Question

我正在使用LWJGL制作游戏并使用openGL，我相信我最好的选择是使用纹理并使用四边形渲染它们。但是，我似乎只能找到有关从整个图像只有一个纹理的图像加载纹理的信息。我想要做的是读取整个spritesheet并能够将它分成不同的纹理。有一种简单的方法吗？

Answer 1

您可以加载图片，例如使用

将.png文件发送到BufferedImage

public static BufferedImage loadImage(String location)
{
    try {
        BufferedImage image = ImageIO.read(new File(location));
        return image;
    } catch (IOException e) {
        System.out.println("Could not load texture: " + location);
    }
    return null;
}

现在，您可以在结果getSubimage(int x, int y, int w, int h)上致电BufferedImage，为您提供分开的部分。您现在只需要创建BufferedImage的纹理。这段代码应该做的工作：

public static int loadTexture(BufferedImage image){
    if (image == null) {
        return 0;
    }

    int[] pixels = new int[image.getWidth() * image.getHeight()];
    image.getRGB(0, 0, image.getWidth(), image.getHeight(), pixels, 0, image.getWidth());

    ByteBuffer buffer = BufferUtils.createByteBuffer(image.getWidth() * image.getHeight() * BYTES_PER_PIXEL); //4 for RGBA, 3 for RGB

    for(int y = 0; y < image.getHeight(); y++){
        for(int x = 0; x < image.getWidth(); x++){
            int pixel = pixels[y * image.getWidth() + x];
            buffer.put((byte) ((pixel >> 16) & 0xFF));     // Red component
            buffer.put((byte) ((pixel >> 8) & 0xFF));      // Green component
            buffer.put((byte) (pixel & 0xFF));               // Blue component
            buffer.put((byte) ((pixel >> 24) & 0xFF));    // Alpha component. Only for RGBA
        }
    }

    buffer.flip(); //FOR THE LOVE OF GOD DO NOT FORGET THIS

     // You now have a ByteBuffer filled with the color data of each pixel.
    // Now just create a texture ID and bind it. Then you can load it using 
    // whatever OpenGL method you want, for example:

    int textureID = glGenTextures();
    glBindTexture(GL_TEXTURE_2D, textureID);

    //setup wrap mode
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL12.GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL12.GL_CLAMP_TO_EDGE);

    //setup texture scaling filtering
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

    //Send texel data to OpenGL
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, image.getWidth(), image.getHeight(), 0, GL_RGBA, GL_UNSIGNED_BYTE, buffer); //GL_RGBA8 was GL_RGB8A

    return textureID;
}

如果您需要纹理，现在可以将返回的textureID与glBindTexture(GL_TEXTURE_2D, textureID);绑定。这样，您只需将BufferedImage拆分为所需的部分。

我建议您阅读：LWJGL Textures and Strings

LWJGL：使用多个纹理从.png获取纹理

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