From f68fce1f1f61997f284b77cca5b5765cd7443240 Mon Sep 17 00:00:00 2001 From: Brian Date: Wed, 24 Oct 2007 11:37:05 -0600 Subject: Implement gl_PointCoord attribute for GLSL fragment shaders. Contains the normalized fragment position within a point sprite. --- src/mesa/swrast/s_points.c | 117 ++++++++++++++++++++++++++------------------- 1 file changed, 67 insertions(+), 50 deletions(-) (limited to 'src/mesa/swrast/s_points.c') diff --git a/src/mesa/swrast/s_points.c b/src/mesa/swrast/s_points.c index 4768fbea972..c0f32e9c91b 100644 --- a/src/mesa/swrast/s_points.c +++ b/src/mesa/swrast/s_points.c @@ -55,7 +55,7 @@ sprite_point(GLcontext *ctx, const SWvertex *vert) SWcontext *swrast = SWRAST_CONTEXT(ctx); SWspan span; GLfloat size; - GLuint tCoords[MAX_TEXTURE_COORD_UNITS]; + GLuint tCoords[MAX_TEXTURE_COORD_UNITS + 1]; GLuint numTcoords = 0; GLfloat t0, dtdy; @@ -99,57 +99,71 @@ sprite_point(GLcontext *ctx, const SWvertex *vert) span.attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0F; span.attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0F; - ATTRIB_LOOP_BEGIN - if (attr >= FRAG_ATTRIB_TEX0 && attr < FRAG_ATTRIB_VAR0) { - const GLuint u = attr - FRAG_ATTRIB_TEX0; - /* a texcoord */ - if (ctx->Point.CoordReplace[u]) { - GLfloat s, r, dsdx; - - s = 0.0; - dsdx = 1.0 / size; - - if (ctx->Point.SpriteOrigin == GL_LOWER_LEFT) { - t0 = 0.0; - dtdy = 1.0 / size; - } - else { - /* GL_UPPER_LEFT */ - t0 = 1.0; - dtdy = -1.0 / size; - } - tCoords[numTcoords++] = attr; - - if (ctx->Point.SpriteRMode == GL_ZERO) - r = 0.0F; - else if (ctx->Point.SpriteRMode == GL_S) - r = vert->attrib[attr][0]; - else /* GL_R */ - r = vert->attrib[attr][2]; - - span.attrStart[attr][0] = s; - span.attrStart[attr][1] = 0.0; /* overwritten below */ - span.attrStart[attr][2] = r; - span.attrStart[attr][3] = 1.0; - - span.attrStepX[attr][0] = dsdx; - span.attrStepX[attr][1] = 0.0; - span.attrStepX[attr][2] = 0.0; - span.attrStepX[attr][3] = 0.0; - - span.attrStepY[attr][0] = 0.0; - span.attrStepY[attr][1] = dtdy; - span.attrStepY[attr][2] = 0.0; - span.attrStepY[attr][3] = 0.0; + { + GLfloat s, r, dsdx; + + /* texcoord / pointcoord interpolants */ + s = 0.0; + dsdx = 1.0 / size; + if (ctx->Point.SpriteOrigin == GL_LOWER_LEFT) { + t0 = 0.0; + dtdy = 1.0 / size; + } + else { + /* GL_UPPER_LEFT */ + t0 = 1.0; + dtdy = -1.0 / size; + } + ATTRIB_LOOP_BEGIN + if (attr >= FRAG_ATTRIB_TEX0 && attr < FRAG_ATTRIB_VAR0) { + const GLuint u = attr - FRAG_ATTRIB_TEX0; + /* a texcoord */ + if (ctx->Point.CoordReplace[u]) { + tCoords[numTcoords++] = attr; + + if (ctx->Point.SpriteRMode == GL_ZERO) + r = 0.0F; + else if (ctx->Point.SpriteRMode == GL_S) + r = vert->attrib[attr][0]; + else /* GL_R */ + r = vert->attrib[attr][2]; + + span.attrStart[attr][0] = s; + span.attrStart[attr][1] = 0.0; /* overwritten below */ + span.attrStart[attr][2] = r; + span.attrStart[attr][3] = 1.0; + + span.attrStepX[attr][0] = dsdx; + span.attrStepX[attr][1] = 0.0; + span.attrStepX[attr][2] = 0.0; + span.attrStepX[attr][3] = 0.0; + + span.attrStepY[attr][0] = 0.0; + span.attrStepY[attr][1] = dtdy; + span.attrStepY[attr][2] = 0.0; + span.attrStepY[attr][3] = 0.0; + + continue; + } + } + else if (attr == FRAG_ATTRIB_FOGC) { + /* GLSL gl_PointCoord is stored in fog.zw */ + span.attrStart[FRAG_ATTRIB_FOGC][2] = 0.0; + span.attrStart[FRAG_ATTRIB_FOGC][3] = 0.0; /* t0 set below */ + span.attrStepX[FRAG_ATTRIB_FOGC][2] = dsdx; + span.attrStepX[FRAG_ATTRIB_FOGC][3] = 0.0; + span.attrStepY[FRAG_ATTRIB_FOGC][2] = 0.0; + span.attrStepY[FRAG_ATTRIB_FOGC][3] = dtdy; + tCoords[numTcoords++] = FRAG_ATTRIB_FOGC; continue; } - } - /* use vertex's texcoord/attrib */ - COPY_4V(span.attrStart[attr], vert->attrib[attr]); - ASSIGN_4V(span.attrStepX[attr], 0, 0, 0, 0); - ASSIGN_4V(span.attrStepY[attr], 0, 0, 0, 0); - ATTRIB_LOOP_END + /* use vertex's texcoord/attrib */ + COPY_4V(span.attrStart[attr], vert->attrib[attr]); + ASSIGN_4V(span.attrStepX[attr], 0, 0, 0, 0); + ASSIGN_4V(span.attrStepY[attr], 0, 0, 0, 0); + ATTRIB_LOOP_END; + } /* compute pos, bounds and render */ { @@ -183,7 +197,10 @@ sprite_point(GLcontext *ctx, const SWvertex *vert) GLuint i; /* setup texcoord T for this row */ for (i = 0; i < numTcoords; i++) { - span.attrStart[tCoords[i]][1] = tcoord; + if (tCoords[i] == FRAG_ATTRIB_FOGC) + span.attrStart[FRAG_ATTRIB_FOGC][3] = tcoord; + else + span.attrStart[tCoords[i]][1] = tcoord; } /* these might get changed by span clipping */ -- cgit v1.2.3