package org.jzy3d.chart;

import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
import java.nio.ByteBuffer;

import com.jogamp.opengl.GL;
import com.jogamp.opengl.GL2;
import com.jogamp.opengl.GL2GL3;

public class AWTScreenshotUtils {
    public BufferedImage toImage(GL2 gl, int w, int h) {

        gl.glReadBuffer(GL.GL_FRONT); // or GL.GL_BACK

        ByteBuffer glBB = ByteBuffer.allocate(3 * w * h);
        gl.glReadPixels(0, 0, w, h, GL2GL3.GL_BGR, GL.GL_BYTE, glBB);

        BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
        int[] bd = ((DataBufferInt) bi.getRaster().getDataBuffer()).getData();

        for (int y = 0; y < h; y++) {
            for (int x = 0; x < w; x++) {
                int b = 2 * glBB.get();
                int g = 2 * glBB.get();
                int r = 2 * glBB.get();

                bd[(h - y - 1) * w + x] = (r << 16) | (g << 8) | b | 0xFF000000;
            }
        }

        return bi;
    }
}