package classwork;

import javax.media.opengl.*;
import jocode.*;

/**
 * GLART_2_cube.java
 *
 * Rotate a cube at the origin.  Demonstrates a simple animation, and
 * includes a function to draw a cube.
 */
public class GLART_2_cube extends JOApp {
 	float rotation = 0f;

	/**
	 * Start the application.  run() calls setup(), handles mouse and keyboard input, preps the OpenGL context.
	 */
    public static void main(String args[]) {
    	// create the app
    	GLART_2_cube demo = new GLART_2_cube();

    	// set title, window size
    	windowTitle   = "Draw a Cube";
    	displayWidth  = 640;
    	displayHeight = 480;

    	// start running: will call init(), setup(), draw(), mouse functions
    	demo.run();
    }

    /**
     * Render the scene.
     */
    public void draw() {
     	rotation += .2f;
        // Clear screen and depth buffer
        gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);

        // Select The Modelview Matrix (controls model orientation)
        gl.glMatrixMode(GL.GL_MODELVIEW);

        // Reset the Modelview matrix
        // this resets the coordinate system to center of screen
        gl.glLoadIdentity();

        // Where is the 'eye'
        glu.gluLookAt(
            0f, 2f, 5f,    // eye position
            0f, 0f, 0f,    // target to look at
            0f, 1f, 0f);   // which way is up

        // draw crosshairs
        drawOrigin();

        // draw large cube at center, turning slowly on its axis
		gl.glColor3f(1f,1f,0f);
        gl.glPushMatrix();
		{
			gl.glRotatef(rotation, 0, 1, 0);
			gl.glScalef(.6f, .6f, .6f);
			draw_a_cube();
		}
        gl.glPopMatrix();
    }

    /**
     * Draw crosshairs at 0,0,0
     */
    public void drawOrigin() {
    	gl.glColor3f(.5f, .5f, .5f);
        gl.glLineWidth(1);
        gl.glBegin(GL.GL_LINES);
	    	gl.glVertex3f( -1f, 0f, 0f);        // left
	    	gl.glVertex3f( 1f, 0f, 0f);         // right

	    	gl.glVertex3f( 0f, -1f, 0f);        // bottom
	    	gl.glVertex3f( 0f, 1f, 0f);         // top

			gl.glVertex3f( 0f, 0f, -1f);        // far
			gl.glVertex3f( 0f, 0f, 1f);         // near
		gl.glEnd();
		gl.glBegin(GL.GL_LINE_STRIP);
			gl.glVertex3f( -1f, 0f, 1f);        // left near
			gl.glVertex3f( 1f, 0f, 1f);         // rite near
			gl.glVertex3f( 1f, 0f, -1f);        // rite far
			gl.glVertex3f( -1f, 0f, -1f);       // left far
			gl.glVertex3f( -1f, 0f, 1f);        // left near (close)
		gl.glEnd();
    }

    /**
     * Draw a 2x2x2 cube centered at the origin
     */
    public void draw_a_cube()
    {
        gl.glBegin(GL.GL_QUADS);
        // Front Face
        gl.glVertex3f(-1.0f, -1.0f,  1.0f);	// Bottom Left
        gl.glVertex3f( 1.0f, -1.0f,  1.0f);	// Bottom Right
        gl.glVertex3f( 1.0f,  1.0f,  1.0f);	// Top Right
        gl.glVertex3f(-1.0f,  1.0f,  1.0f);	// Top Left
        // Back Face
        gl.glVertex3f(-1.0f, -1.0f, -1.0f);	// Bottom Right
        gl.glVertex3f(-1.0f,  1.0f, -1.0f);	// Top Right
        gl.glVertex3f( 1.0f,  1.0f, -1.0f);	// Top Left
        gl.glVertex3f( 1.0f, -1.0f, -1.0f);	// Bottom Left
        // Top Face
        gl.glVertex3f(-1.0f,  1.0f, -1.0f);	// Top Left
        gl.glVertex3f(-1.0f,  1.0f,  1.0f);	// Bottom Left
        gl.glVertex3f( 1.0f,  1.0f,  1.0f);	// Bottom Right
        gl.glVertex3f( 1.0f,  1.0f, -1.0f);	// Top Right
        // Bottom Face
        gl.glVertex3f(-1.0f, -1.0f, -1.0f);	// Top Right
        gl.glVertex3f( 1.0f, -1.0f, -1.0f);	// Top Left
        gl.glVertex3f( 1.0f, -1.0f,  1.0f);	// Bottom Left
        gl.glVertex3f(-1.0f, -1.0f,  1.0f);	// Bottom Right
        // Right face
        gl.glVertex3f( 1.0f, -1.0f, -1.0f);	// Bottom Right
        gl.glVertex3f( 1.0f,  1.0f, -1.0f);	// Top Right
        gl.glVertex3f( 1.0f,  1.0f,  1.0f);	// Top Left
        gl.glVertex3f( 1.0f, -1.0f,  1.0f);	// Bottom Left
        // Left Face
        gl.glVertex3f(-1.0f, -1.0f, -1.0f);	// Bottom Left
        gl.glVertex3f(-1.0f, -1.0f,  1.0f);	// Bottom Right
        gl.glVertex3f(-1.0f,  1.0f,  1.0f);	// Top Right
        gl.glVertex3f(-1.0f,  1.0f, -1.0f);	// Top Left
        gl.glEnd();
    }

}