Examples:SpaceInvaders TextureLoader

 /* * Copyright (c) 2002-2010 LWJGL Project * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright *  notice, this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above copyright *  notice, this list of conditions and the following disclaimer in the *  documentation and/or other materials provided with the distribution. * * * Neither the name of 'LWJGL' nor the names of *  its contributors may be used to endorse or promote products derived *  from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package org.lwjgl.examples.spaceinvaders;

import java.awt.Color; import java.awt.Graphics; import java.awt.Image; import java.awt.color.ColorSpace; import java.awt.image.BufferedImage; import java.awt.image.ColorModel; import java.awt.image.ComponentColorModel; import java.awt.image.DataBuffer; import java.awt.image.DataBufferByte; import java.awt.image.Raster; import java.awt.image.WritableRaster; import java.io.IOException; import java.net.URL; import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.nio.IntBuffer; import java.util.HashMap; import java.util.Hashtable;

import javax.swing.ImageIcon;

import org.lwjgl.BufferUtils;

import static org.lwjgl.opengl.GL11.*;

/** * A utility class to load textures for OpenGL. This source is based * on a texture that can be found in the Java Gaming (www.javagaming.org) * Wiki. It has been simplified slightly for explicit 2D graphics use. * * OpenGL uses a particular image format. Since the images that are * loaded from disk may not match this format this loader introduces * a intermediate image which the source image is copied into. In turn, * this image is used as source for the OpenGL texture. * * @author Kevin Glass * @author Brian Matzon */ public class TextureLoader { /** The table of textures that have been loaded in this loader */ private HashMap table = new HashMap;

/** The colour model including alpha for the GL image */ private ColorModel glAlphaColorModel;

/** The colour model for the GL image */ private ColorModel glColorModel;

/** Scratch buffer for texture ID's */ private IntBuffer textureIDBuffer = BufferUtils.createIntBuffer(1);

/**    * Create a new texture loader based on the game panel */   public TextureLoader { glAlphaColorModel = new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),                                           new int[] {8,8,8,8},                                            true,                                            false,                                            ComponentColorModel.TRANSLUCENT,                                            DataBuffer.TYPE_BYTE);

glColorModel = new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),                                           new int[] {8,8,8,0},                                            false,                                            false,                                            ComponentColorModel.OPAQUE,                                            DataBuffer.TYPE_BYTE); }

/**    * Create a new texture ID     * * @return A new texture ID    */ private int createTextureID { glGenTextures(textureIDBuffer); return textureIDBuffer.get(0); }

/**    * Load a texture *    * @param resourceName The location of the resource to load * @return The loaded texture * @throws IOException Indicates a failure to access the resource */   public Texture getTexture(String resourceName) throws IOException { Texture tex = table.get(resourceName);

if (tex != null) { return tex; }

tex = getTexture(resourceName,                        GL_TEXTURE_2D, // target                         GL_RGBA,     // dst pixel format                         GL_LINEAR, // min filter (unused)                         GL_LINEAR);

table.put(resourceName,tex);

return tex; }

/**    * Load a texture into OpenGL from a image reference on     * disk. *    * @param resourceName The location of the resource to load * @param target The GL target to load the texture against * @param dstPixelFormat The pixel format of the screen * @param minFilter The minimising filter * @param magFilter The magnification filter * @return The loaded texture * @throws IOException Indicates a failure to access the resource */   public Texture getTexture(String resourceName,                              int target,                              int dstPixelFormat,                              int minFilter,                              int magFilter) throws IOException { int srcPixelFormat;

// create the texture ID for this texture int textureID = createTextureID; Texture texture = new Texture(target,textureID);

// bind this texture glBindTexture(target, textureID);

BufferedImage bufferedImage = loadImage(resourceName); texture.setWidth(bufferedImage.getWidth); texture.setHeight(bufferedImage.getHeight);

if (bufferedImage.getColorModel.hasAlpha) { srcPixelFormat = GL_RGBA; } else { srcPixelFormat = GL_RGB; }

// convert that image into a byte buffer of texture data ByteBuffer textureBuffer = convertImageData(bufferedImage,texture);

if (target == GL_TEXTURE_2D) { glTexParameteri(target, GL_TEXTURE_MIN_FILTER, minFilter); glTexParameteri(target, GL_TEXTURE_MAG_FILTER, magFilter); }

// produce a texture from the byte buffer glTexImage2D(target,                     0,                      dstPixelFormat,                      get2Fold(bufferedImage.getWidth),                      get2Fold(bufferedImage.getHeight),                      0,                      srcPixelFormat,                      GL_UNSIGNED_BYTE,                      textureBuffer );

return texture; }

/**    * Get the closest greater power of 2 to the fold number *    * @param fold The target number * @return The power of 2 */   private static int get2Fold(int fold) { int ret = 2; while (ret < fold) { ret *= 2; }       return ret; }

/**    * Convert the buffered image to a texture *    * @param bufferedImage The image to convert to a texture * @param texture The texture to store the data into * @return A buffer containing the data */   private ByteBuffer convertImageData(BufferedImage bufferedImage,Texture texture) { ByteBuffer imageBuffer; WritableRaster raster; BufferedImage texImage;

int texWidth = 2; int texHeight = 2;

// find the closest power of 2 for the width and height // of the produced texture while (texWidth < bufferedImage.getWidth) { texWidth *= 2; }       while (texHeight < bufferedImage.getHeight) { texHeight *= 2; }

texture.setTextureHeight(texHeight); texture.setTextureWidth(texWidth);

// create a raster that can be used by OpenGL as a source // for a texture if (bufferedImage.getColorModel.hasAlpha) { raster = Raster.createInterleavedRaster(DataBuffer.TYPE_BYTE,texWidth,texHeight,4,null); texImage = new BufferedImage(glAlphaColorModel,raster,false,new Hashtable); } else { raster = Raster.createInterleavedRaster(DataBuffer.TYPE_BYTE,texWidth,texHeight,3,null); texImage = new BufferedImage(glColorModel,raster,false,new Hashtable); }

// copy the source image into the produced image Graphics g = texImage.getGraphics; g.setColor(new Color(0f,0f,0f,0f)); g.fillRect(0,0,texWidth,texHeight); g.drawImage(bufferedImage,0,0,null);

// build a byte buffer from the temporary image // that be used by OpenGL to produce a texture. byte[] data = ((DataBufferByte) texImage.getRaster.getDataBuffer).getData;

imageBuffer = ByteBuffer.allocateDirect(data.length); imageBuffer.order(ByteOrder.nativeOrder); imageBuffer.put(data, 0, data.length); imageBuffer.flip;

return imageBuffer; }

/**    * Load a given resource as a buffered image *    * @param ref The location of the resource to load * @return The loaded buffered image * @throws IOException Indicates a failure to find a resource */   private BufferedImage loadImage(String ref) throws IOException { URL url = TextureLoader.class.getClassLoader.getResource(ref);

if (url == null) { throw new IOException("Cannot find: " + ref); }

// due to an issue with ImageIO and mixed signed code // we are now using good oldfashioned ImageIcon to load // images and the paint it on top of a new BufferedImage Image img = new ImageIcon(url).getImage; BufferedImage bufferedImage = new BufferedImage(img.getWidth(null), img.getHeight(null), BufferedImage.TYPE_INT_ARGB); Graphics g = bufferedImage.getGraphics; g.drawImage(img, 0, 0, null); g.dispose;

return bufferedImage; } }