added #version 330 implementation of depth_copy shader.

on osx with opengl 3.3 or higher, use version 330 implementation of depth_copy shader

Shaders/ScreenQuad/depth_copy_330.glsl

+#version 330
+
+uniform sampler2D DepthTex;
+
+uniform float DepthSign;
+
+in vec2 vTexCoord;
+out vec4 oColor;
+
+void main() 
+{
+  oColor = vec4(1.0, 1.0, 1.0, 1.0);
+  
+  gl_FragDepth = texture(DepthTex, vTexCoord).x * DepthSign;
+}
\ No newline at end of file

libs_required/ACG/GL/IRenderer.cc

@@ -1349,10 +1349,18 @@ QString IRenderer::dumpCurrentRenderObjectsToString(ACG::RenderObject** _list, b
 void IRenderer::copyDepthToBackBuffer( GLuint _depthTex, float _scale /*= 1.0f*/ )
 {
   if (!_depthTex) return;
-
+#ifdef __APPLE__
+  if(ACG::openGLVersion(3,3))
+  {
+      if (!depthCopyShader_)
+        depthCopyShader_ = GLSL::loadProgram("ScreenQuad/screenquad.glsl", "ScreenQuad/depth_copy_330.glsl");
+  }
+  else
+#endif
+  {
   if (!depthCopyShader_)
     depthCopyShader_ = GLSL::loadProgram("ScreenQuad/screenquad.glsl", "ScreenQuad/depth_copy.glsl");
-
+  }
 
   if (depthCopyShader_)
   {