【LWJGL2 WIKI】【辅助库篇】Slick-Util库：第一部分－读取图片

原文：http://wiki.lwjgl.org/wiki/Slick-Util_Library_-Part_1-_Loading_Images_for_LWJGL

Slick-Util支持png, jpg, gif, tga格式图片，它可以读取它们用作OpenGL纹理。

用它读图片很简单，图片的细节会被存在Slick-Util的Texture类里。Texture类为你提供一些属性，比如宽和高之类的。用TextureLoader类和getTexuture()方法读取图片到Texture类中，需要先指定图片类型（”PNG”,”TGA”等），然后指定图片路径。下面是个例子：

Texture texture;

public void init() throws IOException {

texture = TextureLoader.getTexture("PNG", ResourceLoader.getResourceAsStream("res/image.png"));
}

读完后，用Texture.bind()绑定纹理。

将一个纹理绑定到OpenGL方形的完整代码如下：

import java.io.IOException;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.GL11;
import org.newdawn.slick.Color;
import org.newdawn.slick.opengl.Texture;
import org.newdawn.slick.opengl.TextureLoader;
import org.newdawn.slick.util.ResourceLoader;

public class TextureExample {

/** The texture that will hold the image details */
private Texture texture;

/**
* Start the example
*/
public void start() {
initGL(800,600);
init();

while (true) {
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT);
render();

Display.update();
Display.sync(100);

if (Display.isCloseRequested()) {
Display.destroy();
System.exit(0);
}
}
}

/**
* Initialise the GL display
*
* @param width The width of the display
* @param height The height of the display
*/
private void initGL(int width, int height) {
try {
Display.setDisplayMode(new DisplayMode(width,height));
Display.create();
Display.setVSyncEnabled(true);
} catch (LWJGLException e) {
e.printStackTrace();
System.exit(0);
}

GL11.glEnable(GL11.GL_TEXTURE_2D);

GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);

// enable alpha blending
GL11.glEnable(GL11.GL_BLEND);
GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);

GL11.glViewport(0,0,width,height);
GL11.glMatrixMode(GL11.GL_MODELVIEW);

GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0, width, height, 0, 1, -1);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
}

/**
* Initialise resources
*/
public void init() {

try {
// load texture from PNG file
texture = TextureLoader.getTexture("PNG", ResourceLoader.getResourceAsStream("res/image.png"));

System.out.println("Texture loaded: "+texture);
System.out.println(">> Image width: "+texture.getImageWidth());
System.out.println(">> Image height: "+texture.getImageHeight());
System.out.println(">> Texture width: "+texture.getTextureWidth());
System.out.println(">> Texture height: "+texture.getTextureHeight());
System.out.println(">> Texture ID: "+texture.getTextureID());
} catch (IOException e) {
e.printStackTrace();
}
}

/**
* draw a quad with the image on it
*/
public void render() {
Color.white.bind();
texture.bind(); // or GL11.glBind(texture.getTextureID());

GL11.glBegin(GL11.GL_QUADS);
GL11.glTexCoord2f(0,0);
GL11.glVertex2f(100,100);
GL11.glTexCoord2f(1,0);
GL11.glVertex2f(100+texture.getTextureWidth(),100);
GL11.glTexCoord2f(1,1);
GL11.glVertex2f(100+texture.getTextureWidth(),100+texture.getTextureHeight());
GL11.glTexCoord2f(0,1);
GL11.glVertex2f(100,100+texture.getTextureHeight());
GL11.glEnd();
}

/**
* Main Class
*/
public static void main(String[] argv) {
TextureExample textureExample = new TextureExample();
textureExample.start();
}
}

Credit

Tutorial Credit - Ninja Cave

Kevin Glass for writing the Slick Library and initial example code.