TextureCube
Retrieves texels from a texture
Declaration
vec4 textureCube(samplerCube sampler, vec3 coord)
vec4 textureCube(samplerCube sampler, vec3 coord, float bias)
Parameters
sampler
specifies the sampler to which the texture from which texels will be retrieved is bound.
coord
specifies the texture coordinates at which texture will be sampled.
bias
specifies an optional bias to be applied during level-of-detail computation.
Description
The textureCube function returns a texel, i.e. the (color) value of the texture for the given coordinates. The function has one input parameter of the type samplerCube and one input parameter of the type vec3 : sampler, the uniform the texture is bound to, and coord, the 3-dimensional coordinates of the texel to look up.
There is an optional third input parameter of the type float: bias. After calculating the appropriate level of detail for a texture with mipmaps the bias is added before the actual texture lookup operation is executed.
Side note: On iOS devices texture lookup functionality is only available in the fragment shader.