2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
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:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
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 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23 * OTHER DEALINGS IN THE SOFTWARE.
27 #include "main/glheader.h"
28 #include "main/colormac.h"
29 #include "main/macros.h"
30 #include "s_context.h"
31 #include "s_feedback.h"
37 * Used to cull points with invalid coords
39 #define CULL_INVALID(V) \
41 float tmp = (V)->attrib[VARYING_SLOT_POS][0] \
42 + (V)->attrib[VARYING_SLOT_POS][1]; \
43 if (IS_INF_OR_NAN(tmp)) \
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.
56 get_size(const struct gl_context *ctx, const SWvertex *vert, GLboolean smoothed)
60 if (ctx->Point._Attenuated || ctx->VertexProgram.PointSizeEnabled) {
61 /* use vertex's point size */
62 size = vert->pointSize;
65 /* use constant point size */
66 size = ctx->Point.Size;
68 /* always clamp to user-specified limits */
69 size = CLAMP(size, ctx->Point.MinSize, ctx->Point.MaxSize);
70 /* clamp to implementation limits */
72 size = CLAMP(size, ctx->Const.MinPointSizeAA, ctx->Const.MaxPointSizeAA);
74 size = CLAMP(size, ctx->Const.MinPointSize, ctx->Const.MaxPointSize);
84 sprite_point(struct gl_context *ctx, const SWvertex *vert)
86 SWcontext *swrast = SWRAST_CONTEXT(ctx);
89 GLuint tCoords[MAX_TEXTURE_COORD_UNITS + 1];
90 GLuint numTcoords = 0;
96 if (ctx->DrawBuffer->Visual.depthBits <= 16)
97 span.z = FloatToFixed(vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
99 span.z = (GLuint) (vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
102 size = get_size(ctx, vert, GL_FALSE);
105 INIT_SPAN(span, GL_POINT);
106 span.interpMask = SPAN_Z | SPAN_RGBA;
108 span.facing = swrast->PointLineFacing;
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]);
119 /* need these for fragment programs */
120 span.attrStart[VARYING_SLOT_POS][3] = 1.0F;
121 span.attrStepX[VARYING_SLOT_POS][3] = 0.0F;
122 span.attrStepY[VARYING_SLOT_POS][3] = 0.0F;
127 /* texcoord / pointcoord interpolants */
130 if (ctx->Point.SpriteOrigin == GL_LOWER_LEFT) {
137 t0 = 1.0F + 0.5F * dtdy;
141 if (attr >= VARYING_SLOT_TEX0 && attr <= VARYING_SLOT_TEX7) {
142 /* a texcoord attribute */
143 const GLuint u = attr - VARYING_SLOT_TEX0;
144 ASSERT(u < Elements(ctx->Point.CoordReplace));
145 if (ctx->Point.CoordReplace[u]) {
146 tCoords[numTcoords++] = attr;
148 if (ctx->Point.SpriteRMode == GL_ZERO)
150 else if (ctx->Point.SpriteRMode == GL_S)
151 r = vert->attrib[attr][0];
153 r = vert->attrib[attr][2];
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;
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;
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;
173 else if (attr == VARYING_SLOT_PNTC) {
174 /* GLSL gl_PointCoord.xy (.zw undefined) */
175 span.attrStart[VARYING_SLOT_PNTC][0] = 0.0;
176 span.attrStart[VARYING_SLOT_PNTC][1] = 0.0; /* t0 set below */
177 span.attrStepX[VARYING_SLOT_PNTC][0] = dsdx;
178 span.attrStepX[VARYING_SLOT_PNTC][1] = 0.0;
179 span.attrStepY[VARYING_SLOT_PNTC][0] = 0.0;
180 span.attrStepY[VARYING_SLOT_PNTC][1] = dtdy;
181 tCoords[numTcoords++] = VARYING_SLOT_PNTC;
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);
191 /* compute pos, bounds and render */
193 const GLfloat x = vert->attrib[VARYING_SLOT_POS][0];
194 const GLfloat y = vert->attrib[VARYING_SLOT_POS][1];
195 GLint iSize = (GLint) (size + 0.5F);
196 GLint xmin, xmax, ymin, ymax, iy;
200 iSize = MAX2(1, iSize);
205 xmin = (GLint) (x - iRadius);
206 xmax = (GLint) (x + iRadius);
207 ymin = (GLint) (y - iRadius);
208 ymax = (GLint) (y + iRadius);
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;
220 for (iy = ymin; iy <= ymax; iy++) {
222 /* setup texcoord T for this row */
223 for (i = 0; i < numTcoords; i++) {
224 span.attrStart[tCoords[i]][1] = tcoord;
227 /* these might get changed by span clipping */
230 span.end = xmax - xmin + 1;
232 _swrast_write_rgba_span(ctx, &span);
241 * Draw smooth/antialiased point. RGB or CI mode.
244 smooth_point(struct gl_context *ctx, const SWvertex *vert)
246 SWcontext *swrast = SWRAST_CONTEXT(ctx);
248 GLfloat size, alphaAtten;
253 if (ctx->DrawBuffer->Visual.depthBits <= 16)
254 span.z = FloatToFixed(vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
256 span.z = (GLuint) (vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
259 size = get_size(ctx, vert, GL_TRUE);
261 /* alpha attenuation / fade factor */
262 if (ctx->Multisample._Enabled) {
263 if (vert->pointSize >= ctx->Point.Threshold) {
267 GLfloat dsize = vert->pointSize / ctx->Point.Threshold;
268 alphaAtten = dsize * dsize;
274 (void) alphaAtten; /* not used */
277 INIT_SPAN(span, GL_POINT);
278 span.interpMask = SPAN_Z | SPAN_RGBA;
279 span.arrayMask = SPAN_COVERAGE | SPAN_MASK;
281 span.facing = swrast->PointLineFacing;
283 span.red = ChanToFixed(vert->color[0]);
284 span.green = ChanToFixed(vert->color[1]);
285 span.blue = ChanToFixed(vert->color[2]);
286 span.alpha = ChanToFixed(vert->color[3]);
292 /* need these for fragment programs */
293 span.attrStart[VARYING_SLOT_POS][3] = 1.0F;
294 span.attrStepX[VARYING_SLOT_POS][3] = 0.0F;
295 span.attrStepY[VARYING_SLOT_POS][3] = 0.0F;
298 COPY_4V(span.attrStart[attr], vert->attrib[attr]);
299 ASSIGN_4V(span.attrStepX[attr], 0, 0, 0, 0);
300 ASSIGN_4V(span.attrStepY[attr], 0, 0, 0, 0);
303 /* compute pos, bounds and render */
305 const GLfloat x = vert->attrib[VARYING_SLOT_POS][0];
306 const GLfloat y = vert->attrib[VARYING_SLOT_POS][1];
307 const GLfloat radius = 0.5F * size;
308 const GLfloat rmin = radius - 0.7071F; /* 0.7071 = sqrt(2)/2 */
309 const GLfloat rmax = radius + 0.7071F;
310 const GLfloat rmin2 = MAX2(0.0F, rmin * rmin);
311 const GLfloat rmax2 = rmax * rmax;
312 const GLfloat cscale = 1.0F / (rmax2 - rmin2);
313 const GLint xmin = (GLint) (x - radius);
314 const GLint xmax = (GLint) (x + radius);
315 const GLint ymin = (GLint) (y - radius);
316 const GLint ymax = (GLint) (y + radius);
319 for (iy = ymin; iy <= ymax; iy++) {
321 /* these might get changed by span clipping */
324 span.end = xmax - xmin + 1;
326 /* compute coverage for each pixel in span */
327 for (ix = xmin; ix <= xmax; ix++) {
328 const GLfloat dx = ix - x + 0.5F;
329 const GLfloat dy = iy - y + 0.5F;
330 const GLfloat dist2 = dx * dx + dy * dy;
334 if (dist2 >= rmin2) {
335 /* compute partial coverage */
336 coverage = 1.0F - (dist2 - rmin2) * cscale;
342 span.array->mask[ix - xmin] = 1;
345 /* zero coverage - fragment outside the radius */
347 span.array->mask[ix - xmin] = 0;
349 span.array->coverage[ix - xmin] = coverage;
353 _swrast_write_rgba_span(ctx, &span);
361 * Draw large (size >= 1) non-AA point. RGB or CI mode.
364 large_point(struct gl_context *ctx, const SWvertex *vert)
366 SWcontext *swrast = SWRAST_CONTEXT(ctx);
373 if (ctx->DrawBuffer->Visual.depthBits <= 16)
374 span.z = FloatToFixed(vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
376 span.z = (GLuint) (vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
379 size = get_size(ctx, vert, GL_FALSE);
382 INIT_SPAN(span, GL_POINT);
383 span.arrayMask = SPAN_XY;
384 span.facing = swrast->PointLineFacing;
386 span.interpMask = SPAN_Z | SPAN_RGBA;
387 span.red = ChanToFixed(vert->color[0]);
388 span.green = ChanToFixed(vert->color[1]);
389 span.blue = ChanToFixed(vert->color[2]);
390 span.alpha = ChanToFixed(vert->color[3]);
396 /* need these for fragment programs */
397 span.attrStart[VARYING_SLOT_POS][3] = 1.0F;
398 span.attrStepX[VARYING_SLOT_POS][3] = 0.0F;
399 span.attrStepY[VARYING_SLOT_POS][3] = 0.0F;
402 COPY_4V(span.attrStart[attr], vert->attrib[attr]);
403 ASSIGN_4V(span.attrStepX[attr], 0, 0, 0, 0);
404 ASSIGN_4V(span.attrStepY[attr], 0, 0, 0, 0);
407 /* compute pos, bounds and render */
409 const GLfloat x = vert->attrib[VARYING_SLOT_POS][0];
410 const GLfloat y = vert->attrib[VARYING_SLOT_POS][1];
411 GLint iSize = (GLint) (size + 0.5F);
412 GLint xmin, xmax, ymin, ymax, ix, iy;
415 iSize = MAX2(1, iSize);
420 xmin = (GLint) (x - iRadius);
421 xmax = (GLint) (x + iRadius);
422 ymin = (GLint) (y - iRadius);
423 ymax = (GLint) (y + iRadius);
427 /* 0.501 factor allows conformance to pass */
428 xmin = (GLint) (x + 0.501) - iRadius;
429 xmax = xmin + iSize - 1;
430 ymin = (GLint) (y + 0.501) - iRadius;
431 ymax = ymin + iSize - 1;
434 /* generate fragments */
436 for (iy = ymin; iy <= ymax; iy++) {
437 for (ix = xmin; ix <= xmax; ix++) {
438 span.array->x[span.end] = ix;
439 span.array->y[span.end] = iy;
443 assert(span.end <= SWRAST_MAX_WIDTH);
444 _swrast_write_rgba_span(ctx, &span);
450 * Draw size=1, single-pixel point
453 pixel_point(struct gl_context *ctx, const SWvertex *vert)
455 SWcontext *swrast = SWRAST_CONTEXT(ctx);
457 * Note that unlike the other functions, we put single-pixel points
458 * into a special span array in order to render as many points as
459 * possible with a single _swrast_write_rgba_span() call.
461 SWspan *span = &(swrast->PointSpan);
467 span->interpMask = 0;
468 span->arrayMask = SPAN_XY | SPAN_Z;
469 span->arrayMask |= SPAN_RGBA;
470 /*span->arrayMask |= SPAN_LAMBDA;*/
471 span->arrayAttribs = swrast->_ActiveAttribMask; /* we'll produce these vals */
473 /* need these for fragment programs */
474 span->attrStart[VARYING_SLOT_POS][3] = 1.0F;
475 span->attrStepX[VARYING_SLOT_POS][3] = 0.0F;
476 span->attrStepY[VARYING_SLOT_POS][3] = 0.0F;
478 /* check if we need to flush */
479 if (span->end >= SWRAST_MAX_WIDTH ||
480 (swrast->_RasterMask & (BLEND_BIT | LOGIC_OP_BIT | MASKING_BIT)) ||
481 span->facing != swrast->PointLineFacing) {
483 _swrast_write_rgba_span(ctx, span);
490 span->facing = swrast->PointLineFacing;
492 /* fragment attributes */
493 span->array->rgba[count][RCOMP] = vert->color[0];
494 span->array->rgba[count][GCOMP] = vert->color[1];
495 span->array->rgba[count][BCOMP] = vert->color[2];
496 span->array->rgba[count][ACOMP] = vert->color[3];
499 COPY_4V(span->array->attribs[attr][count], vert->attrib[attr]);
502 /* fragment position */
503 span->array->x[count] = (GLint) vert->attrib[VARYING_SLOT_POS][0];
504 span->array->y[count] = (GLint) vert->attrib[VARYING_SLOT_POS][1];
505 span->array->z[count] = (GLint) (vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
507 span->end = count + 1;
508 ASSERT(span->end <= SWRAST_MAX_WIDTH);
513 * Add specular color to primary color, draw point, restore original
517 _swrast_add_spec_terms_point(struct gl_context *ctx, const SWvertex *v0)
519 SWvertex *ncv0 = (SWvertex *) v0; /* cast away const */
520 GLfloat rSum, gSum, bSum;
524 COPY_CHAN4(cSave, ncv0->color);
526 rSum = CHAN_TO_FLOAT(ncv0->color[0]) + ncv0->attrib[VARYING_SLOT_COL1][0];
527 gSum = CHAN_TO_FLOAT(ncv0->color[1]) + ncv0->attrib[VARYING_SLOT_COL1][1];
528 bSum = CHAN_TO_FLOAT(ncv0->color[2]) + ncv0->attrib[VARYING_SLOT_COL1][2];
529 UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[0], rSum);
530 UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[1], gSum);
531 UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[2], bSum);
533 SWRAST_CONTEXT(ctx)->SpecPoint(ctx, ncv0);
535 COPY_CHAN4(ncv0->color, cSave);
540 * Examine current state to determine which point drawing function to use.
543 _swrast_choose_point(struct gl_context *ctx)
545 SWcontext *swrast = SWRAST_CONTEXT(ctx);
546 const GLfloat size = CLAMP(ctx->Point.Size,
550 if (ctx->RenderMode == GL_RENDER) {
551 if (ctx->Point.PointSprite) {
552 swrast->Point = sprite_point;
554 else if (ctx->Point.SmoothFlag) {
555 swrast->Point = smooth_point;
557 else if (size > 1.0 ||
558 ctx->Point._Attenuated ||
559 ctx->VertexProgram.PointSizeEnabled) {
560 swrast->Point = large_point;
563 swrast->Point = pixel_point;
566 else if (ctx->RenderMode == GL_FEEDBACK) {
567 swrast->Point = _swrast_feedback_point;
571 swrast->Point = _swrast_select_point;