src/mesa/swrast/s_drawpix.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2007  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/bufferobj.h"
  28 #include "main/condrender.h"
  29 #include "main/context.h"
  30 #include "main/image.h"
  31 #include "main/imports.h"
  32 #include "main/macros.h"
  33 #include "main/pack.h"
  34 #include "main/pbo.h"
  35 #include "main/pixeltransfer.h"
  36 #include "main/state.h"
  37
  38 #include "s_context.h"
  39 #include "s_span.h"
  40 #include "s_stencil.h"
  41 #include "s_zoom.h"
  42
  43
  44
  45 /**
  46  * Try to do a fast and simple RGB(a) glDrawPixels.
  47  * Return:  GL_TRUE if success, GL_FALSE if slow path must be used instead
  48  */
  49 static GLboolean
  50 fast_draw_rgba_pixels(struct gl_context *ctx, GLint x, GLint y,
  51                       GLsizei width, GLsizei height,
  52                       GLenum format, GLenum type,
  53                       const struct gl_pixelstore_attrib *userUnpack,
  54                       const GLvoid *pixels)
  55 {
  56    const GLint imgX = x, imgY = y;
  57    struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];
  58    GLenum rbType;
  59    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  60    SWspan span;
  61    GLboolean simpleZoom;
  62    GLint yStep;  /* +1 or -1 */
  63    struct gl_pixelstore_attrib unpack;
  64    GLint destX, destY, drawWidth, drawHeight; /* post clipping */
  65
  66    if (!rb)
  67       return GL_TRUE; /* no-op */
  68
  69    rbType = rb->DataType;
  70
  71    if ((swrast->_RasterMask & ~CLIP_BIT) ||
  72        ctx->Texture._EnabledCoordUnits ||
  73        userUnpack->SwapBytes ||
  74        ctx->_ImageTransferState) {
  75       /* can't handle any of those conditions */
  76       return GL_FALSE;
  77    }
  78
  79    INIT_SPAN(span, GL_BITMAP);
  80    span.arrayMask = SPAN_RGBA;
  81    span.arrayAttribs = FRAG_BIT_COL0;
  82    _swrast_span_default_attribs(ctx, &span);
  83
  84    /* copy input params since clipping may change them */
  85    unpack = *userUnpack;
  86    destX = x;
  87    destY = y;
  88    drawWidth = width;
  89    drawHeight = height;
  90
  91    /* check for simple zooming and clipping */
  92    if (ctx->Pixel.ZoomX == 1.0F &&
  93        (ctx->Pixel.ZoomY == 1.0F || ctx->Pixel.ZoomY == -1.0F)) {
  94       if (!_mesa_clip_drawpixels(ctx, &destX, &destY,
  95                                  &drawWidth, &drawHeight, &unpack)) {
  96          /* image was completely clipped: no-op, all done */
  97          return GL_TRUE;
  98       }
  99       simpleZoom = GL_TRUE;
 100       yStep = (GLint) ctx->Pixel.ZoomY;
 101       ASSERT(yStep == 1 || yStep == -1);
 102    }
 103    else {
 104       /* non-simple zooming */
 105       simpleZoom = GL_FALSE;
 106       yStep = 1;
 107       if (unpack.RowLength == 0)
 108          unpack.RowLength = width;
 109    }
 110
 111    /*
 112     * Ready to draw!
 113     */
 114
 115    if (format == GL_RGBA && type == rbType) {
 116       const GLubyte *src
 117          = (const GLubyte *) _mesa_image_address2d(&unpack, pixels, width,
 118                                                    height, format, type, 0, 0);
 119       const GLint srcStride = _mesa_image_row_stride(&unpack, width,
 120                                                      format, type);
 121       if (simpleZoom) {
 122          GLint row;
 123          for (row = 0; row < drawHeight; row++) {
 124             rb->PutRow(ctx, rb, drawWidth, destX, destY, src, NULL);
 125             src += srcStride;
 126             destY += yStep;
 127          }
 128       }
 129       else {
 130          /* with zooming */
 131          GLint row;
 132          for (row = 0; row < drawHeight; row++) {
 133             span.x = destX;
 134             span.y = destY + row;
 135             span.end = drawWidth;
 136             span.array->ChanType = rbType;
 137             _swrast_write_zoomed_rgba_span(ctx, imgX, imgY, &span, src);
 138             src += srcStride;
 139          }
 140          span.array->ChanType = CHAN_TYPE;
 141       }
 142       return GL_TRUE;
 143    }
 144
 145    if (format == GL_RGB && type == rbType) {
 146       const GLubyte *src
 147          = (const GLubyte *) _mesa_image_address2d(&unpack, pixels, width,
 148                                                    height, format, type, 0, 0);
 149       const GLint srcStride = _mesa_image_row_stride(&unpack, width,
 150                                                      format, type);
 151       if (simpleZoom) {
 152          GLint row;
 153          for (row = 0; row < drawHeight; row++) {
 154             rb->PutRowRGB(ctx, rb, drawWidth, destX, destY, src, NULL);
 155             src += srcStride;
 156             destY += yStep;
 157          }
 158       }
 159       else {
 160          /* with zooming */
 161          GLint row;
 162          for (row = 0; row < drawHeight; row++) {
 163             span.x = destX;
 164             span.y = destY;
 165             span.end = drawWidth;
 166             span.array->ChanType = rbType;
 167             _swrast_write_zoomed_rgb_span(ctx, imgX, imgY, &span, src);
 168             src += srcStride;
 169             destY++;
 170          }
 171          span.array->ChanType = CHAN_TYPE;
 172       }
 173       return GL_TRUE;
 174    }
 175
 176    /* Remaining cases haven't been tested with alignment != 1 */
 177    if (userUnpack->Alignment != 1)
 178       return GL_FALSE;
 179
 180    if (format == GL_LUMINANCE && type == CHAN_TYPE && rbType == CHAN_TYPE) {
 181       const GLchan *src = (const GLchan *) pixels
 182          + (unpack.SkipRows * unpack.RowLength + unpack.SkipPixels);
 183       if (simpleZoom) {
 184          /* no zooming */
 185          GLint row;
 186          ASSERT(drawWidth <= MAX_WIDTH);
 187          for (row = 0; row < drawHeight; row++) {
 188             GLchan rgb[MAX_WIDTH][3];
 189             GLint i;
 190             for (i = 0;i<drawWidth;i++) {
 191                rgb[i][0] = src[i];
 192                rgb[i][1] = src[i];
 193                rgb[i][2] = src[i];
 194             }
 195             rb->PutRowRGB(ctx, rb, drawWidth, destX, destY, rgb, NULL);
 196             src += unpack.RowLength;
 197             destY += yStep;
 198          }
 199       }
 200       else {
 201          /* with zooming */
 202          GLint row;
 203          ASSERT(drawWidth <= MAX_WIDTH);
 204          for (row = 0; row < drawHeight; row++) {
 205             GLchan rgb[MAX_WIDTH][3];
 206             GLint i;
 207             for (i = 0;i<drawWidth;i++) {
 208                rgb[i][0] = src[i];
 209                rgb[i][1] = src[i];
 210                rgb[i][2] = src[i];
 211             }
 212             span.x = destX;
 213             span.y = destY;
 214             span.end = drawWidth;
 215             _swrast_write_zoomed_rgb_span(ctx, imgX, imgY, &span, rgb);
 216             src += unpack.RowLength;
 217             destY++;
 218          }
 219       }
 220       return GL_TRUE;
 221    }
 222
 223    if (format == GL_LUMINANCE_ALPHA && type == CHAN_TYPE && rbType == CHAN_TYPE) {
 224       const GLchan *src = (const GLchan *) pixels
 225          + (unpack.SkipRows * unpack.RowLength + unpack.SkipPixels)*2;
 226       if (simpleZoom) {
 227          GLint row;
 228          ASSERT(drawWidth <= MAX_WIDTH);
 229          for (row = 0; row < drawHeight; row++) {
 230             GLint i;
 231             const GLchan *ptr = src;
 232             for (i = 0;i<drawWidth;i++) {
 233                span.array->rgba[i][0] = *ptr;
 234                span.array->rgba[i][1] = *ptr;
 235                span.array->rgba[i][2] = *ptr++;
 236                span.array->rgba[i][3] = *ptr++;
 237             }
 238             rb->PutRow(ctx, rb, drawWidth, destX, destY,
 239                        span.array->rgba, NULL);
 240             src += unpack.RowLength*2;
 241             destY += yStep;
 242          }
 243       }
 244       else {
 245          /* with zooming */
 246          GLint row;
 247          ASSERT(drawWidth <= MAX_WIDTH);
 248          for (row = 0; row < drawHeight; row++) {
 249             const GLchan *ptr = src;
 250             GLint i;
 251             for (i = 0;i<drawWidth;i++) {
 252                span.array->rgba[i][0] = *ptr;
 253                span.array->rgba[i][1] = *ptr;
 254                span.array->rgba[i][2] = *ptr++;
 255                span.array->rgba[i][3] = *ptr++;
 256             }
 257             span.x = destX;
 258             span.y = destY;
 259             span.end = drawWidth;
 260             _swrast_write_zoomed_rgba_span(ctx, imgX, imgY, &span,
 261                                            span.array->rgba);
 262             src += unpack.RowLength*2;
 263             destY++;
 264          }
 265       }
 266       return GL_TRUE;
 267    }
 268
 269    if (format == GL_COLOR_INDEX && type == GL_UNSIGNED_BYTE) {
 270       const GLubyte *src = (const GLubyte *) pixels
 271          + unpack.SkipRows * unpack.RowLength + unpack.SkipPixels;
 272       if (rbType == GL_UNSIGNED_BYTE) {
 273          /* convert ubyte/CI data to ubyte/RGBA */
 274          if (simpleZoom) {
 275             GLint row;
 276             for (row = 0; row < drawHeight; row++) {
 277                ASSERT(drawWidth <= MAX_WIDTH);
 278                _mesa_map_ci8_to_rgba8(ctx, drawWidth, src,
 279                                       span.array->rgba8);
 280                rb->PutRow(ctx, rb, drawWidth, destX, destY,
 281                           span.array->rgba8, NULL);
 282                src += unpack.RowLength;
 283                destY += yStep;
 284             }
 285          }
 286          else {
 287             /* ubyte/CI to ubyte/RGBA with zooming */
 288             GLint row;
 289             for (row = 0; row < drawHeight; row++) {
 290                ASSERT(drawWidth <= MAX_WIDTH);
 291                _mesa_map_ci8_to_rgba8(ctx, drawWidth, src,
 292                                       span.array->rgba8);
 293                span.x = destX;
 294                span.y = destY;
 295                span.end = drawWidth;
 296                _swrast_write_zoomed_rgba_span(ctx, imgX, imgY, &span,
 297                                               span.array->rgba8);
 298                src += unpack.RowLength;
 299                destY++;
 300             }
 301          }
 302          return GL_TRUE;
 303       }
 304    }
 305
 306    /* can't handle this pixel format and/or data type */
 307    return GL_FALSE;
 308 }
 309
 310
 311
 312 /*
 313  * Draw stencil image.
 314  */
 315 static void
 316 draw_stencil_pixels( struct gl_context *ctx, GLint x, GLint y,
 317                      GLsizei width, GLsizei height,
 318                      GLenum type,
 319                      const struct gl_pixelstore_attrib *unpack,
 320                      const GLvoid *pixels )
 321 {
 322    const GLboolean zoom = ctx->Pixel.ZoomX != 1.0 || ctx->Pixel.ZoomY != 1.0;
 323    const GLenum destType = GL_UNSIGNED_BYTE;
 324    GLint skipPixels;
 325
 326    /* if width > MAX_WIDTH, have to process image in chunks */
 327    skipPixels = 0;
 328    while (skipPixels < width) {
 329       const GLint spanX = x + skipPixels;
 330       const GLint spanWidth = MIN2(width - skipPixels, MAX_WIDTH);
 331       GLint row;
 332       for (row = 0; row < height; row++) {
 333          const GLint spanY = y + row;
 334          GLubyte values[MAX_WIDTH];
 335          const GLvoid *source = _mesa_image_address2d(unpack, pixels,
 336                                                       width, height,
 337                                                       GL_STENCIL_INDEX, type,
 338                                                       row, skipPixels);
 339          _mesa_unpack_stencil_span(ctx, spanWidth, destType, values,
 340                                    type, source, unpack,
 341                                    ctx->_ImageTransferState);
 342          if (zoom) {
 343             _swrast_write_zoomed_stencil_span(ctx, x, y, spanWidth,
 344                                               spanX, spanY, values);
 345          }
 346          else {
 347             _swrast_write_stencil_span(ctx, spanWidth, spanX, spanY, values);
 348          }
 349       }
 350       skipPixels += spanWidth;
 351    }
 352 }
 353
 354
 355 /*
 356  * Draw depth image.
 357  */
 358 static void
 359 draw_depth_pixels( struct gl_context *ctx, GLint x, GLint y,
 360                    GLsizei width, GLsizei height,
 361                    GLenum type,
 362                    const struct gl_pixelstore_attrib *unpack,
 363                    const GLvoid *pixels )
 364 {
 365    const GLboolean scaleOrBias
 366       = ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
 367    const GLboolean zoom = ctx->Pixel.ZoomX != 1.0 || ctx->Pixel.ZoomY != 1.0;
 368    SWspan span;
 369
 370    INIT_SPAN(span, GL_BITMAP);
 371    span.arrayMask = SPAN_Z;
 372    _swrast_span_default_attribs(ctx, &span);
 373
 374    if (type == GL_UNSIGNED_SHORT
 375        && ctx->DrawBuffer->Visual.depthBits == 16
 376        && !scaleOrBias
 377        && !zoom
 378        && width <= MAX_WIDTH
 379        && !unpack->SwapBytes) {
 380       /* Special case: directly write 16-bit depth values */
 381       GLint row;
 382       for (row = 0; row < height; row++) {
 383          const GLushort *zSrc = (const GLushort *)
 384             _mesa_image_address2d(unpack, pixels, width, height,
 385                                   GL_DEPTH_COMPONENT, type, row, 0);
 386          GLint i;
 387          for (i = 0; i < width; i++)
 388             span.array->z[i] = zSrc[i];
 389          span.x = x;
 390          span.y = y + row;
 391          span.end = width;
 392          _swrast_write_rgba_span(ctx, &span);
 393       }
 394    }
 395    else if (type == GL_UNSIGNED_INT
 396             && !scaleOrBias
 397             && !zoom
 398             && width <= MAX_WIDTH
 399             && !unpack->SwapBytes) {
 400       /* Special case: shift 32-bit values down to Visual.depthBits */
 401       const GLint shift = 32 - ctx->DrawBuffer->Visual.depthBits;
 402       GLint row;
 403       for (row = 0; row < height; row++) {
 404          const GLuint *zSrc = (const GLuint *)
 405             _mesa_image_address2d(unpack, pixels, width, height,
 406                                   GL_DEPTH_COMPONENT, type, row, 0);
 407          if (shift == 0) {
 408             memcpy(span.array->z, zSrc, width * sizeof(GLuint));
 409          }
 410          else {
 411             GLint col;
 412             for (col = 0; col < width; col++)
 413                span.array->z[col] = zSrc[col] >> shift;
 414          }
 415          span.x = x;
 416          span.y = y + row;
 417          span.end = width;
 418          _swrast_write_rgba_span(ctx, &span);
 419       }
 420    }
 421    else {
 422       /* General case */
 423       const GLuint depthMax = ctx->DrawBuffer->_DepthMax;
 424       GLint skipPixels = 0;
 425
 426       /* in case width > MAX_WIDTH do the copy in chunks */
 427       while (skipPixels < width) {
 428          const GLint spanWidth = MIN2(width - skipPixels, MAX_WIDTH);
 429          GLint row;
 430          ASSERT(span.end <= MAX_WIDTH);
 431          for (row = 0; row < height; row++) {
 432             const GLvoid *zSrc = _mesa_image_address2d(unpack,
 433                                                       pixels, width, height,
 434                                                       GL_DEPTH_COMPONENT, type,
 435                                                       row, skipPixels);
 436
 437             /* Set these for each row since the _swrast_write_* function may
 438              * change them while clipping.
 439              */
 440             span.x = x + skipPixels;
 441             span.y = y + row;
 442             span.end = spanWidth;
 443
 444             _mesa_unpack_depth_span(ctx, spanWidth,
 445                                     GL_UNSIGNED_INT, span.array->z, depthMax,
 446                                     type, zSrc, unpack);
 447             if (zoom) {
 448                _swrast_write_zoomed_depth_span(ctx, x, y, &span);
 449             }
 450             else {
 451                _swrast_write_rgba_span(ctx, &span);
 452             }
 453          }
 454          skipPixels += spanWidth;
 455       }
 456    }
 457 }
 458
 459
 460
 461 /**
 462  * Draw RGBA image.
 463  */
 464 static void
 465 draw_rgba_pixels( struct gl_context *ctx, GLint x, GLint y,
 466                   GLsizei width, GLsizei height,
 467                   GLenum format, GLenum type,
 468                   const struct gl_pixelstore_attrib *unpack,
 469                   const GLvoid *pixels )
 470 {
 471    const GLint imgX = x, imgY = y;
 472    const GLboolean zoom = ctx->Pixel.ZoomX!=1.0 || ctx->Pixel.ZoomY!=1.0;
 473    GLfloat *convImage = NULL;
 474    GLbitfield transferOps = ctx->_ImageTransferState;
 475    SWspan span;
 476
 477    /* Try an optimized glDrawPixels first */
 478    if (fast_draw_rgba_pixels(ctx, x, y, width, height, format, type,
 479                              unpack, pixels)) {
 480       return;
 481    }
 482
 483    INIT_SPAN(span, GL_BITMAP);
 484    _swrast_span_default_attribs(ctx, &span);
 485    span.arrayMask = SPAN_RGBA;
 486    span.arrayAttribs = FRAG_BIT_COL0; /* we're fill in COL0 attrib values */
 487
 488    if (ctx->DrawBuffer->_NumColorDrawBuffers > 0 &&
 489        ctx->DrawBuffer->_ColorDrawBuffers[0]->DataType != GL_FLOAT &&
 490        ctx->Color.ClampFragmentColor != GL_FALSE) {
 491       /* need to clamp colors before applying fragment ops */
 492       transferOps |= IMAGE_CLAMP_BIT;
 493    }
 494
 495    /*
 496     * General solution
 497     */
 498    {
 499       const GLbitfield interpMask = span.interpMask;
 500       const GLbitfield arrayMask = span.arrayMask;
 501       const GLint srcStride
 502          = _mesa_image_row_stride(unpack, width, format, type);
 503       GLint skipPixels = 0;
 504       /* use span array for temp color storage */
 505       GLfloat *rgba = (GLfloat *) span.array->attribs[FRAG_ATTRIB_COL0];
 506
 507       /* if the span is wider than MAX_WIDTH we have to do it in chunks */
 508       while (skipPixels < width) {
 509          const GLint spanWidth = MIN2(width - skipPixels, MAX_WIDTH);
 510          const GLubyte *source
 511             = (const GLubyte *) _mesa_image_address2d(unpack, pixels,
 512                                                       width, height, format,
 513                                                       type, 0, skipPixels);
 514          GLint row;
 515
 516          for (row = 0; row < height; row++) {
 517             /* get image row as float/RGBA */
 518             _mesa_unpack_color_span_float(ctx, spanWidth, GL_RGBA, rgba,
 519                                      format, type, source, unpack,
 520                                      transferOps);
 521             /* Set these for each row since the _swrast_write_* functions
 522              * may change them while clipping/rendering.
 523              */
 524             span.array->ChanType = GL_FLOAT;
 525             span.x = x + skipPixels;
 526             span.y = y + row;
 527             span.end = spanWidth;
 528             span.arrayMask = arrayMask;
 529             span.interpMask = interpMask;
 530             if (zoom) {
 531                _swrast_write_zoomed_rgba_span(ctx, imgX, imgY, &span, rgba);
 532             }
 533             else {
 534                _swrast_write_rgba_span(ctx, &span);
 535             }
 536
 537             source += srcStride;
 538          } /* for row */
 539
 540          skipPixels += spanWidth;
 541       } /* while skipPixels < width */
 542
 543       /* XXX this is ugly/temporary, to undo above change */
 544       span.array->ChanType = CHAN_TYPE;
 545    }
 546
 547    if (convImage) {
 548       free(convImage);
 549    }
 550 }
 551
 552
 553 /**
 554  * This is a bit different from drawing GL_DEPTH_COMPONENT pixels.
 555  * The only per-pixel operations that apply are depth scale/bias,
 556  * stencil offset/shift, GL_DEPTH_WRITEMASK and GL_STENCIL_WRITEMASK,
 557  * and pixel zoom.
 558  * Also, only the depth buffer and stencil buffers are touched, not the
 559  * color buffer(s).
 560  */
 561 static void
 562 draw_depth_stencil_pixels(struct gl_context *ctx, GLint x, GLint y,
 563                           GLsizei width, GLsizei height, GLenum type,
 564                           const struct gl_pixelstore_attrib *unpack,
 565                           const GLvoid *pixels)
 566 {
 567    const GLint imgX = x, imgY = y;
 568    const GLboolean scaleOrBias
 569       = ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
 570    const GLuint depthMax = ctx->DrawBuffer->_DepthMax;
 571    const GLuint stencilMask = ctx->Stencil.WriteMask[0];
 572    const GLenum stencilType = GL_UNSIGNED_BYTE;
 573    const GLboolean zoom = ctx->Pixel.ZoomX != 1.0 || ctx->Pixel.ZoomY != 1.0;
 574    struct gl_renderbuffer *depthRb, *stencilRb;
 575    struct gl_pixelstore_attrib clippedUnpack = *unpack;
 576
 577    if (!zoom) {
 578       if (!_mesa_clip_drawpixels(ctx, &x, &y, &width, &height,
 579                                  &clippedUnpack)) {
 580          /* totally clipped */
 581          return;
 582       }
 583    }
 584
 585    depthRb = ctx->ReadBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
 586    stencilRb = ctx->ReadBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
 587    ASSERT(depthRb);
 588    ASSERT(stencilRb);
 589
 590    if (depthRb->_BaseFormat == GL_DEPTH_STENCIL_EXT &&
 591        depthRb->Format == MESA_FORMAT_Z24_S8 &&
 592        type == GL_UNSIGNED_INT_24_8 &&
 593        depthRb == stencilRb &&
 594        depthRb->GetRow &&  /* May be null if depthRb is a wrapper around
 595                             * separate depth and stencil buffers. */
 596        !scaleOrBias &&
 597        !zoom &&
 598        ctx->Depth.Mask &&
 599        (stencilMask & 0xff) == 0xff) {
 600       /* This is the ideal case.
 601        * Drawing GL_DEPTH_STENCIL pixels into a combined depth/stencil buffer.
 602        * Plus, no pixel transfer ops, zooming, or masking needed.
 603        */
 604       GLint i;
 605       for (i = 0; i < height; i++) {
 606          const GLuint *src = (const GLuint *)
 607             _mesa_image_address2d(&clippedUnpack, pixels, width, height,
 608                                   GL_DEPTH_STENCIL_EXT, type, i, 0);
 609          depthRb->PutRow(ctx, depthRb, width, x, y + i, src, NULL);
 610       }
 611    }
 612    else {
 613       /* sub-optimal cases:
 614        * Separate depth/stencil buffers, or pixel transfer ops required.
 615        */
 616       /* XXX need to handle very wide images (skippixels) */
 617       GLint i;
 618
 619       depthRb = ctx->DrawBuffer->_DepthBuffer;
 620
 621       for (i = 0; i < height; i++) {
 622          const GLuint *depthStencilSrc = (const GLuint *)
 623             _mesa_image_address2d(&clippedUnpack, pixels, width, height,
 624                                   GL_DEPTH_STENCIL_EXT, type, i, 0);
 625
 626          if (ctx->Depth.Mask) {
 627             if (!scaleOrBias && ctx->DrawBuffer->Visual.depthBits == 24 &&
 628                 type == GL_UNSIGNED_INT_24_8) {
 629                /* fast path 24-bit zbuffer */
 630                GLuint zValues[MAX_WIDTH];
 631                GLint j;
 632                ASSERT(depthRb->DataType == GL_UNSIGNED_INT);
 633                for (j = 0; j < width; j++) {
 634                   zValues[j] = depthStencilSrc[j] >> 8;
 635                }
 636                if (zoom)
 637                   _swrast_write_zoomed_z_span(ctx, imgX, imgY, width,
 638                                               x, y + i, zValues);
 639                else
 640                   depthRb->PutRow(ctx, depthRb, width, x, y + i, zValues,NULL);
 641             }
 642             else if (!scaleOrBias && ctx->DrawBuffer->Visual.depthBits == 16 &&
 643                      type == GL_UNSIGNED_INT_24_8) {
 644                /* fast path 16-bit zbuffer */
 645                GLushort zValues[MAX_WIDTH];
 646                GLint j;
 647                ASSERT(depthRb->DataType == GL_UNSIGNED_SHORT);
 648                for (j = 0; j < width; j++) {
 649                   zValues[j] = depthStencilSrc[j] >> 16;
 650                }
 651                if (zoom)
 652                   _swrast_write_zoomed_z_span(ctx, imgX, imgY, width,
 653                                               x, y + i, zValues);
 654                else
 655                   depthRb->PutRow(ctx, depthRb, width, x, y + i, zValues,NULL);
 656             }
 657             else {
 658                /* general case */
 659                GLuint zValues[MAX_WIDTH];  /* 16 or 32-bit Z value storage */
 660                _mesa_unpack_depth_span(ctx, width,
 661                                        depthRb->DataType, zValues, depthMax,
 662                                        type, depthStencilSrc, &clippedUnpack);
 663                if (zoom) {
 664                   _swrast_write_zoomed_z_span(ctx, imgX, imgY, width, x,
 665                                               y + i, zValues);
 666                }
 667                else {
 668                   depthRb->PutRow(ctx, depthRb, width, x, y + i, zValues,NULL);
 669                }
 670             }
 671          }
 672
 673          if (stencilMask != 0x0) {
 674             GLubyte stencilValues[MAX_WIDTH];
 675             /* get stencil values, with shift/offset/mapping */
 676             _mesa_unpack_stencil_span(ctx, width, stencilType, stencilValues,
 677                                       type, depthStencilSrc, &clippedUnpack,
 678                                       ctx->_ImageTransferState);
 679             if (zoom)
 680                _swrast_write_zoomed_stencil_span(ctx, imgX, imgY, width,
 681                                                   x, y + i, stencilValues);
 682             else
 683                _swrast_write_stencil_span(ctx, width, x, y + i, stencilValues);
 684          }
 685       }
 686    }
 687 }
 688
 689
 690 /**
 691  * Execute software-based glDrawPixels.
 692  * By time we get here, all error checking will have been done.
 693  */
 694 void
 695 _swrast_DrawPixels( struct gl_context *ctx,
 696                     GLint x, GLint y,
 697                     GLsizei width, GLsizei height,
 698                     GLenum format, GLenum type,
 699                     const struct gl_pixelstore_attrib *unpack,
 700                     const GLvoid *pixels )
 701 {
 702    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 703    GLboolean save_vp_override = ctx->VertexProgram._Overriden;
 704
 705    if (!_mesa_check_conditional_render(ctx))
 706       return; /* don't draw */
 707
 708    /* We are creating fragments directly, without going through vertex
 709     * programs.
 710     *
 711     * This override flag tells the fragment processing code that its input
 712     * comes from a non-standard source, and it may therefore not rely on
 713     * optimizations that assume e.g. constant color if there is no color
 714     * vertex array.
 715     */
 716    _mesa_set_vp_override(ctx, GL_TRUE);
 717
 718    swrast_render_start(ctx);
 719
 720    if (ctx->NewState)
 721       _mesa_update_state(ctx);
 722
 723    if (swrast->NewState)
 724       _swrast_validate_derived( ctx );
 725
 726    pixels = _mesa_map_pbo_source(ctx, unpack, pixels);
 727    if (!pixels) {
 728       swrast_render_finish(ctx);
 729       _mesa_set_vp_override(ctx, save_vp_override);
 730       return;
 731    }
 732
 733    /*
 734     * By time we get here, all error checking should have been done.
 735     */
 736    switch (format) {
 737    case GL_STENCIL_INDEX:
 738       draw_stencil_pixels( ctx, x, y, width, height, type, unpack, pixels );
 739       break;
 740    case GL_DEPTH_COMPONENT:
 741       draw_depth_pixels( ctx, x, y, width, height, type, unpack, pixels );
 742       break;
 743    case GL_DEPTH_STENCIL_EXT:
 744       draw_depth_stencil_pixels(ctx, x, y, width, height, type, unpack, pixels);
 745       break;
 746    default:
 747       /* all other formats should be color formats */
 748       draw_rgba_pixels(ctx, x, y, width, height, format, type, unpack, pixels);
 749    }
 750
 751    swrast_render_finish(ctx);
 752    _mesa_set_vp_override(ctx, save_vp_override);
 753
 754    _mesa_unmap_pbo_source(ctx, unpack);
 755 }