LWJGL纹理渲染为单色

Question

在过去的一个小时左右，我一直在尝试修复一个错误，使我尝试渲染的纹理只是单色。奇怪的是，这种加载纹理的方法以前对我来说非常好，没有这样的问题。以下是我如何加载纹理（从缓冲图像）：

public static int loadTexture(BufferedImage image)
{
    glEnable(GL_TEXTURE_2D);
    TextureImpl.unbind();
    try
    {
        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);
        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));
                buffer.put((byte) ((pixel >> 8) & 0xFF)); // Green component
                buffer.put((byte) (pixel & 0xFF));
                buffer.put((byte) ((pixel >> 24) & 0xFF)); 
            }
        }
        buffer.flip();
        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_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        //Send texel data to OpenGL
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, image.getWidth(),
                image.getHeight(), 0, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
        return textureID;
    }
    catch (Exception e)
    {
        e.printStackTrace();
    }
    glDisable(GL_TEXTURE_2D);
    //Return the texture ID so we can bind it later again
    return 0;
}

这就是纹理被绘制到屏幕上的方式：

glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, blockTexture.getID());
glVertex2i(offsetX * cubeSize + x * cubeSize, y * cubeSize);
glVertex2i((offsetX * cubeSize + x * cubeSize) + cubeSize,
                        y * cubeSize);
glVertex2i((offsetX * cubeSize + x * cubeSize) + cubeSize,
                        (y * cubeSize) + cubeSize);
glVertex2i(offsetX * cubeSize + x * cubeSize,
                        (y * cubeSize) + cubeSize);
glTexCoord2f(0.0f, 0.0f);
glTexCoord2f(1.0f, 0.0f);
glTexCoord2f(1.0f, 1.0f);
glTexCoord2f(0.0f, 1.0f);
glDisable(GL_TEXTURE_2D);

上述代码在显示列表中。知道是什么原因导致四边形渲染为单一颜色吗？

Answer 1

您有两个错误。

首先，不能混合使用glEnable和glVertex2i这样的函数。glVertex2i和glTexCoord2f必须介于glBegin和gEnd之间。

其次，一旦调用glVertex2i，顶点将具有先前指定的纹理状态。

所以我相信你的代码应该看起来像

glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, blockTexture.getID());
glBegin(...); // you have to specify a primitive type
glTexCoord2f(0.0f, 0.0f);
glVertex2i(offsetX * cubeSize + x * cubeSize, y * cubeSize);
glTexCoord2f(1.0f, 0.0f);
glVertex2i((offsetX * cubeSize + x * cubeSize) + cubeSize,
                        y * cubeSize);
glTexCoord2f(1.0f, 1.0f);
glVertex2i((offsetX * cubeSize + x * cubeSize) + cubeSize,
                        (y * cubeSize) + cubeSize);
glTexCoord2f(0.0f, 1.0f);    
glVertex2i(offsetX * cubeSize + x * cubeSize,
                        (y * cubeSize) + cubeSize);
glEnd();
glDisable(GL_TEXTURE_2D);