SimpleCurvedCrtMonitorRender.java

/*
  SimpleCurvedCrtMonitorRender.java

  (c) 2011-2013 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package v9t9.gui.client.swt.gl;

import static org.lwjgl.opengl.GL11.GL_QUADS;
import static org.lwjgl.opengl.GL11.glBegin;
import static org.lwjgl.opengl.GL11.glEnd;
import static org.lwjgl.opengl.GL11.glTexCoord2f;
import static org.lwjgl.opengl.GL11.glVertex2f;
import static org.lwjgl.opengl.GL13.GL_TEXTURE1;
import static org.lwjgl.opengl.GL13.glMultiTexCoord2f;

/**
 * @author Ed
 *
 */
public class SimpleCurvedCrtMonitorRender extends BaseMonitorEffect {
	public static final SimpleCurvedCrtMonitorRender INSTANCE = new SimpleCurvedCrtMonitorRender();
	
	public SimpleCurvedCrtMonitorRender() {
	}

	@Override
	public void init() {
		
	}
	/* (non-Javadoc)
	 * @see v9t9.emulator.clients.builtin.swt.gl.IGLMonitorEffect#render()
	 */
	@Override
	public void render() {
		glBegin(GL_QUADS);

		// vertically taper the screen
		drawVerticalCurves(0.5f, 0.5f, 0.5f, 0.5f);
		drawVerticalCurves(0.5f, -0.5f, 0.5f, -0.5f);

		glEnd();
	}

	private final static float CVMAJOR = 0.3f;
	private final static float TVMAJOR = 0.275f;
	private final static float CHMAJOR = 0.2f;
	private final static float THMAJOR = 0.19f;
	
	private final static float EPSILON = 0.02f;
	
	private void drawVerticalCurves(float cy, float cdy, float ty, float tdy) {
		if (Math.abs(cdy) < EPSILON) {
			drawHorizontalCurves(0.5f, -0.5f, cy, cdy,
					0.5f, -0.5f, ty, tdy);
			drawHorizontalCurves(0.5f, 0.5f, cy, cdy,
					0.5f, 0.5f, ty, tdy);
			return;
		}
		// horizontally taper a curve
		drawHorizontalCurves(0.5f, -0.5f, cy, cdy * CVMAJOR,
				0.5f, -0.5f, ty, tdy * TVMAJOR);
		drawHorizontalCurves(0.5f, 0.5f, cy, cdy * CVMAJOR,
				0.5f, 0.5f, ty, tdy * TVMAJOR);
		
		// inner part
		drawVerticalCurves(cy + cdy * CVMAJOR, cdy * (1 - CVMAJOR), 
				ty + tdy * TVMAJOR, tdy * (1 - TVMAJOR));
	}

	private void drawHorizontalCurves(float cx, float cdx, float cy, float cdy,
			float tx, float tdx, float ty, float tdy) {
		if (Math.abs(cdx) < EPSILON) {
			drawQuad(cx, cy, cx + cdx, cy + cdy, tx, ty, tx + tdx, ty + tdy);
			return;
		}
		// inner half
		drawHorizontalCurves(cx, cdx * CHMAJOR, cy, cdy, 
				tx, tdx * THMAJOR, ty, tdy);
		// outer half
		drawHorizontalCurves(cx + cdx * CHMAJOR, cdx * (1 - CHMAJOR), cy, cdy, 
				tx + tdx * THMAJOR, tdx * (1 - THMAJOR), ty, tdy);
	}
	
	protected void drawQuad(float cx, float cy, float cx2, float cy2,
			float tx, float ty, float tx2, float ty2) {
		glMultiTexCoord2f(GL_TEXTURE1, cx, cy);
		glTexCoord2f(tx, ty);		
		glVertex2f(cx, cy);
		glMultiTexCoord2f(GL_TEXTURE1, cx, cy2);
		glTexCoord2f(tx, ty2);		
		glVertex2f(cx, cy2);
		glMultiTexCoord2f(GL_TEXTURE1, cx2, cy2);
		glTexCoord2f(tx2, ty2);		
		glVertex2f(cx2, cy2);
		glMultiTexCoord2f(GL_TEXTURE1, cx2, cy);
		glTexCoord2f(tx2, ty);		
		glVertex2f(cx2, cy);
	}
}