LWJGL png纹理透明（textureColour.a白色而不是黑色）

Question

我有使用PNG图片纹理的草地模型。并且我得到白色背景颜色而不是黑色，我想要。为何如此，我该如何解决这个问题？我使用LWJGL 3和PNGDecoder.jar

纹理加载器代码：

public int loadTexture(String fileName) { 
    ByteBuffer buf = null; 
    int tWidth = 0; 
    int tHeight = 0; 

    try { 
     // Open the PNG file as an InputStream 
     InputStream in = new FileInputStream("res/" + fileName + ".png"); 
     // Link the PNG decoder to this stream 
     PNGDecoder decoder = new PNGDecoder(in); 

     // Get the width and height of the texture 
     tWidth = decoder.getWidth(); 
     tHeight = decoder.getHeight(); 

     // Decode the PNG file in a ByteBuffer 
     buf = ByteBuffer.allocateDirect(
       4 * decoder.getWidth() * decoder.getHeight()); 
     decoder.decode(buf, decoder.getWidth() * 4, Format.RGBA); 
     buf.flip(); 

     in.close(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
     System.exit(-1); 
    } 

    // Create a new texture object in memory and bind it 
    int textureId = GL11.glGenTextures(); 
    GL13.glActiveTexture(textureId); 
    GL11.glBindTexture(GL11.GL_TEXTURE_2D, textureId); 

    // All RGB bytes are aligned to each other and each component is 1 byte 
    GL11.glPixelStorei(GL11.GL_UNPACK_ALIGNMENT, 1); 

    // Upload the texture data and generate mip maps (for scaling) 
    GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGB, tWidth, tHeight, 0, 
      GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buf); 
    GL30.glGenerateMipmap(GL11.GL_TEXTURE_2D); 

    // Setup the ST coordinate system 
    GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL11.GL_REPEAT); 
    GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_T, GL11.GL_REPEAT); 

    // Setup what to do when the texture has to be scaled 
    GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, 
      GL11.GL_NEAREST); 
    GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, 
      GL11.GL_LINEAR_MIPMAP_LINEAR); 

    return textureId; 
} 

Answer 1

如果你想透明质感看起来透明，您必须启用第一混合。把下面的代码放在你的OpenGL初始化代码中。

glEnable(GL_BLEND); 
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); 

---

你也在内部存储你的纹理在RGB，而不是RGBA格式。

GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGB, tWidth, tHeight, 0, 
    GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buf); 

应该成为

GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGBA8, tWidth, tHeight, 0, 
    GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buf);