BitmapRGB.java

/*
 * Copyright (c) 2009, Harald Kuhr
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * * Neither the name of the copyright holder nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.twelvemonkeys.imageio.plugins.bmp;

import java.awt.*;
import java.awt.image.*;

/**
 * Describes an RGB/true color bitmap structure (16, 24 and 32 bits per pixel).
 *
 * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
 * @version $Id: BitmapRGB.java,v 1.0 25.feb.2006 00:29:44 haku Exp$
 */
final class BitmapRGB extends BitmapDescriptor {

    public BitmapRGB(final DirectoryEntry entry, final DIBHeader header) {
        super(entry, header);
    }

    @Override
    public BufferedImage getImage() {
        // Test is mask != null rather than hasMask(), as 32 bit (w/alpha)
        // might still have bitmask, but we don't read or use it.
        if (mask != null) {
            image = createMaskedImage();
            mask = null;
        }

        return image;
    }

    private BufferedImage createMaskedImage() {
        BufferedImage masked = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_4BYTE_ABGR);

        Graphics2D graphics = masked.createGraphics();
        try {
            graphics.drawImage(image, 0, 0, null);
        }
        finally {
            graphics.dispose();
        }

        WritableRaster alphaRaster = masked.getAlphaRaster();

        byte[] trans = {0x00};
        for (int y = 0; y < getHeight(); y++) {
            for (int x = 0; x < getWidth(); x++) {
                if (mask.isTransparent(x, y)) {
                    alphaRaster.setDataElements(x, y, trans);
                }
            }
        }

        return masked;
    }
}