OpenGL
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====Texture Map Readers==== | ====Texture Map Readers==== | ||
sampler1D for 1D texture map, sampler2D for 2D texture map, higher dimensions are apparently supported. | sampler1D for 1D texture map, sampler2D for 2D texture map, higher dimensions are apparently supported. | ||
| + | Samplers cannot be modified by the shader! | ||
| + | Samplers are read using the texture lookup functions texture1D, texture2D, etc. | ||
Revision as of 06:30, 19 November 2007
Contents |
OpenGL Shading Language Reference
Variable Qualifiers
attribute
frequently changing values from application to vertex shader
uniform
infrequently changing values from application to any shader (vertex or fragment)
varying
interpolated variables from vertex shader to fragment shader
Built-In Variables
If it begins with "gl_" it is a built-in variable. Example is gl_FragColor.
Variable Types
Scalars (regular C-styled variables)
float, int, bool are all supported. Integers are fairly limited and don't behave like they do in C. See orange book, page 66.
Vectors
vec2, vec3, or vec4 (all floating point)
Matrices
mat2, mat3, mat4 (2x2, 3x3, 4x4 matrix respectively)
Texture Map Readers
sampler1D for 1D texture map, sampler2D for 2D texture map, higher dimensions are apparently supported. Samplers cannot be modified by the shader! Samplers are read using the texture lookup functions texture1D, texture2D, etc.
