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////////////////////////////////////////////////////////////////////////////////////////////////////

#ifndef __PARALLEL_SPLIT_SHADOW_MAP_H__

#define __PARALLEL_SPLIT_SHADOW_MAP_H__

#include "compute_types.h"

#include "texture.h"

#include "camera.h"

#include "fbo.h"

class ParallelSplitShadowMapper

{

public:

    typedef enum PassType 

    {

        PSSM_DEPTH_PASS,

        PSSM_SHADOW_PASS

    };

public:

    ParallelSplitShadowMapper();

    ~ParallelSplitShadowMapper();

    bool setup(

        uint uiWidth, uint uiHeight, 

        uint uiSplitCount, 

        float fNear, float fFar);

    void update(const Camera &rkCamera);

    bool enable(PassType ePassType, uint uiSplit = 0);

    bool disable(PassType ePassType, uint uiSplit = 0);  

    void setLightPosition(const float3 &rkV);

    void setLightFrame(

        const float3 &rkUp, 

        const float3 &rkView, 

        const float3 &rkLeft);  

    void setShadowMapTextureUnit(GLenum eUnit)      { m_eShadowMapTextureUnit = eUnit; }

    uint getSplitCount() const                      { return m_uiSplitCount; }

    GLenum getShadowMapTextureUnit() const          { return m_eShadowMapTextureUnit; }

    const float3& getLightPosition() const          { return m_kLightCamera.getPosition(); }

protected:

    void destroy();

    float16 computeLightMatrix(

        float4 akFrustumCorners[8],

        const float16& rkModelviewProjectionMatrix,

        float fFov, float fAspect, 

        float fNearClip, float fFarClip);

    void computeSplitDistances(

        float *afDistances, 

        unsigned int uiCount, 

        float fNear, float fFar);

    void computeFrustumCorners(

        float4 akFrustum[8], 

        const float3 &rkPos, 

        const float3 &rkView, 

        const float3 &rkUp,

        float fNear, float fFar, 

        float fScale, float fFov, 

        float fAspect);

    void enableShadowMap(

        float16 &rkProjection, 

        float16 &rkModelView,

        GLenum eTextureUnit);

    void disableShadowMap(void);

    void enableDepthState();

    void disableDepthState();

    void enableDepthCapture(

        float16 &rkProjection,

        float16 &rkModelView);

    void disableDepthCapture();

    void fillDepthMap(

        const float16 &rkProjection,

        const float16 &rkModelView);

    void renderSceneWithShadows(

        const float16 &rkProjection, 

        const float16 &rkModelView, 

        float fNear, float fFar);

    void renderSceneSplit(void);

protected:

    bool m_bInitialized;

    float* m_afSplitDistances;

    float16 *m_akSplitProjections;

    uint m_uiSplitCount;

    float m_fPolygonOffsetScale;

    float m_fPolygonOffsetBias;

    int m_aiViewport[4];

    Camera m_kLightCamera;

    Texture m_kDepthMap;

    FrameBufferObject m_kFrameBuffer;

    GLenum m_eShadowMapTextureUnit;

};

#endif