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authorBrian Paul <[email protected]>2006-10-31 14:29:01 +0000
committerBrian Paul <[email protected]>2006-10-31 14:29:01 +0000
commitecd1743a0c88b7e574848c0cb100fdcd880979de (patch)
treeea6ef07c9101c846289781fd45945e5be33ea7e9 /src/mesa/swrast/s_nvfragprog.c
parent256c96136c38f47824b5aaf584bc949788f913e7 (diff)
In TEX instructions, use precomputed lambda only if using fragment.texcoord[k]
to sample texture[k]. Use zero otherwise. Not foolproof, but a good compromise.
Diffstat (limited to 'src/mesa/swrast/s_nvfragprog.c')
-rw-r--r--src/mesa/swrast/s_nvfragprog.c67
1 files changed, 33 insertions, 34 deletions
diff --git a/src/mesa/swrast/s_nvfragprog.c b/src/mesa/swrast/s_nvfragprog.c
index b3f03282f10..a34db23fa64 100644
--- a/src/mesa/swrast/s_nvfragprog.c
+++ b/src/mesa/swrast/s_nvfragprog.c
@@ -1265,21 +1265,20 @@ execute_program( GLcontext *ctx,
case OPCODE_TEX: /* Both ARB and NV frag prog */
/* Texel lookup */
{
- /* Note: we're using zero instead of lambda for the LOD.
- * The problem is we didn't necessarily use the right partial
- * derivatives when we called _swrast_compute_lambda() earlier.
- * A texture can be sampled with any coordinate, not just
- * fragment.texcoord[n].
- * Use zero for now because that's better than using a bad
- * lambda value (I've seen a few test programs fail otherwise).
- * We need to overhaul this stuff someday.
+ /* Note: only use the precomputed lambda value when we're
+ * sampling texture unit [K] with texcoord[K].
+ * Otherwise, the lambda value may have no relation to the
+ * instruction's texcoord or texture image. Using the wrong
+ * lambda is usually bad news.
+ * The rest of the time, just use zero (until we get a more
+ * sophisticated way of computing lambda).
*/
-#ifdef LAMBDA_ZERO
- GLfloat lambda = 0.0;
-#else
- GLfloat lambda = span->array->lambda[inst->TexSrcUnit][column];
-#endif
- GLfloat coord[4], color[4];
+ GLfloat coord[4], color[4], lambda;
+ if (inst->SrcReg[0].File == PROGRAM_INPUT &&
+ inst->SrcReg[0].Index == FRAG_ATTRIB_TEX0+inst->TexSrcUnit)
+ lambda = span->array->lambda[inst->TexSrcUnit][column];
+ else
+ lambda = 0.0;
fetch_vector4(ctx, &inst->SrcReg[0], machine, program, coord);
fetch_texel( ctx, coord, lambda, inst->TexSrcUnit, color );
#if DEBUG_FRAG
@@ -1294,12 +1293,12 @@ execute_program( GLcontext *ctx,
case OPCODE_TXB: /* GL_ARB_fragment_program only */
/* Texel lookup with LOD bias */
{
-#ifdef LAMBDA_ZERO
- GLfloat lambda = 0.0;
-#else
- GLfloat lambda = span->array->lambda[inst->TexSrcUnit][column];
-#endif
- GLfloat coord[4], color[4], bias;
+ GLfloat coord[4], color[4], lambda, bias;
+ if (inst->SrcReg[0].File == PROGRAM_INPUT &&
+ inst->SrcReg[0].Index == FRAG_ATTRIB_TEX0+inst->TexSrcUnit)
+ lambda = span->array->lambda[inst->TexSrcUnit][column];
+ else
+ lambda = 0.0;
fetch_vector4(ctx, &inst->SrcReg[0], machine, program, coord);
/* coord[3] is the bias to add to lambda */
bias = ctx->Texture.Unit[inst->TexSrcUnit].LodBias
@@ -1324,12 +1323,12 @@ execute_program( GLcontext *ctx,
case OPCODE_TXP: /* GL_ARB_fragment_program only */
/* Texture lookup w/ projective divide */
{
-#ifdef LAMBDA_ZERO
- GLfloat lambda = 0.0;
-#else
- GLfloat lambda = span->array->lambda[inst->TexSrcUnit][column];
-#endif
- GLfloat texcoord[4], color[4];
+ GLfloat texcoord[4], color[4], lambda;
+ if (inst->SrcReg[0].File == PROGRAM_INPUT &&
+ inst->SrcReg[0].Index == FRAG_ATTRIB_TEX0+inst->TexSrcUnit)
+ lambda = span->array->lambda[inst->TexSrcUnit][column];
+ else
+ lambda = 0.0;
fetch_vector4(ctx, &inst->SrcReg[0], machine, program,texcoord);
/* Not so sure about this test - if texcoord[3] is
* zero, we'd probably be fine except for an ASSERT in
@@ -1347,13 +1346,13 @@ execute_program( GLcontext *ctx,
case OPCODE_TXP_NV: /* GL_NV_fragment_program only */
/* Texture lookup w/ projective divide */
{
-#ifdef LAMBDA_ZERO
- GLfloat lambda = 0.0;
-#else
- GLfloat lambda = span->array->lambda[inst->TexSrcUnit][column];
-#endif
- GLfloat texcoord[4], color[4];
- fetch_vector4( ctx, &inst->SrcReg[0], machine, program, texcoord );
+ GLfloat texcoord[4], color[4], lambda;
+ if (inst->SrcReg[0].File == PROGRAM_INPUT &&
+ inst->SrcReg[0].Index == FRAG_ATTRIB_TEX0+inst->TexSrcUnit)
+ lambda = span->array->lambda[inst->TexSrcUnit][column];
+ else
+ lambda = 0.0;
+ fetch_vector4(ctx, &inst->SrcReg[0], machine, program,texcoord);
if (inst->TexSrcTarget != TEXTURE_CUBE_INDEX &&
texcoord[3] != 0.0) {
texcoord[0] /= texcoord[3];
@@ -1598,7 +1597,7 @@ _swrast_exec_fragment_program( GLcontext *ctx, SWspan *span )
ctx->_CurrentProgram = GL_FRAGMENT_PROGRAM_ARB; /* or NV, doesn't matter */
-#if 1 /* we really shouldn't need this here... */
+#if 0 /* we really shouldn't need this here... */
if (program->Base.Parameters) {
_mesa_load_state_parameters(ctx, program->Base.Parameters);
}