public abstract class Shader
extends NodeComponent

The Shader object is the abstract base class for programmable shader code. Currently, only text-based source code shaders are supported, so the only subclass of Shader is SourceCodeShader. We leave open the possibility for binary (object code) shaders in the future.

Each instance of a Shader object allows an application to specify the source code used in programming the Graphics Pipeline Unit (GPU) of the graphics accelerator. A Shader object is constructed with modes that specify the shading language and the shader type.

The shading language specifies the language and runtime environment used to program the GPU. The currently defined shading languages are GLSL (also known as the OpenGL 2.0 shading language) and Cg. Note that not all shading languages are supported on all platforms. It is up to the application or utility to query whether a particular shading language is supported before using it. The value of the shadingLanguage mode is one of: SHADING_LANGUAGE_GLSL or SHADING_LANGUAGE_CG.

The shader type specifies whether the shader is a vertex shader or a fragment shader. A vertex shader replaces the fixed-function graphics pipeline for vertex operations (transformation and lighting). A fragment shader replaces the fixed-function graphics pipeline for fragment shading operations (texture mapping, texture application, coloring, shading, and so forth). The value of the shaderType mode is one of: SHADER_TYPE_VERTEX or SHADER_TYPE_FRAGMENT.

Both the shading language and shader type are immutable modes of the Shader object.

NOTE: Applications should not extend this class.