How to convert AltlasSprite or Sprite to a Byte Buffer?

(3 posts) (2 voices)

Tags:

ZenSlainer
Member

Hi all,

Let's say I have an AtlasSprite which I've rotated and scaled... Is there a known way to get the pixels data of that AtlasSprite transformed into a RGBA byte buffer?

If the method exists I suppose it will be the same to retrieve pixel datas of a Sprite?

Here is a pseudo example of what I want to achieve:

//-----------------

Sprite *MySprite = [Sprite spriteWithFile: @"catsprite.png"];

[MySprite setRotation: 90.];
[MySprite setScale: 2.0];

unsigned char *RGBA = [self pixelBufferFromSprite: MySprite];

//----------------

Thanks in advance

Posted 2 years ago #
Frank84
Member

Sounds like you would render the sprite you want into a RenderTexture and then grab the contents of that texture. Take a look at getUIImageFromBuffer within RenderTexture to see how to grab the result. After glReadPixels(0,0,tx,ty,GL_RGBA,GL_UNSIGNED_BYTE, &buffer) buffer will store the RGBA data but flipped upside down since OpenGL stores its buffer with the bottom pixels first. If you need it unflipped then start at the top row and iterate to the middle row. swap row i with row height-1-i. Can swap with memmove.

Posted 2 years ago #
ZenSlainer
Member

Okay Frank, that's a good starting point for me. I wasn't aware of RenderTexture thing. Thanks.
Zen

Posted 2 years ago #

Reply

You must log in to post.