/**

 * $Id$

 *

 * Common GL code that doesn't depend on a specific implementation

 *

 * 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_video_gl_H

#define lxdream_video_gl_H 1

#ifdef __cplusplus

extern "C" {

#endif

extern uint32_t video_width, video_height;

/**

 * Set the video size used by the frame blits

 */

void gl_set_video_size( uint32_t width, uint32_t height, int flipped );

/**

 * Generic GL routine to draw the given frame buffer into a texture

 */

void gl_frame_buffer_to_tex( frame_buffer_t frame, int tex_id );

/**

 * Reset the GL state to its initial values

 */

void gl_reset_state();

/**

 * Generic GL routine to draw the given frame buffer into a (texture-backed)

 * render buffer.

 */

void gl_load_frame_buffer( frame_buffer_t frame, render_buffer_t buf );

/**

 * Generic GL routine to blank the display view with the specified colour.

 */

void gl_display_blank( uint32_t colour );

/**

 * Write a rectangular texture (GL_TEXTURE_2D) to the display frame

 */

void gl_display_render_buffer( render_buffer_t buffer );

/**

 * Write a rectangular texture (GL_TEXTURE_2D) to the display frame

 */

void gl_texture_window( int width, int height, int tex_id, gboolean inverted );

/**

 * Convert window coordinates to dreamcast device coords (640x480) using the 

 * same viewable area as gl_texture_window.

 * If the coordinates are outside the viewable area, the result is -1,-1.

 */ 

void gl_window_to_system_coords( int *x, int *y );

/**

 * Generic GL read_render_buffer. This function assumes that the caller

 * has already set the appropriate glReadBuffer(); in other words, unless

 * there's only one buffer this needs to be wrapped.

 */

gboolean gl_read_render_buffer( unsigned char *target, render_buffer_t buffer, 

                                int rowstride, int colour_format );

void gl_framebuffer_setup(void);

void gl_framebuffer_cleanup(void);

/****** FBO handling (gl_fbo.c) ******/

gboolean gl_fbo_is_supported();

void gl_fbo_shutdown();

void gl_fbo_init( display_driver_t driver );

void gl_fbo_detach();

/** VBO/VAR handling (gl_vbo.c) ******/

void gl_vbo_init( display_driver_t driver );

/* Set the fallback vertex buffer handling, for drivers with no GL */

void gl_vbo_fallback_init( display_driver_t driver );

/** Initialize and load SL shaders */

gboolean glsl_init( display_driver_t driver );

/** Initialise common GL functionality (FBO, SL, VBO)

 * @param driver driver to be updated with appropriate calls

 * @param need_fbo if TRUE, FBOs are required (ie main driver has no other way

 * to construct an off-screen buffer)

 * @return TRUE on success, FALSE if we couldn't setup a working context

 */

gboolean gl_init_driver( display_driver_t driver, gboolean need_fbo );

#ifdef __cplusplus

}

#endif

#endif /* !lxdream_video_gl_H */