src/mesa/swrast/s_points.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2007  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 #include "main/glheader.h"
  27 #include "main/colormac.h"
  28 #include "main/context.h"
  29 #include "main/macros.h"
  30 #include "s_context.h"
  31 #include "s_feedback.h"
  32 #include "s_points.h"
  33 #include "s_span.h"
  34
  35
  36 /**
  37  * Used to cull points with invalid coords
  38  */
  39 #define CULL_INVALID(V)                              \
  40    do {                                              \
  41       float tmp = (V)->attrib[FRAG_ATTRIB_WPOS][0]   \
  42                 + (V)->attrib[FRAG_ATTRIB_WPOS][1];  \
  43       if (IS_INF_OR_NAN(tmp))                        \
  44          return;                                     \
  45    } while(0)
  46
  47
  48
  49 /**
  50  * Get/compute the point size.
  51  * The size may come from a vertex shader, or computed with attentuation
  52  * or just the glPointSize value.
  53  * Must also clamp to user-defined range and implmentation limits.
  54  */
  55 static INLINE GLfloat
  56 get_size(const GLcontext *ctx, const SWvertex *vert, GLboolean smoothed)
  57 {
  58    GLfloat size;
  59
  60    if (ctx->Point._Attenuated || ctx->VertexProgram.PointSizeEnabled) {
  61       /* use vertex's point size */
  62       size = vert->pointSize;
  63    }
  64    else {
  65       /* use constant point size */
  66       size = ctx->Point.Size;
  67    }
  68    /* always clamp to user-specified limits */
  69    size = CLAMP(size, ctx->Point.MinSize, ctx->Point.MaxSize);
  70    /* clamp to implementation limits */
  71    if (smoothed)
  72       size = CLAMP(size, ctx->Const.MinPointSizeAA, ctx->Const.MaxPointSizeAA);
  73    else
  74       size = CLAMP(size, ctx->Const.MinPointSize, ctx->Const.MaxPointSize);
  75
  76    return size;
  77 }
  78
  79
  80 /**
  81  * Draw a point sprite
  82  */
  83 static void
  84 sprite_point(GLcontext *ctx, const SWvertex *vert)
  85 {
  86    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  87    SWspan span;
  88    GLfloat size;
  89    GLuint tCoords[MAX_TEXTURE_COORD_UNITS + 1];
  90    GLuint numTcoords = 0;
  91    GLfloat t0, dtdy;
  92
  93    CULL_INVALID(vert);
  94
  95    /* z coord */
  96    if (ctx->DrawBuffer->Visual.depthBits <= 16)
  97       span.z = FloatToFixed(vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
  98    else
  99       span.z = (GLuint) (vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
 100    span.zStep = 0;
 101
 102    size = get_size(ctx, vert, GL_FALSE);
 103
 104    /* span init */
 105    INIT_SPAN(span, GL_POINT);
 106    span.interpMask = SPAN_Z | SPAN_RGBA;
 107
 108    span.facing = swrast->PointLineFacing;
 109
 110    span.red   = ChanToFixed(vert->color[0]);
 111    span.green = ChanToFixed(vert->color[1]);
 112    span.blue  = ChanToFixed(vert->color[2]);
 113    span.alpha = ChanToFixed(vert->color[3]);
 114    span.redStep = 0;
 115    span.greenStep = 0;
 116    span.blueStep = 0;
 117    span.alphaStep = 0;
 118
 119    /* need these for fragment programs */
 120    span.attrStart[FRAG_ATTRIB_WPOS][3] = 1.0F;
 121    span.attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0F;
 122    span.attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0F;
 123
 124    {
 125       GLfloat s, r, dsdx;
 126
 127       /* texcoord / pointcoord interpolants */
 128       s = 0.0;
 129       dsdx = 1.0 / size;
 130       if (ctx->Point.SpriteOrigin == GL_LOWER_LEFT) {
 131          dtdy = 1.0 / size;
 132          t0 = 0.5 * dtdy;
 133       }
 134       else {
 135          /* GL_UPPER_LEFT */
 136          dtdy = -1.0 / size;
 137          t0 = 1.0 + 0.5 * dtdy;
 138       }
 139
 140       ATTRIB_LOOP_BEGIN
 141          if (attr >= FRAG_ATTRIB_TEX0 && attr <= FRAG_ATTRIB_TEX7) {
 142             /* a texcoord attribute */
 143             const GLuint u = attr - FRAG_ATTRIB_TEX0;
 144             ASSERT(u < Elements(ctx->Point.CoordReplace));
 145             if (ctx->Point.CoordReplace[u]) {
 146                tCoords[numTcoords++] = attr;
 147
 148                if (ctx->Point.SpriteRMode == GL_ZERO)
 149                   r = 0.0F;
 150                else if (ctx->Point.SpriteRMode == GL_S)
 151                   r = vert->attrib[attr][0];
 152                else /* GL_R */
 153                   r = vert->attrib[attr][2];
 154
 155                span.attrStart[attr][0] = s;
 156                span.attrStart[attr][1] = 0.0; /* overwritten below */
 157                span.attrStart[attr][2] = r;
 158                span.attrStart[attr][3] = 1.0;
 159
 160                span.attrStepX[attr][0] = dsdx;
 161                span.attrStepX[attr][1] = 0.0;
 162                span.attrStepX[attr][2] = 0.0;
 163                span.attrStepX[attr][3] = 0.0;
 164
 165                span.attrStepY[attr][0] = 0.0;
 166                span.attrStepY[attr][1] = dtdy;
 167                span.attrStepY[attr][2] = 0.0;
 168                span.attrStepY[attr][3] = 0.0;
 169
 170                continue;
 171             }
 172          }
 173          else if (attr == FRAG_ATTRIB_PNTC) {
 174             /* GLSL gl_PointCoord.xy (.zw undefined) */
 175             span.attrStart[FRAG_ATTRIB_PNTC][0] = 0.0;
 176             span.attrStart[FRAG_ATTRIB_PNTC][1] = 0.0; /* t0 set below */
 177             span.attrStepX[FRAG_ATTRIB_PNTC][0] = dsdx;
 178             span.attrStepX[FRAG_ATTRIB_PNTC][1] = 0.0;
 179             span.attrStepY[FRAG_ATTRIB_PNTC][0] = 0.0;
 180             span.attrStepY[FRAG_ATTRIB_PNTC][1] = dtdy;
 181             tCoords[numTcoords++] = FRAG_ATTRIB_PNTC;
 182             continue;
 183          }
 184          /* use vertex's texcoord/attrib */
 185          COPY_4V(span.attrStart[attr], vert->attrib[attr]);
 186          ASSIGN_4V(span.attrStepX[attr], 0, 0, 0, 0);
 187          ASSIGN_4V(span.attrStepY[attr], 0, 0, 0, 0);
 188       ATTRIB_LOOP_END;
 189    }
 190
 191    /* compute pos, bounds and render */
 192    {
 193       const GLfloat x = vert->attrib[FRAG_ATTRIB_WPOS][0];
 194       const GLfloat y = vert->attrib[FRAG_ATTRIB_WPOS][1];
 195       GLint iSize = (GLint) (size + 0.5F);
 196       GLint xmin, xmax, ymin, ymax, iy;
 197       GLint iRadius;
 198       GLfloat tcoord = t0;
 199
 200       iSize = MAX2(1, iSize);
 201       iRadius = iSize / 2;
 202
 203       if (iSize & 1) {
 204          /* odd size */
 205          xmin = (GLint) (x - iRadius);
 206          xmax = (GLint) (x + iRadius);
 207          ymin = (GLint) (y - iRadius);
 208          ymax = (GLint) (y + iRadius);
 209       }
 210       else {
 211          /* even size */
 212          /* 0.501 factor allows conformance to pass */
 213          xmin = (GLint) (x + 0.501) - iRadius;
 214          xmax = xmin + iSize - 1;
 215          ymin = (GLint) (y + 0.501) - iRadius;
 216          ymax = ymin + iSize - 1;
 217       }
 218
 219       /* render spans */
 220       for (iy = ymin; iy <= ymax; iy++) {
 221          GLuint i;
 222          /* setup texcoord T for this row */
 223          for (i = 0; i < numTcoords; i++) {
 224             span.attrStart[tCoords[i]][1] = tcoord;
 225          }
 226
 227          /* these might get changed by span clipping */
 228          span.x = xmin;
 229          span.y = iy;
 230          span.end = xmax - xmin + 1;
 231
 232          _swrast_write_rgba_span(ctx, &span);
 233
 234          tcoord += dtdy;
 235       }
 236    }
 237 }
 238
 239
 240 /**
 241  * Draw smooth/antialiased point.  RGB or CI mode.
 242  */
 243 static void
 244 smooth_point(GLcontext *ctx, const SWvertex *vert)
 245 {
 246    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 247    const GLboolean ciMode = !ctx->Visual.rgbMode;
 248    SWspan span;
 249    GLfloat size, alphaAtten;
 250
 251    CULL_INVALID(vert);
 252
 253    /* z coord */
 254    if (ctx->DrawBuffer->Visual.depthBits <= 16)
 255       span.z = FloatToFixed(vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
 256    else
 257       span.z = (GLuint) (vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
 258    span.zStep = 0;
 259
 260    size = get_size(ctx, vert, GL_TRUE);
 261
 262    /* alpha attenuation / fade factor */
 263    if (ctx->Multisample._Enabled) {
 264       if (vert->pointSize >= ctx->Point.Threshold) {
 265          alphaAtten = 1.0F;
 266       }
 267       else {
 268          GLfloat dsize = vert->pointSize / ctx->Point.Threshold;
 269          alphaAtten = dsize * dsize;
 270       }
 271    }
 272    else {
 273       alphaAtten = 1.0;
 274    }
 275    (void) alphaAtten; /* not used */
 276
 277    /* span init */
 278    INIT_SPAN(span, GL_POINT);
 279    span.interpMask = SPAN_Z | SPAN_RGBA;
 280    span.arrayMask = SPAN_COVERAGE | SPAN_MASK;
 281
 282    span.facing = swrast->PointLineFacing;
 283
 284    span.red   = ChanToFixed(vert->color[0]);
 285    span.green = ChanToFixed(vert->color[1]);
 286    span.blue  = ChanToFixed(vert->color[2]);
 287    span.alpha = ChanToFixed(vert->color[3]);
 288    span.redStep = 0;
 289    span.greenStep = 0;
 290    span.blueStep = 0;
 291    span.alphaStep = 0;
 292
 293    /* need these for fragment programs */
 294    span.attrStart[FRAG_ATTRIB_WPOS][3] = 1.0F;
 295    span.attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0F;
 296    span.attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0F;
 297
 298    ATTRIB_LOOP_BEGIN
 299       COPY_4V(span.attrStart[attr], vert->attrib[attr]);
 300       ASSIGN_4V(span.attrStepX[attr], 0, 0, 0, 0);
 301       ASSIGN_4V(span.attrStepY[attr], 0, 0, 0, 0);
 302    ATTRIB_LOOP_END
 303
 304    /* compute pos, bounds and render */
 305    {
 306       const GLfloat x = vert->attrib[FRAG_ATTRIB_WPOS][0];
 307       const GLfloat y = vert->attrib[FRAG_ATTRIB_WPOS][1];
 308       const GLfloat radius = 0.5F * size;
 309       const GLfloat rmin = radius - 0.7071F;  /* 0.7071 = sqrt(2)/2 */
 310       const GLfloat rmax = radius + 0.7071F;
 311       const GLfloat rmin2 = MAX2(0.0F, rmin * rmin);
 312       const GLfloat rmax2 = rmax * rmax;
 313       const GLfloat cscale = 1.0F / (rmax2 - rmin2);
 314       const GLint xmin = (GLint) (x - radius);
 315       const GLint xmax = (GLint) (x + radius);
 316       const GLint ymin = (GLint) (y - radius);
 317       const GLint ymax = (GLint) (y + radius);
 318       GLint ix, iy;
 319
 320       for (iy = ymin; iy <= ymax; iy++) {
 321
 322          /* these might get changed by span clipping */
 323          span.x = xmin;
 324          span.y = iy;
 325          span.end = xmax - xmin + 1;
 326
 327          /* compute coverage for each pixel in span */
 328          for (ix = xmin; ix <= xmax; ix++) {
 329             const GLfloat dx = ix - x + 0.5F;
 330             const GLfloat dy = iy - y + 0.5F;
 331             const GLfloat dist2 = dx * dx + dy * dy;
 332             GLfloat coverage;
 333
 334             if (dist2 < rmax2) {
 335                if (dist2 >= rmin2) {
 336                   /* compute partial coverage */
 337                   coverage = 1.0F - (dist2 - rmin2) * cscale;
 338                   if (ciMode) {
 339                      /* coverage in [0,15] */
 340                      coverage *= 15.0;
 341                   }
 342                }
 343                else {
 344                   /* full coverage */
 345                   coverage = 1.0F;
 346                }
 347                span.array->mask[ix - xmin] = 1;
 348             }
 349             else {
 350                /* zero coverage - fragment outside the radius */
 351                coverage = 0.0;
 352                span.array->mask[ix - xmin] = 0;
 353             }
 354             span.array->coverage[ix - xmin] = coverage;
 355          }
 356
 357          /* render span */
 358          _swrast_write_rgba_span(ctx, &span);
 359
 360       }
 361    }
 362 }
 363
 364
 365 /**
 366  * Draw large (size >= 1) non-AA point.  RGB or CI mode.
 367  */
 368 static void
 369 large_point(GLcontext *ctx, const SWvertex *vert)
 370 {
 371    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 372    const GLboolean ciMode = !ctx->Visual.rgbMode;
 373    SWspan span;
 374    GLfloat size;
 375
 376    CULL_INVALID(vert);
 377
 378    /* z coord */
 379    if (ctx->DrawBuffer->Visual.depthBits <= 16)
 380       span.z = FloatToFixed(vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
 381    else
 382       span.z = (GLuint) (vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
 383    span.zStep = 0;
 384
 385    size = get_size(ctx, vert, GL_FALSE);
 386
 387    /* span init */
 388    INIT_SPAN(span, GL_POINT);
 389    span.arrayMask = SPAN_XY;
 390    span.facing = swrast->PointLineFacing;
 391
 392    if (ciMode) {
 393       span.interpMask = SPAN_Z | SPAN_INDEX;
 394       span.index = FloatToFixed(vert->attrib[FRAG_ATTRIB_CI][0]);
 395       span.indexStep = 0;
 396    }
 397    else {
 398       span.interpMask = SPAN_Z | SPAN_RGBA;
 399       span.red   = ChanToFixed(vert->color[0]);
 400       span.green = ChanToFixed(vert->color[1]);
 401       span.blue  = ChanToFixed(vert->color[2]);
 402       span.alpha = ChanToFixed(vert->color[3]);
 403       span.redStep = 0;
 404       span.greenStep = 0;
 405       span.blueStep = 0;
 406       span.alphaStep = 0;
 407    }
 408
 409    /* need these for fragment programs */
 410    span.attrStart[FRAG_ATTRIB_WPOS][3] = 1.0F;
 411    span.attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0F;
 412    span.attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0F;
 413
 414    ATTRIB_LOOP_BEGIN
 415       COPY_4V(span.attrStart[attr], vert->attrib[attr]);
 416       ASSIGN_4V(span.attrStepX[attr], 0, 0, 0, 0);
 417       ASSIGN_4V(span.attrStepY[attr], 0, 0, 0, 0);
 418    ATTRIB_LOOP_END
 419
 420    /* compute pos, bounds and render */
 421    {
 422       const GLfloat x = vert->attrib[FRAG_ATTRIB_WPOS][0];
 423       const GLfloat y = vert->attrib[FRAG_ATTRIB_WPOS][1];
 424       GLint iSize = (GLint) (size + 0.5F);
 425       GLint xmin, xmax, ymin, ymax, ix, iy;
 426       GLint iRadius;
 427
 428       iSize = MAX2(1, iSize);
 429       iRadius = iSize / 2;
 430
 431       if (iSize & 1) {
 432          /* odd size */
 433          xmin = (GLint) (x - iRadius);
 434          xmax = (GLint) (x + iRadius);
 435          ymin = (GLint) (y - iRadius);
 436          ymax = (GLint) (y + iRadius);
 437       }
 438       else {
 439          /* even size */
 440          /* 0.501 factor allows conformance to pass */
 441          xmin = (GLint) (x + 0.501) - iRadius;
 442          xmax = xmin + iSize - 1;
 443          ymin = (GLint) (y + 0.501) - iRadius;
 444          ymax = ymin + iSize - 1;
 445       }
 446
 447       /* generate fragments */
 448       span.end = 0;
 449       for (iy = ymin; iy <= ymax; iy++) {
 450          for (ix = xmin; ix <= xmax; ix++) {
 451             span.array->x[span.end] = ix;
 452             span.array->y[span.end] = iy;
 453             span.end++;
 454          }
 455       }
 456       assert(span.end <= MAX_WIDTH);
 457       _swrast_write_rgba_span(ctx, &span);
 458    }
 459 }
 460
 461
 462 /**
 463  * Draw size=1, single-pixel point
 464  */
 465 static void
 466 pixel_point(GLcontext *ctx, const SWvertex *vert)
 467 {
 468    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 469    const GLboolean ciMode = !ctx->Visual.rgbMode;
 470    /*
 471     * Note that unlike the other functions, we put single-pixel points
 472     * into a special span array in order to render as many points as
 473     * possible with a single _swrast_write_rgba_span() call.
 474     */
 475    SWspan *span = &(swrast->PointSpan);
 476    GLuint count;
 477
 478    CULL_INVALID(vert);
 479
 480    /* Span init */
 481    span->interpMask = 0;
 482    span->arrayMask = SPAN_XY | SPAN_Z;
 483    if (ciMode)
 484       span->arrayMask |= SPAN_INDEX;
 485    else
 486       span->arrayMask |= SPAN_RGBA;
 487    /*span->arrayMask |= SPAN_LAMBDA;*/
 488    span->arrayAttribs = swrast->_ActiveAttribMask; /* we'll produce these vals */
 489
 490    /* need these for fragment programs */
 491    span->attrStart[FRAG_ATTRIB_WPOS][3] = 1.0F;
 492    span->attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0F;
 493    span->attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0F;
 494
 495    /* check if we need to flush */
 496    if (span->end >= MAX_WIDTH ||
 497        (swrast->_RasterMask & (BLEND_BIT | LOGIC_OP_BIT | MASKING_BIT)) ||
 498        span->facing != swrast->PointLineFacing) {
 499       if (span->end > 0) {
 500          if (ciMode)
 501             _swrast_write_index_span(ctx, span);
 502          else
 503             _swrast_write_rgba_span(ctx, span);
 504          span->end = 0;
 505       }
 506    }
 507
 508    count = span->end;
 509
 510    span->facing = swrast->PointLineFacing;
 511
 512    /* fragment attributes */
 513    if (ciMode) {
 514       span->array->index[count] = (GLuint) vert->attrib[FRAG_ATTRIB_CI][0];
 515    }
 516    else {
 517       span->array->rgba[count][RCOMP] = vert->color[0];
 518       span->array->rgba[count][GCOMP] = vert->color[1];
 519       span->array->rgba[count][BCOMP] = vert->color[2];
 520       span->array->rgba[count][ACOMP] = vert->color[3];
 521    }
 522    ATTRIB_LOOP_BEGIN
 523       COPY_4V(span->array->attribs[attr][count], vert->attrib[attr]);
 524    ATTRIB_LOOP_END
 525
 526    /* fragment position */
 527    span->array->x[count] = (GLint) vert->attrib[FRAG_ATTRIB_WPOS][0];
 528    span->array->y[count] = (GLint) vert->attrib[FRAG_ATTRIB_WPOS][1];
 529    span->array->z[count] = (GLint) (vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
 530
 531    span->end = count + 1;
 532    ASSERT(span->end <= MAX_WIDTH);
 533 }
 534
 535
 536 /**
 537  * Add specular color to primary color, draw point, restore original
 538  * primary color.
 539  */
 540 void
 541 _swrast_add_spec_terms_point(GLcontext *ctx, const SWvertex *v0)
 542 {
 543    SWvertex *ncv0 = (SWvertex *) v0; /* cast away const */
 544    GLfloat rSum, gSum, bSum;
 545    GLchan cSave[4];
 546
 547    /* save */
 548    COPY_CHAN4(cSave, ncv0->color);
 549    /* sum */
 550    rSum = CHAN_TO_FLOAT(ncv0->color[0]) + ncv0->attrib[FRAG_ATTRIB_COL1][0];
 551    gSum = CHAN_TO_FLOAT(ncv0->color[1]) + ncv0->attrib[FRAG_ATTRIB_COL1][1];
 552    bSum = CHAN_TO_FLOAT(ncv0->color[2]) + ncv0->attrib[FRAG_ATTRIB_COL1][2];
 553    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[0], rSum);
 554    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[1], gSum);
 555    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[2], bSum);
 556    /* draw */
 557    SWRAST_CONTEXT(ctx)->SpecPoint(ctx, ncv0);
 558    /* restore */
 559    COPY_CHAN4(ncv0->color, cSave);
 560 }
 561
 562
 563 /**
 564  * Examine current state to determine which point drawing function to use.
 565  */
 566 void
 567 _swrast_choose_point(GLcontext *ctx)
 568 {
 569    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 570    const GLfloat size = CLAMP(ctx->Point.Size,
 571                               ctx->Point.MinSize,
 572                               ctx->Point.MaxSize);
 573
 574    if (ctx->RenderMode == GL_RENDER) {
 575       if (ctx->Point.PointSprite) {
 576          swrast->Point = sprite_point;
 577       }
 578       else if (ctx->Point.SmoothFlag) {
 579          swrast->Point = smooth_point;
 580       }
 581       else if (size > 1.0 ||
 582                ctx->Point._Attenuated ||
 583                ctx->VertexProgram.PointSizeEnabled) {
 584          swrast->Point = large_point;
 585       }
 586       else {
 587          swrast->Point = pixel_point;
 588       }
 589    }
 590    else if (ctx->RenderMode == GL_FEEDBACK) {
 591       swrast->Point = _swrast_feedback_point;
 592    }
 593    else {
 594       /* GL_SELECT mode */
 595       swrast->Point = _swrast_select_point;
 596    }
 597 }