#ifndef _tgl_zbuffer_h_
#define _tgl_zbuffer_h_


/*
 * Z buffer
 */

#include "TinyGL/gl_zfeatures.h"

#define ZB_Z_BITS 16

#define ZB_POINT_Z_FRAC_BITS 14

#define ZB_POINT_S_MIN     ( (1<<13) )
#define ZB_POINT_S_MAX     ( (1<<22)-(1<<13) )
#define ZB_POINT_T_MIN     ( (1<<21) )
#define ZB_POINT_T_MAX     ( (1<<30)-(1<<21) )

#define ZB_POINT_RED_MIN   ( (1<<10) )
#define ZB_POINT_RED_MAX   ( (1<<16)-(1<<10) )
#define ZB_POINT_GREEN_MIN ( (1<<9) )
#define ZB_POINT_GREEN_MAX ( (1<<16)-(1<<9) )
#define ZB_POINT_BLUE_MIN  ( (1<<10) )
#define ZB_POINT_BLUE_MAX  ( (1<<16)-(1<<10) )

/* display modes */
#define ZB_MODE_5R6G5B  1  /* true color 16 bits */
#define ZB_MODE_INDEX   2  /* color index 8 bits */
#define ZB_MODE_RGBA    3  /* 32 bit rgba mode */
#define ZB_MODE_RGB24   4  /* 24 bit rgb mode */
#define ZB_NB_COLORS    225 /* number of colors for 8 bit display */

#if TGL_FEATURE_RENDER_BITS == 15

#define RGB_TO_PIXEL(r,g,b) \
  ((((r) >> 1) & 0x7c00) | (((g) >> 6) & 0x03e0) | ((b) >> 11))
typedef unsigned short PIXEL;
#define PSZB 2 

#elif TGL_FEATURE_RENDER_BITS == 16

/* 16 bit mode */
#define RGB_TO_PIXEL(r,g,b) \
  (((r) & 0xF800) | (((g) >> 5) & 0x07E0) | ((b) >> 11))
typedef unsigned short PIXEL;
#define PSZB 2 

#elif TGL_FEATURE_RENDER_BITS == 24

#define RGB16_TO_PIXEL(r,g,b) \
  ((((r) << 8) & 0xff0000) | ((g) & 0xff00) | ((b) >> 8))
typedef unsigned int* PIXEL;
#define PSZB 3

#elif TGL_FEATURE_RENDER_BITS == 32

#define RGB_TO_PIXEL(r,g,b) \
  ((((r) << 8) & 0xff0000) | ((g) & 0xff00) | ((b) >> 8))
typedef unsigned int PIXEL;
#define PSZB 4

#else

#error Incorrect number of bits per pixel

#endif

#ifndef PSZB
typedef unsigned int PIXEL;
#define PSZB 2
#error PSZB

#endif
typedef struct {
    int             xsize;
	int             ysize;
    int             linesize; /* line size, in bytes */
    int             mode;    
    unsigned short *zbuf;
    PIXEL          *pbuf;
    int             frame_buffer_allocated;    
    int             nb_colors;
    unsigned char  *dctable;
    int            *ctable;
    unsigned short *current_texture;
} ZBuffer;

typedef struct {
	int   x,y,z;   /* integer coordinates in the zbuffer */
	int   s,t;     /* coordinates for the mapping */
	int   r,g,b;   /* color indexes */  
	float sz,tz;   /* temporary coordinates for mapping */
} ZBufferPoint;

/* zbuffer.c */

ZBuffer *ZB_open(
	int            xsize,
	int            ysize,
	int            mode,
	int            nb_colors,
	unsigned char *color_indexes,
	int           *color_table,
	void          *frame_buffer
);

void ZB_update         ( ZBuffer *zb, void *frame_buzzer, int xsize, int ysize, int linesize );
void ZB_close          ( ZBuffer *zb );
void ZB_resize         ( ZBuffer *zb, void *frame_buffer, int xsize, int ysize );
void ZB_clear          ( ZBuffer *zb, int clear_z, int z, int clear_color, int r, int g, int b );
void ZB_copyFrameBuffer( ZBuffer *zb, void *buf, int linesize );

/* zdither.c */

void ZB_initDither       ( ZBuffer *zb, int nb_colors, unsigned char *color_indexes, int *color_table );
void ZB_closeDither      ( ZBuffer *zb );
void ZB_ditherFrameBuffer( ZBuffer *zb, unsigned char *dest, int linesize );

/* zline.c */

void ZB_plot  ( ZBuffer *zb, ZBufferPoint *p );
void ZB_line  ( ZBuffer *zb, ZBufferPoint *p1, ZBufferPoint *p2 );
void ZB_line_z( ZBuffer *zb, ZBufferPoint *p1, ZBufferPoint *p2 );

/* ztriangle.c */

void ZB_setTexture                    ( ZBuffer *zb, unsigned short *texture );
void ZB_fillTriangleFlat              ( ZBuffer *zb, ZBufferPoint *p1, ZBufferPoint *p2, ZBufferPoint *p3 );
void ZB_fillTriangleSmooth            ( ZBuffer *zb, ZBufferPoint *p1, ZBufferPoint *p2, ZBufferPoint *p3 );
void ZB_fillTriangleMapping           ( ZBuffer *zb, ZBufferPoint *p1, ZBufferPoint *p2, ZBufferPoint *p3 );
void ZB_fillTriangleMappingPerspective( ZBuffer *zb, ZBufferPoint *p0, ZBufferPoint *p1, ZBufferPoint *p2 );


typedef void (*ZB_fillTriangleFunc)(ZBuffer *,ZBufferPoint *,ZBufferPoint *,ZBufferPoint *);



#endif /* _tgl_zbuffer_h_ */