#pragma once

#include <d3dx9.h>

extern IDirect3DDevice9* g_d3d_device;

struct InstanceData
{
	float pos[3];
	float size;
	float intensity;
};

struct FluidSettings
{
	float* Softness;
	float* LightTransferAmmount;
	float* SpecularFactor;
	float* SpecularPower;
	float* TextureScale;
	float* TranslucencyAmmount;
	float* SurfaceTension;
	float* RefractAmmount;
	float* DepthDifferenceBlur;
	int* BlurSteps;
	float* RenderTextureSizeScale;

	IDirect3DBaseTexture9* DiffuseTexture;
};

struct Fluid
{
	FluidSettings Settings;

	IDirect3DTexture9* renderTexturePingPong[4];
	IDirect3DSurface9* renderSurfacePingPong[4];

	D3DXVECTOR4 renderTargetPingPongDDX;
};

struct FluidParticleSystem
{
	bool IsVisible;
	unsigned int InstanceCount;
	IDirect3DVertexBuffer9* InstanceDataBuffer;
};

class FluidContext
{
public:
	void BuildUp(int screenX, int screenY, D3DMULTISAMPLE_TYPE multiSampleType);

	void RenderParticles(const FluidParticleSystem& particleInfo);
	void RenderParticleDepth(const FluidParticleSystem& particleInfo);
	
	void Begin(const Fluid& fluid);
	void End();
	void Display(const Fluid& fluid);

	FluidParticleSystem GenerateFluidParticleSystem(unsigned int instanceCount, InstanceData* initialData = NULL);
	Fluid GenerateFluid(const FluidSettings& settings);

	static void MeltObject(int objectIndex, int fluidIndex, int pointMapIndex, float time);

private:
	IDirect3DVertexDeclaration9* quadVertexDecl;
	IDirect3DVertexDeclaration9* vertexDecl;
	IDirect3DIndexBuffer9* quadIndexBuffer;
	IDirect3DVertexBuffer9* quadVertexBuffer;

	IDirect3DSurface9* renderSurface;

	static const int renderTextureCount = 2; // pos, normal

	int renderTargetWidth;
	int renderTargetHeight;
	D3DXVECTOR4 renderTargetDDX;

	const Fluid* currentFluid;
};

static const float particleQuadVerts[20] =
{
	-1.0f,-1.0f, 0.0f, 
	0.0f, 1.0f,

	-1.0f, 1.0f, 0.0f, 
	0.0f, 0.0f,

	1.0f,  1.0f, 0.0f, 
	1.0f, 0.0f,

	1.0f, -1.0f, 0.0f, 
	1.0f, 1.0f
};

static const float screenQuadVerts[30] =
{
	-1.0f,-1.0f, 1.0f, 
	0.0f, 1.0f,

	-1.0f, 1.0f, 1.0f, 
	0.0f, 0.0f,

	1.0f,  1.0f, 1.0f, 
	1.0f, 0.0f,


	1.0f, -1.0f, 1.0f, 
	1.0f, 1.0f,

	-1.0f,-1.0f, 1.0f, 
	0.0f, 1.0f,

	1.0f,  1.0f, 1.0f, 
	1.0f, 0.0f
};