Flywheel/src/main/java/com/jozufozu/flywheel/util/RenderUtil.java

package com.jozufozu.flywheel.util;

import java.util.function.Supplier;

import com.mojang.blaze3d.matrix.MatrixStack;

import net.minecraft.util.Direction;
import net.minecraft.util.math.vector.Matrix3f;
import net.minecraft.util.math.vector.Matrix4f;
import net.minecraft.util.math.vector.Vector3f;

public class RenderUtil {
	public static int nextPowerOf2(int a) {
		int h = Integer.highestOneBit(a);
		return (h == a) ? h : (h << 1);
	}

	public static boolean isPowerOf2(int n) {
		int b = n & (n - 1);
		return b == 0 && n != 0;
	}

	public static double lengthSqr(double x, double y, double z) {
		return x * x + y * y + z * z;
	}

	public static double length(double x, double y, double z) {
		return Math.sqrt(lengthSqr(x, y, z));
	}

	public static float[] writeMatrixStack(MatrixStack stack) {
		return writeMatrixStack(stack.peek()
										.getModel(), stack.peek()
										.getNormal());
	}

	// GPUs want matrices in column major order.
	public static float[] writeMatrixStack(Matrix4f model, Matrix3f normal) {
		return new float[]{model.a00, model.a10, model.a20, model.a30, model.a01, model.a11, model.a21, model.a31, model.a02, model.a12, model.a22, model.a32, model.a03, model.a13, model.a23, model.a33, normal.a00, normal.a10, normal.a20, normal.a01, normal.a11, normal.a21, normal.a02, normal.a12, normal.a22,};
	}

	public static float[] writeMatrix(Matrix4f model) {
		return new float[]{model.a00, model.a10, model.a20, model.a30, model.a01, model.a11, model.a21, model.a31, model.a02, model.a12, model.a22, model.a32, model.a03, model.a13, model.a23, model.a33,};
	}

	public static Supplier<MatrixStack> rotateToFace(Direction facing) {
		return () -> {
			MatrixStack stack = new MatrixStack();
			//			MatrixStacker.of(stack)
			//					.centre()
			//					.rotateY(AngleHelper.horizontalAngle(facing))
			//					.rotateX(AngleHelper.verticalAngle(facing))
			//					.unCentre();
			stack.peek()
					.getModel()
					.setTranslation(0.5f, 0.5f, 0.5f);
			stack.multiply(Vector3f.POSITIVE_Y.getDegreesQuaternion(AngleHelper.horizontalAngle(facing)));
			stack.multiply(Vector3f.POSITIVE_X.getDegreesQuaternion(AngleHelper.verticalAngle(facing)));
			stack.translate(-0.5f, -0.5f, -0.5f);
			return stack;
		};
	}
}