src/mesa/swrast/s_zoom.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.2
   4  *
   5  * Copyright (C) 1999-2006  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  * Compute the bounds of the region resulting from zooming a pixel span.
  38  * The resulting region will be entirely inside the window/scissor bounds
  39  * so no additional clipping is needed.
  40  * \param imageX, imageY  position of the mage being drawn (gl WindowPos)
  41  * \param spanX, spanY  position of span being drawing
  42  * \param width  number of pixels in span
  43  * \param x0, x1  returned X bounds of zoomed region [x0, x1)
  44  * \param y0, y1  returned Y bounds of zoomed region [y0, y1)
  45  * \return GL_TRUE if any zoomed pixels visible, GL_FALSE if totally clipped
  46  */
  47 static GLboolean
  48 compute_zoomed_bounds(GLcontext *ctx, GLint imageX, GLint imageY,
  49                       GLint spanX, GLint spanY, GLint width,
  50                       GLint *x0, GLint *x1, GLint *y0, GLint *y1)
  51 {
  52    const struct gl_framebuffer *fb = ctx->DrawBuffer;
  53    GLint c0, c1, r0, r1;
  54
  55    ASSERT(spanX >= imageX);
  56    ASSERT(spanY >= imageY);
  57
  58    /*
  59     * Compute destination columns: [c0, c1)
  60     */
  61    c0 = imageX + (GLint) ((spanX - imageX) * ctx->Pixel.ZoomX);
  62    c1 = imageX + (GLint) ((spanX + width - imageX) * ctx->Pixel.ZoomX);
  63    if (c1 < c0) {
  64       /* swap */
  65       GLint tmp = c1;
  66       c1 = c0;
  67       c0 = tmp;
  68    }
  69    c0 = CLAMP(c0, fb->_Xmin, fb->_Xmax);
  70    c1 = CLAMP(c1, fb->_Xmin, fb->_Xmax);
  71    if (c0 == c1) {
  72       return GL_FALSE; /* no width */
  73    }
  74
  75    /*
  76     * Compute destination rows: [r0, r1)
  77     */
  78    r0 = imageY + (GLint) ((spanY - imageY) * ctx->Pixel.ZoomY);
  79    r1 = imageY + (GLint) ((spanY + 1 - imageY) * ctx->Pixel.ZoomY);
  80    if (r1 < r0) {
  81       /* swap */
  82       GLint tmp = r1;
  83       r1 = r0;
  84       r0 = tmp;
  85    }
  86    r0 = CLAMP(r0, fb->_Ymin, fb->_Ymax);
  87    r1 = CLAMP(r1, fb->_Ymin, fb->_Ymax);
  88    if (r0 == r1) {
  89       return GL_FALSE; /* no height */
  90    }
  91
  92    *x0 = c0;
  93    *x1 = c1;
  94    *y0 = r0;
  95    *y1 = r1;
  96
  97    return GL_TRUE;
  98 }
  99
 100
 101 /**
 102  * Convert a zoomed x image coordinate back to an unzoomed x coord.
 103  * 'zx' is screen position of a pixel in the zoomed image, who's left edge
 104  * is at 'imageX'.
 105  * return corresponding x coord in the original, unzoomed image.
 106  * This can use this for unzooming X or Y values.
 107  */
 108 static INLINE GLint
 109 unzoom_x(GLfloat zoomX, GLint imageX, GLint zx)
 110 {
 111    /*
 112    zx = imageX + (x - imageX) * zoomX;
 113    zx - imageX = (x - imageX) * zoomX;
 114    (zx - imageX) / zoomX = x - imageX;
 115    */
 116    GLint x;
 117    if (zoomX < 0.0)
 118       zx++;
 119    x = imageX + (GLint) ((zx - imageX) / zoomX);
 120    return x;
 121 }
 122
 123
 124
 125 /**
 126  * Helper function called from _swrast_write_zoomed_rgba/rgb/
 127  * index/depth_span().
 128  */
 129 static void
 130 zoom_span( GLcontext *ctx, GLint imgX, GLint imgY, const SWspan *span,
 131            const GLvoid *src, GLenum format )
 132 {
 133    SWspan zoomed;
 134    SWspanarrays zoomed_arrays;  /* this is big! */
 135    GLint x0, x1, y0, y1;
 136    GLint zoomedWidth;
 137
 138    if (!compute_zoomed_bounds(ctx, imgX, imgY, span->x, span->y, span->end,
 139                               &x0, &x1, &y0, &y1)) {
 140       return;  /* totally clipped */
 141    }
 142
 143    zoomedWidth = x1 - x0;
 144    ASSERT(zoomedWidth > 0);
 145    ASSERT(zoomedWidth <= MAX_WIDTH);
 146
 147    /* no pixel arrays! must be horizontal spans. */
 148    ASSERT((span->arrayMask & SPAN_XY) == 0);
 149    ASSERT(span->primitive == GL_BITMAP);
 150
 151    INIT_SPAN(zoomed, GL_BITMAP, 0, 0, 0);
 152    zoomed.x = x0;
 153    zoomed.end = zoomedWidth;
 154    zoomed.array = &zoomed_arrays;
 155    zoomed_arrays.ChanType = span->array->ChanType;
 156    /* XXX temporary */
 157 #if CHAN_TYPE == GL_UNSIGNED_BYTE
 158    zoomed_arrays.rgba = zoomed_arrays.rgba8;
 159 #elif CHAN_TYPE == GL_UNSIGNED_SHORT
 160    zoomed_arrays.rgba = zoomed_arrays.rgba16;
 161 #else
 162    zoomed_arrays.rgba = zoomed_arrays.attribs[FRAG_ATTRIB_COL0];
 163 #endif
 164
 165    /* copy attribute info (XXX copy all attribs?) */
 166    COPY_4V(zoomed.attrStart[FRAG_ATTRIB_WPOS], span->attrStart[FRAG_ATTRIB_WPOS]);
 167    COPY_4V(zoomed.attrStepX[FRAG_ATTRIB_WPOS], span->attrStepX[FRAG_ATTRIB_WPOS]);
 168    COPY_4V(zoomed.attrStepY[FRAG_ATTRIB_WPOS], span->attrStepY[FRAG_ATTRIB_WPOS]);
 169
 170    zoomed.attrStart[FRAG_ATTRIB_FOGC][0] = span->attrStart[FRAG_ATTRIB_FOGC][0];
 171    zoomed.attrStepX[FRAG_ATTRIB_FOGC][0] = span->attrStepX[FRAG_ATTRIB_FOGC][0];
 172    zoomed.attrStepY[FRAG_ATTRIB_FOGC][0] = span->attrStepY[FRAG_ATTRIB_FOGC][0];
 173
 174    if (format == GL_RGBA || format == GL_RGB) {
 175       /* copy Z info */
 176       zoomed.z = span->z;
 177       zoomed.zStep = span->zStep;
 178       /* we'll generate an array of colorss */
 179       zoomed.interpMask = span->interpMask & ~SPAN_RGBA;
 180       zoomed.arrayMask |= SPAN_RGBA;
 181       ASSERT(span->arrayMask & SPAN_RGBA);
 182    }
 183    else if (format == GL_COLOR_INDEX) {
 184       /* copy Z info */
 185       zoomed.z = span->z;
 186       zoomed.zStep = span->zStep;
 187       /* we'll generate an array of color indexes */
 188       zoomed.interpMask = span->interpMask & ~SPAN_INDEX;
 189       zoomed.arrayMask |= SPAN_INDEX;
 190       ASSERT(span->arrayMask & SPAN_INDEX);
 191    }
 192    else if (format == GL_DEPTH_COMPONENT) {
 193       /* Copy color info */
 194       zoomed.red = span->red;
 195       zoomed.green = span->green;
 196       zoomed.blue = span->blue;
 197       zoomed.alpha = span->alpha;
 198       zoomed.redStep = span->redStep;
 199       zoomed.greenStep = span->greenStep;
 200       zoomed.blueStep = span->blueStep;
 201       zoomed.alphaStep = span->alphaStep;
 202       /* we'll generate an array of depth values */
 203       zoomed.interpMask = span->interpMask & ~SPAN_Z;
 204       zoomed.arrayMask |= SPAN_Z;
 205       ASSERT(span->arrayMask & SPAN_Z);
 206    }
 207    else {
 208       _mesa_problem(ctx, "Bad format in zoom_span");
 209       return;
 210    }
 211
 212    /* zoom the span horizontally */
 213    if (format == GL_RGBA) {
 214       if (zoomed.array->ChanType == GL_UNSIGNED_BYTE) {
 215          const GLubyte (*rgba)[4] = (const GLubyte (*)[4]) src;
 216          GLint i;
 217          for (i = 0; i < zoomedWidth; i++) {
 218             GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - span->x;
 219             ASSERT(j >= 0);
 220             ASSERT(j < (GLint) span->end);
 221             COPY_4UBV(zoomed.array->rgba8[i], rgba[j]);
 222          }
 223       }
 224       else if (zoomed.array->ChanType == GL_UNSIGNED_SHORT) {
 225          const GLushort (*rgba)[4] = (const GLushort (*)[4]) src;
 226          GLint i;
 227          for (i = 0; i < zoomedWidth; i++) {
 228             GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - span->x;
 229             ASSERT(j >= 0);
 230             ASSERT(j < (GLint) span->end);
 231             COPY_4V(zoomed.array->rgba16[i], rgba[j]);
 232          }
 233       }
 234       else {
 235          const GLfloat (*rgba)[4] = (const GLfloat (*)[4]) src;
 236          GLint i;
 237          for (i = 0; i < zoomedWidth; i++) {
 238             GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - span->x;
 239             ASSERT(j >= 0);
 240             ASSERT(j < span->end);
 241             COPY_4V(zoomed.array->attribs[FRAG_ATTRIB_COL0][i], rgba[j]);
 242          }
 243       }
 244    }
 245    else if (format == GL_RGB) {
 246       if (zoomed.array->ChanType == GL_UNSIGNED_BYTE) {
 247          const GLubyte (*rgb)[3] = (const GLubyte (*)[3]) src;
 248          GLint i;
 249          for (i = 0; i < zoomedWidth; i++) {
 250             GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - span->x;
 251             ASSERT(j >= 0);
 252             ASSERT(j < (GLint) span->end);
 253             zoomed.array->rgba8[i][0] = rgb[j][0];
 254             zoomed.array->rgba8[i][1] = rgb[j][1];
 255             zoomed.array->rgba8[i][2] = rgb[j][2];
 256             zoomed.array->rgba8[i][3] = 0xff;
 257          }
 258       }
 259       else if (zoomed.array->ChanType == GL_UNSIGNED_SHORT) {
 260          const GLushort (*rgb)[3] = (const GLushort (*)[3]) src;
 261          GLint i;
 262          for (i = 0; i < zoomedWidth; i++) {
 263             GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - span->x;
 264             ASSERT(j >= 0);
 265             ASSERT(j < (GLint) span->end);
 266             zoomed.array->rgba16[i][0] = rgb[j][0];
 267             zoomed.array->rgba16[i][1] = rgb[j][1];
 268             zoomed.array->rgba16[i][2] = rgb[j][2];
 269             zoomed.array->rgba16[i][3] = 0xffff;
 270          }
 271       }
 272       else {
 273          const GLfloat (*rgb)[3] = (const GLfloat (*)[3]) src;
 274          GLint i;
 275          for (i = 0; i < zoomedWidth; i++) {
 276             GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - span->x;
 277             ASSERT(j >= 0);
 278             ASSERT(j < span->end);
 279             zoomed.array->attribs[FRAG_ATTRIB_COL0][i][0] = rgb[j][0];
 280             zoomed.array->attribs[FRAG_ATTRIB_COL0][i][1] = rgb[j][1];
 281             zoomed.array->attribs[FRAG_ATTRIB_COL0][i][2] = rgb[j][2];
 282             zoomed.array->attribs[FRAG_ATTRIB_COL0][i][3] = 1.0F;
 283          }
 284       }
 285    }
 286    else if (format == GL_COLOR_INDEX) {
 287       const GLuint *indexes = (const GLuint *) src;
 288       GLint i;
 289       for (i = 0; i < zoomedWidth; i++) {
 290          GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - span->x;
 291          ASSERT(j >= 0);
 292          ASSERT(j < (GLint) span->end);
 293          zoomed.array->index[i] = indexes[j];
 294       }
 295    }
 296    else if (format == GL_DEPTH_COMPONENT) {
 297       const GLuint *zValues = (const GLuint *) src;
 298       GLint i;
 299       for (i = 0; i < zoomedWidth; i++) {
 300          GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - span->x;
 301          ASSERT(j >= 0);
 302          ASSERT(j < (GLint) span->end);
 303          zoomed.array->z[i] = zValues[j];
 304       }
 305       /* Now, fall into either the RGB or COLOR_INDEX path below */
 306       format = ctx->Visual.rgbMode ? GL_RGBA : GL_COLOR_INDEX;
 307    }
 308
 309    /* write the span in rows [r0, r1) */
 310    if (format == GL_RGBA || format == GL_RGB) {
 311       /* Writing the span may modify the colors, so make a backup now if we're
 312        * going to call _swrast_write_zoomed_span() more than once.
 313        * Also, clipping may change the span end value, so store it as well.
 314        */
 315       const GLint end = zoomed.end; /* save */
 316       GLuint rgbaSave[MAX_WIDTH][4];
 317       const GLint pixelSize =
 318          (zoomed.array->ChanType == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) :
 319          ((zoomed.array->ChanType == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort)
 320           : 4 * sizeof(GLfloat));
 321       if (y1 - y0 > 1) {
 322          MEMCPY(rgbaSave, zoomed.array->rgba, zoomed.end * pixelSize);
 323       }
 324       for (zoomed.y = y0; zoomed.y < y1; zoomed.y++) {
 325          _swrast_write_rgba_span(ctx, &zoomed);
 326          zoomed.end = end;  /* restore */
 327          if (y1 - y0 > 1) {
 328             /* restore the colors */
 329             MEMCPY(zoomed.array->rgba, rgbaSave, zoomed.end * pixelSize);
 330          }
 331       }
 332    }
 333    else if (format == GL_COLOR_INDEX) {
 334       /* use specular color array for temp storage */
 335       GLuint *indexSave = (GLuint *) zoomed.array->attribs[FRAG_ATTRIB_FOGC];
 336       const GLint end = zoomed.end; /* save */
 337       if (y1 - y0 > 1) {
 338          MEMCPY(indexSave, zoomed.array->index, zoomed.end * sizeof(GLuint));
 339       }
 340       for (zoomed.y = y0; zoomed.y < y1; zoomed.y++) {
 341          _swrast_write_index_span(ctx, &zoomed);
 342          zoomed.end = end;  /* restore */
 343          if (y1 - y0 > 1) {
 344             /* restore the colors */
 345             MEMCPY(zoomed.array->index, indexSave, zoomed.end * sizeof(GLuint));
 346          }
 347       }
 348    }
 349 }
 350
 351
 352 void
 353 _swrast_write_zoomed_rgba_span(GLcontext *ctx, GLint imgX, GLint imgY,
 354                                const SWspan *span, const GLvoid *rgba)
 355 {
 356    zoom_span(ctx, imgX, imgY, span, rgba, GL_RGBA);
 357 }
 358
 359
 360 void
 361 _swrast_write_zoomed_rgb_span(GLcontext *ctx, GLint imgX, GLint imgY,
 362                               const SWspan *span, const GLvoid *rgb)
 363 {
 364    zoom_span(ctx, imgX, imgY, span, rgb, GL_RGB);
 365 }
 366
 367
 368 void
 369 _swrast_write_zoomed_index_span(GLcontext *ctx, GLint imgX, GLint imgY,
 370                                 const SWspan *span)
 371 {
 372    zoom_span(ctx, imgX, imgY, span,
 373              (const GLvoid *) span->array->index, GL_COLOR_INDEX);
 374 }
 375
 376
 377 void
 378 _swrast_write_zoomed_depth_span(GLcontext *ctx, GLint imgX, GLint imgY,
 379                                 const SWspan *span)
 380 {
 381    zoom_span(ctx, imgX, imgY, span,
 382              (const GLvoid *) span->array->z, GL_DEPTH_COMPONENT);
 383 }
 384
 385
 386 /**
 387  * Zoom/write stencil values.
 388  * No per-fragment operations are applied.
 389  */
 390 void
 391 _swrast_write_zoomed_stencil_span(GLcontext *ctx, GLint imgX, GLint imgY,
 392                                   GLint width, GLint spanX, GLint spanY,
 393                                   const GLstencil stencil[])
 394 {
 395    GLstencil zoomedVals[MAX_WIDTH];
 396    GLint x0, x1, y0, y1, y;
 397    GLint i, zoomedWidth;
 398
 399    if (!compute_zoomed_bounds(ctx, imgX, imgY, spanX, spanY, width,
 400                               &x0, &x1, &y0, &y1)) {
 401       return;  /* totally clipped */
 402    }
 403
 404    zoomedWidth = x1 - x0;
 405    ASSERT(zoomedWidth > 0);
 406    ASSERT(zoomedWidth <= MAX_WIDTH);
 407
 408    /* zoom the span horizontally */
 409    for (i = 0; i < zoomedWidth; i++) {
 410       GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - spanX;
 411       ASSERT(j >= 0);
 412       ASSERT(j < width);
 413       zoomedVals[i] = stencil[j];
 414    }
 415
 416    /* write the zoomed spans */
 417    for (y = y0; y < y1; y++) {
 418       _swrast_write_stencil_span(ctx, zoomedWidth, x0, y, zoomedVals);
 419    }
 420 }
 421
 422
 423 /**
 424  * Zoom/write z values (16 or 32-bit).
 425  * No per-fragment operations are applied.
 426  */
 427 void
 428 _swrast_write_zoomed_z_span(GLcontext *ctx, GLint imgX, GLint imgY,
 429                             GLint width, GLint spanX, GLint spanY,
 430                             const GLvoid *z)
 431 {
 432    struct gl_renderbuffer *rb = ctx->DrawBuffer->_DepthBuffer;
 433    GLushort zoomedVals16[MAX_WIDTH];
 434    GLuint zoomedVals32[MAX_WIDTH];
 435    GLint x0, x1, y0, y1, y;
 436    GLint i, zoomedWidth;
 437
 438    if (!compute_zoomed_bounds(ctx, imgX, imgY, spanX, spanY, width,
 439                               &x0, &x1, &y0, &y1)) {
 440       return;  /* totally clipped */
 441    }
 442
 443    zoomedWidth = x1 - x0;
 444    ASSERT(zoomedWidth > 0);
 445    ASSERT(zoomedWidth <= MAX_WIDTH);
 446
 447    /* zoom the span horizontally */
 448    if (rb->DataType == GL_UNSIGNED_SHORT) {
 449       for (i = 0; i < zoomedWidth; i++) {
 450          GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - spanX;
 451          ASSERT(j >= 0);
 452          ASSERT(j < width);
 453          zoomedVals16[i] = ((GLushort *) z)[j];
 454       }
 455       z = zoomedVals16;
 456    }
 457    else {
 458       ASSERT(rb->DataType == GL_UNSIGNED_INT);
 459       for (i = 0; i < zoomedWidth; i++) {
 460          GLint j = unzoom_x(ctx->Pixel.ZoomX, imgX, x0 + i) - spanX;
 461          ASSERT(j >= 0);
 462          ASSERT(j < width);
 463          zoomedVals32[i] = ((GLuint *) z)[j];
 464       }
 465       z = zoomedVals32;
 466    }
 467
 468    /* write the zoomed spans */
 469    for (y = y0; y < y1; y++) {
 470       rb->PutRow(ctx, rb, zoomedWidth, x0, y, z, NULL);
 471    }
 472 }