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

include/osg/ClipControl

@@ -0,0 +1,85 @@
+/* -*-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.
+*/
+
+#ifndef OSG_CLIPCONTROL
+#define OSG_CLIPCONTROL 1
+
+#include <osg/StateAttribute>
+
+#ifndef GL_VERSION_4_5
+    #define GL_NEGATIVE_ONE_TO_ONE            0x935E
+    #define GL_ZERO_TO_ONE                    0x935F
+#endif
+
+namespace osg {
+
+/** Encapsulate OpenGL glClipControl functions.
+*/
+class OSG_EXPORT ClipControl : public StateAttribute
+{
+    public :
+
+        enum Origin
+        {
+            LOWER_LEFT = GL_LOWER_LEFT,
+            UPPER_LEFT = GL_UPPER_LEFT
+        };
+
+        enum DepthMode
+        {
+            NEGATIVE_ONE_TO_ONE = GL_NEGATIVE_ONE_TO_ONE,
+            ZERO_TO_ONE         = GL_ZERO_TO_ONE
+        };
+
+
+        ClipControl(Origin origin=LOWER_LEFT, DepthMode depthMode=NEGATIVE_ONE_TO_ONE);
+
+        /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
+        ClipControl(const ClipControl& clipControl,const CopyOp& copyop=CopyOp::SHALLOW_COPY);
+
+
+        META_StateAttribute(osg, ClipControl, CLIPCONTROL);
+
+        /** return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs.*/
+        virtual int compare(const StateAttribute& sa) const
+        {
+            // check the types are equal and then create the rhs variable
+            // used by the COMPARE_StateAttribute_Parameter macros below.
+            COMPARE_StateAttribute_Types(ClipControl,sa)
+
+            // compare each parameter in turn against the rhs.
+            COMPARE_StateAttribute_Parameter(_origin)
+            COMPARE_StateAttribute_Parameter(_depthMode)
+
+            return 0; // passed all the above comparison macros, must be equal.
+        }
+
+        void setOrigin(Origin origin) { _origin = origin; }
+        Origin getOrigin() const { return _origin; }
+
+        void setDepthMode(DepthMode depthMode) { _depthMode = depthMode; }
+        DepthMode getDepthMode() const { return _depthMode; }
+
+        virtual void apply(State& state) const;
+
+    protected:
+
+        virtual ~ClipControl();
+
+        Origin              _origin;
+        DepthMode           _depthMode;
+};
+
+}
+
+#endif

include/osg/GLExtensions

@@ -167,6 +167,7 @@ class OSG_EXPORT GLExtensions : public osg::Referenced
         bool isShaderAtomicCountersSupported;
         bool isRectangleSupported;
         bool isCubeMapSupported;
+        bool isClipControlSupported;
 
         void (GL_APIENTRY * glDrawBuffers)(GLsizei n, const GLenum *bufs);
         void (GL_APIENTRY * glAttachShader)(GLuint program, GLuint shader);
@@ -267,6 +268,7 @@ class OSG_EXPORT GLExtensions : public osg::Referenced
         void (GL_APIENTRY * glUniformMatrix4x2fv)( GLint location, GLsizei count, GLboolean transpose, const GLfloat* value );
         void (GL_APIENTRY * glUniformMatrix3x4fv)( GLint location, GLsizei count, GLboolean transpose, const GLfloat* value );
         void (GL_APIENTRY * glUniformMatrix4x3fv)( GLint location, GLsizei count, GLboolean transpose, const GLfloat* value );
+        void (GL_APIENTRY * glClipControl)( GLenum origin, GLenum depthMode );
         void (GL_APIENTRY * glProgramParameteri)( GLuint program, GLenum pname, GLint value );
         void (GL_APIENTRY * glPatchParameteri)( GLenum pname, GLint value );
         void (GL_APIENTRY * glPatchParameterfv)( GLenum pname, const GLfloat* values );

include/osg/StateAttribute

@@ -166,6 +166,7 @@ class OSG_EXPORT StateAttribute : public Object
             HINT,
             SAMPLEMASKI,
             PRIMITIVERESTARTINDEX,
+            CLIPCONTROL,
 
             /// osgFX namespace
             VALIDATOR,

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" );