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Questions tagged [alphablending]

Alpha blending is a convex combination of a translucent foreground color with a background color allowing for transparency effects.

562 questions
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Alpha blending issue with multiple rendering iterations into the same texture (OpenGL)

The scenario I'm creating a frame buffer object and binding a texture to colour attachment 0. I'm not using a depth buffer. After creating it, I unbind it. At some point in time later, the frame buffer is bound, a triangle strip is rendered to it…
bitjeep
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Transparent FrameBuffer background in OpenGL

I want to use glClear and glClearColor to fill a frame buffer with a colour including alpha transparency. However the framebuffer always renders as opaque when binded to a texture which is rendered to the screen. I want everything which is rendered…
Matthew Mitchell
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AlphaBlend in FireMonkey

How can I change AlphaBlend value (of a form) in a FireMonkey Desktop Application? Well It's available in VCL Application but I couldn't find it in FireMonkey. Screenshot:
Sky
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What is the formula for alpha blending for a number of pixels?

I have a number of RGBA pixels, each of them has an alpha component. So I have a list of pixels: (p0 p1 p2 p3 p4 ... pn) where p_0_ is the front pixel and p_n_ is the farthest (at the back). The last (or any) pixel is not necessary opaque, so the…
avp
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Recreate HSV color using blend modes

I’m working on an app that creates images whose hue, saturation, and value change according to different parameters. For performance reasons, it would make sense to render the hue, saturation, and value components separately, and then composite them…
Zev Eisenberg
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Can you override a parent UIView's alpha value on one of its subviews?

I have a somewhat transparent view (alpha = 0.6) that has some subviews. I'd like one of the subviews (a UILabel) to be drawn with alpha of 1.0 because the blending makes the text difficult to read but by adding it as a subview of the main view it…
Meltemi
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blending mode formula for hard-light, soft-light, color-dodge, color-burn?

I'm trying to implement poor-man's blending modes for CSS, in anticipation of browsers rolling out support. (The CSS preprocessor I'm using is Stylus, which isn't important to the discussion.) I've found a source for blending mode calculations from…
Paul d'Aoust
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Android Bitmap Alpha Banding

I have a png of a radial alpha gradient, so at the edges its black and in the center is completely transparent with a nice smooth gradient. When I load my Bitmap and display it on a SurfaceView Canvas, I get bad alpha banding. Instead of a nice…
Kage
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OpenGL alpha blending

I've found 5349574673 pages on alpha blending and I still can't get the desired result. I'm trying to make gif/png files display properly (WITH transparency/translucency) using opengl. Here's my initialization…
adrianton3
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How are `glTexEnv`, `glColor4x` and `glBlendFunc` related in OpenGL ES 1.0?

I'm looking at SurfaceFlinger, i.e. the the code that is doing the composition in Android, and I have trouble understanding some of the OpenGL ES 1.0 calls as I've only programmed ES 2.0 code. Here goes the piece of code that interests…
Albus Dumbledore
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Gradual fading by drawing a transparent rectangle repeatedly

This is a question about Processing.org. I am fading out previously drawn objects by drawing a semi-transparent white rectangle over the view for every frame. However, it appears that they never fade to completely white. The fading has a fixed…
Szabolcs
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Merge two images with transparencies in PHP

I'm attempting to make a composite image of several .png's with background transparencies via php and store the resulting image in my database. My problem is that the transparent sections of my images are being dropped when I merge the images. This…
Casey Flynn
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Blend UIView (Overlay) with app background

I would like to blend a UIView with my app's background, using a special blend mode (in my case, the Overlay mode). However, the view to blend is contained in a complex hierarchy of views. Blending a view with its direct siblings can be achieved…
Morpheus
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How to draw a translucent image on a form?

I want to a draw a translucent image on a Delphi form, but for some reason it is not working. Here is the original PNG (border is semi transparent): I load the image in a TImage object: Image1.Transparent := True; Form1.Color :=…
Little Helper
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Why does OpenGL blending not work on HTC Desire?

Does anyone know how to enable blending in OpenGL (android) on a HTC Desire. I am trying to draw colored triangles and using the alpha value of the color buffer to blend them with the background (or another triangle). It works both on the emulator…
Sunkas
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