n64-emu/third_party/parallel-rdp-standalone/parallel-rdp/shaders/coverage.h
2023-08-06 14:03:29 +09:00

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C

/* Copyright (c) 2020 Themaister
*
* 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, sublicense, 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 above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* 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 NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 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.
*/
#ifndef COVERAGE_H_
#define COVERAGE_H_
#include "data_structures.h"
const int SUBPIXELS_LOG2 = 2;
const int SUBPIXELS = 1 << SUBPIXELS_LOG2;
u8 compute_coverage(u16x4 xleft, u16x4 xright, int x)
{
u16x4 xshift = u16x4(0, 4, 2, 6) + (u16(x) << U16_C(3));
bvec4 clip_lo_x01 = lessThan(xshift, xleft.xxyy);
bvec4 clip_lo_x23 = lessThan(xshift, xleft.zzww);
bvec4 clip_hi_x01 = greaterThanEqual(xshift, xright.xxyy);
bvec4 clip_hi_x23 = greaterThanEqual(xshift, xright.zzww);
u8x4 clip_x0 = u8x4(clip_lo_x01) | u8x4(clip_hi_x01);
u8x4 clip_x1 = u8x4(clip_lo_x23) | u8x4(clip_hi_x23);
u8x4 clip_x = clip_x0 * u8x4(1, 2, 4, 8) + clip_x1 * u8x4(16, 32, 64, 128);
u8 clip_coverage = (clip_x.x | clip_x.y) | (clip_x.z | clip_x.w);
return ~clip_coverage & U8_C(0xff);
}
const int COVERAGE_CLAMP = 0;
const int COVERAGE_WRAP = 1;
const int COVERAGE_ZAP = 2;
const int COVERAGE_SAVE = 3;
int blend_coverage(int coverage, int memory_coverage, bool blend_en, int mode)
{
int res = 0;
switch (mode)
{
case COVERAGE_CLAMP:
{
if (blend_en)
res = min(7, memory_coverage + coverage); // image_read_en to read memory coverage, otherwise, it's 7.
else
res = (coverage - 1) & 7;
break;
}
case COVERAGE_WRAP:
res = (coverage + memory_coverage) & 7;
break;
case COVERAGE_ZAP:
res = 7;
break;
case COVERAGE_SAVE:
res = memory_coverage;
break;
}
return res;
}
#endif