 320             GLubyte *srcRowStart = srcMap + srcRowStride * srcRow;
 321
 322             switch (mode) {
 323             case DIRECT:
 324                memcpy(srcBuffer, srcRowStart, pixelSize * srcWidth);
 325                break;
 326             case UNPACK_RGBA_FLOAT:
 327                _mesa_unpack_rgba_row(readRb->Format, srcWidth, srcRowStart,
 328                                      srcBuffer);
 329                break;
 330             case UNPACK_Z_FLOAT:
 331                _mesa_unpack_float_z_row(readRb->Format, srcWidth, srcRowStart,
 332                                         srcBuffer);
 333                break;
 334             case UNPACK_Z_INT:
 335                _mesa_unpack_uint_z_row(readRb->Format, srcWidth, srcRowStart,
 336                                        srcBuffer);
 337                break;
 338             case UNPACK_S:
 339                _mesa_unpack_ubyte_stencil_row(readRb->Format, srcWidth,
 340                                               srcRowStart, srcBuffer);
 341                break;
 342             }
 343
 344             (*resampleRow)(srcWidth, dstWidth, srcBuffer, dstBuffer, invertX);
 345             prevY = srcRow;
 346          }
 347
 348          /* store pixel row in destination */
 349          switch (mode) {
 350          case DIRECT:
 351             memcpy(dstRowStart, dstBuffer, pixelSize * dstWidth);
 352             break;
 353          case UNPACK_RGBA_FLOAT:
 354             _mesa_pack_float_rgba_row(drawRb->Format, dstWidth, dstBuffer,
 355                                       dstRowStart);
 356             break;
 357          case UNPACK_Z_FLOAT:
 358             _mesa_pack_float_z_row(drawRb->Format, dstWidth, dstBuffer,
 359                                    dstRowStart);
 360             break;
 361          case UNPACK_Z_INT:
 362             _mesa_pack_uint_z_row(drawRb->Format, dstWidth, dstBuffer,
 363                                   dstRowStart);
 364             break;
 365          case UNPACK_S:
 366             _mesa_pack_ubyte_stencil_row(drawRb->Format, dstWidth, dstBuffer,
 367                                          dstRowStart);
 368             break;
 369          }
 370       }
 371
 372       free(srcBuffer);
 373       free(dstBuffer);
 374
 375       ctx->Driver.UnmapRenderbuffer(ctx, readRb);
 376       if (drawRb != readRb) {
 377          ctx->Driver.UnmapRenderbuffer(ctx, drawRb);
 378       }
 379    }
 380 }
 381
 382
 383
 384 #define LERP(T, A, B)  ( (A) + (T) * ((B) - (A)) )
 385
 386 static inline GLfloat
 387 lerp_2d(GLfloat a, GLfloat b,
 388         GLfloat v00, GLfloat v10, GLfloat v01, GLfloat v11)
 389 {
 390    const GLfloat temp0 = LERP(a, v00, v10);
 391    const GLfloat temp1 = LERP(a, v01, v11);
 392    return LERP(b, temp0, temp1);
 393 }
 394
 395
 396 /**
 397  * Bilinear interpolation of two source rows.
 398  * GLubyte pixels.
 399  */
 400 static void
 401 resample_linear_row_ub(GLint srcWidth, GLint dstWidth,
 402                        const GLvoid *srcBuffer0, const GLvoid *srcBuffer1,
 403                        GLvoid *dstBuffer, GLboolean flip, GLfloat rowWeight)
 404 {
 405    const GLubyte (*srcColor0)[4] = (const GLubyte (*)[4]) srcBuffer0;
 406    const GLubyte (*srcColor1)[4] = (const GLubyte (*)[4]) srcBuffer1;
 407    GLubyte (*dstColor)[4] = (GLubyte (*)[4]) dstBuffer;
 408    GLint dstCol;
 409
 410    for (dstCol = 0; dstCol < dstWidth; dstCol++) {
 411       const GLfloat srcCol = (dstCol + 0.5F) / dstWidth * srcWidth - 0.5F;
 412       GLint srcCol0 = MAX2(0, IFLOOR(srcCol));
 413       GLint srcCol1 = srcCol0 + 1;
 414       GLfloat colWeight = srcCol - srcCol0; /* fractional part of srcCol */
 415       GLfloat red, green, blue, alpha;
 416
 417       ASSERT(srcCol0 < srcWidth);
 418       ASSERT(srcCol1 <= srcWidth);
 419
 420       if (srcCol1 == srcWidth) {
 421          /* last column fudge */
 422          srcCol1--;
 423          colWeight = 0.0;
 424       }
 425
 426       if (flip) {
 427          srcCol0 = srcWidth - 1 - srcCol0;
 428          srcCol1 = srcWidth - 1 - srcCol1;
 429       }
 430
 431       red = lerp_2d(colWeight, rowWeight,
 432                     srcColor0[srcCol0][RCOMP], srcColor0[srcCol1][RCOMP],
 433                     srcColor1[srcCol0][RCOMP], srcColor1[srcCol1][RCOMP]);
 434       green = lerp_2d(colWeight, rowWeight,
 435                     srcColor0[srcCol0][GCOMP], srcColor0[srcCol1][GCOMP],
 436                     srcColor1[srcCol0][GCOMP], srcColor1[srcCol1][GCOMP]);
 437       blue = lerp_2d(colWeight, rowWeight,
 438                     srcColor0[srcCol0][BCOMP], srcColor0[srcCol1][BCOMP],
 439                     srcColor1[srcCol0][BCOMP], srcColor1[srcCol1][BCOMP]);
 440       alpha = lerp_2d(colWeight, rowWeight,
 441                     srcColor0[srcCol0][ACOMP], srcColor0[srcCol1][ACOMP],
 442                     srcColor1[srcCol0][ACOMP], srcColor1[srcCol1][ACOMP]);
 443
 444       dstColor[dstCol][RCOMP] = IFLOOR(red);
 445       dstColor[dstCol][GCOMP] = IFLOOR(green);
 446       dstColor[dstCol][BCOMP] = IFLOOR(blue);
 447       dstColor[dstCol][ACOMP] = IFLOOR(alpha);
 448    }
 449 }
 450
 451
 452 /**
 453  * Bilinear interpolation of two source rows.  floating point pixels.
 454  */
 455 static void
 456 resample_linear_row_float(GLint srcWidth, GLint dstWidth,
 457                           const GLvoid *srcBuffer0, const GLvoid *srcBuffer1,
 458                           GLvoid *dstBuffer, GLboolean flip, GLfloat rowWeight)
 459 {
 460    const GLfloat (*srcColor0)[4] = (const GLfloat (*)[4]) srcBuffer0;
 461    const GLfloat (*srcColor1)[4] = (const GLfloat (*)[4]) srcBuffer1;
 462    GLfloat (*dstColor)[4] = (GLfloat (*)[4]) dstBuffer;
 463    GLint dstCol;
 464
 465    for (dstCol = 0; dstCol < dstWidth; dstCol++) {
 466       const GLfloat srcCol = (dstCol + 0.5F) / dstWidth * srcWidth - 0.5F;
 467       GLint srcCol0 = MAX2(0, IFLOOR(srcCol));
 468       GLint srcCol1 = srcCol0 + 1;
 469       GLfloat colWeight = srcCol - srcCol0; /* fractional part of srcCol */
 470       GLfloat red, green, blue, alpha;
 471
 472       ASSERT(srcCol0 < srcWidth);
 473       ASSERT(srcCol1 <= srcWidth);
 474
 475       if (srcCol1 == srcWidth) {
 476          /* last column fudge */
 477          srcCol1--;
 478          colWeight = 0.0;
 479       }
 480
 481       if (flip) {
 482          srcCol0 = srcWidth - 1 - srcCol0;
 483          srcCol1 = srcWidth - 1 - srcCol1;
 484       }
 485
 486       red = lerp_2d(colWeight, rowWeight,
 487                     srcColor0[srcCol0][RCOMP], srcColor0[srcCol1][RCOMP],
 488                     srcColor1[srcCol0][RCOMP], srcColor1[srcCol1][RCOMP]);
 489       green = lerp_2d(colWeight, rowWeight,
 490                     srcColor0[srcCol0][GCOMP], srcColor0[srcCol1][GCOMP],
 491                     srcColor1[srcCol0][GCOMP], srcColor1[srcCol1][GCOMP]);
 492       blue = lerp_2d(colWeight, rowWeight,
 493                     srcColor0[srcCol0][BCOMP], srcColor0[srcCol1][BCOMP],
 494                     srcColor1[srcCol0][BCOMP], srcColor1[srcCol1][BCOMP]);
 495       alpha = lerp_2d(colWeight, rowWeight,
 496                     srcColor0[srcCol0][ACOMP], srcColor0[srcCol1][ACOMP],
 497                     srcColor1[srcCol0][ACOMP], srcColor1[srcCol1][ACOMP]);
 498
 499       dstColor[dstCol][RCOMP] = red;
 500       dstColor[dstCol][GCOMP] = green;
 501       dstColor[dstCol][BCOMP] = blue;
 502       dstColor[dstCol][ACOMP] = alpha;
 503    }
 504 }
 505
 506
 507
 508 /**
 509  * Bilinear filtered blit (color only, non-integer values).
 510  */
 511 static void
 512 blit_linear(struct gl_context *ctx,
 513             GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
 514             GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1)
 515 {
 516    struct gl_framebuffer *drawFb = ctx->DrawBuffer;
 517    struct gl_framebuffer *readFb = ctx->ReadBuffer;
 518    struct gl_renderbuffer *readRb = readFb->_ColorReadBuffer;
 519    struct gl_renderbuffer_attachment *readAtt =
 520       &readFb->Attachment[readFb->_ColorReadBufferIndex];
 521
 522    const GLint srcWidth = ABS(srcX1 - srcX0);
 523    const GLint dstWidth = ABS(dstX1 - dstX0);
 524    const GLint srcHeight = ABS(srcY1 - srcY0);
 525    const GLint dstHeight = ABS(dstY1 - dstY0);
 526
 527    const GLint srcXpos = MIN2(srcX0, srcX1);
 528    const GLint srcYpos = MIN2(srcY0, srcY1);
 529    const GLint dstXpos = MIN2(dstX0, dstX1);
 530    const GLint dstYpos = MIN2(dstY0, dstY1);
 531
 532    const GLboolean invertX = (srcX1 < srcX0) ^ (dstX1 < dstX0);
 533    const GLboolean invertY = (srcY1 < srcY0) ^ (dstY1 < dstY0);
 534
 535    GLint dstRow;
 536
 537    GLint pixelSize;
 538    GLvoid *srcBuffer0, *srcBuffer1;
 539    GLint srcBufferY0 = -1, srcBufferY1 = -1;
 540    GLvoid *dstBuffer;
 541
 542    gl_format readFormat = _mesa_get_srgb_format_linear(readRb->Format);
 543    GLuint bpp = _mesa_get_format_bytes(readFormat);
 544
 545    GLenum pixelType;
 546
 547    GLubyte *srcMap, *dstMap;
 548    GLint srcRowStride, dstRowStride;
 549    GLuint i;
 550
 551
 552    /* Determine datatype for resampling */
 553    if (_mesa_get_format_max_bits(readFormat) == 8 &&
 554        _mesa_get_format_datatype(readFormat) == GL_UNSIGNED_NORMALIZED) {
 555       pixelType = GL_UNSIGNED_BYTE;
 556       pixelSize = 4 * sizeof(GLubyte);
 557    }
 558    else {
 559       pixelType = GL_FLOAT;
 560       pixelSize = 4 * sizeof(GLfloat);
 561    }
 562
 563    /* Allocate the src/dst row buffers.
 564     * Keep two adjacent src rows around for bilinear sampling.
 565     */
 566    srcBuffer0 = malloc(pixelSize * srcWidth);
 567    if (!srcBuffer0) {
 568       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBufferEXT");
 569       return;
 570    }
 571    srcBuffer1 = malloc(pixelSize * srcWidth);
 572    if (!srcBuffer1) {
 573       free(srcBuffer0);
 574       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBufferEXT");
 575       return;
 576    }
 577    dstBuffer = malloc(pixelSize * dstWidth);
 578    if (!dstBuffer) {
 579       free(srcBuffer0);
 580       free(srcBuffer1);
 581       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBufferEXT");
 582       return;
 583    }
 584
 585    for (i = 0; i < drawFb->_NumColorDrawBuffers; i++) {
 586       GLint idx = drawFb->_ColorDrawBufferIndexes[i];
 587       struct gl_renderbuffer_attachment *drawAtt;
 588       struct gl_renderbuffer *drawRb;
 589       gl_format drawFormat;
 590
 591       if (idx == -1)
 592          continue;
 593
 594       drawAtt = &drawFb->Attachment[idx];
 595       drawRb = drawAtt->Renderbuffer;
 596       if (!drawRb)
 597          continue;
 598
 599       drawFormat = _mesa_get_srgb_format_linear(drawRb->Format);
 600
 601       /*
 602        * Map src / dst renderbuffers
 603        */
 604       if ((readRb == drawRb) ||
 605           (readAtt->Texture && drawAtt->Texture &&
 606            (readAtt->Texture == drawAtt->Texture))) {
 607          /* map whole buffer for read/write */
 608          ctx->Driver.MapRenderbuffer(ctx, readRb,
 609                                      0, 0, readRb->Width, readRb->Height,
 610                                      GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
 611                                      &srcMap, &srcRowStride);
 612          if (!srcMap) {
 613             free(srcBuffer0);
 614             free(srcBuffer1);
 615             free(dstBuffer);
 616             _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFramebuffer");
 617             return;
 618          }
 619
 620          dstMap = srcMap;
 621          dstRowStride = srcRowStride;
 622       }
 623       else {
 624          /* different src/dst buffers */
 625          /* XXX with a bit of work we could just map the regions to be
 626           * read/written instead of the whole buffers.
 627           */
 628          ctx->Driver.MapRenderbuffer(ctx, readRb,
 629                                      0, 0, readRb->Width, readRb->Height,
 630                                      GL_MAP_READ_BIT, &srcMap, &srcRowStride);
 631          if (!srcMap) {
 632             free(srcBuffer0);
 633             free(srcBuffer1);
 634             free(dstBuffer);
 635             _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFramebuffer");
 636             return;
 637          }
 638          ctx->Driver.MapRenderbuffer(ctx, drawRb,
 639                                      0, 0, drawRb->Width, drawRb->Height,
 640                                      GL_MAP_WRITE_BIT, &dstMap, &dstRowStride);
 641          if (!dstMap) {
 642             ctx->Driver.UnmapRenderbuffer(ctx, readRb);
 643             free(srcBuffer0);
 644             free(srcBuffer1);
 645             free(dstBuffer);
 646             _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFramebuffer");
 647             return;
 648          }
 649       }
 650
 651       for (dstRow = 0; dstRow < dstHeight; dstRow++) {
 652          const GLint dstY = dstYpos + dstRow;
 653          GLfloat srcRow = (dstRow + 0.5F) / dstHeight * srcHeight - 0.5F;
 654          GLint srcRow0 = MAX2(0, IFLOOR(srcRow));
 655          GLint srcRow1 = srcRow0 + 1;
 656          GLfloat rowWeight = srcRow - srcRow0; /* fractional part of srcRow */
 657
 658          if (srcRow1 == srcHeight) {
 659             /* last row fudge */
 660             srcRow1 = srcRow0;
 661             rowWeight = 0.0;
 662          }
 663
 664          if (invertY) {
 665             srcRow0 = srcHeight - 1 - srcRow0;
 666             srcRow1 = srcHeight - 1 - srcRow1;
 667          }
 668
 669          srcY0 = srcYpos + srcRow0;
 670          srcY1 = srcYpos + srcRow1;
 671
 672          /* get the two source rows */
 673          if (srcY0 == srcBufferY0 && srcY1 == srcBufferY1) {
 674             /* use same source row buffers again */
 675          }
 676          else if (srcY0 == srcBufferY1) {
 677             /* move buffer1 into buffer0 by swapping pointers */
 678             GLvoid *tmp = srcBuffer0;
 679             srcBuffer0 = srcBuffer1;
 680             srcBuffer1 = tmp;
 681             /* get y1 row */
 682             {
 683                GLubyte *src = srcMap + srcY1 * srcRowStride + srcXpos * bpp;
 684                if (pixelType == GL_UNSIGNED_BYTE) {
 685                   _mesa_unpack_ubyte_rgba_row(readFormat, srcWidth,
 686                                               src, srcBuffer1);
 687                }
 688                else {
 689                   _mesa_unpack_rgba_row(readFormat, srcWidth,
 690                                         src, srcBuffer1);
 691                }
 692             }
 693             srcBufferY0 = srcY0;
 694             srcBufferY1 = srcY1;
 695          }
 696          else {
 697             /* get both new rows */
 698             {
 699                GLubyte *src0 = srcMap + srcY0 * srcRowStride + srcXpos * bpp;
 700                GLubyte *src1 = srcMap + srcY1 * srcRowStride + srcXpos * bpp;
 701                if (pixelType == GL_UNSIGNED_BYTE) {
 702                   _mesa_unpack_ubyte_rgba_row(readFormat, srcWidth,
 703                                               src0, srcBuffer0);
 704                   _mesa_unpack_ubyte_rgba_row(readFormat, srcWidth,
 705                                               src1, srcBuffer1);
 706                }
 707                else {
 708                   _mesa_unpack_rgba_row(readFormat, srcWidth, src0, srcBuffer0);
 709                   _mesa_unpack_rgba_row(readFormat, srcWidth, src1, srcBuffer1);
 710                }
 711             }
 712             srcBufferY0 = srcY0;
 713             srcBufferY1 = srcY1;
 714          }
 715
 716          if (pixelType == GL_UNSIGNED_BYTE) {
 717             resample_linear_row_ub(srcWidth, dstWidth, srcBuffer0, srcBuffer1,
 718                                    dstBuffer, invertX, rowWeight);
 719          }
 720          else {
 721             resample_linear_row_float(srcWidth, dstWidth, srcBuffer0, srcBuffer1,
 722                                       dstBuffer, invertX, rowWeight);
 723          }
 724
 725          /* store pixel row in destination */
 726          {
 727             GLubyte *dst = dstMap + dstY * dstRowStride + dstXpos * bpp;
 728             if (pixelType == GL_UNSIGNED_BYTE) {
 729                _mesa_pack_ubyte_rgba_row(drawFormat, dstWidth, dstBuffer, dst);
 730             }
 731             else {
 732                _mesa_pack_float_rgba_row(drawFormat, dstWidth, dstBuffer, dst);
 733             }
 734          }
 735       }
 736
 737       free(srcBuffer0);
 738       free(srcBuffer1);
 739       free(dstBuffer);
 740
 741       ctx->Driver.UnmapRenderbuffer(ctx, readRb);
 742       if (drawRb != readRb) {
 743          ctx->Driver.UnmapRenderbuffer(ctx, drawRb);
 744       }
 745    }
 746 }
 747
 748
 749
 750 /**
 751  * Software fallback for glBlitFramebufferEXT().
 752  */
 753 void
 754 _swrast_BlitFramebuffer(struct gl_context *ctx,
 755                         GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
 756                         GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
 757                         GLbitfield mask, GLenum filter)
 758 {
 759    static const GLbitfield buffers[3] = {
 760       GL_COLOR_BUFFER_BIT,
 761       GL_DEPTH_BUFFER_BIT,
 762       GL_STENCIL_BUFFER_BIT
 763    };
 764    static const GLenum buffer_enums[3] = {
 765       GL_COLOR,
 766       GL_DEPTH,
 767       GL_STENCIL,
 768    };
 769    GLint i;
 770
 771    if (!_mesa_clip_blit(ctx, &srcX0, &srcY0, &srcX1, &srcY1,
 772                         &dstX0, &dstY0, &dstX1, &dstY1)) {
 773       return;
 774    }
 775
 776    if (SWRAST_CONTEXT(ctx)->NewState)
 777       _swrast_validate_derived(ctx);
 778
 779    /* First, try covering whatever buffers possible using the fast 1:1 copy
 780     * path.
 781     */
 782    if (srcX1 - srcX0 == dstX1 - dstX0 &&
 783        srcY1 - srcY0 == dstY1 - dstY0 &&
 784        srcX0 < srcX1 &&
 785        srcY0 < srcY1 &&
 786        dstX0 < dstX1 &&
 787        dstY0 < dstY1) {
 788       for (i = 0; i < 3; i++) {
 789          if (mask & buffers[i]) {
 790             if (swrast_fast_copy_pixels(ctx,
 791                                         srcX0, srcY0,
 792                                         srcX1 - srcX0, srcY1 - srcY0,
 793                                         dstX0, dstY0,
 794                                         buffer_enums[i])) {
 795                mask &= ~buffers[i];
 796             }
 797          }
 798       }
 799
 800       if (!mask)
 801          return;
 802    }
 803
 804    if (filter == GL_NEAREST) {
 805       for (i = 0; i < 3; i++) {
 806          if (mask & buffers[i]) {
 807             blit_nearest(ctx,  srcX0, srcY0, srcX1, srcY1,
 808                          dstX0, dstY0, dstX1, dstY1, buffers[i]);
 809          }
 810       }
 811    }
 812    else {
 813       ASSERT(filter == GL_LINEAR);
 814       if (mask & GL_COLOR_BUFFER_BIT) {  /* depth/stencil not allowed */
 815          blit_linear(ctx,  srcX0, srcY0, srcX1, srcY1,
 816                      dstX0, dstY0, dstX1, dstY1);
 817       }
 818    }
 819
 820 }