package net.minecraft.client.renderer;

import com.mojang.blaze3d.ProjectionType;
import com.mojang.blaze3d.systems.RenderSystem;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import org.joml.Matrix4f;

@Environment(EnvType.CLIENT)
public class Projection {
	private ProjectionType projectionType = ProjectionType.PERSPECTIVE;
	private float zNear;
	private float zFar;
	private float perspectiveFov;
	private float width;
	private float height;
	private boolean orthoInvertY;
	private boolean isMatrixDirty;
	private final Matrix4f matrix = new Matrix4f();
	private long matrixVersion = -1L;

	public void setupPerspective(final float zNear, final float zFar, final float fov, final float width, final float height) {
		if (this.projectionType != ProjectionType.PERSPECTIVE
			|| this.zNear != zNear
			|| this.zFar != zFar
			|| this.perspectiveFov != fov
			|| this.width != width
			|| this.height != height) {
			this.isMatrixDirty = true;
			this.projectionType = ProjectionType.PERSPECTIVE;
			this.zNear = zNear;
			this.zFar = zFar;
			this.perspectiveFov = fov;
			this.width = width;
			this.height = height;
		}
	}

	public void setupOrtho(final float zNear, final float zFar, final float width, final float height, final boolean invertY) {
		if (this.projectionType != ProjectionType.ORTHOGRAPHIC
			|| this.zNear != zNear
			|| this.zFar != zFar
			|| this.width != width
			|| this.height != height
			|| this.orthoInvertY != invertY) {
			this.isMatrixDirty = true;
			this.projectionType = ProjectionType.ORTHOGRAPHIC;
			this.zNear = zNear;
			this.zFar = zFar;
			this.perspectiveFov = 0.0F;
			this.width = width;
			this.height = height;
			this.orthoInvertY = invertY;
		}
	}

	public void setSize(final float width, final float height) {
		this.isMatrixDirty = true;
		this.width = width;
		this.height = height;
	}

	public Matrix4f getMatrix(final Matrix4f dest) {
		if (!this.isMatrixDirty) {
			return dest.set(this.matrix);
		} else {
			this.isMatrixDirty = false;
			this.matrixVersion++;
			float near = this.zFar;
			float far = this.zNear;
			boolean zZeroToOne = RenderSystem.getDevice().getDeviceInfo().isZZeroToOne();
			return this.projectionType == ProjectionType.PERSPECTIVE
				? dest.set(this.matrix.setPerspective(this.perspectiveFov * (float) (Math.PI / 180.0), this.width / this.height, near, far, zZeroToOne))
				: dest.set(this.matrix.setOrtho(0.0F, this.width, this.orthoInvertY ? this.height : 0.0F, this.orthoInvertY ? 0.0F : this.height, near, far, zZeroToOne));
		}
	}

	public long getMatrixVersion() {
		return this.isMatrixDirty ? this.matrixVersion + 1L : this.matrixVersion;
	}

	public float zNear() {
		return this.zNear;
	}

	public float zFar() {
		return this.zFar;
	}

	public float width() {
		return this.width;
	}

	public float height() {
		return this.height;
	}

	public float fov() {
		return this.perspectiveFov;
	}

	public boolean invertY() {
		return this.orthoInvertY;
	}
}