Integrated support for GL_CLAMP_TO_BORDER_ARB extension to osg::Texture,

submitted by Sasa Bistrovic.

include/osg/Texture

@@ -53,6 +53,10 @@
 #define GL_CLAMP_TO_EDGE                  0x812F
 #endif
 
+#ifndef GL_CLAMP_TO_BORDER_ARB
+#define GL_CLAMP_TO_BORDER_ARB 0x812D
+#endif
+
 #ifndef GL_GENERATE_MIPMAP_SGIS
 #define GL_GENERATE_MIPMAP_SGIS           0x8191
 #define GL_GENERATE_MIPMAP_HINT_SGIS      0x8192
@@ -145,7 +149,8 @@ class SG_EXPORT Texture : public StateAttribute
             CLAMP  = GL_CLAMP,
             CLAMP_TO_EDGE = GL_CLAMP_TO_EDGE,
             REPEAT = GL_REPEAT,
-            MIRROR = GL_MIRRORED_REPEAT_IBM
+            MIRROR = GL_MIRRORED_REPEAT_IBM,
+            CLAMP_TO_BORDER_ARB = GL_CLAMP_TO_BORDER_ARB
         };
 
         /** Set the texture wrap mode.*/

src/osg/Texture.cpp

@@ -275,6 +275,15 @@ void Texture::applyImmediateMode(State& state) const
             wt = CLAMP;
     }
 
+    static bool s_borderClampSupported = isGLExtensionSupported("GL_ARB_texture_border_clamp");
+    if(!s_borderClampSupported)
+    {
+        if(ws == CLAMP_TO_BORDER_ARB)
+            ws = CLAMP;
+        if(wt == CLAMP_TO_BORDER_ARB)
+            wt = CLAMP;
+    }
+
     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, ws );
     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wt );