src/mesa/swrast/s_zoom.c

   1
   2 /*
   3  * Mesa 3-D graphics library
   4  * Version:  5.1
   5  *
   6  * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 #include "glheader.h"
  27 #include "macros.h"
  28 #include "imports.h"
  29 #include "colormac.h"
  30
  31 #include "s_context.h"
  32 #include "s_span.h"
  33 #include "s_stencil.h"
  34 #include "s_zoom.h"
  35
  36
  37 /*
  38  * Helper function called from _swrast_write_zoomed_rgba/rgb/index_span().
  39  */
  40 static void
  41 zoom_span( GLcontext *ctx, const struct sw_span *span,
  42            const GLvoid *src, GLint y0, GLenum format, GLint skipPixels )
  43 {
  44    GLint r0, r1, row;
  45    GLint c0, c1, skipCol;
  46    GLint i, j;
  47    const GLuint maxWidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
  48    struct sw_span zoomed;
  49    struct span_arrays zoomed_arrays;  /* this is big! */
  50
  51    /* no pixel arrays! must be horizontal spans. */
  52    ASSERT((span->arrayMask & SPAN_XY) == 0);
  53    ASSERT(span->primitive == GL_BITMAP);
  54
  55    INIT_SPAN(zoomed, GL_BITMAP, 0, 0, 0);
  56    zoomed.array = &zoomed_arrays;
  57
  58    /* copy fog interp info */
  59    zoomed.fog = span->fog;
  60    zoomed.fogStep = span->fogStep;
  61    /* XXX copy texcoord info? */
  62
  63    if (format == GL_RGBA || format == GL_RGB) {
  64       /* copy Z info */
  65       zoomed.z = span->z;
  66       zoomed.zStep = span->zStep;
  67       /* we'll generate an array of colorss */
  68       zoomed.interpMask = span->interpMask & ~SPAN_RGBA;
  69       zoomed.arrayMask |= SPAN_RGBA;
  70    }
  71    else if (format == GL_COLOR_INDEX) {
  72       /* copy Z info */
  73       zoomed.z = span->z;
  74       zoomed.zStep = span->zStep;
  75       /* we'll generate an array of color indexes */
  76       zoomed.interpMask = span->interpMask & ~SPAN_INDEX;
  77       zoomed.arrayMask |= SPAN_INDEX;
  78    }
  79    else {
  80       assert(format == GL_DEPTH_COMPONENT);
  81       /* Copy color info */
  82       zoomed.red = span->red;
  83       zoomed.green = span->green;
  84       zoomed.blue = span->blue;
  85       zoomed.alpha = span->alpha;
  86       zoomed.redStep = span->redStep;
  87       zoomed.greenStep = span->greenStep;
  88       zoomed.blueStep = span->blueStep;
  89       zoomed.alphaStep = span->alphaStep;
  90       /* we'll generate an array of depth values */
  91       zoomed.interpMask = span->interpMask & ~SPAN_Z;
  92       zoomed.arrayMask |= SPAN_Z;
  93    }
  94
  95    /*
  96     * Compute which columns to draw: [c0, c1)
  97     */
  98    c0 = (GLint) (span->x + skipPixels * ctx->Pixel.ZoomX);
  99    c1 = (GLint) (span->x + (skipPixels + span->end) * ctx->Pixel.ZoomX);
 100    if (c0 == c1) {
 101       return;
 102    }
 103    else if (c1 < c0) {
 104       /* swap */
 105       GLint ctmp = c1;
 106       c1 = c0;
 107       c0 = ctmp;
 108    }
 109    if (c0 < 0) {
 110       zoomed.x = 0;
 111       zoomed.start = 0;
 112       zoomed.end = c1;
 113       skipCol = -c0;
 114    }
 115    else {
 116       zoomed.x = c0;
 117       zoomed.start = 0;
 118       zoomed.end = c1 - c0;
 119       skipCol = 0;
 120    }
 121    if (zoomed.end > maxWidth)
 122       zoomed.end = maxWidth;
 123
 124    /*
 125     * Compute which rows to draw: [r0, r1)
 126     */
 127    row = span->y - y0;
 128    r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
 129    r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
 130    if (r0 == r1) {
 131       return;
 132    }
 133    else if (r1 < r0) {
 134       /* swap */
 135       GLint rtmp = r1;
 136       r1 = r0;
 137       r0 = rtmp;
 138    }
 139
 140    ASSERT(r0 < r1);
 141    ASSERT(c0 < c1);
 142
 143    /*
 144     * Trivial clip rejection testing.
 145     */
 146    if (r1 < 0) /* below window */
 147       return;
 148    if (r0 >= (GLint) ctx->DrawBuffer->Height) /* above window */
 149       return;
 150    if (c1 < 0) /* left of window */
 151       return;
 152    if (c0 >= (GLint) ctx->DrawBuffer->Width) /* right of window */
 153       return;
 154
 155    /* zoom the span horizontally */
 156    if (format == GL_RGBA) {
 157       const GLchan (*rgba)[4] = (const GLchan (*)[4]) src;
 158       if (ctx->Pixel.ZoomX == -1.0F) {
 159          /* common case */
 160          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 161             i = span->end - (j + skipCol) - 1;
 162             COPY_CHAN4(zoomed.array->rgba[j], rgba[i]);
 163          }
 164       }
 165       else {
 166          /* general solution */
 167          const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 168          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 169             i = (GLint) ((j + skipCol) * xscale);
 170             if (ctx->Pixel.ZoomX < 0.0) {
 171                ASSERT(i <= 0);
 172                i = span->end + i - 1;
 173             }
 174             ASSERT(i >= 0);
 175             ASSERT(i < (GLint)  span->end);
 176             COPY_CHAN4(zoomed.array->rgba[j], rgba[i]);
 177          }
 178       }
 179    }
 180    else if (format == GL_RGB) {
 181       const GLchan (*rgb)[3] = (const GLchan (*)[3]) src;
 182       if (ctx->Pixel.ZoomX == -1.0F) {
 183          /* common case */
 184          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 185             i = span->end - (j + skipCol) - 1;
 186             zoomed.array->rgba[j][0] = rgb[i][0];
 187             zoomed.array->rgba[j][1] = rgb[i][1];
 188             zoomed.array->rgba[j][2] = rgb[i][2];
 189             zoomed.array->rgba[j][3] = CHAN_MAX;
 190          }
 191       }
 192       else {
 193          /* general solution */
 194          const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 195          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 196             i = (GLint) ((j + skipCol) * xscale);
 197             if (ctx->Pixel.ZoomX < 0.0) {
 198                ASSERT(i <= 0);
 199                i = span->end + i - 1;
 200             }
 201             ASSERT(i >= 0);
 202             ASSERT(i < (GLint) span->end);
 203             zoomed.array->rgba[j][0] = rgb[i][0];
 204             zoomed.array->rgba[j][1] = rgb[i][1];
 205             zoomed.array->rgba[j][2] = rgb[i][2];
 206             zoomed.array->rgba[j][3] = CHAN_MAX;
 207          }
 208       }
 209    }
 210    else if (format == GL_COLOR_INDEX) {
 211       const GLuint *indexes = (const GLuint *) src;
 212       if (ctx->Pixel.ZoomX == -1.0F) {
 213          /* common case */
 214          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 215             i = span->end - (j + skipCol) - 1;
 216             zoomed.array->index[j] = indexes[i];
 217          }
 218       }
 219       else {
 220          /* general solution */
 221          const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 222          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 223             i = (GLint) ((j + skipCol) * xscale);
 224             if (ctx->Pixel.ZoomX < 0.0) {
 225                ASSERT(i <= 0);
 226                i = span->end + i - 1;
 227             }
 228             ASSERT(i >= 0);
 229             ASSERT(i < (GLint) span->end);
 230             zoomed.array->index[j] = indexes[i];
 231          }
 232       }
 233    }
 234    else {
 235       const GLdepth *zValues = (const GLuint *) src;
 236       assert(format == GL_DEPTH_COMPONENT);
 237       if (ctx->Pixel.ZoomX == -1.0F) {
 238          /* common case */
 239          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 240             i = span->end - (j + skipCol) - 1;
 241             zoomed.array->z[j] = zValues[i];
 242          }
 243       }
 244       else {
 245          /* general solution */
 246          const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 247          for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
 248             i = (GLint) ((j + skipCol) * xscale);
 249             if (ctx->Pixel.ZoomX < 0.0) {
 250                ASSERT(i <= 0);
 251                i = span->end + i - 1;
 252             }
 253             ASSERT(i >= 0);
 254             ASSERT(i < (GLint) span->end);
 255             zoomed.array->z[j] = zValues[i];
 256          }
 257       }
 258       /* Now, fall into either the RGB or COLOR_INDEX path below */
 259       if (ctx->Visual.rgbMode)
 260          format = GL_RGBA;
 261       else
 262          format = GL_COLOR_INDEX;
 263    }
 264
 265
 266    /* write the span in rows [r0, r1) */
 267    if (format == GL_RGBA || format == GL_RGB) {
 268       /* Writing the span may modify the colors, so make a backup now if we're
 269        * going to call _swrast_write_zoomed_span() more than once.
 270        * Also, clipping may change the span end value, so store it as well.
 271        */
 272       GLchan rgbaSave[MAX_WIDTH][4];
 273       const GLint end = zoomed.end; /* save */
 274       if (r1 - r0 > 1) {
 275          MEMCPY(rgbaSave, zoomed.array->rgba, zoomed.end * 4 * sizeof(GLchan));
 276       }
 277       for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
 278          _swrast_write_rgba_span(ctx, &zoomed);
 279          zoomed.end = end;  /* restore */
 280          if (r1 - r0 > 1) {
 281             /* restore the colors */
 282             MEMCPY(zoomed.array->rgba, rgbaSave, zoomed.end*4 * sizeof(GLchan));
 283          }
 284       }
 285    }
 286    else if (format == GL_COLOR_INDEX) {
 287       GLuint indexSave[MAX_WIDTH];
 288       const GLint end = zoomed.end; /* save */
 289       if (r1 - r0 > 1) {
 290          MEMCPY(indexSave, zoomed.array->index, zoomed.end * sizeof(GLuint));
 291       }
 292       for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
 293          _swrast_write_index_span(ctx, &zoomed);
 294          zoomed.end = end;  /* restore */
 295          if (r1 - r0 > 1) {
 296             /* restore the colors */
 297             MEMCPY(zoomed.array->index, indexSave, zoomed.end * sizeof(GLuint));
 298          }
 299       }
 300    }
 301 }
 302
 303
 304 void
 305 _swrast_write_zoomed_rgba_span( GLcontext *ctx, const struct sw_span *span,
 306                               CONST GLchan rgba[][4], GLint y0,
 307                               GLint skipPixels )
 308 {
 309    zoom_span(ctx, span, (const GLvoid *) rgba, y0, GL_RGBA, skipPixels);
 310 }
 311
 312
 313 void
 314 _swrast_write_zoomed_rgb_span( GLcontext *ctx, const struct sw_span *span,
 315                              CONST GLchan rgb[][3], GLint y0,
 316                              GLint skipPixels )
 317 {
 318    zoom_span(ctx, span, (const GLvoid *) rgb, y0, GL_RGB, skipPixels);
 319 }
 320
 321
 322 void
 323 _swrast_write_zoomed_index_span( GLcontext *ctx, const struct sw_span *span,
 324                                GLint y0, GLint skipPixels )
 325 {
 326    zoom_span(ctx, span, (const GLvoid *) span->array->index, y0,
 327              GL_COLOR_INDEX, skipPixels);
 328 }
 329
 330
 331 void
 332 _swrast_write_zoomed_depth_span( GLcontext *ctx, const struct sw_span *span,
 333                                  GLint y0, GLint skipPixels )
 334 {
 335    zoom_span(ctx, span, (const GLvoid *) span->array->z, y0,
 336              GL_DEPTH_COMPONENT, skipPixels);
 337 }
 338
 339
 340 /*
 341  * As above, but write stencil values.
 342  */
 343 void
 344 _swrast_write_zoomed_stencil_span( GLcontext *ctx,
 345                                  GLuint n, GLint x, GLint y,
 346                                  const GLstencil stencil[], GLint y0,
 347                                  GLint skipPixels )
 348 {
 349    GLint m;
 350    GLint r0, r1, row, r;
 351    GLint i, j, skipcol;
 352    GLstencil zstencil[MAX_WIDTH];  /* zoomed stencil values */
 353    GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
 354
 355    (void) skipPixels;  /* XXX this shouldn't be ignored */
 356
 357    /* compute width of output row */
 358    m = (GLint) FABSF( n * ctx->Pixel.ZoomX );
 359    if (m==0) {
 360       return;
 361    }
 362    if (ctx->Pixel.ZoomX<0.0) {
 363       /* adjust x coordinate for left/right mirroring */
 364       x = x - m;
 365    }
 366
 367    /* compute which rows to draw */
 368    row = y - y0;
 369    r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
 370    r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
 371    if (r0==r1) {
 372       return;
 373    }
 374    else if (r1<r0) {
 375       GLint rtmp = r1;
 376       r1 = r0;
 377       r0 = rtmp;
 378    }
 379
 380    /* return early if r0...r1 is above or below window */
 381    if (r0<0 && r1<0) {
 382       /* below window */
 383       return;
 384    }
 385    if (r0 >= (GLint) ctx->DrawBuffer->Height &&
 386        r1 >= (GLint) ctx->DrawBuffer->Height) {
 387       /* above window */
 388       return;
 389    }
 390
 391    /* check if left edge is outside window */
 392    skipcol = 0;
 393    if (x<0) {
 394       skipcol = -x;
 395       m += x;
 396    }
 397    /* make sure span isn't too long or short */
 398    if (m>maxwidth) {
 399       m = maxwidth;
 400    }
 401    else if (m<=0) {
 402       return;
 403    }
 404
 405    ASSERT( m <= MAX_WIDTH );
 406
 407    /* zoom the span horizontally */
 408    if (ctx->Pixel.ZoomX==-1.0F) {
 409       /* n==m */
 410       for (j=0;j<m;j++) {
 411          i = n - (j+skipcol) - 1;
 412          zstencil[j] = stencil[i];
 413       }
 414    }
 415    else {
 416       GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 417       for (j=0;j<m;j++) {
 418          i = (GLint) ((j+skipcol) * xscale);
 419          if (i<0)  i = n + i - 1;
 420          zstencil[j] = stencil[i];
 421       }
 422    }
 423
 424    /* write the span */
 425    for (r=r0; r<r1; r++) {
 426       _swrast_write_stencil_span( ctx, m, x+skipcol, r, zstencil );
 427    }
 428 }