*
* Mirroring is trickier. We're going to start out like repeat:
*
- * MUL temp0, texcoord, <scaling factor constant> ; De-mirror across axes
- * MUL temp0, abs(temp0), 0.5 ; Pattern repeats in [0, 2]
+ * MUL temp, texcoord, <scaling factor constant> ; De-mirror across axes
+ * MUL temp, temp, 0.5 ; Pattern repeats in [0, 2]
* ; so scale to [0, 1]
- * FRC temp0, temp0 ; Make the pattern repeat
- * SGE temp1, temp0, 0.5 ; Select components that need to be "reflected"
- * ; across the mirror
- * MAD temp0, neg(0.5), temp1, temp0 ; Add -0.5 to the
- * ; selected components
- * ADD temp0, temp0, temp0 ; Poor man's 2x to undo earlier MUL
+ * FRC temp, temp ; Make the pattern repeat
+ * MAD temp, temp, 2, -1 ; Move the pattern to [-1, 1]
+ * ADD temp, 1, -abs(temp) ; Now comes a neat trick: use abs to mirror the pattern.
+ * ; The pattern is backwards, so reverse it (1-x).
*
* This gives us coords in [0, 1].
*
- * ~ C.
+ * ~ C & M. ;)
*/
if (inst->U.I.Opcode != RC_OPCODE_KIL &&
(inst->U.I.TexSrcTarget == RC_TEXTURE_RECT ||
inst_frc->U.I.DstReg.WriteMask = RC_MASK_XYZ;
inst_frc->U.I.SrcReg[0] = inst->U.I.SrcReg[0];
} else if (wrapmode == RC_WRAP_MIRROR) {
- unsigned temp1;
/*
- * MUL temp0, abs(temp0), 0.5
- * FRC temp0, temp0
- * SGE temp1, temp0, 0.5
- * MAD temp0, neg(0.5), temp1, temp0
- * ADD temp0, temp0, temp0
+ * Function:
+ * f(v) = 1 - abs(frac(v * 0.5) * 2 - 1)
+ *
+ * Code:
+ * MUL temp, src0, 0.5
+ * FRC temp, temp
+ * MAD temp, temp, 2, -1
+ * ADD temp, 1, -abs(temp)
*/
- struct rc_instruction *inst_rect = rc_insert_new_instruction(c, inst->Prev);
-
- inst_rect->U.I.Opcode = RC_OPCODE_MUL;
- inst_rect->U.I.DstReg.File = RC_FILE_TEMPORARY;
- inst_rect->U.I.DstReg.Index = temp;
- inst_rect->U.I.SrcReg[0] = inst->U.I.SrcReg[0];
- inst_rect->U.I.SrcReg[1].Swizzle = RC_MAKE_SWIZZLE_SMEAR(RC_SWIZZLE_HALF);
-
- inst_rect = rc_insert_new_instruction(c, inst->Prev);
-
- inst_rect->U.I.Opcode = RC_OPCODE_FRC;
- inst_rect->U.I.DstReg.File = RC_FILE_TEMPORARY;
- inst_rect->U.I.DstReg.Index = temp;
- inst_rect->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
- inst_rect->U.I.SrcReg[0].Index = temp;
-
- temp1 = rc_find_free_temporary(c);
- inst_rect = rc_insert_new_instruction(c, inst->Prev);
-
- inst_rect->U.I.Opcode = RC_OPCODE_SGE;
- inst_rect->U.I.DstReg.File = RC_FILE_TEMPORARY;
- inst_rect->U.I.DstReg.Index = temp1;
- inst_rect->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
- inst_rect->U.I.SrcReg[0].Index = temp;
- inst_rect->U.I.SrcReg[1].Swizzle = RC_MAKE_SWIZZLE_SMEAR(RC_SWIZZLE_HALF);
-
- inst_rect = rc_insert_new_instruction(c, inst->Prev);
-
- inst_rect->U.I.Opcode = RC_OPCODE_MAD;
- inst_rect->U.I.DstReg.File = RC_FILE_TEMPORARY;
- inst_rect->U.I.DstReg.Index = temp;
- inst_rect->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
- inst_rect->U.I.SrcReg[0].Index = temp1;
- inst_rect->U.I.SrcReg[1].Swizzle = RC_MAKE_SWIZZLE_SMEAR(RC_SWIZZLE_HALF);
- inst_rect->U.I.SrcReg[1].Negate = 1;
- inst_rect->U.I.SrcReg[2].File = RC_FILE_TEMPORARY;
- inst_rect->U.I.SrcReg[2].Index = temp;
-
- inst_rect = rc_insert_new_instruction(c, inst->Prev);
-
- inst_rect->U.I.Opcode = RC_OPCODE_ADD;
- inst_rect->U.I.DstReg.File = RC_FILE_TEMPORARY;
- inst_rect->U.I.DstReg.Index = temp;
- inst_rect->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
- inst_rect->U.I.SrcReg[0].Index = temp;
- inst_rect->U.I.SrcReg[1].File = RC_FILE_TEMPORARY;
- inst_rect->U.I.SrcReg[1].Index = temp;
+ struct rc_instruction *inst_mul, *inst_frc, *inst_mad, *inst_add;
+ unsigned two, two_swizzle;
+
+ inst_mul = rc_insert_new_instruction(c, 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.DstReg.WriteMask = RC_MASK_XYZ;
+ inst_mul->U.I.SrcReg[0] = inst->U.I.SrcReg[0];
+ inst_mul->U.I.SrcReg[1].Swizzle = RC_SWIZZLE_HHHH;
+
+ inst_frc = rc_insert_new_instruction(c, inst->Prev);
+
+ inst_frc->U.I.Opcode = RC_OPCODE_FRC;
+ inst_frc->U.I.DstReg.File = RC_FILE_TEMPORARY;
+ inst_frc->U.I.DstReg.Index = temp;
+ inst_frc->U.I.DstReg.WriteMask = RC_MASK_XYZ;
+ inst_frc->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
+ inst_frc->U.I.SrcReg[0].Index = temp;
+ inst_frc->U.I.SrcReg[0].Swizzle = RC_SWIZZLE_XYZ0;
+
+ two = rc_constants_add_immediate_scalar(&c->Program.Constants, 2, &two_swizzle);
+ inst_mad = rc_insert_new_instruction(c, inst->Prev);
+
+ inst_mad->U.I.Opcode = RC_OPCODE_MAD;
+ inst_mad->U.I.DstReg.File = RC_FILE_TEMPORARY;
+ inst_mad->U.I.DstReg.Index = temp;
+ inst_mad->U.I.DstReg.WriteMask = RC_MASK_XYZ;
+ inst_mad->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
+ inst_mad->U.I.SrcReg[0].Index = temp;
+ inst_mad->U.I.SrcReg[0].Swizzle = RC_SWIZZLE_XYZ0;
+ inst_mad->U.I.SrcReg[1].File = RC_FILE_CONSTANT;
+ inst_mad->U.I.SrcReg[1].Index = two;
+ inst_mad->U.I.SrcReg[1].Swizzle = two_swizzle;
+ inst_mad->U.I.SrcReg[2].Swizzle = RC_SWIZZLE_1111;
+ inst_mad->U.I.SrcReg[2].Negate = RC_MASK_XYZ;
+
+ inst_add = rc_insert_new_instruction(c, inst->Prev);
+
+ inst_add->U.I.Opcode = RC_OPCODE_ADD;
+ inst_add->U.I.DstReg.File = RC_FILE_TEMPORARY;
+ inst_add->U.I.DstReg.Index = temp;
+ inst_add->U.I.DstReg.WriteMask = RC_MASK_XYZ;
+ inst_add->U.I.SrcReg[0].Swizzle = RC_SWIZZLE_1111;
+ inst_add->U.I.SrcReg[1].File = RC_FILE_TEMPORARY;
+ inst_add->U.I.SrcReg[1].Index = temp;
+ inst_add->U.I.SrcReg[1].Swizzle = RC_SWIZZLE_XYZ0;
+ inst_add->U.I.SrcReg[1].Abs = 1;
+ inst_add->U.I.SrcReg[1].Negate = RC_MASK_XYZ;
}
/* Preserve W for TXP/TXB. */