/**

  * $Id$

  *

  * PVR2 scene description structure (pvr2-private)

  *

  * Copyright (c) 2005 Nathan Keynes.

  *

  * 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; either version 2 of the License, or

  * (at your option) any later version.

  *

  * 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 for more details.

  */

 #ifndef lxdream_scene_H

 #define lxdream_scene_H 1

 #ifdef __cplusplus

 extern "C" {

 #endif

 /************************* Intermediate vertex buffer ************************/

 typedef enum { 

     SORT_NEVER = 0, 

     SORT_TILEFLAG = 1, /* In this mode, sorting is controlled by the per-segment flag */

     SORT_ALWAYS = 2 

 } tile_sort_mode_t;

 typedef enum { SHADOW_NONE=0, SHADOW_CHEAP=1, SHADOW_FULL=2 } shadow_mode_t;

 struct vertex_struct {

     float u,v;

     float x,y,z;

     float rgba[4];

     float offset_rgba[4];

 };

 struct polygon_struct {

     uint32_t *context;

     uint32_t vertex_count; // number of vertexes in polygon

     uint32_t tex_id;

     int32_t vertex_index; // index of first vertex in vertex buffer

     uint32_t mod_tex_id;

     int32_t mod_vertex_index; // index of first modified vertex in vertex buffer

     struct polygon_struct *next; // chain for tri/quad arrays

 };

 void pvr2_scene_init(void);

 void pvr2_scene_read(void);

 void pvr2_scene_shutdown();

 uint32_t pvr2_scene_buffer_width();

 uint32_t pvr2_scene_buffer_height();

 extern unsigned char *video_base;

 /**

  * Maximum possible size of the vertex buffer. This is figured as follows:

  * PVR2 polygon buffer is limited to 4MB. The tightest polygon format 

  * is 3 vertexes in 48 bytes = 16 bytes/vertex, (shadow triangle) 

  * (the next tightest is 8 vertex in 140 bytes (6-strip colour-only)).

  * giving a theoretical maximum of 262144 vertexes.

  * The expanded structure is 44 bytes/vertex, giving 

  * 11534336 bytes...

  */

 #define MAX_VERTEXES 262144

 #define MAX_VERTEX_BUFFER_SIZE (MAX_VERTEXES*sizeof(struct vertex_struct))

 /**

  * Maximum polygons - smallest is 1 polygon in 48 bytes, giving

  * 87381, plus 1 for the background

  * 

  */

 #define MAX_POLYGONS 87382

 #define MAX_POLY_BUFFER_SIZE (MAX_POLYGONS*sizeof(struct polygon_struct))

 #define BUF_POLY_MAP_SIZE (4 MB)

 /*************************************************************************/

 /* Scene data - this structure holds all the intermediate data used during

  * the rendering process. 

  *

  * Special note: if vbo_supported == FALSE, then vertex_array points to a

  * malloced chunk of system RAM. Otherwise, vertex_array will be either NULL

  * (if the VBO is unmapped), or a pointer into a chunk of GL managed RAM

  * (possibly direct-mapped VRAM).

  */

 struct pvr2_scene_struct {

     /** GL ID of the VBO used by the scene (or 0 if VBOs are not in use). */

     GLuint vbo_id;

     /** Pointer to the vertex array data, or NULL for unmapped VBOs */

     struct vertex_struct *vertex_array;

     /** Current allocated size (in bytes) of the vertex array */

     uint32_t vertex_array_size;

     /** Total number of vertexes in the scene (note modified vertexes

      * count for 2 vertexes */

     uint32_t vertex_count;

     /** Pointer to the polygon data for the scene (main ram). 

      * This will always have room for at least MAX_POLYGONS */

     struct polygon_struct *poly_array;

     /** Pointer to the background polygon. This is always a quad, and

      * normally the last member of poly_array */

     struct polygon_struct *bkgnd_poly;

     /** Total number of polygons in the scene */

     uint32_t poly_count;

     /** Image bounds in 3D - x1,x2,y1,y2,z1,z2 

      * x and y values are determined by the clip planes, while z values are

      * determined from the vertex data itself.

      */

     float bounds[6];

     /* Total size of the image buffer, determined by the tile map used to

      * render the scene */

     uint32_t buffer_width, buffer_height;

     /** Specifies the translucency auto-sort mode for the scene */

     tile_sort_mode_t sort_mode;

     shadow_mode_t shadow_mode;

     float fog_lut_colour[4];

     float fog_vert_colour[4];

     /** Pointer to the start of the tile segment list in PVR2 VRAM (32-bit) */

     struct tile_segment *segment_list;

     /** Map from PVR2 polygon address to an element of poly_array. */

     struct polygon_struct **buf_to_poly_map;

     /** Pointer to the start of the raw polygon buffer in PVR2 VRAM (32-bit).

      * Also only used during parsing */

     uint32_t *pvr2_pbuf;

     /** Current vertex index during parsing */

     uint32_t vertex_index;

 };

 /**

  * Current scene structure. Note this should only be written to by vertex bufer

  * functions

  */

 extern struct pvr2_scene_struct pvr2_scene;

 #ifdef __cplusplus

 }

 #endif

 #endif /* !lxdream_scene_H */