LWJGL紋理渲染爲單色

Question

過去一個小時左右我一直在試圖修復一個bug，使得我嘗試渲染的紋理只是單一的顏色。奇怪的是，這種加載紋理的方法在我沒有像這樣的問題之前對我來說工作得很好。下面是如何載入紋理（從一個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; 

} 

這是質地如何繪製到屏幕上：

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); 

上面的代碼是一個顯示列表中。 任何想法可能會導致四邊形呈現爲單一顏色？

Answer 1

你有2個錯誤。

首先，你不能混合像glEnable和glVertex2i這樣的函數。 glVertex2i和glTexCoord2f必須位於glBegin和gEnd之間。

其次，一旦您調用glVertex2i，頂點將具有之前指定的紋理狀態。

所以我相信你的代碼看起來應該像

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);