Java Graphics2D颜色问题

Question

I've searched for some time already but haven't been able to find an answer to my question.

First I'll show two comparison pictures:

Method 1: method 1 http://img713.imageshack.us/img713/3558/tcg6.jpg

Method 2: method 2 http://img716.imageshack.us/img716/2755/tcg7.jpg

Method 1 has never given me any trouble, but I recently found out that it simply takes too long, and method 2 fixed that.

Code for method 1:

private void drawDefaultOrientation() {
    for (int x = 0; x < width; x++) {
        for (int y = 0; y < height; y++) {
            int dx = Math.min(x, width - 1 - x);
            int dy = Math.min(y, height - 1 - y);
            if (dx < borderSize || dy < borderSize) {
                inBorder(dx, dy);
            }
            else {
                outBorder(dx, dy);
            }
            bufferedImage.setRGB(xOffset + x, yOffset + y, color.getRGB());
        }
    }
}    

Code for method 2:

private void drawDefaultOrientation() {
    DataBufferInt buffer = (DataBufferInt)bufferedImage.getRaster().getDataBuffer();
    int[] pixelArray = buffer.getData();
    for (int x = 0; x < width; x++) {
        for (int y = 0; y < height; y++) {
            int dx = Math.min(x, width - 1 - x);
            int dy = Math.min(y, height - 1 - y);
            if (dx < borderSize || dy < borderSize) {
                inBorder(dx, dy);
            }
            else {
                outBorder(dx, dy);
            }
            pixelArray[(xOffset + x) + ((yOffset + y) * bufferedImage.getWidth())] = color.getRGB();
        }
    }
}  

Please also note that the inBorder(dx, dy); and outBorder(dx, dy); set the color variable to a color with a Red, Green, Blue and Alpha value.

Callee code:

    new CustomRectangle(bufferedImage, 220, 90, 15, 245, 5, defaultOrientation) {
        @Override
        public void inBorder(final int dx, final int dy) {
            setColor(new Color(red, green, blue, 255 - Math.min(dx, dy)));
        }

        @Override
        public void outBorder(final int dx, final int dy) {
            setColor(new Color(red, green, blue, 128 - Math.min(dx, dy)));
        }
    }.draw();  

I am really lost as to why the color difference is here.

I really hope anyone out there can help me. First I thought it had to do with the Alpha values, but as seen the alpha variaton still exists with method 2.

Regards.

Answer 1

I'd suggest, for "simple" thing (including boxes, shapes, gradients, and a lot more), you use directly the Java2D API. It will be both more efficient and simpler to write.

For example to fill a rectangle in your image with a color:

public void rectangle(Color color, float x1, float y1, float w, float h) {
    Graphics2D g = bufferedImage.createGraphics();
    g.setColor(color);
    g.fill(new Rectangle2D.Float(x1, y1, w, h));
    g.dispose(); // optional but releases the resource earlier
}

You can also use "g" to draw as much things as you need to do.