LWJGL纹理渲染为单色

Question

过去一个小时左右我一直在试图修复一个bug，使得我尝试渲染的纹理只是单一的颜色。奇怪的是，这种加载纹理的方法在我没有像这样的问题之前对我来说工作得很好。下面是如何载入纹理（从一个BufferedImage）：

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; 

} 

这是质地如何绘制到屏幕上：

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); 

上面的代码是一个显示列表中。 任何想法可能会导致四边形呈现为单一颜色？

Answer 1

你有2个错误。

首先，你不能混合像glEnable和glVertex2i这样的函数。 glVertex2i和glTexCoord2f必须位于glBegin和gEnd之间。

其次，一旦您调用glVertex2i，顶点将具有之前指定的纹理状态。

所以我相信你的代码看起来应该像

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);