r300/compiler: fix projective mapping of 2D NPOT textures

NOTE: This is a candidate for the 7.9 branch.

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_program_tex.c b/src/mesa/drivers/dri/r300/compiler/radeon_program_tex.c
index 7ce5fb8639fe811e3d236d1e3faa43094deb6381..09cb8b27f6596f22b03f5515fd6370a5a391a51c 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/radeon_program_tex.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_program_tex.c
@@ -71,6 +71,39 @@ static void scale_texcoords(struct r300_fragment_program_compiler *compiler,
        inst->U.I.SrcReg[0].Index = temp;
 }
 
+static void projective_divide(struct r300_fragment_program_compiler *compiler,
+                             struct rc_instruction *inst)
+{
+       struct rc_instruction *inst_mul, *inst_rcp;
+
+       unsigned temp = rc_find_free_temporary(&compiler->Base);
+
+       inst_rcp = rc_insert_new_instruction(&compiler->Base, inst->Prev);
+       inst_rcp->U.I.Opcode = RC_OPCODE_RCP;
+       inst_rcp->U.I.DstReg.File = RC_FILE_TEMPORARY;
+       inst_rcp->U.I.DstReg.Index = temp;
+       inst_rcp->U.I.DstReg.WriteMask = RC_MASK_W;
+       inst_rcp->U.I.SrcReg[0] = inst->U.I.SrcReg[0];
+       /* Because the input can be arbitrarily swizzled,
+        * read the component mapped to W. */
+       inst_rcp->U.I.SrcReg[0].Swizzle =
+               RC_MAKE_SWIZZLE_SMEAR(GET_SWZ(inst->U.I.SrcReg[0].Swizzle, 3));
+
+       inst_mul = rc_insert_new_instruction(&compiler->Base, inst->Prev);
+       inst_mul->U.I.Opcode = RC_OPCODE_MUL;
+       inst_mul->U.I.DstReg.File = RC_FILE_TEMPORARY;
+       inst_mul->U.I.DstReg.Index = temp;
+       inst_mul->U.I.SrcReg[0] = inst->U.I.SrcReg[0];
+       inst_mul->U.I.SrcReg[1].File = RC_FILE_TEMPORARY;
+       inst_mul->U.I.SrcReg[1].Index = temp;
+       inst_mul->U.I.SrcReg[1].Swizzle = RC_SWIZZLE_WWWW;
+
+       reset_srcreg(&inst->U.I.SrcReg[0]);
+       inst->U.I.Opcode = RC_OPCODE_TEX;
+       inst->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
+       inst->U.I.SrcReg[0].Index = temp;
+}
+
 /**
  * Transform TEX, TXP, TXB, and KIL instructions in the following ways:
  *  - implement texture compare (shadow extensions)
@@ -216,6 +249,12 @@ int radeonTransformTEX(
                inst->U.I.TexSrcTarget = RC_TEXTURE_2D;
        }
 
+       /* Divide by W if needed. */
+       if (inst->U.I.Opcode == RC_OPCODE_TXP &&
+           (wrapmode == RC_WRAP_REPEAT || wrapmode == RC_WRAP_MIRRORED_REPEAT)) {
+               projective_divide(compiler, inst);
+       }
+
        /* Texture wrap modes don't work on NPOT textures.
         *
         * Non-wrapped/clamped texcoords with NPOT are free in HW. Repeat and