Add OpenGL discovery to read/write KTX files

IO/CMakeLists.txt

@@ -87,6 +87,11 @@ INCLUDE_DIRECTORIES( ${FasTC_SOURCE_DIR}/IO/third_party/tga )
 SET( SOURCES ${SOURCES} "src/ImageLoaderTGA.cpp" )
 SET( HEADERS ${HEADERS} "src/ImageLoaderTGA.h" )
 
+FIND_PACKAGE( OpenGL )
+IF(OPENGL_FOUND)
+  INCLUDE_DIRECTORIES( ${OPENGL_INCLUDE_DIRS} )
+ENDIF(OPENGL_FOUND)
+
 CONFIGURE_FILE(
 	"config/ImageLoader.h.in"
 	"include/ImageLoader.h"

IO/config/ImageLoader.h.in

@@ -154,4 +154,8 @@ class ImageLoader {
 #cmakedefine PVRTEXLIB_FOUND
 #endif // PVRTEXLIB_FOUND
 
+#ifndef OPENGL_FOUND
+#cmakedefine OPENGL_FOUND
+#endif // OPENGL_FOUND
+
 #endif // _IMAGE_LOADER_H_

IO/config/ImageWriter.h.in

@@ -95,4 +95,8 @@ class ImageWriter {
 #cmakedefine PVRTEXLIB_FOUND
 #endif // PVRTEXLIB_FOUND
 
+#ifndef OPENGL_FOUND
+#cmakedefine OPENGL_FOUND
+#endif // OPENGL_FOUND
+
 #endif // _IMAGE_LOADER_H_

IO/src/GLDefines.h

@@ -0,0 +1,84 @@
+/* FasTC
+ * Copyright (c) 2014 University of North Carolina at Chapel Hill.
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for educational, research, and non-profit purposes, without
+ * fee, and without a written agreement is hereby granted, provided that the
+ * above copyright notice, this paragraph, and the following four paragraphs
+ * appear in all copies.
+ *
+ * Permission to incorporate this software into commercial products may be
+ * obtained by contacting the authors or the Office of Technology Development
+ * at the University of North Carolina at Chapel Hill <otd@unc.edu>.
+ *
+ * This software program and documentation are copyrighted by the University of
+ * North Carolina at Chapel Hill. The software program and documentation are
+ * supplied "as is," without any accompanying services from the University of
+ * North Carolina at Chapel Hill or the authors. The University of North
+ * Carolina at Chapel Hill and the authors do not warrant that the operation of
+ * the program will be uninterrupted or error-free. The end-user understands
+ * that the program was developed for research purposes and is advised not to
+ * rely exclusively on the program for any reason.
+ *
+ * IN NO EVENT SHALL THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL OR THE
+ * AUTHORS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL,
+ * OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF
+ * THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF NORTH CAROLINA
+ * AT CHAPEL HILL OR THE AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL AND THE AUTHORS SPECIFICALLY
+ * DISCLAIM ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND ANY 
+ * STATUTORY WARRANTY OF NON-INFRINGEMENT. THE SOFTWARE PROVIDED HEREUNDER IS ON
+ * AN "AS IS" BASIS, AND THE UNIVERSITY  OF NORTH CAROLINA AT CHAPEL HILL AND
+ * THE AUTHORS HAVE NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, 
+ * ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Please send all BUG REPORTS to <pavel@cs.unc.edu>.
+ *
+ * The authors may be contacted via:
+ *
+ * Pavel Krajcevski
+ * Dept of Computer Science
+ * 201 S Columbia St
+ * Frederick P. Brooks, Jr. Computer Science Bldg
+ * Chapel Hill, NC 27599-3175
+ * USA
+ * 
+ * <http://gamma.cs.unc.edu/FasTC/>
+ */
+
+#ifndef _IO_SRC_GL_DEFINES_H_
+#define _IO_SRC_GL_DEFINES_H_
+
+#ifdef OPENGL_FOUND
+# ifdef __APPLE__
+#  include <OpenGL/gl.h>
+# else
+#  include <GL/gl.h>
+# endif
+#endif
+
+#ifndef GL_VERSION_1_1
+
+#define GL_BYTE                           0x1400
+#define GL_UNSIGNED_BYTE                  0x1401
+#define GL_SHORT                          0x1402
+#define GL_UNSIGNED_SHORT                 0x1403
+#define GL_INT                            0x1404
+#define GL_UNSIGNED_INT                   0x1405
+#define GL_FLOAT                          0x1406
+#define GL_DOUBLE                         0x140A
+#define GL_RGBA8                          0x8058
+
+#endif  // GL_VERSION_1_1
+
+#ifndef GL_VERTSION_4_2
+
+#define GL_COMPRESSED_RGBA_BPTC_UNORM     0x8E8C
+
+#endif  // GL_VERTSION_4_2
+
+#endif  // _IO_SRC_GL_DEFINES_H_