Method updateScaleOffset

src/effects/LUT3DEffect.js:177–221

* Updates the scale and offset for the LUT sampling coordinates. * * @private

()

	 */

	updateScaleOffset() {

		const lut = this.lut;

		if(lut !== null) {

			const size = Math.min(lut.image.width, lut.image.height);
			const scale = this.uniforms.get("scale").value;
			const offset = this.uniforms.get("offset").value;

			if(this.tetrahedralInterpolation && lut instanceof Data3DTexture) {

				if(this.defines.has("CUSTOM_INPUT_DOMAIN")) {

					const domainScale = lut.domainMax.clone().sub(lut.domainMin);
					scale.setScalar(size - 1).divide(domainScale);
					offset.copy(lut.domainMin).negate().multiply(scale);

				} else {

					scale.setScalar(size - 1);
					offset.setScalar(0);

				}

			} else {

				if(this.defines.has("CUSTOM_INPUT_DOMAIN")) {

					const domainScale = lut.domainMax.clone().sub(lut.domainMin).multiplyScalar(size);
					scale.setScalar(size - 1).divide(domainScale);
					offset.copy(lut.domainMin).negate().multiply(scale).addScalar(1.0 / (2.0 * size));

				} else {

					scale.setScalar((size - 1) / size);
					offset.setScalar(1.0 / (2.0 * size));

				}

			}

		}

	}

	/**
	 * Configures parameters for tetrahedral interpolation.