Multisampling antialiasing (MSAA) in cocos2dx-v4

cocos2d-x C++
1

Hello, we’ve successfully ported our mixed 2d-3d game’s prototype with disabled MSAA to cocos-V4 with only 5% performance drop.

Now I’m trying to enable antialiasing back.

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As far as I understood MSAA is currently unimplemented in v4.

// from CCEAGLView-ios.mm:
// https://github.com/cocos2d/cocos2d-x/blob/v4/cocos/platform/ios/CCEAGLView-ios.mm
- (id) initWithFrame:(CGRect)frame pixelFormat:(NSString*)format depthFormat:(GLuint)depth preserveBackbuffer:(BOOL)retained sharegroup:(EAGLSharegroup*)sharegroup multiSampling:(BOOL)sampling numberOfSamples:(unsigned int)nSamples
{ ..
// numberOfSamples and nSamples are unused here

If I’m not right could you please advise me on how to enable MSAA in cocos2dx-v4.

Or if it’s unimplemented, do you planning to implement it and when?

2

@zhangxm @coulsonwang can you help with this?

1 Like
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Sorry about for MSAA missing in v4, I will take a look when I am finished works at hand.

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Thanks for Your reply. I’ll continue to investigate possible ways of implementing MSAA my self.

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If you fix the MSAA issue, it will be appreciated to post a PR to v4 branch, and we will review it.

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After a month and a half passed I finally made a pull request with my MSAA solutions.

My first goal was to implement OpenGL-like multisampling over metal. And now it works fine for most cases.

But not in my game. Where I found that Renderer has to create the new MTL-encoder on each 2d/3d sprite change during scene draw.

It takes a lot of time to create encoder with multisample attachments. To achieve acceptable rendering speed I made a unified MTL-encoder for drawing to texture with MSAA and depth enabled.

You may check the performance advantage of this encoder by running the new test “RenderTextureWithMsaaSprite3D”.

I understand that this solution is pretty dirty and situational to be merged to cocos-2d master. But its a good start point for future development. Here is the capture of this test running on a 6 scale.

The speedup was 12 to 60 fps on my iPhone 10.

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Hello @zhangxm @coulsonwang. Sorry for auto-tests failed by my previous commit. I’m not a very experienced GitHub user and didn’t notice the test’s status.