From 6bc644fe62adad6656be3f29c118045fc5630510 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Fri, 5 Mar 2010 16:07:54 -0700 Subject: [PATCH] gallivm: checkpoint: texture LOD computation code gen --- .../auxiliary/gallivm/lp_bld_sample_soa.c | 129 +++++++++++++++++- 1 file changed, 126 insertions(+), 3 deletions(-) diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c index 2b04becc8cb..6b643fa85f8 100644 --- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c +++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c @@ -1040,6 +1040,127 @@ lp_build_sample_compare(struct lp_build_sample_context *bld, } +static int +texture_dims(enum pipe_texture_target tex) +{ + switch (tex) { + case PIPE_TEXTURE_1D: + return 1; + case PIPE_TEXTURE_2D: + case PIPE_TEXTURE_CUBE: + return 2; + case PIPE_TEXTURE_3D: + return 3; + default: + assert(0 && "bad texture target in texture_dims()"); + return 2; + } +} + + +/** + * Generate code to compute texture level of detail (lambda). + * \param s vector of texcoord s values + * \param t vector of texcoord t values + * \param r vector of texcoord r values + * \param width scalar int texture width + * \param height scalar int texture height + * \param depth scalar int texture depth + */ +static LLVMValueRef +lp_build_lod_selector(struct lp_build_sample_context *bld, + LLVMValueRef s, + LLVMValueRef t, + LLVMValueRef r, + LLVMValueRef width, + LLVMValueRef height, + LLVMValueRef depth) + +{ + const int dims = texture_dims(bld->static_state->target); + struct lp_build_context *coord_bld = &bld->coord_bld; + + LLVMValueRef lod_bias = lp_build_const_scalar(bld->coord_bld.type, + bld->static_state->lod_bias); + LLVMValueRef min_lod = lp_build_const_scalar(bld->coord_bld.type, + bld->static_state->min_lod); + LLVMValueRef max_lod = lp_build_const_scalar(bld->coord_bld.type, + bld->static_state->max_lod); + + LLVMValueRef index0 = LLVMConstInt(LLVMInt32Type(), 0, 0); + LLVMValueRef index1 = LLVMConstInt(LLVMInt32Type(), 1, 0); + LLVMValueRef index2 = LLVMConstInt(LLVMInt32Type(), 2, 0); + + LLVMValueRef s0, s1, s2; + LLVMValueRef t0, t1, t2; + LLVMValueRef r0, r1, r2; + LLVMValueRef dsdx, dsdy, dtdx, dtdy, drdx, drdy; + LLVMValueRef rho, lod; + + /* + * dsdx = abs(s[1] - s[0]); + * dsdy = abs(s[2] - s[0]); + * dtdx = abs(t[1] - t[0]); + * dtdy = abs(t[2] - t[0]); + * drdx = abs(r[1] - r[0]); + * drdy = abs(r[2] - r[0]); + * XXX we're assuming a four-element quad in 2x2 layout here. + */ + s0 = LLVMBuildExtractElement(bld->builder, s, index0, "s0"); + s1 = LLVMBuildExtractElement(bld->builder, s, index1, "s1"); + s2 = LLVMBuildExtractElement(bld->builder, s, index2, "s2"); + dsdx = lp_build_abs(coord_bld, lp_build_sub(coord_bld, s1, s0)); + dsdy = lp_build_abs(coord_bld, lp_build_sub(coord_bld, s2, s0)); + if (dims > 1) { + t0 = LLVMBuildExtractElement(bld->builder, t, index0, "t0"); + t1 = LLVMBuildExtractElement(bld->builder, t, index1, "t1"); + t2 = LLVMBuildExtractElement(bld->builder, t, index2, "t2"); + dtdx = lp_build_abs(coord_bld, lp_build_sub(coord_bld, t1, t0)); + dtdy = lp_build_abs(coord_bld, lp_build_sub(coord_bld, t2, t0)); + if (dims > 2) { + r0 = LLVMBuildExtractElement(bld->builder, r, index0, "r0"); + r1 = LLVMBuildExtractElement(bld->builder, r, index1, "r1"); + r2 = LLVMBuildExtractElement(bld->builder, r, index2, "r2"); + drdx = lp_build_abs(coord_bld, lp_build_sub(coord_bld, r1, r0)); + drdy = lp_build_abs(coord_bld, lp_build_sub(coord_bld, r2, r0)); + } + } + + /* Compute rho = max of all partial derivatives scaled by texture size. + * XXX this can be vectorized somewhat + */ + rho = lp_build_mul(coord_bld, + lp_build_max(coord_bld, dsdx, dsdy), + lp_build_int_to_float(coord_bld, width)); + if (dims > 1) { + LLVMValueRef max; + max = lp_build_mul(coord_bld, + lp_build_max(coord_bld, dtdx, dtdy), + lp_build_int_to_float(coord_bld, height)); + rho = lp_build_max(coord_bld, rho, max); + if (dims > 2) { + max = lp_build_mul(coord_bld, + lp_build_max(coord_bld, drdx, drdy), + lp_build_int_to_float(coord_bld, depth)); + rho = lp_build_max(coord_bld, rho, max); + } + } + + /* compute lod = log2(rho) */ + lod = lp_build_log2(coord_bld, rho); + + /* add lod bias */ + lod = lp_build_add(coord_bld, lod, lod_bias); + + /* clamp lod */ + lod = lp_build_clamp(coord_bld, lod, min_lod, max_lod); + + return lod; +} + + + + /** * Build texture sampling code. * 'texel' will return a vector of four LLVMValueRefs corresponding to @@ -1063,7 +1184,9 @@ lp_build_sample_soa(LLVMBuilderRef builder, LLVMValueRef data_ptr; LLVMValueRef s; LLVMValueRef t; - LLVMValueRef p; + LLVMValueRef r; + + (void) lp_build_lod_selector; /* temporary to silence warning */ /* Setup our build context */ memset(&bld, 0, sizeof bld); @@ -1088,7 +1211,7 @@ lp_build_sample_soa(LLVMBuilderRef builder, s = coords[0]; t = coords[1]; - p = coords[2]; + r = coords[2]; width = lp_build_broadcast_scalar(&bld.uint_coord_bld, width); height = lp_build_broadcast_scalar(&bld.uint_coord_bld, height); @@ -1119,5 +1242,5 @@ lp_build_sample_soa(LLVMBuilderRef builder, /* FIXME: respect static_state->min_mip_filter */; /* FIXME: respect static_state->mag_img_filter */; - lp_build_sample_compare(&bld, p, texel); + lp_build_sample_compare(&bld, r, texel); } -- 2.30.2