// 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_PixelRoutine_hpp
#define sw_PixelRoutine_hpp

#include "Device/QuadRasterizer.hpp"

namespace sw
{
	class PixelShader;
	class SamplerCore;

	class PixelRoutine : public sw::QuadRasterizer, public ShaderCore
	{
	public:
		PixelRoutine(const PixelProcessor::State &state,
			vk::PipelineLayout const *pipelineLayout,
			SpirvShader const *spirvShader);

		virtual ~PixelRoutine();

		void generate() override;

	protected:
		Float4 z[4]; // Multisampled z
		Float4 w;    // Used as is
		Float4 rhw;  // Reciprocal w

		SpirvRoutine routine;

		// Depth output
		Float4 oDepth;

		virtual void setBuiltins(Int &x, Int &y, Float4(&z)[4], Float4 &w) = 0;
		virtual void applyShader(Int cMask[4]) = 0;
		virtual Bool alphaTest(Int cMask[4]) = 0;
		virtual void rasterOperation(Pointer<Byte> cBuffer[4], Int &x, Int sMask[4], Int zMask[4], Int cMask[4]) = 0;

		void quad(Pointer<Byte> cBuffer[4], Pointer<Byte> &zBuffer, Pointer<Byte> &sBuffer, Int cMask[4], Int &x, Int &y) override;

		void alphaTest(Int &aMask, Short4 &alpha);
		void alphaToCoverage(Int cMask[4], Float4 &alpha);

		// Raster operations
		void alphaBlend(int index, Pointer<Byte> &cBuffer, Vector4s &current, Int &x);
		void writeColor(int index, Pointer<Byte> &cBuffer, Int &i, Vector4s &current, Int &sMask, Int &zMask, Int &cMask);
		void alphaBlend(int index, Pointer<Byte> &cBuffer, Vector4f &oC, Int &x);
		void writeColor(int index, Pointer<Byte> &cBuffer, Int &i, Vector4f &oC, Int &sMask, Int &zMask, Int &cMask);

		bool isSRGB(int index) const;
		UShort4 convertFixed16(Float4 &cf, bool saturate = true);
		void linearToSRGB12_16(Vector4s &c);

	private:
		Float4 interpolateCentroid(Float4 &x, Float4 &y, Float4 &rhw, Pointer<Byte> planeEquation, bool flat, bool perspective);
		void stencilTest(Pointer<Byte> &sBuffer, int q, Int &x, Int &sMask, Int &cMask);
		void stencilTest(Byte8 &value, VkCompareOp stencilCompareMode, bool isBack);
		void stencilOperation(Byte8 &newValue, Byte8 &bufferValue, VkStencilOpState const &ops, bool isBack, Int &zMask, Int &sMask);
		void stencilOperation(Byte8 &output, Byte8 &bufferValue, VkStencilOp operation, bool isBack);
		Bool depthTest(Pointer<Byte> &zBuffer, int q, Int &x, Float4 &z, Int &sMask, Int &zMask, Int &cMask);

		// Raster operations
		void blendFactor(Vector4s &blendFactor, const Vector4s &current, const Vector4s &pixel, VkBlendFactor blendFactorActive);
		void blendFactorAlpha(Vector4s &blendFactor, const Vector4s &current, const Vector4s &pixel, VkBlendFactor blendFactorAlphaActive);
		void readPixel(int index, Pointer<Byte> &cBuffer, Int &x, Vector4s &pixel);
		void blendFactor(Vector4f &blendFactor, const Vector4f &oC, const Vector4f &pixel, VkBlendFactor blendFactorActive);
		void blendFactorAlpha(Vector4f &blendFactor, const Vector4f &oC, const Vector4f &pixel, VkBlendFactor blendFactorAlphaActive);
		void writeStencil(Pointer<Byte> &sBuffer, int q, Int &x, Int &sMask, Int &zMask, Int &cMask);
		void writeDepth(Pointer<Byte> &zBuffer, int q, Int &x, Float4 &z, Int &zMask);

		void sRGBtoLinear16_12_16(Vector4s &c);
		void linearToSRGB16_12_16(Vector4s &c);
		Float4 sRGBtoLinear(const Float4 &x);

		Bool depthTest32F(Pointer<Byte> &zBuffer, int q, Int &x, Float4 &z, Int &sMask, Int &zMask, Int &cMask);
		Bool depthTest16(Pointer<Byte> &zBuffer, int q, Int &x, Float4 &z, Int &sMask, Int &zMask, Int &cMask);

		void writeDepth32F(Pointer<Byte> &zBuffer, int q, Int &x, Float4 &z, Int &zMask);
		void writeDepth16(Pointer<Byte> &zBuffer, int q, Int &x, Float4 &z, Int &zMask);

		bool colorUsed();
	};
}

#endif   // sw_PixelRoutine_hpp