HueProcedural.java

        /** Converts the components of a color, as specified by the HSB model, to an
	 * equivalent set of values for the default RGB model.
	 * <p>
	 * The <code>saturation</code> and <code>brightness</code> components should
	 * be floating-point values between zero and one (numbers in the range
	 * 0.0-1.0). The <code>hue</code> component can be any floating-point
	 * number. The floor of this number is subtracted from it to create a
	 * fraction between 0 and 1. This fractional number is then multiplied by
	 * 360 to produce the hue angle in the HSB color model.
	 * <p>
	 * The integer that is returned by <code>HSBtoRGB</code> encodes the value
	 * of a color in bits 0-23 of an integer value that is the same format used
	 * by the method {@link #getRGB() <code>getRGB</code>}. This integer can be
	 * supplied as an argument to the <code>Color</code> constructor that takes
	 * a single integer argument.
	 * 
	 * @param hue the hue component of the color
	 * @param saturation the saturation of the color
	 * @param brightness the brightness of the color
	 * @return the RGB value of the color with the indicated hue, saturation,
	 * and brightness.
	 * @see java.awt.Color#getRGB()
	 * @see java.awt.Color#Color(int)
	 * @see java.awt.image.ColorModel#getRGBdefault()
	 * @since JDK1.0 */
	public static int HSBtoRGBA8888(float hue, float saturation, float brightness) {
		int r = 0, g = 0, b = 0;
		if (saturation == 0) {
			r = g = b = (int)(brightness * 255.0f + 0.5f);
		} else {
			float h = (hue - (float)Math.floor(hue)) * 6.0f;
			float f = h - (float)java.lang.Math.floor(h);
			float p = brightness * (1.0f - saturation);
			float q = brightness * (1.0f - saturation * f);
			float t = brightness * (1.0f - (saturation * (1.0f - f)));
			switch ((int)h) {
			case 0:
				r = (int)(brightness * 255.0f + 0.5f);
				g = (int)(t * 255.0f + 0.5f);
				b = (int)(p * 255.0f + 0.5f);
				break;
			case 1:
				r = (int)(q * 255.0f + 0.5f);
				g = (int)(brightness * 255.0f + 0.5f);
				b = (int)(p * 255.0f + 0.5f);
				break;
			case 2:
				r = (int)(p * 255.0f + 0.5f);
				g = (int)(brightness * 255.0f + 0.5f);
				b = (int)(t * 255.0f + 0.5f);
				break;
			case 3:
				r = (int)(p * 255.0f + 0.5f);
				g = (int)(q * 255.0f + 0.5f);
				b = (int)(brightness * 255.0f + 0.5f);
				break;
			case 4:
				r = (int)(t * 255.0f + 0.5f);
				g = (int)(p * 255.0f + 0.5f);
				b = (int)(brightness * 255.0f + 0.5f);
				break;
			case 5:
				r = (int)(brightness * 255.0f + 0.5f);
				g = (int)(p * 255.0f + 0.5f);
				b = (int)(q * 255.0f + 0.5f);
				break;
			}
		}
		return (r << 24) | (g << 16) | (b << 8) | 0x000000ff;
	}

	public void create() {
		Pixmap px = new Pixmap(256, 16, Format.RGBA8888);
		for (int x=0; x<px.getWidth(); x++) {
			int rgb = HSBtoRGBA8888(x / (float)px.getWidth(), 1f, 1f);

			// change the current color
			px.setColor(rgb);

			// perform a fill operation with current color
			px.drawRectangle(x, 0, 1, px.getHeight());
		}

		tex0 = new Texture(px);
		px.dispose();
  	
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