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-rw-r--r--src/mesa/swrast/s_span.c159
1 files changed, 127 insertions, 32 deletions
diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
index d164ad961ad..b74f62b6c68 100644
--- a/src/mesa/swrast/s_span.c
+++ b/src/mesa/swrast/s_span.c
@@ -340,10 +340,16 @@ _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
return lambda;
}
-/*
+
+/**
* Fill in the span.texcoords array from the interpolation values.
- * XXX We could optimize here for the case when dq = 0. That would
- * usually be the case when using an orthographic projection.
+ * Note: in the places where we divide by Q (or mult by invQ) we're
+ * really doing two things: perspective correction and texcoord
+ * projection. Remember, for texcoord (s,t,r,q) we need to index
+ * texels with (s/q, t/q, r/q).
+ * If we're using a fragment program, we never do the division
+ * for texcoord projection. That's done by the TXP instruction
+ * or user-written code.
*/
static void
interpolate_texcoords(GLcontext *ctx, struct sw_span *span)
@@ -368,6 +374,7 @@ interpolate_texcoords(GLcontext *ctx, struct sw_span *span)
texH = img->HeightScale;
}
else {
+ /* using a fragment program */
texW = 1.0;
texH = 1.0;
needLambda = GL_FALSE;
@@ -387,19 +394,42 @@ interpolate_texcoords(GLcontext *ctx, struct sw_span *span)
GLfloat r = span->tex[u][2];
GLfloat q = span->tex[u][3];
GLuint i;
- for (i = 0; i < span->end; i++) {
- const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
- texcoord[i][0] = s * invQ;
- texcoord[i][1] = t * invQ;
- texcoord[i][2] = r * invQ;
- texcoord[i][3] = q;
- lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
- dqdx, dqdy, texW, texH,
- s, t, q, invQ);
- s += dsdx;
- t += dtdx;
- r += drdx;
- q += dqdx;
+ if (ctx->FragmentProgram.Enabled) {
+ /* do perspective correction but don't divide s, t, r by q */
+ const GLfloat dwdx = span->dwdx;
+ GLfloat w = span->w;
+ for (i = 0; i < span->end; i++) {
+ const GLfloat invW = 1.0F / w;
+ texcoord[i][0] = s * invW;
+ texcoord[i][1] = t * invW;
+ texcoord[i][2] = r * invW;
+ texcoord[i][3] = q * invW;
+ lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
+ dqdx, dqdy, texW, texH,
+ s, t, q, invW);
+ s += dsdx;
+ t += dtdx;
+ r += drdx;
+ q += dqdx;
+ w += dwdx;
+ }
+
+ }
+ else {
+ for (i = 0; i < span->end; i++) {
+ const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
+ texcoord[i][0] = s * invQ;
+ texcoord[i][1] = t * invQ;
+ texcoord[i][2] = r * invQ;
+ texcoord[i][3] = q;
+ lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
+ dqdx, dqdy, texW, texH,
+ s, t, q, invQ);
+ s += dsdx;
+ t += dtdx;
+ r += drdx;
+ q += dqdx;
+ }
}
span->arrayMask |= SPAN_LAMBDA;
}
@@ -415,7 +445,25 @@ interpolate_texcoords(GLcontext *ctx, struct sw_span *span)
GLfloat r = span->tex[u][2];
GLfloat q = span->tex[u][3];
GLuint i;
- if (dqdx == 0.0) {
+ if (ctx->FragmentProgram.Enabled) {
+ /* do perspective correction but don't divide s, t, r by q */
+ const GLfloat dwdx = span->dwdx;
+ GLfloat w = span->w;
+ for (i = 0; i < span->end; i++) {
+ const GLfloat invW = 1.0F / w;
+ texcoord[i][0] = s * invW;
+ texcoord[i][1] = t * invW;
+ texcoord[i][2] = r * invW;
+ texcoord[i][3] = q * invW;
+ lambda[i] = 0.0;
+ s += dsdx;
+ t += dtdx;
+ r += drdx;
+ q += dqdx;
+ w += dwdx;
+ }
+ }
+ else if (dqdx == 0.0F) {
/* Ortho projection or polygon's parallel to window X axis */
const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
for (i = 0; i < span->end; i++) {
@@ -480,19 +528,46 @@ interpolate_texcoords(GLcontext *ctx, struct sw_span *span)
GLfloat r = span->tex[0][2];
GLfloat q = span->tex[0][3];
GLuint i;
- for (i = 0; i < span->end; i++) {
- const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
- lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
- dqdx, dqdy, texW, texH,
- s, t, q, invQ);
- texcoord[i][0] = s * invQ;
- texcoord[i][1] = t * invQ;
- texcoord[i][2] = r * invQ;
- texcoord[i][3] = q;
- s += dsdx;
- t += dtdx;
- r += drdx;
- q += dqdx;
+ if (ctx->FragmentProgram.Enabled) {
+ /* do perspective correction but don't divide s, t, r by q */
+ const GLfloat dwdx = span->dwdx;
+ GLfloat w = span->w;
+ for (i = 0; i < span->end; i++) {
+ const GLfloat invW = 1.0F / w;
+ texcoord[i][0] = s * invW;
+ texcoord[i][1] = t * invW;
+ texcoord[i][2] = r * invW;
+ texcoord[i][3] = q * invW;
+ lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
+ dqdx, dqdy, texW, texH,
+ s, t, q, invW);
+ s += dsdx;
+ t += dtdx;
+ r += drdx;
+ q += dqdx;
+ w += dwdx;
+ }
+ }
+ else {
+ /* tex.c */
+ GLfloat w = span->w;
+ GLfloat dwdx = span->dwdx;
+ assert(span->interpMask & SPAN_W);
+ for (i = 0; i < span->end; i++) {
+ const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
+ lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
+ dqdx, dqdy, texW, texH,
+ s, t, q, invQ);
+ texcoord[i][0] = s * invQ;
+ texcoord[i][1] = t * invQ;
+ texcoord[i][2] = r * invQ;
+ texcoord[i][3] = q;
+ s += dsdx;
+ t += dtdx;
+ r += drdx;
+ q += dqdx;
+ w += dwdx;
+ }
}
span->arrayMask |= SPAN_LAMBDA;
}
@@ -508,7 +583,24 @@ interpolate_texcoords(GLcontext *ctx, struct sw_span *span)
GLfloat r = span->tex[0][2];
GLfloat q = span->tex[0][3];
GLuint i;
- if (dqdx == 0.0) {
+ if (ctx->FragmentProgram.Enabled) {
+ /* do perspective correction but don't divide s, t, r by q */
+ const GLfloat dwdx = span->dwdx;
+ GLfloat w = span->w;
+ for (i = 0; i < span->end; i++) {
+ const GLfloat invW = 1.0F / w;
+ texcoord[i][0] = s * invW;
+ texcoord[i][1] = t * invW;
+ texcoord[i][2] = r * invW;
+ texcoord[i][3] = q * invW;
+ s += dsdx;
+ t += dtdx;
+ r += drdx;
+ q += dqdx;
+ w += dwdx;
+ }
+ }
+ else if (dqdx == 0.0F) {
/* Ortho projection or polygon's parallel to window X axis */
const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
for (i = 0; i < span->end; i++) {
@@ -1007,7 +1099,7 @@ _swrast_write_rgba_span( GLcontext *ctx, struct sw_span *span)
/* Fragment program */
if (ctx->FragmentProgram.Enabled) {
- /* Now we may need to interpolate the colors */
+ /* Now we may need to interpolate the colors and texcoords */
if ((span->interpMask & SPAN_RGBA) &&
(span->arrayMask & SPAN_RGBA) == 0) {
interpolate_colors(ctx, span);
@@ -1016,6 +1108,9 @@ _swrast_write_rgba_span( GLcontext *ctx, struct sw_span *span)
if (span->interpMask & SPAN_SPEC) {
interpolate_specular(ctx, span);
}
+ if ((span->interpMask & SPAN_TEXTURE)
+ && (span->arrayMask & SPAN_TEXTURE) == 0)
+ interpolate_texcoords(ctx, span);
_swrast_exec_fragment_program(ctx, span);
monoColor = GL_FALSE;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-30 16:22:42 +0000