Panel.java 文件源码

/** Draws every character of every row onto the canvas. */
public void draw() {
    final BufferStrategy bs = this.getBufferStrategy();

    do {
        do {
            final Graphics2D gc;

            try {
                gc = (Graphics2D) bs.getDrawGraphics();
            } catch (final NullPointerException | IllegalStateException e) {
                // BufferStrategy may not have been created on the first call,
                // so just do a recursive call until it works.
                // This may be a bad idea.
                draw();
                return;
            }

            gc.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_SPEED);
            gc.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
            gc.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY);
            gc.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);

            // Font characters are pre-rendered images, so no need for AA.
            gc.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_OFF);

            // No-need for text rendering related options.
            gc.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_OFF);
            gc.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_OFF);

            // If alpha is used in the character images, we want computations related to drawing them to be fast.
            gc.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_SPEED);

            screen.draw(gc, imageCache);
            gc.dispose();
        } while (bs.contentsRestored()); // Repeat render if drawing buffer contents were restored.

        bs.show();
    } while (bs.contentsLost()); // Repeat render if drawing buffer was lost.
}