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1
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1answer
720 views

How can I implement “cut outs” for lighting in OpenGL?

So, I'm working with OpenGL (I'm not exactly sure of the version), and I want to do an old-style lighting setup by essentially drawing a black rectangle over the screen, and drawing white circles over ...
9
votes
1answer
10k views

Blend Modes in Cocos2D with glBlendFunc

We've been trying to replicate the most common blending modes that are available in Photoshop and Quartz 2D, but we've only come up with 3 and that's after some long searching online. For anyone ...
8
votes
1answer
198 views

How to dynamically animate a part of a 3d model towards something

I'm curious about how this sort of animation is typically done code-wise. A few examples: A character picks something up - only hand is animated towards the target ...
0
votes
1answer
485 views

How can I make a 32-bit render target with a 16-bit alpha channel in Direct3D?

I want to create a render target that is 32-bit, with 16 bits each for alpha and luminance. The closest surface formats I can find in the DirectX SDK are: D3DFMT_A8L8 // 16-bit, 8 bits each for ...
3
votes
2answers
2k views

blending alpha textures in gluOrtho2D

i'm doing a simple game/application with some minimal 2d graphics: png textures and ploygons with standard glVertex calls my setting: glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(0, w, ...
9
votes
2answers
6k views

How do I use depth testing and texture transparency together in my 2.5D world?

Note: I've already found an answer (which I will post after this question) - I was just wondering if I was doing it right, or if there is a better way. I'm making a "2.5D" isometric game using OpenGL ...
1
vote
1answer
1k views

OpenGL ES Shader help (Blending)

Earlier I required assistance getting to grips with how to retain the alpha channel of a transparent texture in my colourised texture shader program. Whilst playing with that first version of my ...
4
votes
2answers
2k views

Blending 2d images to subtract alpha

I'm looking into doing a 2d lighting system with a result similar to this: http://forums.tigsource.com/index.php?topic=15619.0 This thread I believe disregards color, as well as doesn't really list a ...