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path: root/mesalib/src/mesa/program/programopt.c
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Diffstat (limited to 'mesalib/src/mesa/program/programopt.c')
-rw-r--r--mesalib/src/mesa/program/programopt.c33
1 files changed, 21 insertions, 12 deletions
diff --git a/mesalib/src/mesa/program/programopt.c b/mesalib/src/mesa/program/programopt.c
index 5ad9571f7..a239da2c6 100644
--- a/mesalib/src/mesa/program/programopt.c
+++ b/mesalib/src/mesa/program/programopt.c
@@ -230,15 +230,25 @@ _mesa_insert_mvp_code(struct gl_context *ctx, struct gl_vertex_program *vprog)
/**
- * Append extra instructions onto the given fragment program to implement
- * the fog mode specified by fprog->FogOption.
- * The fragment.fogcoord input is used to compute the fog blend factor.
+ * Append instructions to implement fog
*
- * XXX with a little work, this function could be adapted to add fog code
+ * The \c fragment.fogcoord input is used to compute the fog blend factor.
+ *
+ * \param ctx The GL context
+ * \param fprog Fragment program that fog instructions will be appended to.
+ * \param fog_mode Fog mode. One of \c GL_EXP, \c GL_EXP2, or \c GL_LINEAR.
+ * \param saturate True if writes to color outputs should be clamped to [0, 1]
+ *
+ * \note
+ * This function sets \c FRAG_BIT_FOGC in \c fprog->Base.InputsRead.
+ *
+ * \todo With a little work, this function could be adapted to add fog code
* to vertex programs too.
*/
void
-_mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog, GLboolean saturate)
+_mesa_append_fog_code(struct gl_context *ctx,
+ struct gl_fragment_program *fprog, GLenum fog_mode,
+ GLboolean saturate)
{
static const gl_state_index fogPStateOpt[STATE_LENGTH]
= { STATE_INTERNAL, STATE_FOG_PARAMS_OPTIMIZED, 0, 0, 0 };
@@ -251,9 +261,9 @@ _mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog,
GLint fogPRefOpt, fogColorRef; /* state references */
GLuint colorTemp, fogFactorTemp; /* temporary registerss */
- if (fprog->FogOption == GL_NONE) {
+ if (fog_mode == GL_NONE) {
_mesa_problem(ctx, "_mesa_append_fog_code() called for fragment program"
- " with FogOption == GL_NONE");
+ " with fog_mode == GL_NONE");
return;
}
@@ -301,7 +311,7 @@ _mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog,
/* emit instructions to compute fog blending factor */
/* this is always clamped to [0, 1] regardless of fragment clamping */
- if (fprog->FogOption == GL_LINEAR) {
+ if (fog_mode == GL_LINEAR) {
/* MAD fogFactorTemp.x, fragment.fogcoord.x, fogPRefOpt.x, fogPRefOpt.y; */
inst->Opcode = OPCODE_MAD;
inst->DstReg.File = PROGRAM_TEMPORARY;
@@ -320,7 +330,7 @@ _mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog,
inst++;
}
else {
- ASSERT(fprog->FogOption == GL_EXP || fprog->FogOption == GL_EXP2);
+ ASSERT(fog_mode == GL_EXP || fog_mode == GL_EXP2);
/* fogPRefOpt.z = d/ln(2), fogPRefOpt.w = d/sqrt(ln(2) */
/* EXP: MUL fogFactorTemp.x, fogPRefOpt.z, fragment.fogcoord.x; */
/* EXP2: MUL fogFactorTemp.x, fogPRefOpt.w, fragment.fogcoord.x; */
@@ -331,12 +341,12 @@ _mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog,
inst->SrcReg[0].File = PROGRAM_STATE_VAR;
inst->SrcReg[0].Index = fogPRefOpt;
inst->SrcReg[0].Swizzle
- = (fprog->FogOption == GL_EXP) ? SWIZZLE_ZZZZ : SWIZZLE_WWWW;
+ = (fog_mode == GL_EXP) ? SWIZZLE_ZZZZ : SWIZZLE_WWWW;
inst->SrcReg[1].File = PROGRAM_INPUT;
inst->SrcReg[1].Index = FRAG_ATTRIB_FOGC;
inst->SrcReg[1].Swizzle = SWIZZLE_XXXX;
inst++;
- if (fprog->FogOption == GL_EXP2) {
+ if (fog_mode == GL_EXP2) {
/* MUL fogFactorTemp.x, fogFactorTemp.x, fogFactorTemp.x; */
inst->Opcode = OPCODE_MUL;
inst->DstReg.File = PROGRAM_TEMPORARY;
@@ -397,7 +407,6 @@ _mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog,
fprog->Base.Instructions = newInst;
fprog->Base.NumInstructions = inst - newInst;
fprog->Base.InputsRead |= FRAG_BIT_FOGC;
- /* XXX do this? fprog->FogOption = GL_NONE; */
}