SvgTransform.java

/****************************************************************************
 * Copyright (c) 2008, 2009 Jeremy Dowdall
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Jeremy Dowdall <jeremyd@aspencloud.com> - initial API and implementation
 *****************************************************************************/
package org.eclipse.nebula.cwt.svg;

import static java.lang.Math.cos;
import static java.lang.Math.sin;
import static java.lang.Math.toRadians;

class SvgTransform {

	enum Type {
		Matrix, Translate, Scale, Rotate, SkewX, SkewY
	}

	SvgTransform next;
	float[] data;

	SvgTransform() {
		data = new float[] { 1, 0, 0, 1, 0, 0 };
	}

	float[] apply(float x, float y) {
		float[] v = new float[2];
		v[0] = data[0] * x + data[2] * y + data[4];
		v[1] = data[1] * x + data[3] * y + data[5];
		return v;
	}

	boolean isIdentity() {
		return data.length == 6 && data[0] == 1 && data[1] == 0 && data[2] == 0
				&& data[3] == 1 && data[4] == 0 && data[5] == 0;
	}

	void scale(float s) {
		scale(s, s);
	}

	void scale(float x, float y) {
		data[0] = x;
		data[3] = y;
	}

	
	void setData(Type type, String[] sa) {
		data = new float[] { 1, 0, 0, 1, 0, 0 };
		switch (type) {
		case Matrix: {
			for (int i = 0; i < sa.length; i++) {
				data[i] = Float.parseFloat(sa[i]);
			}
			break;
		}
		case Translate: {
			data[4] = Float.parseFloat(sa[0]);
			if (sa.length > 1) {
				data[5] = Float.parseFloat(sa[1]);
			}
			break;
		}
		case Scale: {
			if (sa.length == 1) {
				scale(Float.parseFloat(sa[0]));
			} else if (sa.length == 2) {
				scale(Float.parseFloat(sa[0]), Float.parseFloat(sa[1]));
			}
			break;
		}
		case Rotate: {
			float angle = Float.parseFloat(sa[0]);
			data[0] = (float) cos(toRadians(angle));
			data[1] = (float) sin(toRadians(angle));
			data[2] = (float) -sin(toRadians(angle));
			data[3] = (float) cos(toRadians(angle));
			if (sa.length > 1) {
				data[4] = Float.parseFloat(sa[1]);
				data[5] = Float.parseFloat(sa[2]);
			}
			break;
		}
		case SkewX: {
			data[2] = Float.parseFloat(sa[0]);
			break;
		}
		case SkewY: {
			data[1] = Float.parseFloat(sa[0]);
			break;
		}
		}
	}

	void skew(float x, float y) {
		data[2] = x;
		data[1] = y;
	}
	
	void translate(float x, float y) {
		data[4] = x;
		data[5] = y;
	}
}