src/mesa/swrast/s_zoom.c

   1 /* $Id: s_zoom.c,v 1.2 2000/11/05 18:24:41 keithw Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.5
   6  *
   7  * Copyright (C) 1999-2000  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 #include "glheader.h"
  28 #include "macros.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 /*
  38  * Write a span of pixels to the frame buffer while applying a pixel zoom.
  39  * This is only used by glDrawPixels and glCopyPixels.
  40  * Input:  n - number of pixels in input row
  41  *         x, y - destination of the span
  42  *         z - depth values for the span
  43  *         red, green, blue, alpha - array of colors
  44  *         y0 - location of first row in the image we're drawing.
  45  */
  46 void
  47 gl_write_zoomed_rgba_span( GLcontext *ctx,
  48                            GLuint n, GLint x, GLint y, const GLdepth z[],
  49                            const GLfixed *fog,
  50                            CONST GLchan rgba[][4], GLint y0 )
  51 {
  52    GLint m;
  53    GLint r0, r1, row, r;
  54    GLint i, j, skipcol;
  55    GLchan zrgba[MAX_WIDTH][4];  /* zoomed pixel colors */
  56    GLdepth zdepth[MAX_WIDTH];  /* zoomed depth values */
  57    GLfixed zfog[MAX_WIDTH];  /* zoomed fog values */
  58    GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
  59    const GLuint *srcRGBA32 = (const GLuint *) rgba;
  60    GLuint *dstRGBA32 = (GLuint *) zrgba;
  61
  62    /* compute width of output row */
  63    m = (GLint) ABSF( n * ctx->Pixel.ZoomX );
  64    if (m==0) {
  65       return;
  66    }
  67    if (ctx->Pixel.ZoomX<0.0) {
  68       /* adjust x coordinate for left/right mirroring */
  69       x = x - m;
  70    }
  71
  72    /* compute which rows to draw */
  73    row = y-y0;
  74    r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
  75    r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
  76    if (r0==r1) {
  77       return;
  78    }
  79    else if (r1<r0) {
  80       GLint rtmp = r1;
  81       r1 = r0;
  82       r0 = rtmp;
  83    }
  84
  85    /* return early if r0...r1 is above or below window */
  86    if (r0<0 && r1<0) {
  87       /* below window */
  88       return;
  89    }
  90    if (r0>=ctx->DrawBuffer->Height && r1>=ctx->DrawBuffer->Height) {
  91       /* above window */
  92       return;
  93    }
  94
  95    /* check if left edge is outside window */
  96    skipcol = 0;
  97    if (x<0) {
  98       skipcol = -x;
  99       m += x;
 100    }
 101    /* make sure span isn't too long or short */
 102    if (m>maxwidth) {
 103       m = maxwidth;
 104    }
 105    else if (m<=0) {
 106       return;
 107    }
 108
 109    assert( m <= MAX_WIDTH );
 110
 111    /* zoom the span horizontally */
 112    if (ctx->Pixel.ZoomX==-1.0F) {
 113       /* n==m */
 114       for (j=0;j<m;j++) {
 115          i = n - (j+skipcol) - 1;
 116          dstRGBA32[j] = srcRGBA32[i];
 117          zdepth[j] = z[i];
 118       }
 119       if (fog && ctx->Fog.Enabled) {
 120          for (j=0;j<m;j++) {
 121             i = n - (j+skipcol) - 1;
 122             zfog[j] = fog[i];
 123          }
 124       }
 125    }
 126    else {
 127       GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 128       for (j=0;j<m;j++) {
 129          i = (GLint) ((j+skipcol) * xscale);
 130          if (i<0)  i = n + i - 1;
 131          dstRGBA32[j] = srcRGBA32[i];
 132          zdepth[j] = z[i];
 133       }
 134       if (fog && ctx->Fog.Enabled) {
 135          for (j=0;j<m;j++) {
 136             i = (GLint) ((j+skipcol) * xscale);
 137             if (i<0)  i = n + i - 1;
 138             zfog[j] = fog[i];
 139          }
 140       }
 141    }
 142
 143    /* write the span */
 144    for (r=r0; r<r1; r++) {
 145       gl_write_rgba_span( ctx, m, x+skipcol, r, zdepth,
 146                           (fog ? zfog : 0),
 147                           zrgba, GL_BITMAP );
 148    }
 149 }
 150
 151
 152
 153 void
 154 gl_write_zoomed_rgb_span( GLcontext *ctx,
 155                           GLuint n, GLint x, GLint y, const GLdepth z[],
 156                           const GLfixed *fog,
 157                           CONST GLchan rgb[][3], GLint y0 )
 158 {
 159    GLint m;
 160    GLint r0, r1, row, r;
 161    GLint i, j, skipcol;
 162    GLchan zrgba[MAX_WIDTH][4];  /* zoomed pixel colors */
 163    GLdepth zdepth[MAX_WIDTH];  /* zoomed depth values */
 164    GLfixed zfog[MAX_WIDTH];  /* zoomed fog values */
 165    GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
 166
 167    /* compute width of output row */
 168    m = (GLint) ABSF( n * ctx->Pixel.ZoomX );
 169    if (m==0) {
 170       return;
 171    }
 172    if (ctx->Pixel.ZoomX<0.0) {
 173       /* adjust x coordinate for left/right mirroring */
 174       x = x - m;
 175    }
 176
 177    /* compute which rows to draw */
 178    row = y-y0;
 179    r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
 180    r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
 181    if (r0==r1) {
 182       return;
 183    }
 184    else if (r1<r0) {
 185       GLint rtmp = r1;
 186       r1 = r0;
 187       r0 = rtmp;
 188    }
 189
 190    /* return early if r0...r1 is above or below window */
 191    if (r0<0 && r1<0) {
 192       /* below window */
 193       return;
 194    }
 195    if (r0>=ctx->DrawBuffer->Height && r1>=ctx->DrawBuffer->Height) {
 196       /* above window */
 197       return;
 198    }
 199
 200    /* check if left edge is outside window */
 201    skipcol = 0;
 202    if (x<0) {
 203       skipcol = -x;
 204       m += x;
 205    }
 206    /* make sure span isn't too long or short */
 207    if (m>maxwidth) {
 208       m = maxwidth;
 209    }
 210    else if (m<=0) {
 211       return;
 212    }
 213
 214    assert( m <= MAX_WIDTH );
 215
 216    /* zoom the span horizontally */
 217    if (ctx->Pixel.ZoomX==-1.0F) {
 218       /* n==m */
 219       for (j=0;j<m;j++) {
 220          i = n - (j+skipcol) - 1;
 221          zrgba[j][0] = rgb[i][0];
 222          zrgba[j][1] = rgb[i][1];
 223          zrgba[j][2] = rgb[i][2];
 224          zrgba[j][3] = CHAN_MAX;
 225          zdepth[j] = z[i];
 226       }
 227       if (fog && ctx->Fog.Enabled) {
 228          for (j=0;j<m;j++) {
 229             i = n - (j+skipcol) - 1;
 230             zfog[j] = fog[i];
 231          }
 232       }
 233    }
 234    else {
 235       GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 236       for (j=0;j<m;j++) {
 237          i = (GLint) ((j+skipcol) * xscale);
 238          if (i<0)  i = n + i - 1;
 239          zrgba[j][0] = rgb[i][0];
 240          zrgba[j][1] = rgb[i][1];
 241          zrgba[j][2] = rgb[i][2];
 242          zrgba[j][3] = CHAN_MAX;
 243          zdepth[j] = z[i];
 244       }
 245       if (fog && ctx->Fog.Enabled) {
 246          for (j=0;j<m;j++) {
 247             i = (GLint) ((j+skipcol) * xscale);
 248             if (i<0)  i = n + i - 1;
 249             zfog[j] = fog[i];
 250          }
 251       }
 252    }
 253
 254    /* write the span */
 255    for (r=r0; r<r1; r++) {
 256       gl_write_rgba_span( ctx, m, x+skipcol, r, zdepth,
 257                           (fog ? zfog : 0), zrgba, GL_BITMAP );
 258    }
 259 }
 260
 261
 262
 263 /*
 264  * As above, but write CI pixels.
 265  */
 266 void
 267 gl_write_zoomed_index_span( GLcontext *ctx,
 268                             GLuint n, GLint x, GLint y, const GLdepth z[],
 269                             const GLfixed *fog,
 270                             const GLuint indexes[], GLint y0 )
 271 {
 272    GLint m;
 273    GLint r0, r1, row, r;
 274    GLint i, j, skipcol;
 275    GLuint zindexes[MAX_WIDTH];  /* zoomed color indexes */
 276    GLdepth zdepth[MAX_WIDTH];  /* zoomed depth values */
 277    GLfixed zfog[MAX_WIDTH];  /* zoomed fog values */
 278    GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
 279
 280    /* compute width of output row */
 281    m = (GLint) ABSF( n * ctx->Pixel.ZoomX );
 282    if (m==0) {
 283       return;
 284    }
 285    if (ctx->Pixel.ZoomX<0.0) {
 286       /* adjust x coordinate for left/right mirroring */
 287       x = x - m;
 288    }
 289
 290    /* compute which rows to draw */
 291    row = y-y0;
 292    r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
 293    r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
 294    if (r0==r1) {
 295       return;
 296    }
 297    else if (r1<r0) {
 298       GLint rtmp = r1;
 299       r1 = r0;
 300       r0 = rtmp;
 301    }
 302
 303    /* return early if r0...r1 is above or below window */
 304    if (r0<0 && r1<0) {
 305       /* below window */
 306       return;
 307    }
 308    if (r0>=ctx->DrawBuffer->Height && r1>=ctx->DrawBuffer->Height) {
 309       /* above window */
 310       return;
 311    }
 312
 313    /* check if left edge is outside window */
 314    skipcol = 0;
 315    if (x<0) {
 316       skipcol = -x;
 317       m += x;
 318    }
 319    /* make sure span isn't too long or short */
 320    if (m>maxwidth) {
 321       m = maxwidth;
 322    }
 323    else if (m<=0) {
 324       return;
 325    }
 326
 327    assert( m <= MAX_WIDTH );
 328
 329    /* zoom the span horizontally */
 330    if (ctx->Pixel.ZoomX==-1.0F) {
 331       /* n==m */
 332       for (j=0;j<m;j++) {
 333          i = n - (j+skipcol) - 1;
 334          zindexes[j] = indexes[i];
 335          zdepth[j]   = z[i];
 336       }
 337       if (fog && ctx->Fog.Enabled) {
 338          for (j=0;j<m;j++) {
 339             i = n - (j+skipcol) - 1;
 340             zfog[j] = fog[i];
 341          }
 342       }
 343    }
 344    else {
 345       GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 346       for (j=0;j<m;j++) {
 347          i = (GLint) ((j+skipcol) * xscale);
 348          if (i<0)  i = n + i - 1;
 349          zindexes[j] = indexes[i];
 350          zdepth[j] = z[i];
 351       }
 352       if (fog && ctx->Fog.Enabled) {
 353          for (j=0;j<m;j++) {
 354             i = (GLint) ((j+skipcol) * xscale);
 355             if (i<0)  i = n + i - 1;
 356             zfog[j] = fog[i];
 357          }
 358       }
 359    }
 360
 361    /* write the span */
 362    for (r=r0; r<r1; r++) {
 363       gl_write_index_span( ctx, m, x+skipcol, r, zdepth,
 364                            (fog ? zfog : 0), zindexes, GL_BITMAP );
 365    }
 366 }
 367
 368
 369
 370 /*
 371  * As above, but write stencil values.
 372  */
 373 void
 374 gl_write_zoomed_stencil_span( GLcontext *ctx,
 375                               GLuint n, GLint x, GLint y,
 376                               const GLstencil stencil[], GLint y0 )
 377 {
 378    GLint m;
 379    GLint r0, r1, row, r;
 380    GLint i, j, skipcol;
 381    GLstencil zstencil[MAX_WIDTH];  /* zoomed stencil values */
 382    GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
 383
 384    /* compute width of output row */
 385    m = (GLint) ABSF( n * ctx->Pixel.ZoomX );
 386    if (m==0) {
 387       return;
 388    }
 389    if (ctx->Pixel.ZoomX<0.0) {
 390       /* adjust x coordinate for left/right mirroring */
 391       x = x - m;
 392    }
 393
 394    /* compute which rows to draw */
 395    row = y-y0;
 396    r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
 397    r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
 398    if (r0==r1) {
 399       return;
 400    }
 401    else if (r1<r0) {
 402       GLint rtmp = r1;
 403       r1 = r0;
 404       r0 = rtmp;
 405    }
 406
 407    /* return early if r0...r1 is above or below window */
 408    if (r0<0 && r1<0) {
 409       /* below window */
 410       return;
 411    }
 412    if (r0>=ctx->DrawBuffer->Height && r1>=ctx->DrawBuffer->Height) {
 413       /* above window */
 414       return;
 415    }
 416
 417    /* check if left edge is outside window */
 418    skipcol = 0;
 419    if (x<0) {
 420       skipcol = -x;
 421       m += x;
 422    }
 423    /* make sure span isn't too long or short */
 424    if (m>maxwidth) {
 425       m = maxwidth;
 426    }
 427    else if (m<=0) {
 428       return;
 429    }
 430
 431    assert( m <= MAX_WIDTH );
 432
 433    /* zoom the span horizontally */
 434    if (ctx->Pixel.ZoomX==-1.0F) {
 435       /* n==m */
 436       for (j=0;j<m;j++) {
 437          i = n - (j+skipcol) - 1;
 438          zstencil[j] = stencil[i];
 439       }
 440    }
 441    else {
 442       GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
 443       for (j=0;j<m;j++) {
 444          i = (GLint) ((j+skipcol) * xscale);
 445          if (i<0)  i = n + i - 1;
 446          zstencil[j] = stencil[i];
 447       }
 448    }
 449
 450    /* write the span */
 451    for (r=r0; r<r1; r++) {
 452       _mesa_write_stencil_span( ctx, m, x+skipcol, r, zstencil );
 453    }
 454 }