From Mathias Froehlich, "Attached a new state attribute implementing the glClipControl that appeared with GL4.5."

git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@14928 16af8721-9629-0410-8352-f15c8da7e697

src/osg/CMakeLists.txt

@@ -46,6 +46,7 @@ SET(TARGET_H
     ${HEADER_PATH}/Capability
     ${HEADER_PATH}/ClampColor
     ${HEADER_PATH}/ClearNode
+    ${HEADER_PATH}/ClipControl
     ${HEADER_PATH}/ClipNode
     ${HEADER_PATH}/ClipPlane
     ${HEADER_PATH}/ClusterCullingCallback
@@ -246,6 +247,7 @@ SET(TARGET_SRC
     CameraView.cpp
     ClampColor.cpp
     ClearNode.cpp
+    ClipControl.cpp
     ClipNode.cpp
     ClipPlane.cpp
     ClusterCullingCallback.cpp

src/osg/ClipControl.cpp

@@ -0,0 +1,44 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
+ *
+ * This library is open source and may be redistributed and/or modified under
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ *
+ * This library 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
+ * OpenSceneGraph Public License for more details.
+*/
+#include <osg/ClipControl>
+
+#include <osg/GLExtensions>
+#include <osg/State>
+
+using namespace osg;
+
+ClipControl::ClipControl(Origin origin, DepthMode depthMode):
+    _origin(origin),
+    _depthMode(depthMode)
+{
+}
+
+ClipControl::ClipControl(const ClipControl& clipControl, const CopyOp& copyop):
+    StateAttribute(clipControl, copyop),
+    _origin(clipControl._origin),
+    _depthMode(clipControl._depthMode)
+{
+}
+
+ClipControl::~ClipControl()
+{
+}
+
+void ClipControl::apply(State& state) const
+{
+    const GLExtensions* extensions = state.get<GLExtensions>();
+    
+    if (!extensions->isClipControlSupported) return;
+
+    extensions->glClipControl((GLenum)_origin, (GLenum)_depthMode);
+}

src/osg/GLExtensions.cpp

@@ -467,6 +467,8 @@ GLExtensions::GLExtensions(unsigned int contextID)
                           isGLExtensionSupported(contextID,"GL_EXT_texture_cube_map") ||
                           (glVersion >= 1.3f);
 
+    isClipControlSupported = isGLExtensionSupported(contextID,"GL_ARB_clip_control") ||
+                             (glVersion >= 4.5f);
 
 
     isGlslSupported = ( glVersion >= 2.0f ) ||
@@ -601,6 +603,9 @@ GLExtensions::GLExtensions(unsigned int contextID)
     setGLExtensionFuncPtr(glUniformMatrix3x4fv,  "glUniformMatrix3x4fv" );
     setGLExtensionFuncPtr(glUniformMatrix4x3fv,  "glUniformMatrix4x3fv" );
 
+    // ARB_clip_control
+    setGLExtensionFuncPtr(glClipControl, "glClipControl");
+
     // EXT_geometry_shader4
     setGLExtensionFuncPtr(glProgramParameteri,  "glProgramParameteri", "glProgramParameteriEXT" );