[Mesa-dev] [PATCH 1/3] gallivm: ignore rho approximation for cube maps
sroland at vmware.com
sroland at vmware.com
Fri Oct 4 18:36:06 PDT 2013
From: Roland Scheidegger <sroland at vmware.com>
There's two reasons for this:
1) even when ignoring rho approximation for cube maps, the result is still
not correct, but it's better as the max error at edges is now sqrt(2) instead
of 2 (which was a full mip level), same as it is for ordinary 2d maps when
doing rho approximations (so the error actually goes from factor 2 at edges and
sqrt(2) completely inside a face to sqrt(2) at edges and 0 inside a face).
2) I want to repurpose rho_no_approx for cubemaps for fully correct cubemap
derivatives (so don't need yet another debug var).
---
src/gallium/auxiliary/gallivm/lp_bld_sample.c | 50 ++++++++++---------------
1 file changed, 20 insertions(+), 30 deletions(-)
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample.c b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
index c775382..dc593aa 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
@@ -269,10 +269,8 @@ lp_build_rho(struct lp_build_sample_context *bld,
/* Could optimize this for single quad just skip the broadcast */
cubesize = lp_build_extract_broadcast(gallivm, bld->float_size_in_type,
rho_bld->type, float_size, index0);
- if (no_rho_opt) {
- /* skipping sqrt hence returning rho squared */
- cubesize = lp_build_mul(rho_bld, cubesize, cubesize);
- }
+ /* skipping sqrt hence returning rho squared */
+ cubesize = lp_build_mul(rho_bld, cubesize, cubesize);
rho = lp_build_mul(rho_bld, cubesize, rho);
}
else if (derivs && !(bld->static_texture_state->target == PIPE_TEXTURE_CUBE)) {
@@ -757,8 +755,8 @@ lp_build_lod_selector(struct lp_build_sample_context *bld,
}
else {
LLVMValueRef rho;
- boolean rho_squared = (gallivm_debug & GALLIVM_DEBUG_NO_RHO_APPROX) &&
- (bld->dims > 1);
+ boolean rho_squared = ((gallivm_debug & GALLIVM_DEBUG_NO_RHO_APPROX) &&
+ (bld->dims > 1)) || cube_rho;
rho = lp_build_rho(bld, texture_unit, s, t, r, cube_rho, derivs);
@@ -1519,6 +1517,8 @@ lp_build_cube_lookup(struct lp_build_sample_context *bld,
*/
struct lp_build_context *cint_bld = &bld->int_coord_bld;
struct lp_type intctype = cint_bld->type;
+ LLVMTypeRef coord_vec_type = coord_bld->vec_type;
+ LLVMTypeRef cint_vec_type = cint_bld->vec_type;
LLVMValueRef signs, signt, signr, signma;
LLVMValueRef as, at, ar, face, face_s, face_t;
LLVMValueRef as_ge_at, maxasat, ar_ge_as_at;
@@ -1602,40 +1602,32 @@ lp_build_cube_lookup(struct lp_build_sample_context *bld,
* know the texture is square which simplifies things (we can omit the
* size mul which happens very early completely here and do it at the
* very end).
+ * Also always do calculations according to GALLIVM_DEBUG_NO_RHO_APPROX
+ * since the error can get quite big otherwise at edges.
+ * (With no_rho_approx max error is sqrt(2) at edges, same as it is
+ * without no_rho_approx for 2d textures, otherwise it would be factor 2.)
*/
ddx_ddy[0] = lp_build_packed_ddx_ddy_twocoord(coord_bld, s, t);
ddx_ddy[1] = lp_build_packed_ddx_ddy_onecoord(coord_bld, r);
- if (gallivm_debug & GALLIVM_DEBUG_NO_RHO_APPROX) {
- ddx_ddy[0] = lp_build_mul(coord_bld, ddx_ddy[0], ddx_ddy[0]);
- ddx_ddy[1] = lp_build_mul(coord_bld, ddx_ddy[1], ddx_ddy[1]);
- }
- else {
- ddx_ddy[0] = lp_build_abs(coord_bld, ddx_ddy[0]);
- ddx_ddy[1] = lp_build_abs(coord_bld, ddx_ddy[1]);
- }
+ ddx_ddy[0] = lp_build_mul(coord_bld, ddx_ddy[0], ddx_ddy[0]);
+ ddx_ddy[1] = lp_build_mul(coord_bld, ddx_ddy[1], ddx_ddy[1]);
tmp[0] = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle01);
tmp[1] = lp_build_swizzle_aos(coord_bld, ddx_ddy[0], swizzle23);
tmp[2] = lp_build_swizzle_aos(coord_bld, ddx_ddy[1], swizzle02);
- if (gallivm_debug & GALLIVM_DEBUG_NO_RHO_APPROX) {
- rho_vec = lp_build_add(coord_bld, tmp[0], tmp[1]);
- rho_vec = lp_build_add(coord_bld, rho_vec, tmp[2]);
- }
- else {
- rho_vec = lp_build_max(coord_bld, tmp[0], tmp[1]);
- rho_vec = lp_build_max(coord_bld, rho_vec, tmp[2]);
- }
+ rho_vec = lp_build_add(coord_bld, tmp[0], tmp[1]);
+ rho_vec = lp_build_add(coord_bld, rho_vec, tmp[2]);
tmp[0] = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle0);
tmp[1] = lp_build_swizzle_aos(coord_bld, rho_vec, swizzle1);
*rho = lp_build_max(coord_bld, tmp[0], tmp[1]);
}
- si = LLVMBuildBitCast(builder, s, lp_build_vec_type(gallivm, intctype), "");
- ti = LLVMBuildBitCast(builder, t, lp_build_vec_type(gallivm, intctype), "");
- ri = LLVMBuildBitCast(builder, r, lp_build_vec_type(gallivm, intctype), "");
+ si = LLVMBuildBitCast(builder, s, cint_vec_type, "");
+ ti = LLVMBuildBitCast(builder, t, cint_vec_type, "");
+ ri = LLVMBuildBitCast(builder, r, cint_vec_type, "");
signs = LLVMBuildAnd(builder, si, signmask, "");
signt = LLVMBuildAnd(builder, ti, signmask, "");
signr = LLVMBuildAnd(builder, ri, signmask, "");
@@ -1684,17 +1676,15 @@ lp_build_cube_lookup(struct lp_build_sample_context *bld,
face_t = lp_build_select(cint_bld, ar_ge_as_at, tnewz, face_t);
face = lp_build_select(cint_bld, ar_ge_as_at, facez, face);
- face_s = LLVMBuildBitCast(builder, face_s,
- lp_build_vec_type(gallivm, coord_bld->type), "");
- face_t = LLVMBuildBitCast(builder, face_t,
- lp_build_vec_type(gallivm, coord_bld->type), "");
+ face_s = LLVMBuildBitCast(builder, face_s, coord_vec_type, "");
+ face_t = LLVMBuildBitCast(builder, face_t, coord_vec_type, "");
/* add +1 for neg face */
/* XXX with AVX probably want to use another select here -
* as long as we ensure vblendvps gets used we can actually
* skip the comparison and just use sign as a "mask" directly.
*/
- mai = LLVMBuildBitCast(builder, ma, lp_build_vec_type(gallivm, intctype), "");
+ mai = LLVMBuildBitCast(builder, ma, cint_vec_type, "");
signma = LLVMBuildLShr(builder, mai, signshift, "");
coords[2] = LLVMBuildOr(builder, face, signma, "face");
--
1.7.9.5
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