java - 如何设置实体纹理

Question

我的纹理实体有问题，加载纹理但未显示纹理时没有错误或异常。这是我的代码：

public class StartClass {

private static class Button extends AbstractButtonEntity {

    public Button(int x, int y, int width, int height, Texture texture) {
        super(x, y, width, height, texture);

    }

    @Override
    public void draw() {

        texture.bind();
        glBegin(GL_QUADS);

        glTexCoord2f(0, 0);
        glVertex2i(x, y);

        glTexCoord2f(1, 0);
        glVertex2i(x + width, y);

        glTexCoord2f(1, 1);
        glVertex2i(x + width, y + height);

        glTexCoord2f(0, 1);
        glVertex2i(x, y + height);

        glEnd();

    }

}

Texture background, logo;

public StartClass() {

    try {
        Display.setDisplayMode(new DisplayMode(800, 600));
        Display.setTitle("Space Project");
        Display.create();
    } catch (LWJGLException e) {
        e.printStackTrace();
    }

    background = loadTexture("main_menu/bg");
    logo = loadTexture("main_menu/logo");

    Button ngButton = new Button(300, 200, 200, 45,
            loadTexture("main_menu/ng_button"));

    glMatrixMode(GL_PROJECTION);
    GL11.glViewport(0, 0, 800, 600);
    glLoadIdentity();
    glOrtho(0, 800, 600, 0, 1, -1);
    glMatrixMode(GL_MODELVIEW);
    glEnable(GL_TEXTURE_2D);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    while (!Display.isCloseRequested()) {

        glClear(GL_COLOR_BUFFER_BIT);

        ngButton.draw();

        drawBackground();

        Display.update();
        Display.sync(60);
    }
    Display.destroy();
}

private Texture loadTexture(String key) {
    try {
        return TextureLoader.getTexture("PNG", new FileInputStream(
                new File("res/" + key + ".png")));
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}

public void drawBackground() {

    background.bind();

    glBegin(GL_QUADS);

    glTexCoord2f(0, 0);
    glVertex2i(0, 0);

    glTexCoord2f(1, 0);
    glVertex2i(800, 0);

    glTexCoord2f(1, 1);
    glVertex2i(800, 600);

    glTexCoord2f(0, 1);
    glVertex2i(0, 600);

    glEnd();

    logo.bind();

    glBegin(GL_QUADS);

    glTexCoord2f(0, 0);
    glVertex2i(44, 44);

    glTexCoord2f(1, 0);
    glVertex2i(756, 44);

    glTexCoord2f(1, 1);
    glVertex2i(756, 115);

    glTexCoord2f(0, 1);
    glVertex2i(44, 115);

    glEnd();

}

public static void main(String[] args) {
    new StartClass();
}

    }

这是AbstractButtonEntity：

    public abstract class AbstractButtonEntity implements ButtonEntity {

protected int x, y, width, height;

protected String key;

protected Texture texture;

protected Rectangle hitbox = new Rectangle();

public AbstractButtonEntity(int x, int y, int width,
        int height, Texture texture) {

    this.x = x;
    this.y = y;
    this.width = width;
    this.height = height;
    this.texture = texture;
}



@Override
public void setLocation(int x, int y) {
    this.x = x;
    this.y = y;

}

@Override
public void setX(int x) {
    this.x = x;
}

@Override
public void setY(int y) {
    this.y = y;

}

@Override
public void setWidth(int width) {
    this.width = width;

}

@Override
public void setHeight(int height) {
    this.height = height;

}

@Override
public int getX() {
    return x;
}

@Override
public int getY() {
    return y;
}

@Override
public int getWidth() {
    return width;
}

@Override
public int getHeight() {
    return height;
}


@Override
public boolean intersects(ButtonEntity other) {
    hitbox.setBounds(x, y, width, height);
    return hitbox.intersects(other.getX(), other.getY(), other.getWidth(),
            other.getHeight());
}

}

对不起，如果是新手问题，但我是java新手

Answer 1

为什么在方法 loadTexture 中有 2 个返回值？

Answer 2

问题已解决 - 在 loadTexture 方法中必须在 catch 中返回 null

private Texture loadTexture(String key) {
try {
    return TextureLoader.getTexture("PNG", new FileInputStream(
            new File("res/" + key + ".png")));
} catch (FileNotFoundException e) {
    e.printStackTrace();
    return null;
} catch (IOException e) {
    e.printStackTrace();
    return null;
}

}