// Copyright (c) 2012- PPSSPP Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0 or later versions.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.

#pragma once

#include "base/basictypes.h"
#include "GPU/Common/ShaderCommon.h"

struct CardboardSettings {
	bool enabled;
	float leftEyeXPosition;
	float rightEyeXPosition;
	float screenYPosition;
	float screenWidth;
	float screenHeight;
};

struct PostShaderUniforms {
	float texelDelta[2]; float pixelDelta[2];
	float time[4];
	float setting[4];
	float video; float pad[3];
	// Used on Direct3D9.
	float gl_HalfPixel[4];
};

// Could use UI::Bounds but don't want to depend on that here.
struct FRect {
	float x;
	float y;
	float w;
	float h;
};

FRect GetScreenFrame(float pixelWidth, float pixelHeight);
void CenterDisplayOutputRect(FRect *rc, float origW, float origH, const FRect &frame, int rotation);

namespace Draw {
class Buffer;
class DrawContext;
class Framebuffer;
class Pipeline;
class SamplerState;
class ShaderModule;
class Texture;
}

struct ShaderInfo;
class TextureCacheCommon;

enum class OutputFlags {
	LINEAR = 0x0000,
	NEAREST = 0x0001,
	RB_SWIZZLE = 0x0002,
	BACKBUFFER_FLIPPED = 0x0004,
	POSITION_FLIPPED = 0x0008,
	PILLARBOX = 0x0010,
};
ENUM_CLASS_BITOPS(OutputFlags);

class PresentationCommon {
public:
	PresentationCommon(Draw::DrawContext *draw);
	~PresentationCommon();

	void UpdateSize(int w, int h, int rw, int rh) {
		pixelWidth_ = w;
		pixelHeight_ = h;
		renderWidth_ = rw;
		renderHeight_ = rh;
	}
	void SetLanguage(ShaderLanguage lang) {
		lang_ = lang;
	}

	bool HasPostShader() {
		return usePostShader_;
	}

	bool UpdatePostShader();

	void DeviceLost();
	void DeviceRestore(Draw::DrawContext *draw);

	void UpdateUniforms(bool hasVideo);
	void SourceTexture(Draw::Texture *texture, int bufferWidth, int bufferHeight);
	void SourceFramebuffer(Draw::Framebuffer *fb, int bufferWidth, int bufferHeight);
	void CopyToOutput(OutputFlags flags, int uvRotation, float u0, float v0, float u1, float v1);

	void CalculateRenderResolution(int *width, int *height, bool *upscaling, bool *ssaa);

protected:
	void CreateDeviceObjects();
	void DestroyDeviceObjects();
	void DestroyPostShader();

	void ShowPostShaderError(const std::string &errorString);

	Draw::ShaderModule *CompileShaderModule(Draw::ShaderStage stage, ShaderLanguage lang, const std::string &src, std::string *errorString);
	Draw::Pipeline *CreatePipeline(std::vector<Draw::ShaderModule *> shaders, bool postShader, const Draw::UniformBufferDesc *uniformDesc);
	bool BuildPostShader(const ShaderInfo *shaderInfo, const ShaderInfo *next);
	bool AllocateFramebuffer(int w, int h);

	void BindSource(int binding);

	void GetCardboardSettings(CardboardSettings *cardboardSettings);
	void CalculatePostShaderUniforms(int bufferWidth, int bufferHeight, int targetWidth, int targetHeight, const ShaderInfo *shaderInfo, PostShaderUniforms *uniforms);

	Draw::DrawContext *draw_;
	Draw::Pipeline *texColor_ = nullptr;
	Draw::Pipeline *texColorRBSwizzle_ = nullptr;
	Draw::SamplerState *samplerNearest_ = nullptr;
	Draw::SamplerState *samplerLinear_ = nullptr;
	Draw::Buffer *vdata_ = nullptr;
	Draw::Buffer *idata_ = nullptr;

	std::vector<Draw::ShaderModule *> postShaderModules_;
	std::vector<Draw::Pipeline *> postShaderPipelines_;
	std::vector<Draw::Framebuffer *> postShaderFramebuffers_;
	std::vector<ShaderInfo> postShaderInfo_;

	Draw::Texture *srcTexture_ = nullptr;
	Draw::Framebuffer *srcFramebuffer_ = nullptr;
	int srcWidth_ = 0;
	int srcHeight_ = 0;
	bool hasVideo_ = false;

	int pixelWidth_ = 0;
	int pixelHeight_ = 0;
	int renderWidth_ = 0;
	int renderHeight_ = 0;

	bool usePostShader_ = false;
	bool restorePostShader_ = false;
	ShaderLanguage lang_;

	struct PrevFBO {
		Draw::Framebuffer *fbo;
		int w;
		int h;
	};
	std::vector<PrevFBO> postShaderFBOUsage_;
};