Application: gvSIG desktop

/* gvSIG. Desktop Geographic Information System.

 *

 * Copyright ? 2007-${year} gvSIG Association

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.fmap.geom.impl;

import java.awt.geom.AffineTransform;

import java.awt.geom.PathIterator;

import org.gvsig.fmap.geom.primitive.GeneralPathX;

import org.gvsig.fmap.geom.primitive.Point;

/**

 * AWT {@link PathIterator} to draw a {@link GeneralPathX} object.

 * 

 * While iterating the {@link GeneralPathX) each point coordinates are 

 * converted to int. If a segment is a PathIterator#SEG_LINETO and the 

 * integer coordinates are the same as the previous point ones, the point 

 * is ignored and the next one is looked for.

 * 

 * @author gvSIG Team

 */

public class DrawGeneralPathXIterator implements PathIterator {

    protected int typeIdx = -1;

    protected int pointIdx = 0;

    protected GeneralPathX path;

    protected AffineTransform affine;

    /**

     * This array keeps the "real" coordinates (double precision) which

     * will afterwards be rounded to int. It is final and created with

     * its maximum possible size. This does not have a performance cost

     * because only relevant indices are read/written (also when applying

     * an affine transformation)

     */

    private final double[] currentPointRealCoords = new double[] { 0, 0, 0, 0, 0, 0 };

    /**

     * This array keeps the rounded (int) coordinates.

     * It is final and created with

     * its maximum possible size. This does not have a performance cost

     * because only relevant indices are read/written.

     */

    private final int[] currentPointCoords = new int[] { 0, 0, 0, 0, 0, 0 };

    private final int[] previousPointCoords = new int[] { 0, 0 };

    private int currentType = -1;

    private int previousType = -1;

    private static final int curvesize[] = { 1, 1, 2, 3, 0 };

    private final int numTypes;

    private final int numPoints;

    /**

     * Constructs an iterator given a GeneralPathX.

     * 

     * @see GeneralPathX#getPathIterator

     */

    public DrawGeneralPathXIterator(GeneralPathX path) {

        this(path, null);

    }

    /**

     * Constructs an iterator given a GeneralPathX and an optional

     * AffineTransform.

     * 

     * @see GeneralPathX#getPathIterator

     */

    public DrawGeneralPathXIterator(GeneralPathX path, AffineTransform at) {

        this.path = path;

        this.affine = at;

        // Go to the first segment

        this.pointIdx = 0;

        this.numPoints = path.getNumCoords();

        this.typeIdx = 0;

        this.numTypes = path.getNumTypes();

        if (numTypes > 0) {

            currentType = path.getTypeAt(typeIdx);

            readCurrentSegmentCoordsAsInt();

            previousType = currentType;

            previousPointCoords[0] = currentPointCoords[0];

            previousPointCoords[1] = currentPointCoords[1];

        }

    }

    public int getWindingRule() {

        return path.getWindingRule();

    }

    public boolean isDone() {

        return typeIdx >= numTypes;

    }

    public void next() {

        do {

            typeIdx++;

            pointIdx += curvesize[currentType];

            if (typeIdx < numTypes) {

                currentType = path.getTypeAt(typeIdx);

                if (SEG_CLOSE != currentType) {

                    readCurrentSegmentCoordsAsInt();

                }

            } else {

                // We have reached past the last segment

                return;

            }

        } while (isSameSegment());

        previousType = currentType;

        previousPointCoords[0] = currentPointCoords[0];

        previousPointCoords[1] = currentPointCoords[1];

    }

    private final boolean isSameSegment() {

        return SEG_LINETO == currentType

            && (SEG_LINETO == previousType || SEG_MOVETO == previousType)

            && currentPointCoords[0] == previousPointCoords[0]

            && currentPointCoords[1] == previousPointCoords[1];

    }

    private void readCurrentSegmentCoordsAsInt() {

        int currentSize = curvesize[currentType];

        for (int i = 0; i < currentSize; i++) {

            readPoint(i * 2, pointIdx + i);

        }

        if (affine != null && !affine.isIdentity()) {

            affine.transform(currentPointRealCoords, 0, currentPointRealCoords,

                0, currentSize);

        }

        for (int i = 0; i < currentSize * 2; i++) {

            currentPointCoords[i] = (int) currentPointRealCoords[i];

        }

    }

    private void readPoint(int currentCoordsPos, int currentPointIdx) {

        Point point = path.getPointAt(currentPointIdx);

        currentPointRealCoords[currentCoordsPos] = point.getX();

        currentPointRealCoords[currentCoordsPos + 1] = point.getY();

    }

    public int currentSegment(float[] coords) {

        if (SEG_CLOSE != currentType) {

            int size = curvesize[currentType] * 2;

            for (int i = 0; i < size; i++) {

                coords[i] = currentPointCoords[i];

            }

        }

        return currentType;

    }

    public int currentSegment(double[] coords) {

        int size = curvesize[currentType] * 2;

        for (int i = 0; i < size; i++) {

            coords[i] = currentPointCoords[i];

        }

        return currentType;

    }

}