/*
 * $Id$
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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. The Blender
 * Foundation also sells licenses for use in proprietary software under
 * the Blender License.  See http://www.blender.org/BL/ for information
 * about this.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2005 Blender Foundation.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): Brecht Van Lommel.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file GPU_buffers.h
 *  \ingroup gpu
 */

#ifndef __GPU_BUFFERS_H__
#define __GPU_BUFFERS_H__

#ifdef _DEBUG
/*#define DEBUG_VBO(X) printf(X)*/
#define DEBUG_VBO(X)
#else
#define DEBUG_VBO(X)
#endif

struct DerivedMesh;
struct DMGridData;
struct GHash;
struct DMGridData;
struct GPUVertPointLink;

typedef struct GPUBuffer {
	int size;	/* in bytes */
	void *pointer;	/* used with vertex arrays */
	unsigned int id;	/* used with vertex buffer objects */
} GPUBuffer;

typedef struct GPUBufferMaterial {
	/* range of points used for this material */
	int start;
	int totpoint;

	/* original material index */
	short mat_nr;
} GPUBufferMaterial;

/* meshes are split up by material since changing materials requires
   GL state changes that can't occur in the middle of drawing an
   array.

   some simplifying assumptions are made:
   * all quads are treated as two triangles.
   * no vertex sharing is used; each triangle gets its own copy of the
     vertices it uses (this makes it easy to deal with a vertex used
     by faces with different properties, such as smooth/solid shading,
     different MCols, etc.)

   to avoid confusion between the original MVert vertices and the
   arrays of OpenGL vertices, the latter are referred to here and in
   the source as `points'. similarly, the OpenGL triangles generated
   for MFaces are referred to as triangles rather than faces.
 */
typedef struct GPUDrawObject {
	GPUBuffer *points;
	GPUBuffer *normals;
	GPUBuffer *uv;
	GPUBuffer *colors;
	GPUBuffer *edges;
	GPUBuffer *uvedges;

	/* for each triangle, the original MFace index */
	int *triangle_to_mface;

	/* for each original vertex, the list of related points */
	struct GPUVertPointLink *vert_points;
	/* storage for the vert_points lists */
	struct GPUVertPointLink *vert_points_mem;
	int vert_points_usage;
	
	int colType;

	GPUBufferMaterial *materials;
	int totmaterial;
	
	int tot_triangle_point;
	int tot_loose_point;
	
	/* caches of the original DerivedMesh values */
	int totvert;
	int totedge;

	/* if there was a failure allocating some buffer, use old
	   rendering code */
	int legacy;
} GPUDrawObject;

/* used for GLSL materials */
typedef struct GPUAttrib {
	int index;
	int size;
	int type;
} GPUAttrib;

void GPU_global_buffer_pool_free(void);

GPUBuffer *GPU_buffer_alloc(int size);
void GPU_buffer_free(GPUBuffer *buffer);

GPUDrawObject *GPU_drawobject_new( struct DerivedMesh *dm );
void GPU_drawobject_free( struct DerivedMesh *dm );

/* called before drawing */
void GPU_vertex_setup( struct DerivedMesh *dm );
void GPU_normal_setup( struct DerivedMesh *dm );
void GPU_uv_setup( struct DerivedMesh *dm );
void GPU_color_setup( struct DerivedMesh *dm );
void GPU_edge_setup( struct DerivedMesh *dm );	/* does not mix with other data */
void GPU_uvedge_setup( struct DerivedMesh *dm );
void GPU_interleaved_setup( GPUBuffer *buffer, int data[] );
int GPU_attrib_element_size( GPUAttrib data[], int numdata );
void GPU_interleaved_attrib_setup( GPUBuffer *buffer, GPUAttrib data[], int numdata );

/* can't lock more than one buffer at once */
void *GPU_buffer_lock( GPUBuffer *buffer );	
void *GPU_buffer_lock_stream( GPUBuffer *buffer );
void GPU_buffer_unlock( GPUBuffer *buffer );

/* upload three unsigned chars, representing RGB colors, for each vertex. Resets dm->drawObject->colType to -1 */
void GPU_color3_upload( struct DerivedMesh *dm, unsigned char *data );
/* upload four unsigned chars, representing RGBA colors, for each vertex. Resets dm->drawObject->colType to -1 */
void GPU_color4_upload( struct DerivedMesh *dm, unsigned char *data );
/* switch color rendering on=1/off=0 */
void GPU_color_switch( int mode );

/* used for drawing edges */
void GPU_buffer_draw_elements( GPUBuffer *elements, unsigned int mode, int start, int count );

/* called after drawing */
void GPU_buffer_unbind(void);

/* used to check whether to use the old (without buffers) code */
int GPU_buffer_legacy( struct DerivedMesh *dm );

/* Buffers for non-DerivedMesh drawing */
void *GPU_build_mesh_buffers(struct GHash *map, struct MVert *mvert,
			struct MFace *mface, int *face_indices,
			int totface, int *vert_indices, int uniq_verts,
			int totvert);
void GPU_update_mesh_buffers(void *buffers, struct MVert *mvert,
			int *vert_indices, int totvert);
void *GPU_build_grid_buffers(struct DMGridData **grids,
	int *grid_indices, int totgrid, int gridsize);
void GPU_update_grid_buffers(void *buffers_v, struct DMGridData **grids,
	int *grid_indices, int totgrid, int gridsize, int smooth);
void GPU_draw_buffers(void *buffers);
void GPU_free_buffers(void *buffers);

#endif