// Copyright 2016 The SwiftShader Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef sw_Constants_hpp
#define sw_Constants_hpp

#include "System/Types.hpp"
#include "System/Math.hpp"
#include "Vulkan/VkConfig.h"

namespace sw
{
	struct Constants
	{
		Constants();

		unsigned int transposeBit0[16];
		unsigned int transposeBit1[16];
		unsigned int transposeBit2[16];

		ushort4 cWeight[17];
		float4 uvWeight[17];
		float4 uvStart[17];

		unsigned int occlusionCount[16];

		byte8 maskB4Q[16];
		byte8 invMaskB4Q[16];
		word4 maskW4Q[16];
		word4 invMaskW4Q[16];
		dword4 maskD4X[16];
		dword4 invMaskD4X[16];
		qword maskQ0Q[16];
		qword maskQ1Q[16];
		qword maskQ2Q[16];
		qword maskQ3Q[16];
		qword invMaskQ0Q[16];
		qword invMaskQ1Q[16];
		qword invMaskQ2Q[16];
		qword invMaskQ3Q[16];
		dword4 maskX0X[16];
		dword4 maskX1X[16];
		dword4 maskX2X[16];
		dword4 maskX3X[16];
		dword4 invMaskX0X[16];
		dword4 invMaskX1X[16];
		dword4 invMaskX2X[16];
		dword4 invMaskX3X[16];
		dword2 maskD01Q[16];
		dword2 maskD23Q[16];
		dword2 invMaskD01Q[16];
		dword2 invMaskD23Q[16];
		qword2 maskQ01X[16];
		qword2 maskQ23X[16];
		qword2 invMaskQ01X[16];
		qword2 invMaskQ23X[16];
		word4 maskW01Q[4];
		dword4 maskD01X[4];
		word4 mask565Q[8];
		dword2 mask10Q[16];		// 4 bit writemask -> A2B10G10R10 bit patterns, replicated 2x
		word4 mask5551Q[16];	// 4 bit writemask -> A1R5G5B5 bit patterns, replicated 4x

		unsigned short sRGBtoLinear8_16[256];

		unsigned short linearToSRGB12_16[4096];
		unsigned short sRGBtoLinear12_16[4096];

		// Centroid parameters
		float4 sampleX[4][16];
		float4 sampleY[4][16];
		float4 weight[16];

		// Fragment offsets
		int Xf[4];
		int Yf[4];

		float4 X[4];
		float4 Y[4];

		// VK_SAMPLE_COUNT_4_BIT
		// https://www.khronos.org/registry/vulkan/specs/1.1/html/vkspec.html#primsrast-multisampling
		static constexpr float VkSampleLocations4[][2] = {
			{0.375, 0.125},
			{0.875, 0.375},
			{0.125, 0.625},
			{0.625, 0.875},
		};

		// Vulkan spec sample positions are relative to 0,0 in top left corner, with Y+ going down.
		// Convert to our space, with 0,0 in center, and Y+ going up.
		static constexpr float SampleLocationsX[4] = {
			VkSampleLocations4[0][0] - 0.5f,
			VkSampleLocations4[1][0] - 0.5f,
			VkSampleLocations4[2][0] - 0.5f,
			VkSampleLocations4[3][0] - 0.5f,
		};

		static constexpr float SampleLocationsY[4] = {
			-(VkSampleLocations4[0][1] - 0.5f),
			-(VkSampleLocations4[1][1] - 0.5f),
			-(VkSampleLocations4[2][1] - 0.5f),
			-(VkSampleLocations4[3][1] - 0.5f),
		};

		// Compute the yMin and yMax multisample offsets so that they are just
		// large enough (+/- max range - epsilon) to include sample points
		static constexpr int yMinMultiSampleOffset = sw::toFixedPoint(1, vk::SUBPIXEL_PRECISION_BITS) - sw::toFixedPoint(sw::max(SampleLocationsY[0], SampleLocationsY[1], SampleLocationsY[2], SampleLocationsY[3]), vk::SUBPIXEL_PRECISION_BITS) - 1;
		static constexpr int yMaxMultiSampleOffset = sw::toFixedPoint(1, vk::SUBPIXEL_PRECISION_BITS) + sw::toFixedPoint(sw::max(SampleLocationsY[0], SampleLocationsY[1], SampleLocationsY[2], SampleLocationsY[3]), vk::SUBPIXEL_PRECISION_BITS) - 1;

		dword maxX[16];
		dword maxY[16];
		dword maxZ[16];
		dword minX[16];
		dword minY[16];
		dword minZ[16];
		dword fini[16];

		dword4 maxPos;

		float4 unscaleByte;
		float4 unscaleSByte;
		float4 unscaleShort;
		float4 unscaleUShort;
		float4 unscaleInt;
		float4 unscaleUInt;
		float4 unscaleFixed;

		float half2float[65536];
	};

	extern Constants constants;
}

#endif   // sw_Constants_hpp