Question

我想“杀死”纹理的黑色。或者，我想显示png文件，没有背景（透明bg）

我怎么能这样做？任何一个例子？

Answer 1

这并不困难。这是主要部分：

public static Bitmap loadBitmapFromId(Context context, int bitmapId) {
        InputStream is = context.getResources().openRawResource(bitmapId);
        try {
            BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
            bitmapOptions.inPreferredConfig = Bitmap.Config.RGB_565;
            return BitmapFactory.decodeStream(is, null, bitmapOptions);
        } catch (Exception ex) {
            Log.e("bitmap loading exeption", ex.getLocalizedMessage());
            return null;
        }
    }

Bitmap.Config.RGB_565在这里非常重要。然后添加位图并像往常一样获取纹理ID。

现在在你的渲染器的onSurfaceCreated（GL10 gl，EGLConfig配置）中添加：

    // Transparancy
    // important: transparent objects have to be drawn last!
    gl.glEnable(GL10.GL_BLEND);
    gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);

绘图部分（你可能已经这样做了）：

        // first disable color_array for save:
        gl.glDisableClientState(GL10.GL_COLOR_ARRAY);

        // Enabled the vertices buffer for writing and to be used during
        // rendering.
        gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
        // Specifies the location and data format of an array of vertex
        // coordinates to use when rendering.
        gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);

        gl.glEnable(GL10.GL_TEXTURE_2D);

        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
                GL10.GL_LINEAR);
        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER,
                GL10.GL_LINEAR);

        gl.glBindTexture(GL10.GL_TEXTURE_2D, myTextureId);
        gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
        gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);

        gl.glDrawArrays(drawMode, 0, verticesCount);

        gl.glDisable(GL10.GL_TEXTURE_2D);
        // Disable the vertices buffer.
        gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);

Android OpenGL ES纹理 - alphablending

1 个答案: