src/mesa/main/drawpix.c

   1 /* $Id: drawpix.c,v 1.4 1999/10/19 20:33:57 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.1
   6  *
   7  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28
  29
  30
  31 #ifdef PC_HEADER
  32 #include "all.h"
  33 #else
  34 #ifndef XFree86Server
  35 #include <assert.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #else
  39 #include "GL/xf86glx.h"
  40 #endif
  41 #include "context.h"
  42 #include "drawpix.h"
  43 #include "feedback.h"
  44 #include "image.h"
  45 #include "macros.h"
  46 #include "mmath.h"
  47 #include "pixel.h"
  48 #include "span.h"
  49 #include "stencil.h"
  50 #include "types.h"
  51 #include "zoom.h"
  52 #ifdef XFree86Server
  53 #include "GL/xf86glx.h"
  54 #endif
  55 #endif
  56
  57
  58
  59 /* TODO:  apply texture mapping to fragments */
  60
  61
  62 /*
  63  * Try to do a fast glDrawPixels.  Conditions include:
  64  *   not using a display list
  65  *   simple pixel unpacking
  66  *   no raster ops
  67  *   etc....
  68  * Return:  GL_TRUE if success, GL_FALSE if slow path must be used instead
  69  */
  70 GLboolean gl_direct_DrawPixels( GLcontext *ctx,
  71                                 const struct gl_pixelstore_attrib *unpack,
  72                                 GLsizei width, GLsizei height,
  73                                 GLenum format, GLenum type,
  74                                 const GLvoid *pixels )
  75 {
  76    GLubyte rgb[MAX_WIDTH][3];
  77    GLubyte rgba[MAX_WIDTH][4];
  78
  79    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH_WITH_RETVAL(ctx, "glDrawPixels",
  80                                                   GL_FALSE);
  81
  82
  83    if (!ctx->Current.RasterPosValid) {
  84       /* no-op */
  85       return GL_TRUE;
  86    }
  87
  88    if (ctx->NewState) {
  89       gl_update_state(ctx);
  90    }
  91
  92    /* see if device driver can do the drawpix */
  93    if (ctx->Driver.DrawPixels) {
  94       GLint x = (GLint) (ctx->Current.RasterPos[0] + 0.5F);
  95       GLint y = (GLint) (ctx->Current.RasterPos[1] + 0.5F);
  96       if ((*ctx->Driver.DrawPixels)(ctx, x, y, width, height, format, type,
  97                                     unpack, pixels))
  98          return GL_TRUE;
  99    }
 100
 101    if ((ctx->RasterMask&(~(SCISSOR_BIT|WINCLIP_BIT)))==0
 102        && ctx->Pixel.RedBias==0.0 && ctx->Pixel.RedScale==1.0
 103        && ctx->Pixel.GreenBias==0.0 && ctx->Pixel.GreenScale==1.0
 104        && ctx->Pixel.BlueBias==0.0 && ctx->Pixel.BlueScale==1.0
 105        && ctx->Pixel.AlphaBias==0.0 && ctx->Pixel.AlphaScale==1.0
 106        && ctx->Pixel.IndexShift==0 && ctx->Pixel.IndexOffset==0
 107        && ctx->Pixel.MapColorFlag==0
 108        && unpack->Alignment==1
 109        && !unpack->SwapBytes
 110        && !unpack->LsbFirst) {
 111
 112       GLint destX = (GLint) (ctx->Current.RasterPos[0] + 0.5F);
 113       GLint destY = (GLint) (ctx->Current.RasterPos[1] + 0.5F);
 114       GLint drawWidth = width;           /* actual width drawn */
 115       GLint drawHeight = height;         /* actual height drawn */
 116       GLint skipPixels = unpack->SkipPixels;
 117       GLint skipRows = unpack->SkipRows;
 118       GLint rowLength;
 119       GLdepth zSpan[MAX_WIDTH];  /* only used when zooming */
 120       GLint zoomY0;
 121
 122       if (unpack->RowLength > 0)
 123          rowLength = unpack->RowLength;
 124       else
 125          rowLength = width;
 126
 127       /* If we're not using pixel zoom then do all clipping calculations
 128        * now.  Otherwise, we'll let the gl_write_zoomed_*_span() functions
 129        * handle the clipping.
 130        */
 131       if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
 132          /* horizontal clipping */
 133          if (destX < ctx->Buffer->Xmin) {
 134             skipPixels += (ctx->Buffer->Xmin - destX);
 135             drawWidth  -= (ctx->Buffer->Xmin - destX);
 136             destX = ctx->Buffer->Xmin;
 137          }
 138          if (destX + drawWidth > ctx->Buffer->Xmax)
 139             drawWidth -= (destX + drawWidth - ctx->Buffer->Xmax - 1);
 140          if (drawWidth <= 0)
 141             return GL_TRUE;
 142
 143          /* vertical clipping */
 144          if (destY < ctx->Buffer->Ymin) {
 145             skipRows   += (ctx->Buffer->Ymin - destY);
 146             drawHeight -= (ctx->Buffer->Ymin - destY);
 147             destY = ctx->Buffer->Ymin;
 148          }
 149          if (destY + drawHeight > ctx->Buffer->Ymax)
 150             drawHeight -= (destY + drawHeight - ctx->Buffer->Ymax - 1);
 151          if (drawHeight <= 0)
 152             return GL_TRUE;
 153       }
 154       else {
 155          /* setup array of fragment Z value to pass to zoom function */
 156          GLdepth z = (GLdepth) (ctx->Current.RasterPos[2] * DEPTH_SCALE);
 157          GLint i;
 158          assert(drawWidth < MAX_WIDTH);
 159          for (i=0; i<drawWidth; i++)
 160             zSpan[i] = z;
 161
 162          /* save Y value of first row */
 163          zoomY0 = (GLint) (ctx->Current.RasterPos[1] + 0.5F);
 164       }
 165
 166
 167       /*
 168        * Ready to draw!
 169        * The window region at (destX, destY) of size (drawWidth, drawHeight)
 170        * will be written to.
 171        * We'll take pixel data from buffer pointed to by "pixels" but we'll
 172        * skip "skipRows" rows and skip "skipPixels" pixels/row.
 173        */
 174
 175       if (format==GL_RGBA && type==GL_UNSIGNED_BYTE) {
 176          if (ctx->Visual->RGBAflag) {
 177             GLubyte *src = (GLubyte *) pixels
 178                + (skipRows * rowLength + skipPixels) * 4;
 179             if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
 180                /* no zooming */
 181                GLint row;
 182                for (row=0; row<drawHeight; row++) {
 183                   (*ctx->Driver.WriteRGBASpan)(ctx, drawWidth, destX, destY,
 184                                                (void *) src, NULL);
 185                   src += rowLength * 4;
 186                   destY++;
 187                }
 188             }
 189             else {
 190                /* with zooming */
 191                GLint row;
 192                for (row=0; row<drawHeight; row++) {
 193                   gl_write_zoomed_rgba_span(ctx, drawWidth, destX, destY,
 194                                             zSpan, (void *) src, zoomY0);
 195                   src += rowLength * 4;
 196                   destY++;
 197                }
 198             }
 199          }
 200          return GL_TRUE;
 201       }
 202       else if (format==GL_RGB && type==GL_UNSIGNED_BYTE) {
 203          if (ctx->Visual->RGBAflag) {
 204             GLubyte *src = (GLubyte *) pixels
 205                + (skipRows * rowLength + skipPixels) * 3;
 206             if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
 207                GLint row;
 208                for (row=0; row<drawHeight; row++) {
 209                   (*ctx->Driver.WriteRGBSpan)(ctx, drawWidth, destX, destY,
 210                                               (void *) src, NULL);
 211                   src += rowLength * 3;
 212                   destY++;
 213                }
 214             }
 215             else {
 216                /* with zooming */
 217                GLint row;
 218                for (row=0; row<drawHeight; row++) {
 219                   gl_write_zoomed_rgb_span(ctx, drawWidth, destX, destY,
 220                                            zSpan, (void *) src, zoomY0);
 221                   src += rowLength * 3;
 222                   destY++;
 223                }
 224             }
 225          }
 226          return GL_TRUE;
 227       }
 228       else if (format==GL_LUMINANCE && type==GL_UNSIGNED_BYTE) {
 229          if (ctx->Visual->RGBAflag) {
 230             GLubyte *src = (GLubyte *) pixels
 231                + (skipRows * rowLength + skipPixels);
 232             if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
 233                /* no zooming */
 234                GLint row;
 235                assert(drawWidth < MAX_WIDTH);
 236                for (row=0; row<drawHeight; row++) {
 237                   GLint i;
 238                   for (i=0;i<drawWidth;i++) {
 239                      rgb[i][0] = src[i];
 240                      rgb[i][1] = src[i];
 241                      rgb[i][2] = src[i];
 242                   }
 243                   (*ctx->Driver.WriteRGBSpan)(ctx, drawWidth, destX, destY,
 244                                               (void *) rgb, NULL);
 245                   src += rowLength;
 246                   destY++;
 247                }
 248             }
 249             else {
 250                /* with zooming */
 251                GLint row;
 252                assert(drawWidth < MAX_WIDTH);
 253                for (row=0; row<drawHeight; row++) {
 254                   GLint i;
 255                   for (i=0;i<drawWidth;i++) {
 256                      rgb[i][0] = src[i];
 257                      rgb[i][1] = src[i];
 258                      rgb[i][2] = src[i];
 259                   }
 260                   gl_write_zoomed_rgb_span(ctx, drawWidth, destX, destY,
 261                                            zSpan, (void *) rgb, zoomY0);
 262                   src += rowLength;
 263                   destY++;
 264                }
 265             }
 266          }
 267          return GL_TRUE;
 268       }
 269       else if (format==GL_LUMINANCE_ALPHA && type==GL_UNSIGNED_BYTE) {
 270          if (ctx->Visual->RGBAflag) {
 271             GLubyte *src = (GLubyte *) pixels
 272                + (skipRows * rowLength + skipPixels)*2;
 273             if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
 274                /* no zooming */
 275                GLint row;
 276                assert(drawWidth < MAX_WIDTH);
 277                for (row=0; row<drawHeight; row++) {
 278                   GLint i;
 279                   GLubyte *ptr = src;
 280                   for (i=0;i<drawWidth;i++) {
 281                      rgba[i][0] = *ptr;
 282                      rgba[i][1] = *ptr;
 283                      rgba[i][2] = *ptr++;
 284                      rgba[i][3] = *ptr++;
 285                   }
 286                   (*ctx->Driver.WriteRGBASpan)(ctx, drawWidth, destX, destY,
 287                                                (void *) rgba, NULL);
 288                   src += rowLength*2;
 289                   destY++;
 290                }
 291             }
 292             else {
 293                /* with zooming */
 294                GLint row;
 295                assert(drawWidth < MAX_WIDTH);
 296                for (row=0; row<drawHeight; row++) {
 297                   GLubyte *ptr = src;
 298                   GLint i;
 299                   for (i=0;i<drawWidth;i++) {
 300                      rgba[i][0] = *ptr;
 301                      rgba[i][1] = *ptr;
 302                      rgba[i][2] = *ptr++;
 303                      rgba[i][3] = *ptr++;
 304                   }
 305                   gl_write_zoomed_rgba_span(ctx, drawWidth, destX, destY,
 306                                             zSpan, (void *) rgba, zoomY0);
 307                   src += rowLength*2;
 308                   destY++;
 309                }
 310             }
 311          }
 312          return GL_TRUE;
 313       }
 314       else if (format==GL_COLOR_INDEX && type==GL_UNSIGNED_BYTE) {
 315          GLubyte *src = (GLubyte *) pixels + skipRows * rowLength + skipPixels;
 316          if (ctx->Visual->RGBAflag) {
 317             /* convert CI data to RGBA */
 318             if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
 319                /* no zooming */
 320                GLint row;
 321                for (row=0; row<drawHeight; row++) {
 322                   assert(drawWidth < MAX_WIDTH);
 323                   gl_map_ci8_to_rgba(ctx, drawWidth, src, rgba);
 324                   (*ctx->Driver.WriteRGBASpan)(ctx, drawWidth, destX, destY,
 325                                                (const GLubyte (*)[4])rgba,
 326                                                NULL);
 327                   src += rowLength;
 328                   destY++;
 329                }
 330                return GL_TRUE;
 331             }
 332             else {
 333                /* with zooming */
 334                GLint row;
 335                for (row=0; row<drawHeight; row++) {
 336                   assert(drawWidth < MAX_WIDTH);
 337                   gl_map_ci8_to_rgba(ctx, drawWidth, src, rgba);
 338                   gl_write_zoomed_rgba_span(ctx, drawWidth, destX, destY,
 339                                             zSpan, (void *) rgba, zoomY0);
 340                   src += rowLength;
 341                   destY++;
 342                }
 343                return GL_TRUE;
 344             }
 345          }
 346          else {
 347             /* write CI data to CI frame buffer */
 348             GLint row;
 349             if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
 350                /* no zooming */
 351                for (row=0; row<drawHeight; row++) {
 352                   (*ctx->Driver.WriteCI8Span)(ctx, drawWidth, destX, destY,
 353                                               src, NULL);
 354                   src += rowLength;
 355                   destY++;
 356                }
 357                return GL_TRUE;
 358             }
 359             else {
 360                /* with zooming */
 361                return GL_FALSE;
 362             }
 363          }
 364       }
 365       else {
 366          /* can't handle this pixel format and/or data type here */
 367          return GL_FALSE;
 368       }
 369    }
 370    else {
 371       /* can't do direct render, have to use slow path */
 372       return GL_FALSE;
 373    }
 374 }
 375
 376
 377
 378 /*
 379  * Do glDrawPixels of index pixels.
 380  */
 381 static void draw_index_pixels( GLcontext *ctx, GLint x, GLint y,
 382                                const struct gl_image *image )
 383 {
 384    GLint width, height, widthInBytes;
 385    const GLint desty = y;
 386    GLint i, j;
 387    GLdepth zspan[MAX_WIDTH];
 388    const GLboolean zoom = ctx->Pixel.ZoomX!=1.0 || ctx->Pixel.ZoomY!=1.0;
 389
 390    assert(image);
 391    assert(image->Format == GL_COLOR_INDEX);
 392
 393    width = image->Width;
 394    height = image->Height;
 395    if (image->Type == GL_BITMAP)
 396       widthInBytes = (width + 7) / 8;
 397    else
 398       widthInBytes = width;
 399
 400    /* Fragment depth values */
 401    if (ctx->Depth.Test) {
 402       GLdepth zval = (GLdepth) (ctx->Current.RasterPos[2] * DEPTH_SCALE);
 403       for (i=0;i<width;i++) {
 404          zspan[i] = zval;
 405       }
 406    }
 407
 408    /* process the image row by row */
 409    for (i=0;i<height;i++,y++) {
 410       GLuint ispan[MAX_WIDTH];
 411
 412       /* convert to uints */
 413       switch (image->Type) {
 414          case GL_UNSIGNED_BYTE:
 415             {
 416                GLubyte *src = (GLubyte *) image->Data + i * width;
 417                for (j=0;j<width;j++) {
 418                   ispan[j] = (GLuint) *src++;
 419                }
 420             }
 421             break;
 422          case GL_FLOAT:
 423             {
 424                GLfloat *src = (GLfloat *) image->Data + i * width;
 425                for (j=0;j<width;j++) {
 426                   ispan[j] = (GLuint) (GLint) *src++;
 427                }
 428             }
 429             break;
 430          case GL_BITMAP:
 431             {
 432                GLubyte *src = (GLubyte *) image->Data + i * widthInBytes;
 433                for (j=0;j<width;j++) {
 434                   ispan[j] = ( src[j >> 3] >> (7 - (j & 0x7)) ) & 1;
 435                }
 436             }
 437             break;
 438          default:
 439             gl_problem( ctx, "draw_index_pixels type" );
 440             return;
 441       }
 442
 443       /* apply shift and offset */
 444       if (ctx->Pixel.IndexOffset || ctx->Pixel.IndexShift) {
 445          gl_shift_and_offset_ci( ctx, width, ispan );
 446       }
 447
 448       if (ctx->Visual->RGBAflag) {
 449          /* Convert index to RGBA and write to frame buffer */
 450          GLubyte rgba[MAX_WIDTH][4];
 451          gl_map_ci_to_rgba( ctx, width, ispan, rgba );
 452          if (zoom) {
 453             gl_write_zoomed_rgba_span( ctx, width, x, y, zspan,
 454                                        (const GLubyte (*)[4])rgba, desty );
 455          }
 456          else {
 457             gl_write_rgba_span( ctx, width, x, y, zspan, rgba, GL_BITMAP );
 458          }
 459       }
 460       else {
 461          /* optionally apply index map then write to frame buffer */
 462          if (ctx->Pixel.MapColorFlag) {
 463             gl_map_ci(ctx, width, ispan);
 464          }
 465          if (zoom) {
 466             gl_write_zoomed_index_span( ctx, width, x, y, zspan, ispan, desty );
 467          }
 468          else {
 469             gl_write_index_span( ctx, width, x, y, zspan, ispan, GL_BITMAP );
 470          }
 471       }
 472    }
 473
 474 }
 475
 476
 477
 478 /*
 479  * Do glDrawPixels of stencil image.  The image datatype may either
 480  * be GLubyte or GLbitmap.
 481  */
 482 static void draw_stencil_pixels( GLcontext *ctx, GLint x, GLint y,
 483                                  const struct gl_image *image )
 484 {
 485    GLint widthInBytes, width, height;
 486    const GLint desty = y;
 487    GLint i;
 488    const GLboolean zoom = ctx->Pixel.ZoomX!=1.0 || ctx->Pixel.ZoomY!=1.0;
 489
 490    if (image->Type != GL_BYTE &&
 491        image->Type != GL_UNSIGNED_BYTE &&
 492        image->Type != GL_SHORT &&
 493        image->Type != GL_UNSIGNED_SHORT &&
 494        image->Type != GL_INT &&
 495        image->Type != GL_UNSIGNED_INT &&
 496        image->Type != GL_FLOAT &&
 497        image->Type != GL_BITMAP) {
 498       gl_error( ctx, GL_INVALID_OPERATION, "glDrawPixels(stencil type)");
 499       return;
 500    }
 501
 502    assert(image);
 503    assert(image->Format == GL_STENCIL_INDEX);
 504    assert(image->Type == GL_UNSIGNED_BYTE || image->Type == GL_BITMAP);
 505
 506    if (image->Type == GL_UNSIGNED_BYTE)
 507       widthInBytes = image->Width;
 508    else
 509       widthInBytes = (image->Width + 7) / 8;
 510    width = image->Width;
 511    height = image->Height;
 512
 513    /* process the image row by row */
 514    for (i=0;i<height;i++,y++) {
 515       GLstencil *src = (GLstencil*)image->Data + i * widthInBytes;
 516       GLstencil *stencilValues;
 517       GLstencil stencilCopy[MAX_WIDTH];
 518
 519       if (image->Type == GL_BITMAP) {
 520          /* convert bitmap data to GLubyte (0 or 1) data */
 521          GLint j;
 522          for (j = 0; j < width; j++) {
 523             stencilCopy[j] = ( src[j >> 3] >> (7 - (j & 0x7)) ) & 1;
 524          }
 525          src = stencilCopy;
 526       }
 527
 528       if (ctx->Pixel.IndexOffset || ctx->Pixel.IndexShift
 529           || ctx->Pixel.MapStencilFlag) {
 530
 531          /* make copy of stencil values */
 532          if (src != stencilCopy)
 533             MEMCPY( stencilCopy, src, width * sizeof(GLstencil));
 534
 535          /* apply shift and offset */
 536          if (ctx->Pixel.IndexOffset || ctx->Pixel.IndexShift) {
 537             gl_shift_and_offset_stencil( ctx, width, stencilCopy );
 538          }
 539
 540          /* mapping */
 541          if (ctx->Pixel.MapStencilFlag) {
 542             gl_map_stencil( ctx, width, stencilCopy );
 543          }
 544
 545          stencilValues = stencilCopy;
 546       }
 547       else {
 548          /* use stencil values in-place */
 549          stencilValues = src;
 550       }
 551
 552       /* write stencil values to stencil buffer */
 553       if (zoom) {
 554          gl_write_zoomed_stencil_span( ctx, (GLuint) width, x, y,
 555                                        stencilValues, desty );
 556       }
 557       else {
 558          gl_write_stencil_span( ctx, (GLuint) width, x, y, stencilValues );
 559       }
 560    }
 561 }
 562
 563
 564
 565 /*
 566  * Do a glDrawPixels of depth values.
 567  */
 568 static void draw_depth_pixels( GLcontext *ctx, GLint x, GLint y,
 569                                const struct gl_image *image )
 570 {
 571    GLint width, height;
 572    const GLint desty = y;
 573    GLubyte rgba[MAX_WIDTH][4];
 574    GLuint ispan[MAX_WIDTH];
 575    const GLboolean bias_or_scale = ctx->Pixel.DepthBias!=0.0 || ctx->Pixel.DepthScale!=1.0;
 576    const GLboolean zoom = ctx->Pixel.ZoomX!=1.0 || ctx->Pixel.ZoomY!=1.0;
 577
 578    assert(image);
 579    assert(image->Format == GL_DEPTH_COMPONENT);
 580
 581    width = image->Width;
 582    height = image->Height;
 583
 584    /* Color or index */
 585    if (ctx->Visual->RGBAflag) {
 586       GLint r = (GLint) (ctx->Current.RasterColor[0] * 255.0F);
 587       GLint g = (GLint) (ctx->Current.RasterColor[1] * 255.0F);
 588       GLint b = (GLint) (ctx->Current.RasterColor[2] * 255.0F);
 589       GLint a = (GLint) (ctx->Current.RasterColor[3] * 255.0F);
 590       GLint i;
 591       for (i=0; i<width; i++) {
 592          rgba[i][RCOMP] = r;
 593          rgba[i][GCOMP] = g;
 594          rgba[i][BCOMP] = b;
 595          rgba[i][ACOMP] = a;
 596       }
 597    }
 598    else {
 599       GLint i;
 600       for (i=0;i<width;i++) {
 601          ispan[i] = ctx->Current.RasterIndex;
 602       }
 603    }
 604
 605    if (image->Type==GL_UNSIGNED_SHORT && sizeof(GLdepth)==sizeof(GLushort)
 606        && !bias_or_scale && !zoom && ctx->Visual->RGBAflag) {
 607       /* Special case: directly write 16-bit depth values */
 608       GLint j;
 609       for (j=0;j<height;j++,y++) {
 610          GLdepth *zptr = (GLdepth *) image->Data + j * width;
 611          gl_write_rgba_span( ctx, width, x, y, zptr, rgba, GL_BITMAP );
 612       }
 613    }
 614    else if (image->Type==GL_UNSIGNED_INT && sizeof(GLdepth)==sizeof(GLuint)
 615        && !bias_or_scale && !zoom && ctx->Visual->RGBAflag) {
 616       /* Special case: directly write 32-bit depth values */
 617       GLint i, j;
 618       /* Compute shift value to scale 32-bit uints down to depth values. */
 619       GLuint shift = 0;
 620       GLuint max = MAX_DEPTH;
 621       while ((max&0x80000000)==0) {
 622          max = max << 1;
 623          shift++;
 624       }
 625       for (j=0;j<height;j++,y++) {
 626          GLdepth zspan[MAX_WIDTH];
 627          GLuint *zptr = (GLuint *) image->Data + j * width;
 628          for (i=0;i<width;i++) {
 629             zspan[i] = zptr[i] >> shift;
 630          }
 631          gl_write_rgba_span( ctx, width, x, y, zspan, rgba, GL_BITMAP );
 632       }
 633    }
 634    else {
 635       /* General case (slower) */
 636       GLint i, j;
 637
 638       /* process image row by row */
 639       for (i=0;i<height;i++,y++) {
 640          GLfloat depth[MAX_WIDTH];
 641          GLdepth zspan[MAX_WIDTH];
 642
 643          switch (image->Type) {
 644             case GL_UNSIGNED_SHORT:
 645                {
 646                   GLushort *src = (GLushort *) image->Data + i * width;
 647                   for (j=0;j<width;j++) {
 648                      depth[j] = USHORT_TO_FLOAT( *src++ );
 649                   }
 650                }
 651                break;
 652             case GL_UNSIGNED_INT:
 653                {
 654                   GLuint *src = (GLuint *) image->Data + i * width;
 655                   for (j=0;j<width;j++) {
 656                      depth[j] = UINT_TO_FLOAT( *src++ );
 657                   }
 658                }
 659                break;
 660             case GL_FLOAT:
 661                {
 662                   GLfloat *src = (GLfloat *) image->Data + i * width;
 663                   for (j=0;j<width;j++) {
 664                      depth[j] = *src++;
 665                   }
 666                }
 667                break;
 668             default:
 669                gl_problem(ctx, "Bad type in draw_depth_pixels");
 670                return;
 671          }
 672
 673          /* apply depth scale and bias */
 674          if (ctx->Pixel.DepthScale!=1.0 || ctx->Pixel.DepthBias!=0.0) {
 675             for (j=0;j<width;j++) {
 676                depth[j] = depth[j] * ctx->Pixel.DepthScale + ctx->Pixel.DepthBias;
 677             }
 678          }
 679
 680          /* clamp depth values to [0,1] and convert from floats to integers */
 681          for (j=0;j<width;j++) {
 682             zspan[j] = (GLdepth) (CLAMP( depth[j], 0.0F, 1.0F ) * DEPTH_SCALE);
 683          }
 684
 685          if (ctx->Visual->RGBAflag) {
 686             if (zoom) {
 687                gl_write_zoomed_rgba_span( ctx, width, x, y, zspan,
 688                                           (const GLubyte (*)[4])rgba, desty );
 689             }
 690             else {
 691                gl_write_rgba_span( ctx, width, x, y, zspan, rgba, GL_BITMAP );
 692             }
 693          }
 694          else {
 695             if (zoom) {
 696                gl_write_zoomed_index_span( ctx, width, x, y, zspan,
 697                                            ispan, GL_BITMAP );
 698             }
 699             else {
 700                gl_write_index_span( ctx, width, x, y, zspan, ispan, GL_BITMAP );
 701             }
 702          }
 703
 704       }
 705    }
 706 }
 707
 708
 709
 710 /* Simple unpacking parameters: */
 711 static struct gl_pixelstore_attrib NoUnpack = {
 712    1,            /* Alignment */
 713    0,            /* RowLength */
 714    0,            /* SkipPixels */
 715    0,            /* SkipRows */
 716    0,            /* ImageHeight */
 717    0,            /* SkipImages */
 718    GL_FALSE,     /* SwapBytes */
 719    GL_FALSE      /* LsbFirst */
 720 };
 721
 722
 723 /*
 724  * Do glDrawPixels of RGBA pixels.
 725  */
 726 static void draw_rgba_pixels( GLcontext *ctx, GLint x, GLint y,
 727                               const struct gl_image *image )
 728 {
 729    GLint width, height;
 730    GLint i, j;
 731    const GLint desty = y;
 732    GLdepth zspan[MAX_WIDTH];
 733    GLboolean quickDraw;
 734    const GLboolean zoom = ctx->Pixel.ZoomX!=1.0 || ctx->Pixel.ZoomY!=1.0;
 735
 736    assert(image);
 737
 738    /* Try an optimized glDrawPixels first */
 739    if (gl_direct_DrawPixels(ctx, &NoUnpack, image->Width, image->Height,
 740                             image->Format, image->Type, image->Data ))
 741       return;
 742
 743    width = image->Width;
 744    height = image->Height;
 745
 746    /* Fragment depth values */
 747    if (ctx->Depth.Test) {
 748       /* fill in array of z values */
 749       GLdepth z = (GLdepth) (ctx->Current.RasterPos[2] * DEPTH_SCALE);
 750       for (i=0;i<width;i++) {
 751          zspan[i] = z;
 752       }
 753    }
 754
 755    if (ctx->RasterMask==0 && !zoom && x>=0 && y>=0
 756        && x+width<=ctx->Buffer->Width && y+height<=ctx->Buffer->Height) {
 757       quickDraw = GL_TRUE;
 758    }
 759    else {
 760       quickDraw = GL_FALSE;
 761    }
 762
 763    {
 764       /* General solution */
 765       GLboolean r_flag, g_flag, b_flag, a_flag, l_flag;
 766       GLuint components;
 767       GLubyte rgba[MAX_WIDTH][4];
 768       GLfloat  rf[MAX_WIDTH];
 769       GLfloat  gf[MAX_WIDTH];
 770       GLfloat  bf[MAX_WIDTH];
 771       DEFARRAY(GLfloat,af,MAX_WIDTH);
 772       CHECKARRAY(af,return);
 773
 774       r_flag = g_flag = b_flag = a_flag = l_flag = GL_FALSE;
 775       switch (image->Format) {
 776          case GL_RED:
 777             r_flag = GL_TRUE;
 778             components = 1;
 779             break;
 780          case GL_GREEN:
 781             g_flag = GL_TRUE;
 782             components = 1;
 783             break;
 784          case GL_BLUE:
 785             b_flag = GL_TRUE;
 786             components = 1;
 787             break;
 788          case GL_ALPHA:
 789             a_flag = GL_TRUE;
 790             components = 1;
 791             break;
 792          case GL_RGB:
 793             r_flag = g_flag = b_flag = GL_TRUE;
 794             components = 3;
 795             break;
 796          case GL_LUMINANCE:
 797             l_flag = GL_TRUE;
 798             components = 1;
 799             break;
 800          case GL_LUMINANCE_ALPHA:
 801             l_flag = a_flag = GL_TRUE;
 802             components = 2;
 803             break;
 804          case GL_RGBA:
 805             r_flag = g_flag = b_flag = a_flag = GL_TRUE;
 806             components = 4;
 807             break;
 808          default:
 809             gl_problem(ctx, "Bad type in draw_rgba_pixels");
 810             goto cleanup;
 811       }
 812
 813       /* process the image row by row */
 814       for (i=0;i<height;i++,y++) {
 815          /* convert to floats */
 816          switch (image->Type) {
 817             case GL_UNSIGNED_BYTE:
 818                {
 819                   GLubyte *src = (GLubyte *) image->Data + i * width * components;
 820                   for (j=0;j<width;j++) {
 821                      if (l_flag) {
 822                         rf[j] = gf[j] = bf[j] = UBYTE_TO_FLOAT(*src++);
 823                      }
 824                      else {
 825                         rf[j] = r_flag ? UBYTE_TO_FLOAT(*src++) : 0.0;
 826                         gf[j] = g_flag ? UBYTE_TO_FLOAT(*src++) : 0.0;
 827                         bf[j] = b_flag ? UBYTE_TO_FLOAT(*src++) : 0.0;
 828                      }
 829                      af[j] = a_flag ? UBYTE_TO_FLOAT(*src++) : 1.0;
 830                   }
 831                }
 832                break;
 833             case GL_FLOAT:
 834                {
 835                   GLfloat *src = (GLfloat *) image->Data + i * width * components;
 836                   for (j=0;j<width;j++) {
 837                      if (l_flag) {
 838                         rf[j] = gf[j] = bf[j] = *src++;
 839                      }
 840                      else {
 841                         rf[j] = r_flag ? *src++ : 0.0;
 842                         gf[j] = g_flag ? *src++ : 0.0;
 843                         bf[j] = b_flag ? *src++ : 0.0;
 844                      }
 845                      af[j] = a_flag ? *src++ : 1.0;
 846                   }
 847                }
 848                break;
 849             default:
 850                gl_problem( ctx, "draw_rgba_pixels type" );
 851                goto cleanup;
 852          }
 853
 854          /* apply scale and bias */
 855          if (ctx->Pixel.ScaleOrBiasRGBA) {
 856             gl_scale_and_bias_color(ctx, width, rf, gf, bf, af);
 857          }
 858
 859          /* apply pixel mappings */
 860          if (ctx->Pixel.MapColorFlag) {
 861             gl_map_color(ctx, width, rf, gf, bf, af);
 862          }
 863
 864          /* convert to integers */
 865          for (j=0;j<width;j++) {
 866             rgba[j][RCOMP] = (GLint) (rf[j] * 255.0F);
 867             rgba[j][GCOMP] = (GLint) (gf[j] * 255.0F);
 868             rgba[j][BCOMP] = (GLint) (bf[j] * 255.0F);
 869             rgba[j][ACOMP] = (GLint) (af[j] * 255.0F);
 870          }
 871
 872          /* write to frame buffer */
 873          if (quickDraw) {
 874             (*ctx->Driver.WriteRGBASpan)( ctx, width, x, y,
 875                                           (const GLubyte (*)[4])rgba, NULL);
 876          }
 877          else if (zoom) {
 878             gl_write_zoomed_rgba_span( ctx, width, x, y, zspan,
 879                                        (const GLubyte (*)[4])rgba, desty );
 880          }
 881          else {
 882             gl_write_rgba_span( ctx, (GLuint) width, x, y, zspan, rgba, GL_BITMAP);
 883          }
 884       }
 885 cleanup:
 886       UNDEFARRAY(af);
 887    }
 888 }
 889
 890
 891
 892 /*
 893  * Execute glDrawPixels
 894  */
 895 void gl_DrawPixels( GLcontext* ctx, struct gl_image *image )
 896 {
 897    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glDrawPixels");
 898
 899
 900    if (gl_image_error_test( ctx, image, "glDrawPixels" ))
 901       return;
 902
 903    if (ctx->RenderMode==GL_RENDER) {
 904       GLint x, y;
 905       if (!ctx->Current.RasterPosValid) {
 906          return;
 907       }
 908
 909       x = (GLint) (ctx->Current.RasterPos[0] + 0.5F);
 910       y = (GLint) (ctx->Current.RasterPos[1] + 0.5F);
 911
 912       switch (image->Format) {
 913          case GL_COLOR_INDEX:
 914             draw_index_pixels( ctx, x, y, image );
 915             break;
 916          case GL_STENCIL_INDEX:
 917             draw_stencil_pixels( ctx, x, y, image );
 918             break;
 919          case GL_DEPTH_COMPONENT:
 920             draw_depth_pixels( ctx, x, y, image );
 921             break;
 922          case GL_RED:
 923          case GL_GREEN:
 924          case GL_BLUE:
 925          case GL_ALPHA:
 926          case GL_RGB:
 927          case GL_LUMINANCE:
 928          case GL_LUMINANCE_ALPHA:
 929          case GL_RGBA:
 930             draw_rgba_pixels( ctx, x, y, image );
 931             break;
 932          default:
 933             gl_error( ctx, GL_INVALID_ENUM, "glDrawPixels" );
 934             return;
 935       }
 936    }
 937    else if (ctx->RenderMode==GL_FEEDBACK) {
 938       if (ctx->Current.RasterPosValid) {
 939          GLfloat color[4];
 940          GLfloat texcoord[4], invq;
 941          UBYTE_RGBA_TO_FLOAT_RGBA(color, ctx->Current.ByteColor);
 942          invq = 1.0F / ctx->Current.Texcoord[0][3];
 943          texcoord[0] = ctx->Current.Texcoord[0][0] * invq;
 944          texcoord[1] = ctx->Current.Texcoord[0][1] * invq;
 945          texcoord[2] = ctx->Current.Texcoord[0][2] * invq;
 946          texcoord[3] = ctx->Current.Texcoord[0][3];
 947          FEEDBACK_TOKEN( ctx, (GLfloat) (GLint) GL_DRAW_PIXEL_TOKEN );
 948          gl_feedback_vertex( ctx,
 949                              ctx->Current.RasterPos,
 950                              color, ctx->Current.Index, texcoord );
 951       }
 952    }
 953    else if (ctx->RenderMode==GL_SELECT) {
 954       if (ctx->Current.RasterPosValid) {
 955          gl_update_hitflag( ctx, ctx->Current.RasterPos[2] );
 956       }
 957    }
 958 }
 959