package destr.jogl.buffer;

import java.awt.Graphics2D;
import java.awt.color.ColorSpace;
import java.awt.image.BufferedImage;
import java.awt.image.ComponentColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.nio.ByteBuffer;

import javax.imageio.ImageIO;
import javax.media.opengl.GL;
import javax.media.opengl.GL2;

public class GLTexture implements GLBuffer {
	private int id;
	
	public static GLTexture loadURL(GL gl1, String src) throws IOException {
		URL url = new URL(src);
		URLConnection urlConn = url.openConnection(); 
	    urlConn.setDoInput(true); 
	    urlConn.setUseCaches(false);
	    InputStream in = new DataInputStream(urlConn.getInputStream());
	    GLTexture image = new GLTexture(gl1, in);
	    in.close();
		return image;
	}
	
	public static GLTexture loadClassPath(GL gl1, String src) throws IOException {
	    InputStream in = GLTexture.class.getResourceAsStream(src);
	    GLTexture image = new GLTexture(gl1, in);
	    in.close();
		return image;
	}
	
	public static ComponentColorModel colorModel=
		new ComponentColorModel (ColorSpace.getInstance(ColorSpace.CS_sRGB),
		new int[] {8,8,8,8},
		true,
		false,
		ComponentColorModel.TRANSLUCENT,
		DataBuffer.TYPE_BYTE
	);

	private int width, height;
	
	public GLTexture(GL gl1, InputStream in) throws IOException {
		GL2 gl = gl1.getGL2();
		
		int[] glID = new int[1];
		gl.glGenTextures(1, glID, 0);
		this.id = glID[0];
		
		BufferedImage bufferedImage = ImageIO.read(in);
	    
	    width = bufferedImage.getWidth();
	    height = bufferedImage.getHeight();
	    WritableRaster raster = Raster.createInterleavedRaster (DataBuffer.TYPE_BYTE, width, height, 4, null);
	    BufferedImage dukeImg = new BufferedImage (colorModel, raster, false, null);
	    Graphics2D g = dukeImg.createGraphics();
	    g.drawImage(bufferedImage, null, null);
	    DataBufferByte dukeBuf = (DataBufferByte)raster.getDataBuffer();
	    byte[] dukeRGBA = dukeBuf.getData();
	    ByteBuffer bb = ByteBuffer.wrap(dukeRGBA);
	    bb.position(0);
		bb.mark();
		gl.glBindTexture(GL.GL_TEXTURE_2D, this.id);
		gl.glPixelStorei(GL.GL_UNPACK_ALIGNMENT, 1);
		gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_WRAP_S, GL2.GL_CLAMP);
		gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_WRAP_T, GL2.GL_CLAMP);
		gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MAG_FILTER, GL.GL_LINEAR);
		gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MIN_FILTER, GL.GL_LINEAR);
		gl.glTexEnvf(GL2.GL_TEXTURE_ENV, GL2.GL_TEXTURE_ENV_MODE, GL.GL_REPLACE);
		gl.glTexImage2D (GL.GL_TEXTURE_2D, 0, GL.GL_RGBA, width, height, 0, GL.GL_RGBA, GL.GL_UNSIGNED_BYTE, bb);
	}

	@Override
	public void bind(GL gl) {
		gl.glEnable(GL.GL_TEXTURE_2D);
		gl.glBindTexture (GL.GL_TEXTURE_2D, this.id);
	}

	@Override
	public void free(GL gl) {
		gl.glDeleteTextures(1, new int[]{this.id}, 0);		
	}

}