Texture.java

/*
  Texture.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 org.lwjgl.opengl.GL11;

/**
 * A texture to be bound within LWJGL. This object is responsible for 
 * keeping track of a given OpenGL texture and for calculating the
 * texturing mapping coordinates of the full image.
 * 
 * Since textures need to be powers of 2 the actual texture may be
 * considerably bigged that the source image and hence the texture
 * mapping coordinates need to be adjusted to matchup drawing the
 * sprite against the texture.
 *
 * @author Kevin Glass
 * @author Brian Matzon
 */
public class Texture {
    /** The GL target type */
    private int target; 
    /** The GL texture ID */
    private int textureID;
    /** The height of the image */
    private int height;
    /** The width of the image */
    private int width;
    /** The width of the texture */
    private int texWidth;
    /** The height of the texture */
    private int texHeight;
    /** The ratio of the width of the image to the texture */
    private float widthRatio;
    /** The ratio of the height of the image to the texture */
    private float heightRatio;
    
    /**
     * Create a new texture
     *
     * @param target The GL target 
     * @param textureID The GL texture ID
     */
    public Texture(int target,int textureID) {
        this.target = target;
        this.textureID = textureID;
    }
    
    
    public int getTextureID()
    {
    	return this.textureID;
    }
    
    /**
     * Bind the specified GL context to a texture
     *
     * @param gl The GL context to bind to
     */
    public void bind() {
      GL11.glBindTexture(target, textureID); 
    }
    
    /**
     * Set the height of the image
     *
     * @param height The height of the image
     */
    public void setHeight(int height) {
        this.height = height;
        setHeight();
    }
    
    /**
     * Set the width of the image
     *
     * @param width The width of the image
     */
    public void setWidth(int width) {
        this.width = width;
        setWidth();
    }
    
    /**
     * Get the height of the original image
     *
     * @return The height of the original image
     */
    public int getImageHeight() {
        return height;
    }
    
    /** 
     * Get the width of the original image
     *
     * @return The width of the original image
     */
    public int getImageWidth() {
        return width;
    }
    
    /**
     * Get the height of the physical texture
     *
     * @return The height of physical texture
     */
    public float getHeight() {
        return heightRatio;
    }
    
    /**
     * Get the width of the physical texture
     *
     * @return The width of physical texture
     */
    public float getWidth() {
        return widthRatio;
    }
    
    /**
     * Set the height of this texture 
     *
     * @param texHeight The height of the texture
     */
    public void setTextureHeight(int texHeight) {
        this.texHeight = texHeight;
        setHeight();
    }
    
    /**
     * Set the width of this texture 
     *
     * @param texWidth The width of the texture
     */
    public void setTextureWidth(int texWidth) {
        this.texWidth = texWidth;
        setWidth();
    }
    
    /**
     * Set the height of the texture. This will update the
     * ratio also.
     */
    private void setHeight() {
        if (texHeight != 0) {
            heightRatio = ((float) height)/texHeight;
        }
    }
    
    /**
     * Set the width of the texture. This will update the
     * ratio also.
     */
    private void setWidth() {
        if (texWidth != 0) {
            widthRatio = ((float) width)/texWidth;
        }
    }
}