/**

 * $Id$

 *

 * GL-based support functions 

 *

 * 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_glutil_H

#define lxdream_glutil_H

#include <stdio.h>

#include "display.h"

#ifdef __cplusplus

extern "C" {

#endif

/**

 * Test if a specific extension is supported. From opengl.org

 * @param extension extension name to check for

 * @return TRUE if supported, otherwise FALSE.

 */

gboolean isGLExtensionSupported( const char *extension );

gboolean isOpenGLES2();

/**

 * Dump GL information to the output stream, usually for debugging purposes

 */

void glPrintInfo( FILE *out );

/**

 * Check for a GL error and print a message if there is one

 * @param context If not null, a string to be printed along side an error message

 * @return FALSE if there was an error, otherwise TRUE

 */

gboolean gl_check_error( const char *context );

/**

 * Test if secondary color (GL_COLOR_SUM) is supported.

 */

gboolean isGLSecondaryColorSupported();

gboolean isGLVertexBufferSupported();

gboolean isGLVertexRangeSupported();

gboolean isGLPixelBufferSupported();

gboolean isGLMultitextureSupported();

gboolean isGLMirroredTextureSupported();

gboolean isGLBGRATextureSupported();

gboolean isGLShaderSupported();

GLint glGetMaxColourAttachments();

/**

 * Wrapper function for glTexImage2D calls that may have BGRA data - on systems

 * where this isn't directly supported, swizzle the data into an acceptable RGBA

 * equivalent. If preserveData is true, data will not be modified - otherwise

 * the method may swizzle data in-place.

 */

void glTexImage2DBGRA( int level, GLint intFormat, int width, int height, GLint format, GLint type, unsigned char *data, int preserveData );

void glTexSubImage2DBGRA( int level, int xoff, int yoff, int width, int height, GLint format, GLint type, unsigned char *data, int preserveData );

/****** Extension variant wrangling *****/

#if defined(GL_MIRRORED_REPEAT_ARB) && !defined(GL_MIRRORED_REPEAT)

#define GL_MIRRORED_REPEAT GL_MIRRORED_REPEAT_ARB

#endif

#if defined(GL_MAX_TEXTURE_UNITS_ARB) && !defined(GL_MAX_TEXTURE_UNITS)

#define GL_MAX_TEXTURE_UNITS GL_MAX_TEXTURE_UNITS_ARB

#endif

#if defined(GL_FRAMEBUFFER_EXT) && !defined(GL_FRAMEBUFFER)

#define GL_FRAMEBUFFER GL_FRAMEBUFFER_EXT

#endif

#if defined(GL_RENDERBUFFER_EXT) && !defined(GL_RENDERBUFFER)

#define GL_RENDERBUFFER GL_RENDERBUFFER_EXT

#endif

#if defined(GL_COLOR_ATTACHMENT0_EXT) && !defined(GL_COLOR_ATTACHMENT0)

#define GL_COLOR_ATTACHMENT0 GL_COLOR_ATTACHMENT0_EXT

#endif

#if defined(GL_MAX_COLOR_ATTACHMENTS_EXT) && !defined(GL_MAX_COLOR_ATTACHMENTS)

#define GL_MAX_COLOR_ATTACHMENTS GL_MAX_COLOR_ATTACHMENTS_EXT

#endif

#if defined(GL_STENCIL_ATTACHMENT_EXT) && !defined(GL_STENCIL_ATTACHMENT)

#define GL_STENCIL_ATTACHMENT GL_STENCIL_ATTACHMENT_EXT

#endif

#if defined(GL_DEPTH_ATTACHMENT_EXT) && !defined(GL_DEPTH_ATTACHMENT)

#define GL_DEPTH_ATTACHMENT GL_DEPTH_ATTACHMENT_EXT

#endif

#if defined(GL_DEPTH_COMPONENT24_OES) && !defined(GL_DEPTH_COMPONENT24)

#define GL_DEPTH_COMPONENT24 GL_DEPTH_COMPONENT24_OES

#endif

#ifndef GL_DEPTH24_STENCIL8

#if defined(GL_DEPTH24_STENCIL8_EXT)

#define GL_DEPTH24_STENCIL8 GL_DEPTH24_STENCIL8_EXT

#elif defined(GL_DEPTH24_STENCIL8_OES)

#define GL_DEPTH24_STENCIL8 GL_DEPTH24_STENCIL8_OES

#endif

#endif

#if defined(GL_FRAMEBUFFER_COMPLETE_EXT) && !defined(GL_FRAMEBUFFER_COMPLETE)

#define GL_FRAMEBUFFER_COMPLETE GL_FRAMEBUFFER_COMPLETE_EXT

#endif

#if defined(GL_UNSIGNED_SHORT_1_5_5_5_REV_EXT) && !defined(GL_UNSIGNED_SHORT_1_5_5_5_REV)

#define GL_UNSIGNED_SHORT_1_5_5_5_REV GL_UNSIGNED_SHORT_1_5_5_5_REV_EXT

#endif

#if defined(GL_UNSIGNED_SHORT_4_4_4_4_REV_EXT) && !defined(GL_UNSIGNED_SHORT_4_4_4_4_REV)

#define GL_UNSIGNED_SHORT_4_4_4_4_REV GL_UNSIGNED_SHORT_4_4_4_4_REV_EXT

#endif

#if defined(GL_BGRA_EXT) && !defined(GL_BGRA)

#define GL_BGRA GL_BGRA_EXT

#endif

#if defined(GL_SHADING_LANGUAGE_VERSION_ARB) && !defined(GL_SHADING_LANGUAGE_VERSION)

#define GL_SHADING_LANGUAGE_VERSION GL_SHADING_LANGUAGE_VERSION_ARB

#endif

#if defined(HAVE_OPENGL_FBO_EXT) && !defined(HAVE_OPENGL_FBO)

#define glGenFramebuffers glGenFramebuffersEXT

#define glGenRenderbuffers glGenRenderbuffersEXT

#define glBindFramebuffer glBindFramebufferEXT

#define glDeleteFramebuffers glDeleteFramebuffersEXT

#define glDeleteRenderbuffers glDeleteRenderbuffersEXT

#define glBindFramebuffer glBindFramebufferEXT

#define glBindRenderbuffer glBindRenderbufferEXT

#define glRenderbufferStorage glRenderbufferStorageEXT

#define glFramebufferRenderbuffer glFramebufferRenderbufferEXT

#define glFramebufferTexture2D glFramebufferTexture2DEXT

#define glCheckFramebufferStatus glCheckFramebufferStatusEXT

#endif

/* Define an orthographic transform matrix, given the bounding box (assuming origin at 0) */

void defineOrthoMatrix( GLfloat *matrix, GLfloat width, GLfloat height, GLfloat znear, GLfloat zfar );

/* Convenience formatting function for driver use */

void fprint_extensions( FILE *out, const char *extensions );

/****** Texture formats (missing definitions) *****/

#ifndef GL_UNSIGNED_SHORT_4_4_4_4_REV

#define GL_UNSIGNED_SHORT_4_4_4_4_REV 0x8365

#endif

#ifndef GL_UNSIGNED_SHORT_1_5_5_5_REV

#define GL_UNSIGNED_SHORT_1_5_5_5_REV 0x8366

#endif

#ifndef GL_BGRA

#define GL_BGRA 0x80E1

#endif

#ifdef __cplusplus

}

#endif

#endif /* !lxdream_glutil_H */