gistfile1.java

package org.eiennohito.drawing;

import org.eiennohito.math.Matrix;
import org.eiennohito.math.Vector;
import org.eiennohito.model.Vertex;
import org.eiennohito.services.GLCallbackHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.media.opengl.GL;
import static javax.media.opengl.GL.*;

/**
 * @author eiennohito
 * @date 17.02.2008
 */
@Service
public class GLRenderer implements Renderer {
    private GL gl = null;

    @Autowired
    private GLCallbackHolder callbacks;

    public GL getGl() {
        return gl;
    }

    public void setGl(GL gl) {
        this.gl = gl;
    }

    public GLRenderer applyGL(GL gl) {
        setGl(gl);
        return this;
    }

    public void drawLineSegment(Vertex start, Vertex end) {        
        gl.glPushAttrib(GL_CURRENT_BIT);

        gl.glBegin(GL_LINES);
        start.fillGL(gl);
        end.fillGL(gl);
        gl.glEnd();

        gl.glPopAttrib();
    }

    public void start() {
        gl.glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        gl.glLoadIdentity();

        gl.glLightfv(GL.GL_LIGHT0, GL_POSITION, new float[] {0, 0, 1000, 1}, 0);

        while (!callbacks.isEmpty()) {
            callbacks.pop().doInGl(gl);
        }
    }

    public void end() {
        gl = null;
    }

    public void applyMatrix(Matrix currentMatrix) {
        currentMatrix.fillGL(gl);
    }

    public void renderPolygon(Vertex[] vertices) {
        gl.glPushAttrib(GL_CURRENT_BIT);

        Vector s1 = vertices[1].getPosition().substract(vertices[0].getPosition());
        Vector s2 = vertices[2].getPosition().substract(vertices[0].getPosition());

        Vector normal = s1.crossProduct(s2).normalized();
        gl.glNormal3fv(normal.getBuffer(), 0);

        gl.glBegin(GL_POLYGON);
        for (Vertex vertex : vertices) {
            vertex.fillGL(gl);
        }
        
        gl.glEnd();

        gl.glPopAttrib();
    }
}