/*
 *------------------------------------------------------------
 * Copyright(c) 2009-2010 by Digital Media Professionals Inc.
 * All rights reserved.
 *------------------------------------------------------------
 * This source code is the confidential and proprietary
 * of Digital Media Professionals Inc.
 *------------------------------------------------------------
 */
#ifndef __GAS_H__
#define __GAS_H__

/*
 * Definitions
 */

#include <nn/gx.h>
#include <nn/math.h>

#define APP_NAME "PartsysGas"

/* accumulation buffer should have same size as display buffer */
#define GAS_ACC_WIDTH       (nn::gx::DISPLAY0_WIDTH)
#define GAS_ACC_HEIGHT      (nn::gx::DISPLAY0_HEIGHT)
/* texture should have powered by 2 size which is bigger than DISPLAY size */
#define GAS_TEX_WIDTH       (512)
#define GAS_TEX_HEIGHT      (512)

/* Default buffer ID */
#define DISPLAY_BUFFER      (0)     /* default frame buffer */

/* Particle pattern */
#define PARTICLE_PATTERNS   (1)
#define PARTICLE_FILES       "rom:/resources/ptcl0.tga"

struct _particleSys 
{
    GLuint      m_pSysPositionID;
    
    nn::math::Matrix44    m_partsys_center;
    nn::math::Matrix44    m_partsys_color;
    nn::math::Matrix44    m_partsys_radius;
    nn::math::Matrix44    m_partsys_aspect;

    float       m_speed;
    float       m_particleCountMax;
    float       m_size_min_max[2];
    float       m_prng[4];                  /* constant for the Pseudo Random Number Generator (modulo based) */
    float       m_random_seed[4];           /* seeds for the PRNG */

    float       simulationTime;             /* application side. Holds the current time for particle system */
    float       dTime;                      /* application side. Holds the time interval between each frame */
    int         NFrame;                     /* application side. Number of frames for this particle system */
};


struct gas_data
{
    /* Gas geometry definition (accumulation pass) */
    struct _particleSys     pSys;
    GLuint                  pattern[PARTICLE_PATTERNS]; /* Texture ID applied to each particle */
    GLfloat                 _dela_z;                    /* used in accumulation pass, to control final alpha blending*/

    GLint                   _autoAcc;                   /* used in post synthesis pass */
    float                   _densMax;                   /* used in post synthesis pass. Shading control*/
    GLfloat                 _lightDirX;                 /* used in post synthesis pass. Shading control */
    GLfloat                 _lightDirY;                 /* used in post synthesis pass. Shading control */
    GLfloat                 _LightXY[4];                /* used in post synthesis pass. Shading control */
    GLfloat                 _LightZ[4];                 /* used in post synthesis pass. Shading control */
    GLuint                  FogLut_ID;                  /* used in post synthesis pass. Look up table ID */
    GLuint                  CollectionLUT_ID;           /* used in post synthesis pass. Texture collection ID */
    GLuint                  gasTransfert_ID[3];         /* used in post synthesis pass. Lookup table ID for gas color look up table */
    float                   RR[16],GG[16],BB[16];       /* used in post synthesis pass. Lookup table for gas color content */
    float                   fogTable[256];              /* used in post synthesis pass. Fog look up table for density to alpha conversion*/
    GLenum                  shadingDensitySrc;          /* used in post synthesis pass. Density selection for shading input*/
    GLenum                  colorLutInput;              /* used in post synthesis pass. Input selection for the gas color look up*/
    /* Gas geometry definition / simple quad (post synthesis pass) */
    GLuint                  quad_index_ID;              /* used in post synthesis pass. Vertex Index buffer ID */
    GLuint                  quad_vertBuf_ID;            /* used in post synthesis pass. Vertex position buffer ID */
    GLuint                  quad_texBuf_ID;             /* used in post synthesis pass. Vertex Texture coordinates buffer ID */
    GLuint                  quad_colBuf_ID;             /* used in post synthesis pass. Vertex color buffer ID */

};

/*
 * Function declarations
 */

/* buffer initialization */
void GasInitialize(void);

/* gaseous object data structure default initialization */
void DefaultGasObject(struct gas_data *gas,float *gasColorTable);

/* utility function to update the gas color lookup table */
void SetGasColorTable(struct gas_data *gas,float *gasColorTable);

/* accumulation pass */
void GasAccumulation();

/* shading pass */
void GasShading(void);


#endif /* __GAS_H__ */