ac_llvm_cull.h

/*
 * 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,
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 * 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,
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 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
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 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */

#ifndef AC_LLVM_CULL_H
#define AC_LLVM_CULL_H

#include "ac_llvm_build.h"

struct ac_cull_options {
   /* In general, I recommend setting all to true except view Z culling,
    * which isn't so effective because W culling is cheaper and partially
    * replaces near Z culling, and you don't need to set Position.z
    * if Z culling is disabled.
    *
    * If something doesn't work, turn some of these off to find out what.
    */
   bool cull_front;
   bool cull_back;
   bool cull_view_xy;
   bool cull_view_near_z;
   bool cull_view_far_z;
   bool cull_small_prims;
   bool cull_zero_area;
   bool cull_w; /* cull primitives with all W < 0 */

   bool use_halfz_clip_space;
};

/* Callback invoked in the inner-most branch where the primitive is accepted. */
typedef void (*ac_cull_accept_func)(struct ac_llvm_context *ctx, LLVMValueRef accepted,
                                    void *userdata);

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);

#endif