alphablending

I'd like to draw antialiased text on a transparent bitmap and have the antialiasing drawn as alpha blended pixels. This way, I can draw the bitmap onto any color surface (or an image, for that matter) and the antialiasing still looks fine. Here is a simplified sample showing the problem: protected override void OnPaint(PaintEventArgs e) { base.OnPaint(e); Bitmap bitmap = new Bitmap(this.Width, this.Height); Graphics g = Graphics.FromImage(bitmap); g.Clear(Color.Empty); g.DrawString("hello world", new Font(this.Font.FontFamily, 24), Brushes.Blue, new Point(50, 50)); e.Graphics.DrawImage(bitmap,

I'm creating what should be a very simple Win32 C++ app who's sole purpose it to ONLY display a semi-transparent PNG. The window shouldn't have any chrome, and all the opacity should be controlled in the PNG itself. My problem is that the window doesn't repaint when the content under the window changes, so the transparent areas of the PNG are "stuck" with what was under the window when the application was initially started. Here's the line where I setup the new window: hWnd = CreateWindowEx(WS_EX_TOPMOST, szWindowClass, szTitle, WS_POPUP, 0, height/2 - 20, 40, 102, NULL, NULL, hInstance, 0);

I'm writing a colour picker that gets the pixel RGB values from wherever you point to on the screen. I want to also have the option of specifying that the colour I picked already has an alpha value. I'm just wondering how I can calculate the resulting colour. For example: The resulting pixel colour is 240,247,249 but I know that the original colour had a 10% opacity and was on top of a white (255,255,255) background. What's the calculation to work out the original RGB values? The standard blending equation is: out = alpha * new + (1 - alpha) * old Where out , new and old are RGB colors, and

Is it possible to lay multiple textures on top of each other on the same face in Three.js so that the alpha blending is done GPU accelerated in webGL? The textures are (or should be) applied to the same face so that the bottom texture (texture 1) is without alpha channel and the above textures are alpha channeled in a way like texture 2 in the below image example. This blending can be achieved using HTML5 Canvas as pre-step, but because texture bitmaps can be huge, I prefer to skip Canvas blending operations. I tested by creating a copy of the mesh and applying one texture per mesh and made

I'm trying to blend a background with a foreground image, where the foreground image is a transparent image with lines on it. I am trying to do it this way. UIGraphicsBeginImageContext(CGSizeMake(320, 480)); CGContextRef context = UIGraphicsGetCurrentContext(); // create rect that fills screen CGRect bounds = CGRectMake( 0,0, 320, 480); // This is my bkgnd image CGContextDrawImage(context, bounds, [UIImage imageNamed:@"bkgnd.jpg"].CGImage); CGContextSetBlendMode(context, kCGBlendModeSourceIn); // This is my image to blend in CGContextDrawImage(context, bounds, [UIImage imageNamed:@"over.png"]