1 // Created on: 2013-10-10
2 // Created by: Denis BOGOLEPOV
3 // Copyright (c) 2013-2014 OPEN CASCADE SAS
5 // This file is part of Open CASCADE Technology software library.
7 // This library is free software; you can redistribute it and/or modify it under
8 // the terms of the GNU Lesser General Public License version 2.1 as published
9 // by the Free Software Foundation, with special exception defined in the file
10 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
11 // distribution for complete text of the license and disclaimer of any warranty.
13 // Alternatively, this file may be used under the terms of Open CASCADE
14 // commercial license or contractual agreement.
16 varying vec3 View; //!< Direction to the viewer
17 varying vec3 Normal; //!< Vertex normal in view space
18 varying vec4 Position; //!< Vertex position in view space
19 varying vec4 PositionWorld; //!< Vertex position in world space
21 //! Computes the normal in view space
22 vec3 TransformNormal (in vec3 theNormal)
24 vec4 aResult = occWorldViewMatrixInverseTranspose
25 * occModelWorldMatrixInverseTranspose
26 * vec4 (theNormal, 0.0);
27 return normalize (aResult.xyz);
30 //! Entry point to the Vertex Shader
33 PositionWorld = occModelWorldMatrix * occVertex;
34 Position = occWorldViewMatrix * PositionWorld;
35 Normal = TransformNormal (occNormal);
37 // Note: The specified view vector is absolutely correct only for the orthogonal projection.
38 // For perspective projection it will be approximate, but it is in good agreement with the OpenGL calculations.
39 View = vec3 (0.0, 0.0, 1.0);
41 // Do fixed functionality vertex transform
42 gl_Position = occProjectionMatrix * occWorldViewMatrix * occModelWorldMatrix * occVertex;