# tests the support to pass generic vertex attributes to be used in Cg shaders.

set xmlMaterial {<?xml version="1.0" encoding="UTF-8"?>
<Material name="GenericAttributes1">
  <Shader 
    scope="Vertex" 
    name="VertexShader" 
    location="Inline"
    language="GLSL"
    entry="main">
    attribute vec3 genAttrVector;
    varying vec4 color;

    void main(void)
    {
      gl_Position = gl_ModelViewProjectionMatrix *gl_Vertex;
      color = vec4(normalize(genAttrVector), 1.0);
    }
  </Shader>

  <Shader scope="Fragment" name="FragmentShader" location="Inline"
    language="GLSL" entry="main">
    varying vec4 color;
    void main(void)
    {
      gl_FragColor = color;
    }
  </Shader>
</Material>
}

package require vtk
package require vtkinteraction

vtkRenderWindow renWin
vtkRenderWindowInteractor iren
iren SetRenderWindow renWin

vtkRenderer renderer
renWin AddRenderer renderer

vtkSphereSource src1
src1 SetRadius 5
src1 SetPhiResolution 20
src1 SetThetaResolution 20

vtkBrownianPoints randomVectors
randomVectors SetMinimumSpeed 0
randomVectors SetMaximumSpeed 1
randomVectors SetInputConnection [src1 GetOutputPort]

vtkPolyDataMapper mapper
mapper SetInputConnection [randomVectors GetOutputPort]

vtkActor actor
actor SetMapper mapper
# Load the material. Here, we are loading a material
# defined in the Vtk Library. One can also specify
# a filename to a material description xml.
[actor GetProperty] LoadMaterialFromString $xmlMaterial

# Set red color to show if shading fails.
[actor GetProperty] SetColor 1.0 0 0

# Turn shading on. Otherwise, shaders are not used.
[actor GetProperty] ShadingOn

# Map PointData.BrownianVectors (all 3 components) to genAttrVector
mapper MapDataArrayToVertexAttribute "genAttrVector" "BrownianVectors" 0 -1

renderer AddActor actor
renderer SetBackground 0.5 0.5 0.5
renWin Render

[renderer GetActiveCamera] Azimuth -50
[renderer GetActiveCamera] Roll 70
renWin Render
wm withdraw .