src/mesa/swrast/s_zoom.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  *
   5  * Copyright (C) 1999-2005  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 #include "glheader.h"
  26 #include "macros.h"
  27 #include "imports.h"
  28 #include "colormac.h"
  29
  30 #include "s_context.h"
  31 #include "s_span.h"
  32 #include "s_stencil.h"
  33 #include "s_zoom.h"
  34
  35
  36 /*
  37  * Helper function called from _swrast_write_zoomed_rgba/rgb/index_span().
  38  */
  39 static void
  40 zoom_span( GLcontext *ctx, const struct sw_span *span,
  41            const GLvoid *src, GLint y0, GLenum format, GLint skipPixels )
  42 {
  43    GLint r0, r1, row;
  44    GLint c0, c1, skipCol;
  45    GLint i, j;
  46    const GLuint maxWidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
  47    struct sw_span zoomed;
  48    struct span_arrays zoomed_arrays;  /* this is big! */
  49
  50    /* no pixel arrays! must be horizontal spans. */
  51    ASSERT((span->arrayMask & SPAN_XY) == 0);
  52    ASSERT(span->primitive == GL_BITMAP);
  53
  54    INIT_SPAN(zoomed, GL_BITMAP, 0, 0, 0);
  55    zoomed.array = &zoomed_arrays;
  56
  57    /* copy fog interp info */
  58    zoomed.fog = span->fog;
  59    zoomed.fogStep = span->fogStep;
  60    /* XXX copy texcoord info? */
  61
  62    if (format == GL_RGBA || format == GL_RGB) {
  63       /* copy Z info */
  64       zoomed.z = span->z;
  65       zoomed.zStep = span->zStep;
  66       /* we'll generate an array of colorss */
  67       zoomed.interpMask = span->interpMask & ~SPAN_RGBA;
  68       zoomed.arrayMask |= SPAN_RGBA;
  69    }
  70    else if (format == GL_COLOR_INDEX) {
  71       /* copy Z info */
  72       zoomed.z = span->z;
  73       zoomed.zStep = span->zStep;
  74       /* we'll generate an array of color indexes */
  75       zoomed.interpMask = span->interpMask & ~SPAN_INDEX;
  76       zoomed.arrayMask |= SPAN_INDEX;
  77    }
  78    else if (format == GL_DEPTH_COMPONENT) {
  79       /* Copy color info */
  80       zoomed.red = span->red;
  81       zoomed.green = span->green;
  82       zoomed.blue = span->blue;
  83       zoomed.alpha = span->alpha;
  84       zoomed.redStep = span->redStep;
  85       zoomed.greenStep = span->greenStep;
  86       zoomed.blueStep = span->blueStep;
  87       zoomed.alphaStep = span->alphaStep;
  88       /* we'll generate an array of depth values */
  89       zoomed.interpMask = span->interpMask & ~SPAN_Z;
  90       zoomed.arrayMask |= SPAN_Z;
  91    }
  92    else if (format == GL_DEPTH_COMPONENT16 ||
  93             format == GL_DEPTH_COMPONENT32) {
  94       /* writing Z values directly to depth buffer, bypassing fragment ops */
  95    }
  96    else {
  97       _mesa_problem(ctx, "Bad format in zoom_span");
  98       return;
  99    }
 100
 101    /*
 102     * Compute which columns to draw: [c0, c1)
 103     */
 104    c0 = (GLint) (span->x + skipPixels * ctx->Pixel.ZoomX);
 105    c1 = (GLint) (span->x + (skipPixels + span->end) * ctx->Pixel.ZoomX);
 106    if (c0 == c1) {
 107       return;
 108    }
 109    else if (c1 < c0) {
 110       /* swap */
 111       GLint ctmp = c1;
 112       c1 = c0;
 113       c0 = ctmp;
 114    }
 115    if (c0 < 0) {
 116       zoomed.x = 0;
 117       zoomed.start = 0;
 118       zoomed.end = c1;
 119       skipCol = -c0;
 120    }
 121    else {
 122       zoomed.x = c0;
 123       zoomed.start = 0;
 124       zoomed.end = c1 - c0;
 125       skipCol = 0;
 126    }
 127    if (zoomed.end > maxWidth)
 128       zoomed.end = maxWidth;
 129
 130    /*
 131     * Compute which rows to draw: [r0, r1)
 132     */
 133    row = span->y - y0;
 134    r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
 135    r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
 136    if (r0 == r1) {
 137       return;
 138    }
 139    else if (r1 < r0) {
 140       /* swap */
 141       GLint rtmp = r1;
 142       r1 = r0;
 143       r0 = rtmp;
 144    }
 145
 146    ASSERT(r0 < r1);
 147    ASSERT(c0 < c1);
 148
 149    /*
 150     * Trivial clip rejection testing.
 151     */
 152    if (r1 < 0) /* below window */
 153       return;
 154    if (r0 >= (GLint) ctx->DrawBuffer->Height) /* above window */
 155       return;
 156    if (c1 < 0) /* left of window */
 157       return;
 158    if (c0 >= (GLint) ctx->DrawBuffer->Width) /* right of window */
 159       return;
 160
 161    /* zoom the span horizontally */
 162    if (format == GL_RGBA) {
 163       const GLchan (*rgba)[4] = (const GLchan (*)[4]) src;
 164       if (ctx->Pixel.ZoomX == -1.0F) {
 165          /* common case */
 166          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 167             i = span->end - (j + skipCol) - 1;
 168             COPY_CHAN4(zoomed.array->rgba[j], rgba[i]);
 169          }
 170       }
 171       else {
 172          /* general solution */
 173          const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 174          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 175             i = (GLint) ((j + skipCol) * xscale);
 176             if (ctx->Pixel.ZoomX < 0.0) {
 177                ASSERT(i <= 0);
 178                i = span->end + i - 1;
 179             }
 180             ASSERT(i >= 0);
 181             ASSERT(i < (GLint)  span->end);
 182             COPY_CHAN4(zoomed.array->rgba[j], rgba[i]);
 183          }
 184       }
 185    }
 186    else if (format == GL_RGB) {
 187       const GLchan (*rgb)[3] = (const GLchan (*)[3]) src;
 188       if (ctx->Pixel.ZoomX == -1.0F) {
 189          /* common case */
 190          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 191             i = span->end - (j + skipCol) - 1;
 192             zoomed.array->rgba[j][0] = rgb[i][0];
 193             zoomed.array->rgba[j][1] = rgb[i][1];
 194             zoomed.array->rgba[j][2] = rgb[i][2];
 195             zoomed.array->rgba[j][3] = CHAN_MAX;
 196          }
 197       }
 198       else {
 199          /* general solution */
 200          const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 201          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 202             i = (GLint) ((j + skipCol) * xscale);
 203             if (ctx->Pixel.ZoomX < 0.0) {
 204                ASSERT(i <= 0);
 205                i = span->end + i - 1;
 206             }
 207             ASSERT(i >= 0);
 208             ASSERT(i < (GLint) span->end);
 209             zoomed.array->rgba[j][0] = rgb[i][0];
 210             zoomed.array->rgba[j][1] = rgb[i][1];
 211             zoomed.array->rgba[j][2] = rgb[i][2];
 212             zoomed.array->rgba[j][3] = CHAN_MAX;
 213          }
 214       }
 215    }
 216    else if (format == GL_COLOR_INDEX) {
 217       const GLuint *indexes = (const GLuint *) src;
 218       if (ctx->Pixel.ZoomX == -1.0F) {
 219          /* common case */
 220          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 221             i = span->end - (j + skipCol) - 1;
 222             zoomed.array->index[j] = indexes[i];
 223          }
 224       }
 225       else {
 226          /* general solution */
 227          const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 228          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 229             i = (GLint) ((j + skipCol) * xscale);
 230             if (ctx->Pixel.ZoomX < 0.0) {
 231                ASSERT(i <= 0);
 232                i = span->end + i - 1;
 233             }
 234             ASSERT(i >= 0);
 235             ASSERT(i < (GLint) span->end);
 236             zoomed.array->index[j] = indexes[i];
 237          }
 238       }
 239    }
 240    else if (format == GL_DEPTH_COMPONENT) {
 241       const GLuint *zValues = (const GLuint *) src;
 242       if (ctx->Pixel.ZoomX == -1.0F) {
 243          /* common case */
 244          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 245             i = span->end - (j + skipCol) - 1;
 246             zoomed.array->z[j] = zValues[i];
 247          }
 248       }
 249       else {
 250          /* general solution */
 251          const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 252          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 253             i = (GLint) ((j + skipCol) * xscale);
 254             if (ctx->Pixel.ZoomX < 0.0) {
 255                ASSERT(i <= 0);
 256                i = span->end + i - 1;
 257             }
 258             ASSERT(i >= 0);
 259             ASSERT(i < (GLint) span->end);
 260             zoomed.array->z[j] = zValues[i];
 261          }
 262       }
 263       /* Now, fall into either the RGB or COLOR_INDEX path below */
 264       if (ctx->Visual.rgbMode)
 265          format = GL_RGBA;
 266       else
 267          format = GL_COLOR_INDEX;
 268    }
 269    else if (format == GL_DEPTH_COMPONENT32) {
 270       /* 32-bit Z values */
 271       struct gl_renderbuffer *rb
 272          = ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
 273       const GLuint *zSrc32 = (const GLuint *) src;
 274       GLuint zDst32[MAX_WIDTH];
 275       const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 276       for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 277          i = (GLint) ((j + skipCol) * xscale);
 278          if (ctx->Pixel.ZoomX < 0.0) {
 279             ASSERT(i <= 0);
 280             i = span->end + i - 1;
 281          }
 282          ASSERT(i >= 0);
 283          ASSERT(i < (GLint) span->end);
 284          zDst32[j] = zSrc32[i];
 285       }
 286       rb->PutRow(ctx, rb, zoomed.end, zoomed.x, zoomed.y, zDst32, NULL);
 287       return;
 288    }
 289
 290    /* write the span in rows [r0, r1) */
 291    if (format == GL_RGBA || format == GL_RGB) {
 292       /* Writing the span may modify the colors, so make a backup now if we're
 293        * going to call _swrast_write_zoomed_span() more than once.
 294        * Also, clipping may change the span end value, so store it as well.
 295        */
 296       GLchan rgbaSave[MAX_WIDTH][4];
 297       const GLint end = zoomed.end; /* save */
 298       if (r1 - r0 > 1) {
 299          MEMCPY(rgbaSave, zoomed.array->rgba, zoomed.end * 4 * sizeof(GLchan));
 300       }
 301       for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
 302          _swrast_write_rgba_span(ctx, &zoomed);
 303          zoomed.end = end;  /* restore */
 304          if (r1 - r0 > 1) {
 305             /* restore the colors */
 306             MEMCPY(zoomed.array->rgba, rgbaSave, zoomed.end*4 * sizeof(GLchan));
 307          }
 308       }
 309    }
 310    else if (format == GL_COLOR_INDEX) {
 311       GLuint indexSave[MAX_WIDTH];
 312       const GLint end = zoomed.end; /* save */
 313       if (r1 - r0 > 1) {
 314          MEMCPY(indexSave, zoomed.array->index, zoomed.end * sizeof(GLuint));
 315       }
 316       for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
 317          _swrast_write_index_span(ctx, &zoomed);
 318          zoomed.end = end;  /* restore */
 319          if (r1 - r0 > 1) {
 320             /* restore the colors */
 321             MEMCPY(zoomed.array->index, indexSave, zoomed.end * sizeof(GLuint));
 322          }
 323       }
 324    }
 325 }
 326
 327
 328 void
 329 _swrast_write_zoomed_rgba_span( GLcontext *ctx, const struct sw_span *span,
 330                               CONST GLchan rgba[][4], GLint y0,
 331                               GLint skipPixels )
 332 {
 333    zoom_span(ctx, span, (const GLvoid *) rgba, y0, GL_RGBA, skipPixels);
 334 }
 335
 336
 337 void
 338 _swrast_write_zoomed_rgb_span( GLcontext *ctx, const struct sw_span *span,
 339                              CONST GLchan rgb[][3], GLint y0,
 340                              GLint skipPixels )
 341 {
 342    zoom_span(ctx, span, (const GLvoid *) rgb, y0, GL_RGB, skipPixels);
 343 }
 344
 345
 346 void
 347 _swrast_write_zoomed_index_span( GLcontext *ctx, const struct sw_span *span,
 348                                GLint y0, GLint skipPixels )
 349 {
 350    zoom_span(ctx, span, (const GLvoid *) span->array->index, y0,
 351              GL_COLOR_INDEX, skipPixels);
 352 }
 353
 354
 355 void
 356 _swrast_write_zoomed_depth_span( GLcontext *ctx, const struct sw_span *span,
 357                                  GLint y0, GLint skipPixels )
 358 {
 359    zoom_span(ctx, span, (const GLvoid *) span->array->z, y0,
 360              GL_DEPTH_COMPONENT, skipPixels);
 361 }
 362
 363
 364 /*
 365  * As above, but write stencil values.
 366  */
 367 void
 368 _swrast_write_zoomed_stencil_span( GLcontext *ctx,
 369                                  GLuint n, GLint x, GLint y,
 370                                  const GLstencil stencil[], GLint y0,
 371                                  GLint skipPixels )
 372 {
 373    GLint m;
 374    GLint r0, r1, row, r;
 375    GLint i, j, skipcol;
 376    GLstencil zstencil[MAX_WIDTH];  /* zoomed stencil values */
 377    GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
 378
 379    (void) skipPixels;  /* XXX this shouldn't be ignored */
 380
 381    /* compute width of output row */
 382    m = (GLint) FABSF( n * ctx->Pixel.ZoomX );
 383    if (m==0) {
 384       return;
 385    }
 386    if (ctx->Pixel.ZoomX<0.0) {
 387       /* adjust x coordinate for left/right mirroring */
 388       x = x - m;
 389    }
 390
 391    /* compute which rows to draw */
 392    row = y - y0;
 393    r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
 394    r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
 395    if (r0==r1) {
 396       return;
 397    }
 398    else if (r1<r0) {
 399       GLint rtmp = r1;
 400       r1 = r0;
 401       r0 = rtmp;
 402    }
 403
 404    /* return early if r0...r1 is above or below window */
 405    if (r0<0 && r1<0) {
 406       /* below window */
 407       return;
 408    }
 409    if (r0 >= (GLint) ctx->DrawBuffer->Height &&
 410        r1 >= (GLint) ctx->DrawBuffer->Height) {
 411       /* above window */
 412       return;
 413    }
 414
 415    /* check if left edge is outside window */
 416    skipcol = 0;
 417    if (x<0) {
 418       skipcol = -x;
 419       m += x;
 420    }
 421    /* make sure span isn't too long or short */
 422    if (m>maxwidth) {
 423       m = maxwidth;
 424    }
 425    else if (m<=0) {
 426       return;
 427    }
 428
 429    ASSERT( m <= MAX_WIDTH );
 430
 431    /* zoom the span horizontally */
 432    if (ctx->Pixel.ZoomX==-1.0F) {
 433       /* n==m */
 434       for (j=0;j<m;j++) {
 435          i = n - (j+skipcol) - 1;
 436          zstencil[j] = stencil[i];
 437       }
 438    }
 439    else {
 440       GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 441       for (j=0;j<m;j++) {
 442          i = (GLint) ((j+skipcol) * xscale);
 443          if (i<0)  i = n + i - 1;
 444          zstencil[j] = stencil[i];
 445       }
 446    }
 447
 448    /* write the span */
 449    for (r=r0; r<r1; r++) {
 450       _swrast_write_stencil_span( ctx, m, x+skipcol, r, zstencil );
 451    }
 452 }