diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c | 245 |
1 files changed, 171 insertions, 74 deletions
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c index b67a089c47b..def731e9d95 100644 --- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c +++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c @@ -218,34 +218,42 @@ lp_build_sample_texel_soa(struct lp_build_sample_context *bld, /** - * Helper to compute the mirror function for the PIPE_WRAP_MIRROR modes. + * Helper to compute the mirror function for the PIPE_WRAP_MIRROR_REPEAT mode. + * (Note that with pot sizes could do this much more easily post-scale + * with some bit arithmetic.) */ static LLVMValueRef lp_build_coord_mirror(struct lp_build_sample_context *bld, - LLVMValueRef coord) + LLVMValueRef coord, boolean posOnly) { struct lp_build_context *coord_bld = &bld->coord_bld; - struct lp_build_context *int_coord_bld = &bld->int_coord_bld; - LLVMValueRef fract, flr, isOdd; - - lp_build_ifloor_fract(coord_bld, coord, &flr, &fract); - /* kill off NaNs */ - /* XXX: not safe without arch rounding, fract can be anything. */ - fract = lp_build_max_ext(coord_bld, fract, coord_bld->zero, - GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN); - - /* isOdd = flr & 1 */ - isOdd = LLVMBuildAnd(bld->gallivm->builder, flr, int_coord_bld->one, ""); + LLVMValueRef fract; + LLVMValueRef half = lp_build_const_vec(bld->gallivm, coord_bld->type, 0.5); - /* make coord positive or negative depending on isOdd */ - /* XXX slight overkill masking out sign bit is unnecessary */ - coord = lp_build_set_sign(coord_bld, fract, isOdd); + /* + * We can just use 2*(x - round(0.5*x)) to do all the mirroring, + * it all works out. (The result is in range [-1, 1.0], negative if + * the coord is in the "odd" section, otherwise positive.) + */ - /* convert isOdd to float */ - isOdd = lp_build_int_to_float(coord_bld, isOdd); + coord = lp_build_mul(coord_bld, coord, half); + fract = lp_build_round(coord_bld, coord); + fract = lp_build_sub(coord_bld, coord, fract); + coord = lp_build_add(coord_bld, fract, fract); - /* add isOdd to coord */ - coord = lp_build_add(coord_bld, coord, isOdd); + if (posOnly) { + /* + * Theoretically it's not quite 100% accurate because the spec says + * that ultimately a scaled coord of -x.0 should map to int coord + * -x + 1 with mirroring, not -x (this does not matter for bilinear + * filtering). + */ + coord = lp_build_abs(coord_bld, coord); + /* kill off NaNs */ + /* XXX: not safe without arch rounding, fract can be anything. */ + coord = lp_build_max_ext(coord_bld, coord, coord_bld->zero, + GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN); + } return coord; } @@ -362,7 +370,13 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld, coord = lp_build_add(coord_bld, coord, offset); } - /* clamp to [0, length] */ + /* + * clamp to [0, length] + * + * Unlike some other wrap modes, this should be correct for gather + * too. GL_CLAMP explicitly does this clamp on the coord prior to + * actual wrapping (which is per sample). + */ coord = lp_build_clamp(coord_bld, coord, coord_bld->zero, length_f); coord = lp_build_sub(coord_bld, coord, half); @@ -426,8 +440,13 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld, offset = lp_build_int_to_float(coord_bld, offset); coord = lp_build_add(coord_bld, coord, offset); } - /* was: clamp to [-0.5, length + 0.5], then sub 0.5 */ - /* can skip clamp (though might not work for very large coord values) */ + /* + * We don't need any clamp. Technically, for very large (pos or neg) + * (or infinite) values, clamp against [-length, length] would be + * correct, but we don't need to guarantee any specific + * result for such coords (the ifloor will be undefined, but for modes + * requiring border all resulting coords are safe). + */ coord = lp_build_sub(coord_bld, coord, half); /* convert to int, compute lerp weight */ lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight); @@ -440,28 +459,64 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld, offset = lp_build_div(coord_bld, offset, length_f); coord = lp_build_add(coord_bld, coord, offset); } - /* compute mirror function */ - /* - * XXX: This looks incorrect wrt gather. Due to wrap specification, - * it is possible the first coord ends up larger than the second one. - * However, with our simplifications the coordinates will be swapped - * in this case. (Albeit some other api tests don't like it even - * with this fixed...) - */ - coord = lp_build_coord_mirror(bld, coord); + if (!is_gather) { + /* compute mirror function */ + coord = lp_build_coord_mirror(bld, coord, TRUE); - /* scale coord to length */ - coord = lp_build_mul(coord_bld, coord, length_f); - coord = lp_build_sub(coord_bld, coord, half); + /* scale coord to length */ + coord = lp_build_mul(coord_bld, coord, length_f); + coord = lp_build_sub(coord_bld, coord, half); - /* 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); + /* 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); + + /* coord0 = max(coord0, 0) */ + coord0 = lp_build_max(int_coord_bld, coord0, int_coord_bld->zero); + /* coord1 = min(coord1, length-1) */ + coord1 = lp_build_min(int_coord_bld, coord1, length_minus_one); + } else { + /* + * This is pretty reasonable in the end, all what the tests care + * about is nasty edge cases (scaled coords x.5, so the individual + * coords are actually integers, which is REALLY tricky to get right + * due to this working differently both for negative numbers as well + * as for even/odd cases). But with enough magic it's not too complex + * after all. + * Maybe should try a bit arithmetic one though for POT textures... + */ + LLVMValueRef isNeg; + /* + * Wrapping just once still works, even though it means we can + * get "wrong" sign due to performing mirror in the middle of the + * two coords (because this can only happen very near the odd/even + * edges, so both coords will actually end up as 0 or length - 1 + * in the end). + * For GL4 gather with per-sample offsets we'd need to the mirroring + * per coord too. + */ + coord = lp_build_coord_mirror(bld, coord, FALSE); + coord = lp_build_mul(coord_bld, coord, length_f); + + /* + * NaNs should be safe here, we'll do away with them with + * the ones' complement plus min. + */ + coord0 = lp_build_sub(coord_bld, coord, half); + coord0 = lp_build_ifloor(coord_bld, coord0); + coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one); + /* ones complement for neg numbers (mirror(negX) = X - 1) */ + isNeg = lp_build_cmp(int_coord_bld, PIPE_FUNC_LESS, + coord0, int_coord_bld->zero); + coord0 = lp_build_xor(int_coord_bld, coord0, isNeg); + isNeg = lp_build_cmp(int_coord_bld, PIPE_FUNC_LESS, + coord1, int_coord_bld->zero); + coord1 = lp_build_xor(int_coord_bld, coord1, isNeg); + coord0 = lp_build_min(int_coord_bld, coord0, length_minus_one); + coord1 = lp_build_min(int_coord_bld, coord1, length_minus_one); - /* coord0 = max(coord0, 0) */ - coord0 = lp_build_max(int_coord_bld, coord0, int_coord_bld->zero); - /* coord1 = min(coord1, length-1) */ - coord1 = lp_build_min(int_coord_bld, coord1, length_minus_one); + weight = coord_bld->undef; + } break; case PIPE_TEX_WRAP_MIRROR_CLAMP: @@ -473,10 +528,19 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld, offset = lp_build_int_to_float(coord_bld, offset); coord = lp_build_add(coord_bld, coord, offset); } + /* + * XXX: probably not correct for gather, albeit I'm not + * entirely sure as it's poorly specified. The wrapping looks + * correct according to the spec which is against gl 1.2.1, + * however negative values will be swapped - gl re-specified + * wrapping with newer versions (no more pre-clamp except with + * GL_CLAMP). + */ coord = lp_build_abs(coord_bld, coord); /* clamp to [0, length] */ - coord = lp_build_min(coord_bld, coord, length_f); + coord = lp_build_min_ext(coord_bld, coord, length_f, + GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN); coord = lp_build_sub(coord_bld, coord, half); @@ -498,35 +562,59 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld, offset = lp_build_int_to_float(coord_bld, offset); coord = lp_build_add(coord_bld, coord, offset); } - /* - * XXX: This looks incorrect wrt gather. Due to wrap specification, - * the first and second texel actually end up with "different order" - * for negative coords. For example, if the scaled coord would - * be -0.6, then the first coord should end up as 1 - * (floor(-0.6 - 0.5) == -2, mirror makes that 1), the second as 0 - * (floor(-0.6 - 0.5) + 1 == -1, mirror makes that 0). - * But with our simplifications the second coord will always be the - * larger one. The other two mirror_clamp modes have the same problem. - * Moreover, for coords close to zero we should end up with both - * coords being 0, but we will end up with coord1 being 1 instead - * (with bilinear filtering this is ok as the weight is 0.0) (this - * problem is specific to mirror_clamp_to_edge). - */ - coord = lp_build_abs(coord_bld, coord); + if (!is_gather) { + coord = lp_build_abs(coord_bld, coord); - /* clamp to length max */ - coord = lp_build_min_ext(coord_bld, coord, length_f, - GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN); - /* subtract 0.5 */ - coord = lp_build_sub(coord_bld, coord, half); - /* clamp to [0, length - 0.5] */ - coord = lp_build_max(coord_bld, coord, coord_bld->zero); + /* clamp to length max */ + coord = lp_build_min_ext(coord_bld, coord, length_f, + GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN); + /* subtract 0.5 */ + coord = lp_build_sub(coord_bld, coord, half); + /* clamp to [0, length - 0.5] */ + coord = lp_build_max(coord_bld, coord, coord_bld->zero); - /* convert to int, compute lerp weight */ - lp_build_ifloor_fract(&abs_coord_bld, coord, &coord0, &weight); - coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one); - /* coord1 = min(coord1, length-1) */ - coord1 = lp_build_min(int_coord_bld, coord1, length_minus_one); + /* convert to int, compute lerp weight */ + lp_build_ifloor_fract(&abs_coord_bld, coord, &coord0, &weight); + coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one); + /* coord1 = min(coord1, length-1) */ + coord1 = lp_build_min(int_coord_bld, coord1, length_minus_one); + } else { + /* + * The non-gather path will swap coord0/1 if coord was negative, + * which is ok for filtering since the filter weight matches + * accordingly. Also, if coord is close to zero, coord0/1 will + * be 0 and 1, instead of 0 and 0 (again ok due to filter + * weight being 0.0). Both issues need to be fixed for gather. + */ + LLVMValueRef isNeg; + + /* + * Actually wanted to cheat here and use: + * coord1 = lp_build_iround(coord_bld, coord); + * but it's not good enough for some tests (even piglit + * textureGather is set up in a way so the coords area always + * .5, that is right at the crossover points). + * So do ordinary sub/floor, then do ones' complement + * for negative numbers. + * (Note can't just do sub|add/abs/itrunc per coord neither - + * because the spec demands that mirror(3.0) = 3 but + * mirror(-3.0) = 2.) + */ + coord = lp_build_sub(coord_bld, coord, half); + coord0 = lp_build_ifloor(coord_bld, coord); + coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one); + isNeg = lp_build_cmp(int_coord_bld, PIPE_FUNC_LESS, coord0, + int_coord_bld->zero); + coord0 = lp_build_xor(int_coord_bld, isNeg, coord0); + coord0 = lp_build_min(int_coord_bld, coord0, length_minus_one); + + isNeg = lp_build_cmp(int_coord_bld, PIPE_FUNC_LESS, coord1, + int_coord_bld->zero); + coord1 = lp_build_xor(int_coord_bld, isNeg, coord1); + coord1 = lp_build_min(int_coord_bld, coord1, length_minus_one); + + weight = coord_bld->undef; + } } break; @@ -540,11 +628,20 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld, offset = lp_build_int_to_float(coord_bld, offset); coord = lp_build_add(coord_bld, coord, offset); } + /* + * XXX: probably not correct for gather due to swapped + * order if coord is negative (same rationale as for + * MIRROR_CLAMP). + */ coord = lp_build_abs(coord_bld, coord); - /* was: clamp to [-0.5, length + 0.5] then sub 0.5 */ - /* skip clamp - always positive, and other side - only potentially matters for very large coords */ + /* + * We don't need any clamp. Technically, for very large + * (or infinite) values, clamp against length would be + * correct, but we don't need to guarantee any specific + * result for such coords (the ifloor will be undefined, but + * for modes requiring border all resulting coords are safe). + */ coord = lp_build_sub(coord_bld, coord, half); /* convert to int, compute lerp weight */ @@ -652,7 +749,7 @@ lp_build_sample_wrap_nearest(struct lp_build_sample_context *bld, coord = lp_build_add(coord_bld, coord, offset); } /* compute mirror function */ - coord = lp_build_coord_mirror(bld, coord); + coord = lp_build_coord_mirror(bld, coord, TRUE); /* scale coord to length */ assert(bld->static_sampler_state->normalized_coords); |