src/mesa/swrast/s_aalinetemp.h

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