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authorRoland Scheidegger <sroland@vmware.com>2010-10-08 21:06:04 +0200
committerRoland Scheidegger <sroland@vmware.com>2010-10-09 00:36:38 +0200
commit318bb080b04c961141a962d440d0e1296f8adda6 (patch)
treee019cb68cd74f19d5fc1f011a51bc6682126b21f /src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
parent99ade19e6e0dc9f5a4507bdcd7fb9704ca6c1df5 (diff)
gallivm: more linear tex wrap mode calculation simplification
Rearrange order of operations a bit to make some clamps easier. All calculations should be equivalent. Note there seems to be some inconsistency in the clamp to edge case wrt normalized/non-normalized coords, could potentially simplify this too.
Diffstat (limited to 'src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c')
-rw-r--r--src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c21
1 files changed, 9 insertions, 12 deletions
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
index 29adb57928..242e8d3d50 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
@@ -291,6 +291,8 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
coord = lp_build_mul(coord_bld, coord, length_f);
coord = lp_build_sub(coord_bld, coord, half);
}
+ /* XXX this is odd normalized ranges from -0.5 to length-0.5 after denorm
+ but non-normalized ranges from to 0.5 to length-0.5 after clamp */
else {
LLVMValueRef min, max;
/* clamp to [0.5, length - 0.5] */
@@ -309,16 +311,15 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
{
- LLVMValueRef min, max;
+ LLVMValueRef min;
if (bld->static_state->normalized_coords) {
/* scale coord to length */
coord = lp_build_mul(coord_bld, coord, length_f);
}
- /* clamp to [-0.5, length + 0.5] */
- min = lp_build_const_vec(coord_bld->type, -0.5F);
- max = lp_build_sub(coord_bld, length_f, min);
- coord = lp_build_clamp(coord_bld, coord, min, max);
+ /* was: clamp to [-0.5, length + 0.5], then sub 0.5 */
coord = lp_build_sub(coord_bld, coord, half);
+ min = lp_build_const_vec(coord_bld->type, -1.0F);
+ coord = lp_build_clamp(coord_bld, coord, min, length_f);
/* convert to int, compute lerp weight */
lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
@@ -388,8 +389,6 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
{
- LLVMValueRef min, max;
-
coord = lp_build_abs(coord_bld, coord);
if (bld->static_state->normalized_coords) {
@@ -397,12 +396,10 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
coord = lp_build_mul(coord_bld, coord, length_f);
}
- /* clamp to [-0.5, length + 0.5] */
- min = lp_build_negate(coord_bld, half);
- max = lp_build_sub(coord_bld, length_f, min);
- coord = lp_build_clamp(coord_bld, coord, min, max);
-
+ /* was: clamp to [-0.5, length + 0.5] then sub 0.5 */
+ /* skip -0.5 clamp (always positive), do sub first */
coord = lp_build_sub(coord_bld, coord, half);
+ coord = lp_build_min(coord_bld, coord, length_f);
/* convert to int, compute lerp weight */
lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);