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authorBrian Paul <[email protected]>2005-11-15 15:08:03 +0000
committerBrian Paul <[email protected]>2005-11-15 15:08:03 +0000
commitdaeb0056df58afaa1a96a1eaea699571205c8d4b (patch)
tree5f260a22af8074e58e39d0a58858fa15c652e25a /src/mesa/swrast
parent7edf68e08178106a37094e1aed2df1898f3027cd (diff)
fix color interpolation problem reported on VMS
Diffstat (limited to 'src/mesa/swrast')
-rw-r--r--src/mesa/swrast/s_tritemp.h102
1 files changed, 38 insertions, 64 deletions
diff --git a/src/mesa/swrast/s_tritemp.h b/src/mesa/swrast/s_tritemp.h
index 93454346bd5..d4c9fdd7cb9 100644
--- a/src/mesa/swrast/s_tritemp.h
+++ b/src/mesa/swrast/s_tritemp.h
@@ -141,6 +141,24 @@
#endif
+
+/*
+ * Some code we unfortunately need to prevent negative interpolated colors.
+ */
+#ifndef CLAMP_INTERPOLANT
+#define CLAMP_INTERPOLANT(CHANNEL, CHANNELSTEP, LEN) \
+do { \
+ GLfixed endVal = span.CHANNEL + (LEN) * span.CHANNELSTEP; \
+ if (endVal < 0) { \
+ span.CHANNEL -= endVal; \
+ } \
+ if (span.CHANNEL < 0) { \
+ span.CHANNEL = 0; \
+ } \
+} while (0)
+#endif
+
+
static void NAME(GLcontext *ctx, const SWvertex *v0,
const SWvertex *v1,
const SWvertex *v2 )
@@ -304,6 +322,7 @@ static void NAME(GLcontext *ctx, const SWvertex *v0,
oneOverArea = 1.0F / area;
}
+
span.facing = ctx->_Facing; /* for 2-sided stencil test */
/* Edge setup. For a triangle strip these could be reused... */
@@ -510,7 +529,7 @@ static void NAME(GLcontext *ctx, const SWvertex *v0,
# endif /* INTERP_ALPHA */
}
else {
- ASSERT (ctx->Light.ShadeModel == GL_FLAT);
+ ASSERT(ctx->Light.ShadeModel == GL_FLAT);
span.interpMask |= SPAN_FLAT;
span.drdx = span.drdy = 0.0F;
span.dgdx = span.dgdy = 0.0F;
@@ -903,7 +922,7 @@ static void NAME(GLcontext *ctx, const SWvertex *v0,
# endif
}
else {
- ASSERT (ctx->Light.ShadeModel == GL_FLAT);
+ ASSERT(ctx->Light.ShadeModel == GL_FLAT);
# if CHAN_TYPE == GL_FLOAT
rLeft = v2->color[RCOMP];
gLeft = v2->color[GCOMP];
@@ -925,7 +944,8 @@ static void NAME(GLcontext *ctx, const SWvertex *v0,
# endif
# endif
}
-#endif
+#endif /* INTERP_RGB */
+
#ifdef INTERP_SPEC
if (ctx->Light.ShadeModel == GL_SMOOTH) {
@@ -946,6 +966,7 @@ static void NAME(GLcontext *ctx, const SWvertex *v0,
# endif
}
else {
+ ASSERT(ctx->Light.ShadeModel == GL_FLAT);
#if CHAN_TYPE == GL_FLOAT
srLeft = v2->specular[RCOMP];
sgLeft = v2->specular[GCOMP];
@@ -967,6 +988,7 @@ static void NAME(GLcontext *ctx, const SWvertex *v0,
diOuter = SignedFloatToFixed(didy + dxOuter * didx);
}
else {
+ ASSERT(ctx->Light.ShadeModel == GL_FLAT);
iLeft = FloatToFixed(v2->index);
diOuter = 0;
}
@@ -1114,77 +1136,29 @@ static void NAME(GLcontext *ctx, const SWvertex *v0,
)
#endif
- if (span.end > 1) {
- /* Under rare circumstances, we might have to fudge the
- * colors. XXX does this really happen anymore???
- */
+ /* This is where we actually generate fragments */
+ /* XXX the test for span.y > 0 _shouldn't_ be needed but
+ * it fixes a problem on 64-bit Opterons (bug 4842).
+ */
+ if (span.end > 0 && span.y >= 0) {
const GLint len = span.end - 1;
(void) len;
#ifdef INTERP_RGB
- {
- GLfixed ffrend = span.red + len * span.redStep;
- GLfixed ffgend = span.green + len * span.greenStep;
- GLfixed ffbend = span.blue + len * span.blueStep;
- if (ffrend < 0) {
- span.red -= ffrend;
- if (span.red < 0)
- span.red = 0;
- }
- if (ffgend < 0) {
- span.green -= ffgend;
- if (span.green < 0)
- span.green = 0;
- }
- if (ffbend < 0) {
- span.blue -= ffbend;
- if (span.blue < 0)
- span.blue = 0;
- }
- }
+ CLAMP_INTERPOLANT(red, redStep, len);
+ CLAMP_INTERPOLANT(green, greenStep, len);
+ CLAMP_INTERPOLANT(blue, blueStep, len);
#endif
#ifdef INTERP_ALPHA
- {
- GLfixed ffaend = span.alpha + len * span.alphaStep;
- if (ffaend < 0) {
- span.alpha -= ffaend;
- if (span.alpha < 0)
- span.alpha = 0;
- }
- }
+ CLAMP_INTERPOLANT(alpha, alphaStep, len);
#endif
#ifdef INTERP_SPEC
- {
- GLfixed ffsrend = span.specRed + len * span.specRedStep;
- GLfixed ffsgend = span.specGreen + len * span.specGreenStep;
- GLfixed ffsbend = span.specBlue + len * span.specBlueStep;
- if (ffsrend < 0) {
- span.specRed -= ffsrend;
- if (span.specRed < 0)
- span.specRed = 0;
- }
- if (ffsgend < 0) {
- span.specGreen -= ffsgend;
- if (span.specGreen < 0)
- span.specGreen = 0;
- }
- if (ffsbend < 0) {
- span.specBlue -= ffsbend;
- if (span.specBlue < 0)
- span.specBlue = 0;
- }
- }
+ CLAMP_INTERPOLANT(specRed, specRedStep, len);
+ CLAMP_INTERPOLANT(specGreen, specGreenStep, len);
+ CLAMP_INTERPOLANT(specBlue, specBlueStep, len);
#endif
#ifdef INTERP_INDEX
- if (span.index < 0)
- span.index = 0;
+ CLAMP_INTERPOLANT(index, indexStep, len);
#endif
- } /* span.end > 1 */
-
- /* This is where we actually generate fragments */
- /* XXX the test for span.y > 0 _shouldn't_ be needed but
- * it fixes a problem on 64-bit Opterons (bug 4842).
- */
- if (span.end > 0 && span.y >= 0) {
RENDER_SPAN( span );
}