WhitePoint.kt
/*
* Copyright 2019 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.compose.ui.graphics.colorspace
import androidx.compose.ui.util.annotation.Size
/**
* Class for constructing white points used in [RGB][Rgb] color space. The value is
* stored in the CIE xyY color space. The Y component of the white point is assumed
* to be 1.
*
* @see Illuminant
*/
data class WhitePoint(val x: Float, val y: Float) {
/**
* Illuminant for CIE XYZ white point
*/
constructor(x: Float, y: Float, z: Float) : this(x, y, z, x + y + z)
@Suppress("UNUSED_PARAMETER")
private constructor(x: Float, y: Float, z: Float, sum: Float) : this(x / sum, y / sum)
/**
* Converts a value from CIE xyY to CIE XYZ. Y is assumed to be 1 so the
* input xyY array only contains the x and y components.
*
* @return A new float array of length 3 containing XYZ values
*/
@Size(3)
internal fun toXyz(): FloatArray {
return floatArrayOf(x / y, 1.0f, (1f - x - y) / y)
}
}