EG/Cesium-1.132/packages/engine/Source/Shaders/Builtin/Functions/shadowDepthCompare.glsl

float czm_sampleShadowMap(highp samplerCube shadowMap, vec3 d)
{
    return czm_unpackDepth(czm_textureCube(shadowMap, d));
}

float czm_sampleShadowMap(highp sampler2D shadowMap, vec2 uv)
{
#ifdef USE_SHADOW_DEPTH_TEXTURE
    return texture(shadowMap, uv).r;
#else
    return czm_unpackDepth(texture(shadowMap, uv));
#endif
}

float czm_shadowDepthCompare(samplerCube shadowMap, vec3 uv, float depth)
{
    return step(depth, czm_sampleShadowMap(shadowMap, uv));
}

float czm_shadowDepthCompare(sampler2D shadowMap, vec2 uv, float depth)
{
    return step(depth, czm_sampleShadowMap(shadowMap, uv));
}