WarpPI/desktop/src/main/java/it/cavallium/warppi/desktop/DesktopImageReader.java

package it.cavallium.warppi.desktop;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;

import javax.imageio.ImageIO;

import ar.com.hjg.pngj.ImageLineInt;
import it.cavallium.warppi.WarpPI;
import it.cavallium.warppi.Platform.ImageUtils.ImageReader;

public class DesktopImageReader implements ImageReader {

	private ar.com.hjg.pngj.PngReader r;

	public DesktopImageReader(final InputStream resourceStream) throws IOException {
		r = new ar.com.hjg.pngj.PngReader(resourceStream);
		// Try to read image converting it to png
		if (r == null) {
			final File f = File.createTempFile("picalculator-png", ".png");
			f.deleteOnExit();
			final BufferedImage img = ImageIO.read(resourceStream);
			ImageIO.write(img, "PNG", f);
			r = new ar.com.hjg.pngj.PngReader(f);
		}
	}

	@Override
	public int[] getImageMatrix() {
		final int width = r.imgInfo.cols;
		final int height = r.imgInfo.rows;
		final int channels = r.imgInfo.channels;
		final int[] pixels = new int[width * height];
		int pi = 0;
		ImageLineInt lint;
		while (r.hasMoreRows()) {
			lint = (ImageLineInt) r.readRow();
			final int[] scanLine = lint.getScanline();

			for (int i = 0; i < width; i++) {
				final int offset = i * channels;

				// Adjust the following code depending on your source image.
				// I need the to set the alpha channel to 0xFF000000 since my destination image
				// is TRANSLUCENT : BufferedImage bi = CONFIG.createCompatibleImage( width, height, Transparency.TRANSLUCENT );
				// my source was 3 channels RGB without transparency
				int nextPixel;
				if (channels == 4)
					nextPixel = scanLine[offset] << 16 | scanLine[offset + 1] << 8 | scanLine[offset + 2] | scanLine[offset + 3] << 24;
				else if (channels == 3)
					nextPixel = scanLine[offset] << 16 | scanLine[offset + 1] << 8 | scanLine[offset + 2] | 0xFF << 24;
				else if (channels == 2)
					nextPixel = scanLine[offset] << 16 | scanLine[offset + 1] << 8 | 0xFF | 0xFF << 24;
				else
					nextPixel = scanLine[offset] << 16 | scanLine[offset] << 8 | scanLine[offset] | 0xFF << 24;

				// I'm placing the pixels on a memory mapped file
				pixels[pi] = nextPixel;
				pi++;
			}

		}

		return pixels;
	}

	@Override
	public int[] getSize() {
		return new int[] { r.imgInfo.cols, r.imgInfo.rows };
	}

}