32 lines
1.1 KiB
GLSL
32 lines
1.1 KiB
GLSL
/**
|
|
* Reads a value previously transformed with {@link czm_writeNonPerspective}
|
|
* by dividing it by `w`, the value used in the perspective divide.
|
|
* This function is intended to be called in a fragment shader to access a
|
|
* `varying` that should not be subject to perspective interpolation.
|
|
* For example, screen-space texture coordinates. The value should have been
|
|
* previously written in the vertex shader with a call to
|
|
* {@link czm_writeNonPerspective}.
|
|
*
|
|
* @name czm_readNonPerspective
|
|
* @glslFunction
|
|
*
|
|
* @param {float|vec2|vec3|vec4} value The non-perspective value to be read.
|
|
* @param {float} oneOverW One over the perspective divide value, `w`. Usually this is simply `gl_FragCoord.w`.
|
|
* @returns {float|vec2|vec3|vec4} The usable value.
|
|
*/
|
|
float czm_readNonPerspective(float value, float oneOverW) {
|
|
return value * oneOverW;
|
|
}
|
|
|
|
vec2 czm_readNonPerspective(vec2 value, float oneOverW) {
|
|
return value * oneOverW;
|
|
}
|
|
|
|
vec3 czm_readNonPerspective(vec3 value, float oneOverW) {
|
|
return value * oneOverW;
|
|
}
|
|
|
|
vec4 czm_readNonPerspective(vec4 value, float oneOverW) {
|
|
return value * oneOverW;
|
|
}
|