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casic-smartcity-well-front / static / Cesium / Shaders / Builtin / Functions / writeNonPerspective.glsl
[wangxitong] on 8 Jul 2021 1 KB mars3d总览
/**
 * Transforms a value for non-perspective interpolation by multiplying
 * it by w, the value used in the perspective divide. This function is
 * intended to be called in a vertex shader to compute the value of a
 * `varying` that should not be subject to perspective interpolation.
 * For example, screen-space texture coordinates. The fragment shader
 * must call {@link czm_readNonPerspective} to retrieve the final
 * non-perspective value.
 *
 * @name czm_writeNonPerspective
 * @glslFunction
 *
 * @param {float|vec2|vec3|vec4} value The value to be interpolated without accounting for perspective.
 * @param {float} w The perspective divide value. Usually this is the computed `gl_Position.w`.
 * @returns {float|vec2|vec3|vec4} The transformed value, intended to be stored in a `varying` and read in the
 *          fragment shader with {@link czm_readNonPerspective}.
 */
float czm_writeNonPerspective(float value, float w) {
    return value * w;
}

vec2 czm_writeNonPerspective(vec2 value, float w) {
    return value * w;
}

vec3 czm_writeNonPerspective(vec3 value, float w) {
    return value * w;
}

vec4 czm_writeNonPerspective(vec4 value, float w) {
    return value * w;
}