src/mesa/swrast/s_aalinetemp.h

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.1
   4  *
   5  * Copyright (C) 1999-2004  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
  26 /*
  27  * Antialiased line template.
  28  */
  29
  30
  31 /*
  32  * Function to render each fragment in the AA line.
  33  */
  34 static void
  35 NAME(plot)(GLcontext *ctx, struct LineInfo *line, int ix, int iy)
  36 {
  37    const GLfloat fx = (GLfloat) ix;
  38    const GLfloat fy = (GLfloat) iy;
  39 #ifdef DO_INDEX
  40    const GLfloat coverage = compute_coveragei(line, ix, iy);
  41 #else
  42    const GLfloat coverage = compute_coveragef(line, ix, iy);
  43 #endif
  44    const GLuint i = line->span.end;
  45
  46    if (coverage == 0.0)
  47       return;
  48
  49    line->span.end++;
  50    line->span.array->coverage[i] = coverage;
  51    line->span.array->x[i] = ix;
  52    line->span.array->y[i] = iy;
  53
  54    /*
  55     * Compute Z, color, texture coords, fog for the fragment by
  56     * solving the plane equations at (ix,iy).
  57     */
  58 #ifdef DO_Z
  59    line->span.array->z[i] = (GLdepth) IROUND(solve_plane(fx, fy, line->zPlane));
  60 #endif
  61 #ifdef DO_FOG
  62    line->span.array->fog[i] = solve_plane(fx, fy, line->fPlane);
  63 #endif
  64 #ifdef DO_RGBA
  65    line->span.array->rgba[i][RCOMP] = solve_plane_chan(fx, fy, line->rPlane);
  66    line->span.array->rgba[i][GCOMP] = solve_plane_chan(fx, fy, line->gPlane);
  67    line->span.array->rgba[i][BCOMP] = solve_plane_chan(fx, fy, line->bPlane);
  68    line->span.array->rgba[i][ACOMP] = solve_plane_chan(fx, fy, line->aPlane);
  69 #endif
  70 #ifdef DO_INDEX
  71    line->span.array->index[i] = (GLint) solve_plane(fx, fy, line->iPlane);
  72 #endif
  73 #ifdef DO_SPEC
  74    line->span.array->spec[i][RCOMP] = solve_plane_chan(fx, fy, line->srPlane);
  75    line->span.array->spec[i][GCOMP] = solve_plane_chan(fx, fy, line->sgPlane);
  76    line->span.array->spec[i][BCOMP] = solve_plane_chan(fx, fy, line->sbPlane);
  77 #endif
  78 #ifdef DO_TEX
  79    {
  80       const GLfloat invQ = solve_plane_recip(fx, fy, line->vPlane[0]);
  81       line->span.array->texcoords[0][i][0] = solve_plane(fx, fy, line->sPlane[0]) * invQ;
  82       line->span.array->texcoords[0][i][1] = solve_plane(fx, fy, line->tPlane[0]) * invQ;
  83       line->span.array->texcoords[0][i][2] = solve_plane(fx, fy, line->uPlane[0]) * invQ;
  84       line->span.array->lambda[0][i] = compute_lambda(line->sPlane[0], line->tPlane[0], invQ,
  85                                           line->texWidth[0], line->texHeight[0]);
  86    }
  87 #elif defined(DO_MULTITEX)
  88    {
  89       GLuint unit;
  90       for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
  91          if (ctx->Texture.Unit[unit]._ReallyEnabled) {
  92             const GLfloat invQ = solve_plane_recip(fx, fy, line->vPlane[unit]);
  93             line->span.array->texcoords[unit][i][0] = solve_plane(fx, fy, line->sPlane[unit]) * invQ;
  94             line->span.array->texcoords[unit][i][1] = solve_plane(fx, fy, line->tPlane[unit]) * invQ;
  95             line->span.array->texcoords[unit][i][2] = solve_plane(fx, fy, line->uPlane[unit]) * invQ;
  96             line->span.array->lambda[unit][i] = compute_lambda(line->sPlane[unit],
  97                                                line->tPlane[unit], invQ,
  98                                                line->texWidth[unit], line->texHeight[unit]);
  99          }
 100       }
 101    }
 102 #endif
 103
 104    if (line->span.end == MAX_WIDTH) {
 105 #if defined(DO_TEX) || defined(DO_MULTITEX)
 106       _swrast_write_texture_span(ctx, &(line->span));
 107 #elif defined(DO_RGBA)
 108       _swrast_write_rgba_span(ctx, &(line->span));
 109 #else
 110       _swrast_write_index_span(ctx, &(line->span));
 111 #endif
 112       line->span.end = 0; /* reset counter */
 113    }
 114 }
 115
 116
 117
 118 /*
 119  * Line setup
 120  */
 121 static void
 122 NAME(line)(GLcontext *ctx, const SWvertex *v0, const SWvertex *v1)
 123 {
 124    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 125    GLfloat tStart, tEnd;   /* segment start, end along line length */
 126    GLboolean inSegment;
 127    GLint iLen, i;
 128
 129    /* Init the LineInfo struct */
 130    struct LineInfo line;
 131    line.x0 = v0->win[0];
 132    line.y0 = v0->win[1];
 133    line.x1 = v1->win[0];
 134    line.y1 = v1->win[1];
 135    line.dx = line.x1 - line.x0;
 136    line.dy = line.y1 - line.y0;
 137    line.len = SQRTF(line.dx * line.dx + line.dy * line.dy);
 138    line.halfWidth = 0.5F * ctx->Line.Width;
 139
 140    if (line.len == 0.0 || IS_INF_OR_NAN(line.len))
 141       return;
 142
 143    INIT_SPAN(line.span, GL_LINE, 0, 0, SPAN_XY | SPAN_COVERAGE);
 144
 145    line.xAdj = line.dx / line.len * line.halfWidth;
 146    line.yAdj = line.dy / line.len * line.halfWidth;
 147
 148 #ifdef DO_Z
 149    line.span.arrayMask |= SPAN_Z;
 150    compute_plane(line.x0, line.y0, line.x1, line.y1,
 151                  v0->win[2], v1->win[2], line.zPlane);
 152 #endif
 153 #ifdef DO_FOG
 154    line.span.arrayMask |= SPAN_FOG;
 155    compute_plane(line.x0, line.y0, line.x1, line.y1,
 156                  v0->fog, v1->fog, line.fPlane);
 157 #endif
 158 #ifdef DO_RGBA
 159    line.span.arrayMask |= SPAN_RGBA;
 160    if (ctx->Light.ShadeModel == GL_SMOOTH) {
 161       compute_plane(line.x0, line.y0, line.x1, line.y1,
 162                     v0->color[RCOMP], v1->color[RCOMP], line.rPlane);
 163       compute_plane(line.x0, line.y0, line.x1, line.y1,
 164                     v0->color[GCOMP], v1->color[GCOMP], line.gPlane);
 165       compute_plane(line.x0, line.y0, line.x1, line.y1,
 166                     v0->color[BCOMP], v1->color[BCOMP], line.bPlane);
 167       compute_plane(line.x0, line.y0, line.x1, line.y1,
 168                     v0->color[ACOMP], v1->color[ACOMP], line.aPlane);
 169    }
 170    else {
 171       constant_plane(v1->color[RCOMP], line.rPlane);
 172       constant_plane(v1->color[GCOMP], line.gPlane);
 173       constant_plane(v1->color[BCOMP], line.bPlane);
 174       constant_plane(v1->color[ACOMP], line.aPlane);
 175    }
 176 #endif
 177 #ifdef DO_SPEC
 178    line.span.arrayMask |= SPAN_SPEC;
 179    if (ctx->Light.ShadeModel == GL_SMOOTH) {
 180       compute_plane(line.x0, line.y0, line.x1, line.y1,
 181                     v0->specular[RCOMP], v1->specular[RCOMP], line.srPlane);
 182       compute_plane(line.x0, line.y0, line.x1, line.y1,
 183                     v0->specular[GCOMP], v1->specular[GCOMP], line.sgPlane);
 184       compute_plane(line.x0, line.y0, line.x1, line.y1,
 185                     v0->specular[BCOMP], v1->specular[BCOMP], line.sbPlane);
 186    }
 187    else {
 188       constant_plane(v1->specular[RCOMP], line.srPlane);
 189       constant_plane(v1->specular[GCOMP], line.sgPlane);
 190       constant_plane(v1->specular[BCOMP], line.sbPlane);
 191    }
 192 #endif
 193 #ifdef DO_INDEX
 194    line.span.arrayMask |= SPAN_INDEX;
 195    if (ctx->Light.ShadeModel == GL_SMOOTH) {
 196       compute_plane(line.x0, line.y0, line.x1, line.y1,
 197                     v0->index, v1->index, line.iPlane);
 198    }
 199    else {
 200       constant_plane(v1->index, line.iPlane);
 201    }
 202 #endif
 203 #ifdef DO_TEX
 204    {
 205       const struct gl_texture_object *obj = ctx->Texture.Unit[0]._Current;
 206       const struct gl_texture_image *texImage = obj->Image[0][obj->BaseLevel];
 207       const GLfloat invW0 = v0->win[3];
 208       const GLfloat invW1 = v1->win[3];
 209       const GLfloat s0 = v0->texcoord[0][0] * invW0;
 210       const GLfloat s1 = v1->texcoord[0][0] * invW1;
 211       const GLfloat t0 = v0->texcoord[0][1] * invW0;
 212       const GLfloat t1 = v1->texcoord[0][1] * invW0;
 213       const GLfloat r0 = v0->texcoord[0][2] * invW0;
 214       const GLfloat r1 = v1->texcoord[0][2] * invW0;
 215       const GLfloat q0 = v0->texcoord[0][3] * invW0;
 216       const GLfloat q1 = v1->texcoord[0][3] * invW0;
 217       line.span.arrayMask |= (SPAN_TEXTURE | SPAN_LAMBDA);
 218       compute_plane(line.x0, line.y0, line.x1, line.y1, s0, s1, line.sPlane[0]);
 219       compute_plane(line.x0, line.y0, line.x1, line.y1, t0, t1, line.tPlane[0]);
 220       compute_plane(line.x0, line.y0, line.x1, line.y1, r0, r1, line.uPlane[0]);
 221       compute_plane(line.x0, line.y0, line.x1, line.y1, q0, q1, line.vPlane[0]);
 222       line.texWidth[0] = (GLfloat) texImage->Width;
 223       line.texHeight[0] = (GLfloat) texImage->Height;
 224    }
 225 #elif defined(DO_MULTITEX)
 226    {
 227       GLuint u;
 228       line.span.arrayMask |= (SPAN_TEXTURE | SPAN_LAMBDA);
 229       for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
 230          if (ctx->Texture.Unit[u]._ReallyEnabled) {
 231             const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
 232             const struct gl_texture_image *texImage = obj->Image[0][obj->BaseLevel];
 233             const GLfloat invW0 = v0->win[3];
 234             const GLfloat invW1 = v1->win[3];
 235             const GLfloat s0 = v0->texcoord[u][0] * invW0;
 236             const GLfloat s1 = v1->texcoord[u][0] * invW1;
 237             const GLfloat t0 = v0->texcoord[u][1] * invW0;
 238             const GLfloat t1 = v1->texcoord[u][1] * invW0;
 239             const GLfloat r0 = v0->texcoord[u][2] * invW0;
 240             const GLfloat r1 = v1->texcoord[u][2] * invW0;
 241             const GLfloat q0 = v0->texcoord[u][3] * invW0;
 242             const GLfloat q1 = v1->texcoord[u][3] * invW0;
 243             compute_plane(line.x0, line.y0, line.x1, line.y1, s0, s1, line.sPlane[u]);
 244             compute_plane(line.x0, line.y0, line.x1, line.y1, t0, t1, line.tPlane[u]);
 245             compute_plane(line.x0, line.y0, line.x1, line.y1, r0, r1, line.uPlane[u]);
 246             compute_plane(line.x0, line.y0, line.x1, line.y1, q0, q1, line.vPlane[u]);
 247             line.texWidth[u]  = (GLfloat) texImage->Width;
 248             line.texHeight[u] = (GLfloat) texImage->Height;
 249          }
 250       }
 251    }
 252 #endif
 253
 254    tStart = tEnd = 0.0;
 255    inSegment = GL_FALSE;
 256    iLen = (GLint) line.len;
 257
 258    if (ctx->Line.StippleFlag) {
 259       for (i = 0; i < iLen; i++) {
 260          const GLuint bit = (swrast->StippleCounter / ctx->Line.StippleFactor) & 0xf;
 261          if ((1 << bit) & ctx->Line.StipplePattern) {
 262             /* stipple bit is on */
 263             const GLfloat t = (GLfloat) i / (GLfloat) line.len;
 264             if (!inSegment) {
 265                /* start new segment */
 266                inSegment = GL_TRUE;
 267                tStart = t;
 268             }
 269             else {
 270                /* still in the segment, extend it */
 271                tEnd = t;
 272             }
 273          }
 274          else {
 275             /* stipple bit is off */
 276             if (inSegment && (tEnd > tStart)) {
 277                /* draw the segment */
 278                segment(ctx, &line, NAME(plot), tStart, tEnd);
 279                inSegment = GL_FALSE;
 280             }
 281             else {
 282                /* still between segments, do nothing */
 283             }
 284          }
 285          swrast->StippleCounter++;
 286       }
 287
 288       if (inSegment) {
 289          /* draw the final segment of the line */
 290          segment(ctx, &line, NAME(plot), tStart, 1.0F);
 291       }
 292    }
 293    else {
 294       /* non-stippled */
 295       segment(ctx, &line, NAME(plot), 0.0, 1.0);
 296    }
 297
 298 #if defined(DO_TEX) || defined(DO_MULTITEX)
 299    _swrast_write_texture_span(ctx, &(line.span));
 300 #elif defined(DO_RGBA)
 301    _swrast_write_rgba_span(ctx, &(line.span));
 302 #else
 303    _swrast_write_index_span(ctx, &(line.span));
 304 #endif
 305 }
 306
 307
 308
 309
 310 #undef DO_Z
 311 #undef DO_FOG
 312 #undef DO_RGBA
 313 #undef DO_INDEX
 314 #undef DO_SPEC
 315 #undef DO_TEX
 316 #undef DO_MULTITEX
 317 #undef NAME