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Diffstat (limited to 'src/amd/llvm/ac_llvm_cull.c')
| -rw-r--r-- | src/amd/llvm/ac_llvm_cull.c | 251 |
1 files changed, 0 insertions, 251 deletions
diff --git a/src/amd/llvm/ac_llvm_cull.c b/src/amd/llvm/ac_llvm_cull.c deleted file mode 100644 index 3ef1dab8311..00000000000 --- a/src/amd/llvm/ac_llvm_cull.c +++ /dev/null @@ -1,251 +0,0 @@ -/* - * Copyright 2019 Advanced Micro Devices, Inc. - * - * Permission is hereby granted, free of charge, to any person obtaining a - * copy of this software and associated documentation files (the - * "Software"), to deal in the Software without restriction, including - * without limitation the rights to use, copy, modify, merge, publish, - * distribute, sub license, and/or sell copies of the Software, and to - * permit persons to whom the Software is furnished to do so, subject to - * the following conditions: - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL - * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, - * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR - * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE - * USE OR OTHER DEALINGS IN THE SOFTWARE. - * - * The above copyright notice and this permission notice (including the - * next paragraph) shall be included in all copies or substantial portions - * of the Software. - * - */ - -#include "ac_llvm_cull.h" - -#include <llvm-c/Core.h> - -struct ac_position_w_info { - /* If a primitive intersects the W=0 plane, it causes a reflection - * of the determinant used for face culling. Every vertex behind - * the W=0 plane negates the determinant, so having 2 vertices behind - * the plane has no effect. This is i1 true if the determinant should be - * negated. - */ - LLVMValueRef w_reflection; - - /* If we simplify the "-w <= p <= w" view culling equation, we get - * "-w <= w", which can't be satisfied when w is negative. - * In perspective projection, a negative W means that the primitive - * is behind the viewer, but the equation is independent of the type - * of projection. - * - * w_accepted is false when all W are negative and therefore - * the primitive is invisible. - */ - LLVMValueRef w_accepted; - - /* The bounding box culling doesn't work and should be skipped when this is true. */ - LLVMValueRef any_w_negative; -}; - -static void ac_analyze_position_w(struct ac_llvm_context *ctx, LLVMValueRef pos[3][4], - struct ac_position_w_info *w) -{ - LLVMBuilderRef builder = ctx->builder; - LLVMValueRef all_w_negative = ctx->i1true; - - w->w_reflection = ctx->i1false; - w->any_w_negative = ctx->i1false; - - for (unsigned i = 0; i < 3; i++) { - LLVMValueRef neg_w; - - neg_w = LLVMBuildFCmp(builder, LLVMRealOLT, pos[i][3], ctx->f32_0, ""); - /* If neg_w is true, negate w_reflection. */ - w->w_reflection = LLVMBuildXor(builder, w->w_reflection, neg_w, ""); - w->any_w_negative = LLVMBuildOr(builder, w->any_w_negative, neg_w, ""); - all_w_negative = LLVMBuildAnd(builder, all_w_negative, neg_w, ""); - } - w->w_accepted = LLVMBuildNot(builder, all_w_negative, ""); -} - -/* Perform front/back face culling and return true if the primitive is accepted. */ -static LLVMValueRef ac_cull_face(struct ac_llvm_context *ctx, LLVMValueRef pos[3][4], - struct ac_position_w_info *w, bool cull_front, bool cull_back, - bool cull_zero_area) -{ - LLVMBuilderRef builder = ctx->builder; - - if (cull_front && cull_back) - return ctx->i1false; - - if (!cull_front && !cull_back && !cull_zero_area) - return ctx->i1true; - - /* Front/back face culling. Also if the determinant == 0, the triangle - * area is 0. - */ - LLVMValueRef det_t0 = LLVMBuildFSub(builder, pos[2][0], pos[0][0], ""); - LLVMValueRef det_t1 = LLVMBuildFSub(builder, pos[1][1], pos[0][1], ""); - LLVMValueRef det_t2 = LLVMBuildFSub(builder, pos[0][0], pos[1][0], ""); - LLVMValueRef det_t3 = LLVMBuildFSub(builder, pos[0][1], pos[2][1], ""); - LLVMValueRef det_p0 = LLVMBuildFMul(builder, det_t0, det_t1, ""); - LLVMValueRef det_p1 = LLVMBuildFMul(builder, det_t2, det_t3, ""); - LLVMValueRef det = LLVMBuildFSub(builder, det_p0, det_p1, ""); - - /* Negative W negates the determinant. */ - det = LLVMBuildSelect(builder, w->w_reflection, LLVMBuildFNeg(builder, det, ""), det, ""); - - LLVMValueRef accepted = NULL; - if (cull_front) { - LLVMRealPredicate cond = cull_zero_area ? LLVMRealOGT : LLVMRealOGE; - accepted = LLVMBuildFCmp(builder, cond, det, ctx->f32_0, ""); - } else if (cull_back) { - LLVMRealPredicate cond = cull_zero_area ? LLVMRealOLT : LLVMRealOLE; - accepted = LLVMBuildFCmp(builder, cond, det, ctx->f32_0, ""); - } else if (cull_zero_area) { - accepted = LLVMBuildFCmp(builder, LLVMRealONE, det, ctx->f32_0, ""); - } - return accepted; -} - -/* Perform view culling and small primitive elimination and return true - * if the primitive is accepted and initially_accepted == true. */ -static void cull_bbox(struct ac_llvm_context *ctx, LLVMValueRef pos[3][4], - LLVMValueRef initially_accepted, struct ac_position_w_info *w, - LLVMValueRef vp_scale[2], LLVMValueRef vp_translate[2], - LLVMValueRef small_prim_precision, bool cull_view_xy, - bool cull_view_near_z, bool cull_view_far_z, bool cull_small_prims, - bool use_halfz_clip_space, ac_cull_accept_func accept_func, - void *userdata) -{ - LLVMBuilderRef builder = ctx->builder; - - if (!cull_view_xy && !cull_view_near_z && !cull_view_far_z && !cull_small_prims) { - if (accept_func) - accept_func(ctx, initially_accepted, userdata); - return; - } - - ac_build_ifcc(ctx, initially_accepted, 10000000); - { - LLVMValueRef bbox_min[3], bbox_max[3]; - LLVMValueRef accepted = ctx->i1true; - - /* Compute the primitive bounding box for easy culling. */ - for (unsigned chan = 0; chan < (cull_view_near_z || cull_view_far_z ? 3 : 2); chan++) { - bbox_min[chan] = ac_build_fmin(ctx, pos[0][chan], pos[1][chan]); - bbox_min[chan] = ac_build_fmin(ctx, bbox_min[chan], pos[2][chan]); - - bbox_max[chan] = ac_build_fmax(ctx, pos[0][chan], pos[1][chan]); - bbox_max[chan] = ac_build_fmax(ctx, bbox_max[chan], pos[2][chan]); - } - - /* View culling. */ - if (cull_view_xy || cull_view_near_z || cull_view_far_z) { - for (unsigned chan = 0; chan < 3; chan++) { - LLVMValueRef visible; - - if ((cull_view_xy && chan <= 1) || (cull_view_near_z && chan == 2)) { - float t = chan == 2 && use_halfz_clip_space ? 0 : -1; - visible = LLVMBuildFCmp(builder, LLVMRealOGE, bbox_max[chan], - LLVMConstReal(ctx->f32, t), ""); - accepted = LLVMBuildAnd(builder, accepted, visible, ""); - } - - if ((cull_view_xy && chan <= 1) || (cull_view_far_z && chan == 2)) { - visible = LLVMBuildFCmp(builder, LLVMRealOLE, bbox_min[chan], ctx->f32_1, ""); - accepted = LLVMBuildAnd(builder, accepted, visible, ""); - } - } - } - - /* Small primitive elimination. */ - if (cull_small_prims) { - /* Assuming a sample position at (0.5, 0.5), if we round - * the bounding box min/max extents and the results of - * the rounding are equal in either the X or Y direction, - * the bounding box does not intersect the sample. - * - * See these GDC slides for pictures: - * https://frostbite-wp-prd.s3.amazonaws.com/wp-content/uploads/2016/03/29204330/GDC_2016_Compute.pdf - */ - LLVMValueRef min, max, not_equal[2], visible; - - for (unsigned chan = 0; chan < 2; chan++) { - /* Convert the position to screen-space coordinates. */ - min = ac_build_fmad(ctx, bbox_min[chan], vp_scale[chan], vp_translate[chan]); - max = ac_build_fmad(ctx, bbox_max[chan], vp_scale[chan], vp_translate[chan]); - /* Scale the bounding box according to the precision of - * the rasterizer and the number of MSAA samples. */ - min = LLVMBuildFSub(builder, min, small_prim_precision, ""); - max = LLVMBuildFAdd(builder, max, small_prim_precision, ""); - - /* Determine if the bbox intersects the sample point. - * It also works for MSAA, but vp_scale, vp_translate, - * and small_prim_precision are computed differently. - */ - min = ac_build_round(ctx, min); - max = ac_build_round(ctx, max); - not_equal[chan] = LLVMBuildFCmp(builder, LLVMRealONE, min, max, ""); - } - visible = LLVMBuildAnd(builder, not_equal[0], not_equal[1], ""); - accepted = LLVMBuildAnd(builder, accepted, visible, ""); - } - - /* Disregard the bounding box culling if any W is negative because the code - * doesn't work with that. - */ - accepted = LLVMBuildOr(builder, accepted, w->any_w_negative, ""); - - if (accept_func) - accept_func(ctx, accepted, userdata); - } - ac_build_endif(ctx, 10000000); -} - -/** - * Return i1 true if the primitive is accepted (not culled). - * - * \param pos Vertex positions 3x vec4 - * \param initially_accepted AND'ed with the result. Some computations can be - * skipped if this is false. - * \param vp_scale Viewport scale XY. - * For MSAA, multiply them by the number of samples. - * \param vp_translate Viewport translation XY. - * For MSAA, multiply them by the number of samples. - * \param small_prim_precision Precision of small primitive culling. This should - * be the same as or greater than the precision of - * the rasterizer. Set to num_samples / 2^subpixel_bits. - * subpixel_bits are defined by the quantization mode. - * \param options See ac_cull_options. - * \param accept_func Callback invoked in the inner-most branch where the primitive is accepted. - */ -void ac_cull_triangle(struct ac_llvm_context *ctx, LLVMValueRef pos[3][4], - LLVMValueRef initially_accepted, LLVMValueRef vp_scale[2], - LLVMValueRef vp_translate[2], LLVMValueRef small_prim_precision, - struct ac_cull_options *options, ac_cull_accept_func accept_func, - void *userdata) -{ - struct ac_position_w_info w; - ac_analyze_position_w(ctx, pos, &w); - - /* W culling. */ - LLVMValueRef accepted = options->cull_w ? w.w_accepted : ctx->i1true; - accepted = LLVMBuildAnd(ctx->builder, accepted, initially_accepted, ""); - - /* Face culling. */ - accepted = LLVMBuildAnd( - ctx->builder, accepted, - ac_cull_face(ctx, pos, &w, options->cull_front, options->cull_back, options->cull_zero_area), - ""); - - /* View culling and small primitive elimination. */ - cull_bbox(ctx, pos, accepted, &w, vp_scale, vp_translate, small_prim_precision, - options->cull_view_xy, options->cull_view_near_z, options->cull_view_far_z, - options->cull_small_prims, options->use_halfz_clip_space, accept_func, - userdata); -} |