name.martingeisse.swtlib.color.OpenGlColors.java Source code

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Here is the source code for name.martingeisse.swtlib.color.OpenGlColors.java

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/**
 * Copyright (c) 2010 Martin Geisse
 *
 * This file is distributed under the terms of the MIT license.
 */
package name.martingeisse.swtlib.color;

import org.lwjgl.opengl.GL11;

/**
 * This class wraps OpenGL color constants. The constants are
 * only exposed as a useColor() method.
 */
public class OpenGlColors {

    /**
     * Uses the color with the specified index as the current OpenGL
     * color via glColor3*(). 
     * @param index the index of the color to use
     */
    public static void useColor(int index) {
        index = index & 15;
        if (index == 7) {
            GL11.glColor3f(0.75f, 0.75f, 0.75f);
        } else if (index == 8) {
            GL11.glColor3f(0.5f, 0.5f, 0.5f);
        } else {
            float baseValue = (index > 7) ? 1.0f : 0.5f;
            float red = ((index & 4) == 0) ? 0.0f : baseValue;
            float green = ((index & 2) == 0) ? 0.0f : baseValue;
            float blue = ((index & 1) == 0) ? 0.0f : baseValue;
            GL11.glColor3f(red, green, blue);
        }
    }

}