FreeMat: vtkGLSLShader

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vtkGLSLShader

Section: Visualization Toolkit Rendering Classes

# Usage

vtkGLSLShader is a concrete class that creates and compiles hardware shaders written in the OpenGL Shadering Language (GLSL, OpenGL2.0). While step linking a vertex and a fragment shader is performed by vtkGLSLShaderProgram, all shader parameters are initialized in this class.

.Section vtkOpenGLExtensionManager All OpenGL calls are made through vtkOpenGLExtensionManager.

.Section Supported Basic Shader Types:

Scalar Types uniform float uniform int uniform int – boolean scalar not yet tested

Vector Types: uniform vec{2|3|4} uniform ivec{2|3|4} uniform bvec{2|3|4} – boolean vector not yet tested

Matrix Types: uniform mat{2|3|4}

Texture Samplers: sample1D – Not yet implemented in this cless. sample2D – Not yet implemented in this class. sample3D – Not yet implemented in this class. sampler1DShadow – Not yet implemented in this class. sampler1DShadow – Not yet implemented in this class.

User-Defined structures: uniform struct NOTE: these must be defined and declared outside of the 'main' shader function.

.SECTION Thanks Shader support in VTK includes key contributions by Gary Templet at Sandia National Labs.

To create an instance of class vtkGLSLShader, simply invoke its constructor as follows

      obj = vtkGLSLShader

# Methods

The class vtkGLSLShader has several methods that can be used. They are listed below. Note that the documentation is translated automatically from the VTK sources, and may not be completely intelligible. When in doubt, consult the VTK website. In the methods listed below, `obj` is an instance of the vtkGLSLShader class.

- `string = obj.GetClassName ()`
- `int = obj.IsA (string name)`
- `vtkGLSLShader = obj.NewInstance ()`
- `vtkGLSLShader = obj.SafeDownCast (vtkObject o)`
- `int = obj.Compile ()` - Called to compile the shader code. The subclasses must only compile the code in this method. Returns if the compile was successful. Subclasses should compile the code only if it was not already compiled.
- `int = obj.GetHandle ()` - The Shader needs the id of the ShaderProgram to obtain uniform variable locations. This is set by vtkGLSLShaderProgram.
- `obj.SetProgram (int )` - The Shader needs the id of the ShaderProgram to obtain uniform variable locations. This is set by vtkGLSLShaderProgram.
- `int = obj.GetProgram ()` - The Shader needs the id of the ShaderProgram to obtain uniform variable locations. This is set by vtkGLSLShaderProgram.
- `obj.ReleaseGraphicsResources (vtkWindow )` - Release any graphics resources that are being consumed by this actor. The parameter window could be used to determine which graphic resources to release.