Add runtime detection of glActiveTextureARB

diff --git a/simgear/screen/extensions.hxx b/simgear/screen/extensions.hxx
index c15269865161378f6aca17e738035c752a2fe11d..43a7e348d8fc8ca97c3be1a48d11cdd3ddf89a3f 100644 (file)
--- a/simgear/screen/extensions.hxx
+++ b/simgear/screen/extensions.hxx
@@ -75,12 +75,18 @@ inline void (*SGLookupFunction(const char *func))()
 
 
 /* OpenGL extension declarations */
+
+/*
+ * glPointParameterf and glPointParameterfv
+ */
 #ifndef GL_EXT_point_parameters
+#define GL_EXT_point_parameters 1
 #define GL_POINT_SIZE_MIN_EXT                                   0x8126
 #define GL_DISTANCE_ATTENUATION_EXT                             0x8129
 #endif
 
 #ifndef GL_ARB_point_parameters
+#define GL_ARB_point_parameters 1
 #define GL_POINT_SIZE_MIN_ARB                                  0x8126
 #define GL_DISTANCE_ATTENUATION_ARB                            0x8129
 #endif
@@ -88,6 +94,51 @@ inline void (*SGLookupFunction(const char *func))()
 typedef void (APIENTRY * glPointParameterfProc)(GLenum pname, GLfloat param);
 typedef void (APIENTRY * glPointParameterfvProc)(GLenum pname, const GLfloat *params);
 
+/*
+ * glActiveTextureARB
+ */
+
+#ifndef GL_ARB_multitexture
+#define GL_ARB_multitexture 1
+#define GL_TEXTURE0_ARB                                         0x84C0
+#define GL_TEXTURE1_ARB                                         0x84C1
+#define GL_TEXTURE2_ARB                                         0x84C2
+#define GL_TEXTURE3_ARB                                         0x84C3
+#define GL_TEXTURE4_ARB                                         0x84C4
+#define GL_TEXTURE5_ARB                                         0x84C5
+#define GL_TEXTURE6_ARB                                         0x84C6
+#define GL_TEXTURE7_ARB                                         0x84C7
+#define GL_TEXTURE8_ARB                                         0x84C8
+#define GL_TEXTURE9_ARB                                         0x84C9
+#define GL_TEXTURE10_ARB                                        0x84CA
+#define GL_TEXTURE11_ARB                                        0x84CB
+#define GL_TEXTURE12_ARB                                        0x84CC
+#define GL_TEXTURE13_ARB                                        0x84CD
+#define GL_TEXTURE14_ARB                                        0x84CE
+#define GL_TEXTURE15_ARB                                        0x84CF
+#define GL_TEXTURE16_ARB                                        0x84D0
+#define GL_TEXTURE17_ARB                                        0x84D1
+#define GL_TEXTURE18_ARB                                        0x84D2
+#define GL_TEXTURE19_ARB                                        0x84D3
+#define GL_TEXTURE20_ARB                                        0x84D4
+#define GL_TEXTURE21_ARB                                        0x84D5
+#define GL_TEXTURE22_ARB                                        0x84D6
+#define GL_TEXTURE23_ARB                                        0x84D7
+#define GL_TEXTURE24_ARB                                        0x84D8
+#define GL_TEXTURE25_ARB                                        0x84D9
+#define GL_TEXTURE26_ARB                                        0x84DA
+#define GL_TEXTURE27_ARB                                        0x84DB
+#define GL_TEXTURE28_ARB                                        0x84DC
+#define GL_TEXTURE29_ARB                                        0x84DD
+#define GL_TEXTURE30_ARB                                        0x84DE
+#define GL_TEXTURE31_ARB                                        0x84DF
+#define GL_ACTIVE_TEXTURE_ARB                                   0x84E0
+#define GL_CLIENT_ACTIVE_TEXTURE_ARB                            0x84E1
+#define GL_MAX_TEXTURE_UNITS_ARB                                0x84E2
+#endif
+
+typedef void (APIENTRY * glActiveTextureProc)(GLenum texture);
+
 #if defined(__cplusplus)
 }
 #endif