com.golden.gamedev.engine.lwjgl.Texture.java Source code

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Here is the source code for com.golden.gamedev.engine.lwjgl.Texture.java

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/*
 * Copyright (c) 2008 Golden T Studios.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.golden.gamedev.engine.lwjgl;

// LWJGL
import org.lwjgl.opengl.GL11;

/**
 * A texture to be bound within OpenGL. 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 {

    private int target; // the GL target type
    private int textureID; // the GL texture ID

    private int width; // the width of the image
    private int height; // the height of the image

    private int texWidth; // the width of the texture
    private int texHeight; // the height of the texture

    private float widthRatio; // the ratio of
    // image width and texture width
    private float heightRatio; // the ratio of

    // image height and texture height

    /** ************************************************************************* */
    /** ***************************** CONSTRUCTOR ******************************* */
    /** ************************************************************************* */

    /**
     * Creates 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;
    }

    /** ************************************************************************* */
    /** ********************** BIND TEXTURE TO OPENGL *************************** */
    /** ************************************************************************* */

    /**
     * Bind the specified GL context to a texture.
     * 
     * @param gl the GL context to bind to
     */
    public void bind() {
        GL11.glBindTexture(this.target, this.textureID);
    }

    /** ************************************************************************* */
    /** ****************** SET IMAGE, TEXTURE WIDTH / HEIGHT ******************** */
    /** ************************************************************************* */

    /**
     * Sets the height of the image.
     * 
     * @param height the height of the image
     */
    public void setHeight(int height) {
        this.height = height;
        this.setHeight();
    }

    /**
     * Sets the width of the image.
     * 
     * @param width the width of the image
     */
    public void setWidth(int width) {
        this.width = width;
        this.setWidth();
    }

    /**
     * Set the height of this texture
     * 
     * @param texHeight The height of the texture
     */
    public void setTextureHeight(int texHeight) {
        this.texHeight = texHeight;
        this.setHeight();
    }

    /**
     * Set the width of this texture
     * 
     * @param texWidth The width of the texture
     */
    public void setTextureWidth(int texWidth) {
        this.texWidth = texWidth;
        this.setWidth();
    }

    /** ************************************************************************* */
    /** ************ GET IMAGE, TEXTURE, RATIO WIDTH / HEIGHT ******************* */
    /** ************************************************************************* */

    /**
     * Returns the height of the original image.
     */
    public int getImageHeight() {
        return this.height;
    }

    /**
     * Returns the width of the original image.
     */
    public int getImageWidth() {
        return this.width;
    }

    /**
     * Returns the width of the texture.
     */
    public int getTextureWidth() {
        return this.texWidth;
    }

    /**
     * Returns the height of the texture.
     */
    public int getTextureHeight() {
        return this.texHeight;
    }

    /**
     * Returns the height of the physical texture.
     */
    public float getHeight() {
        return this.heightRatio;
    }

    /**
     * Returns the width of the physical texture.
     */
    public float getWidth() {
        return this.widthRatio;
    }

    /**
     * Set the height of the texture. This will update the ratio also.
     */
    private void setHeight() {
        if (this.texHeight != 0) {
            this.heightRatio = ((float) this.height) / this.texHeight;
        }
    }

    /**
     * Set the width of the texture. This will update the ratio also.
     */
    private void setWidth() {
        if (this.texWidth != 0) {
            this.widthRatio = ((float) this.width) / this.texWidth;
        }
    }

}