game.engine.gfx.Sprite.java Source code

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Here is the source code for game.engine.gfx.Sprite.java

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/**
 * Copyright (c) 2013 Martin Geisse
 *
 * This file is distributed under the terms of the MIT license.
 */

package game.engine.gfx;

import game.engine.game.GameObject;

import org.lwjgl.opengl.GL11;

/**
 * Contains the information for a textured quad that represents
 * a game object. In concrete terms, this class stores a texture
 * as well as the extents of the quad from the "hotspot", i.e.
 * the position of the game object.
 * 
 * A sprite acting as a {@link SpriteProvider} just returns itself.
 */
public final class Sprite implements SpriteProvider {

    /**
     * the texture
     */
    private final Texture texture;

    /**
     * the leftExtent
     */
    private final float leftExtent;

    /**
     * the rightExtent
     */
    private final float rightExtent;

    /**
     * the topExtent
     */
    private final float topExtent;

    /**
     * the bottomExtent
     */
    private final float bottomExtent;

    /**
     * Constructor.
     * @param texture the texture
     * @param leftExtent the extent to the left
     * @param rightExtent the extent to the right
     * @param topExtent the extent to the top
     * @param bottomExtent the extent to the bottom
     */
    public Sprite(Texture texture, float leftExtent, float rightExtent, float topExtent, float bottomExtent) {
        this.texture = texture;
        this.leftExtent = leftExtent;
        this.rightExtent = rightExtent;
        this.topExtent = topExtent;
        this.bottomExtent = bottomExtent;
    }

    /**
     * Getter method for the texture.
     * @return the texture
     */
    public Texture getTexture() {
        return texture;
    }

    /**
     * Getter method for the leftExtent.
     * @return the leftExtent
     */
    public float getLeftExtent() {
        return leftExtent;
    }

    /**
     * Getter method for the rightExtent.
     * @return the rightExtent
     */
    public float getRightExtent() {
        return rightExtent;
    }

    /**
     * Getter method for the topExtent.
     * @return the topExtent
     */
    public float getTopExtent() {
        return topExtent;
    }

    /**
     * Getter method for the bottomExtent.
     * @return the bottomExtent
     */
    public float getBottomExtent() {
        return bottomExtent;
    }

    /**
     * Calls glBindTexture() on the sprite texture.
     */
    public void glBindTexture() {
        texture.glBindTexture();
    }

    /**
     * Calls glTexCoord() / glVertex() on the sprite vertices, assuming the hotspot is at (0, 0).
     */
    public void glVertices() {
        GL11.glTexCoord2f(0.0f, 1.0f);
        GL11.glVertex2f(-leftExtent, -topExtent);
        GL11.glTexCoord2f(1.0f, 1.0f);
        GL11.glVertex2f(rightExtent, -topExtent);
        GL11.glTexCoord2f(1.0f, 0.0f);
        GL11.glVertex2f(rightExtent, bottomExtent);
        GL11.glTexCoord2f(0.0f, 0.0f);
        GL11.glVertex2f(-leftExtent, bottomExtent);
    }

    /**
     * Draws this sprite at the current origin.
     */
    public void draw() {
        GL11.glEnable(GL11.GL_TEXTURE_2D);
        glBindTexture();
        GL11.glColor3ub((byte) 255, (byte) 255, (byte) 255);
        GL11.glBegin(GL11.GL_QUADS);
        glVertices();
        GL11.glEnd();
    }

    /* (non-Javadoc)
     * @see game.core.gfx.SpriteProvider#provideSprite(game.core.GameObject)
     */
    @Override
    public Sprite provideSprite(GameObject object) {
        return this;
    }

}