2 files changed, 38 insertions, 1 deletions
diff --git a/src/classes/com/sun/opengl/util/texture/Texture.java b/src/classes/com/sun/opengl/util/texture/Texture.java
index 167b4e073..9ceff7cd8 100755
--- a/src/classes/com/sun/opengl/util/texture/Texture.java
+++ b/src/classes/com/sun/opengl/util/texture/Texture.java
@@ -892,6 +892,8 @@ public class Texture {
   }
 
   private static boolean haveTexRect(GL gl) {
-    return (!disableTexRect && gl.isExtensionAvailable("GL_ARB_texture_rectangle"));
+    return (!disableTexRect &&
+            TextureIO.isTexRectEnabled() &&
+            gl.isExtensionAvailable("GL_ARB_texture_rectangle"));
   }
 }
diff --git a/src/classes/com/sun/opengl/util/texture/TextureIO.java b/src/classes/com/sun/opengl/util/texture/TextureIO.java
index e537f4276..f1ac85ebd 100755
--- a/src/classes/com/sun/opengl/util/texture/TextureIO.java
+++ b/src/classes/com/sun/opengl/util/texture/TextureIO.java
@@ -140,6 +140,12 @@ public class TextureIO {
 
   private static final boolean DEBUG = Debug.debug("TextureIO");
 
+  // For manually disabling the use of the texture rectangle
+  // extensions so you know the texture target is GL_TEXTURE_2D; this
+  // is useful for shader writers (thanks to Chris Campbell for this
+  // observation)
+  private static boolean texRectEnabled = true;
+
   //----------------------------------------------------------------------
   // methods that *do not* require a current context
   // These methods assume RGB or RGBA textures.
@@ -692,6 +698,35 @@ public class TextureIO {
     textureWriters.add(0, writer);
   }
 
+  //---------------------------------------------------------------------------
+  // Global disabling of texture rectangle extension
+  //
+
+  /** Toggles the use of the GL_ARB_texture_rectangle extension by the
+      TextureIO classes. By default, on hardware supporting this
+      extension, the TextureIO classes may use the
+      GL_ARB_texture_rectangle extension for non-power-of-two
+      textures. (If the hardware supports the
+      GL_ARB_texture_non_power_of_two extension, that one is
+      preferred.) In some situations, for example when writing
+      shaders, it is advantageous to force the texture target to
+      always be GL_TEXTURE_2D in order to have one version of the
+      shader, even at the expense of texture memory in the case where
+      NPOT textures are not supported. This method allows the use of
+      the GL_ARB_texture_rectangle extension to be turned off globally
+      for this purpose. The default is that the use of the extension
+      is enabled. */
+  public static void setTexRectEnabled(boolean enabled) {
+    texRectEnabled = enabled;
+  }
+
+  /** Indicates whether the GL_ARB_texture_rectangle extension is
+      allowed to be used for non-power-of-two textures; see {@link
+      #setTexRectEnabled setTexRectEnabled}. */
+  public static boolean isTexRectEnabled() {
+    return texRectEnabled;
+  }
+
   //----------------------------------------------------------------------
   // Internals only below this point
   //