FloatBlitter.java

package ij.process;
import ij.Prefs;
import java.awt.*;

public class FloatBlitter implements Blitter {

    public static float divideByZeroValue;
    
    private FloatProcessor ip;
    private int width, height;
    private float[] pixels;
    
    static {
        divideByZeroValue = (float)Prefs.getDouble(Prefs.DIV_BY_ZERO_VALUE, Float.POSITIVE_INFINITY);
        if (divideByZeroValue==Float.MAX_VALUE)
            divideByZeroValue = Float.POSITIVE_INFINITY;
    }
    
    public FloatBlitter(FloatProcessor ip) {
        this.ip = ip;
        width = ip.getWidth();
        height = ip.getHeight();
        pixels = (float[])ip.getPixels();
    }

    public void setTransparentColor(Color c) {
    }

    public void copyBits(ImageProcessor ip, int xloc, int yloc, int mode) {
        Rectangle r1, r2;
        int srcIndex, dstIndex;
        int xSrcBase, ySrcBase;
        float[] srcPixels;
        
        if (!(ip instanceof FloatProcessor))
            ip = ip.convertToFloat();
        int srcWidth = ip.getWidth();
        int srcHeight = ip.getHeight();
        r1 = new Rectangle(srcWidth, srcHeight);
        r1.setLocation(xloc, yloc);
        r2 = new Rectangle(width, height);
        if (!r1.intersects(r2))
            return;
        srcPixels = (float [])ip.getPixels();
        r1 = r1.intersection(r2);
        xSrcBase = (xloc<0)?-xloc:0;
        ySrcBase = (yloc<0)?-yloc:0;
        boolean useDBZValue = !Float.isInfinite(divideByZeroValue);
        float src, dst;
        for (int y=r1.y; y<(r1.y+r1.height); y++) {
            srcIndex = (y-yloc)*srcWidth + (r1.x-xloc);
            dstIndex = y * width + r1.x;
            switch (mode) {
                case COPY: case COPY_INVERTED:
                    for (int i=r1.width; --i>=0;)
                        pixels[dstIndex++] = srcPixels[srcIndex++];
                    break;
                case ADD:
                    for (int i=r1.width; --i>=0; srcIndex++, dstIndex++)
                        pixels[dstIndex] = srcPixels[srcIndex]+pixels[dstIndex];
                    break;
                case AVERAGE:
                    for (int i=r1.width; --i>=0;) {
                        dst =(srcPixels[srcIndex++]+pixels[dstIndex])/2;
                        pixels[dstIndex++] = dst;
                    }
                    break;
                case DIFFERENCE:
                    for (int i=r1.width; --i>=0; srcIndex++, dstIndex++) {
                        dst = pixels[dstIndex]-srcPixels[srcIndex];
                        pixels[dstIndex] = dst<0?-dst:dst;
                    }
                    break;
                case SUBTRACT:
                    for (int i=r1.width; --i>=0; srcIndex++, dstIndex++)
                        pixels[dstIndex] = pixels[dstIndex]-srcPixels[srcIndex];
                    break;
                case MULTIPLY:
                    for (int i=r1.width; --i>=0; srcIndex++, dstIndex++)
                        pixels[dstIndex] = srcPixels[srcIndex]*pixels[dstIndex];
                    break;
                case DIVIDE:
                    for (int i=r1.width; --i>=0; srcIndex++, dstIndex++) {
                            src = srcPixels[srcIndex];
                            if (useDBZValue && src==0.0)
                                pixels[dstIndex] = divideByZeroValue;
                            else
                                pixels[dstIndex] = pixels[dstIndex]/src;
                        }
                    break;
                case AND: case OR: case XOR:
                    break;
                case MIN:
                    for (int i=r1.width; --i>=0;) {
                        src = srcPixels[srcIndex++];
                        dst = pixels[dstIndex];
                        if (src<dst) dst = src;
                        pixels[dstIndex++] = dst;
                    }
                    break;
                case MAX:
                    for (int i=r1.width; --i>=0;) {
                        src = srcPixels[srcIndex++];
                        dst = pixels[dstIndex];
                        if (src>dst) dst = src;
                        pixels[dstIndex++] = dst;
                    }
                    break;
            }
            if (y%20==0)
                ip.showProgress((double)(y-r1.y)/r1.height);
        }
        ip.hideProgress();
    }
}