/**

  * $Id$

  *

  * 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 */