Draw / Play Animated Gif (C++)

[Aaron Symons]

Hi guys,

 

I was just wondering if there's a way to draw/play an animated gif image on screen in C++ using Leadwerks?

 

Many thanks

[mbarhon]

Hi,

i like your idea. The way is maybe create your own loader/class. For every frame of GIF create texture using function Texture:Create and fill data with Texture:SetPixel (look for it in API) Description of GIF format will be on internet or look for some GIF loader for pure opengl, it will be similar i guess

[Aaron Symons]

Hi mbarhon,

 

Thank you for the guidance. I'll try your suggestions when I have time and update the thread accordingly.

 

Many thanks

[Aaron Symons]

I thought I'd update this thread, seeing as I said I would!

 

During my research I came across issues with GIF licensing, and why the GNU - and others - pretty much refuse to even deal with GIF now.

 

However, I came across Animated-PNG which is an extension to the PNG format developed by Mozilla! I think APNG is a viable substitute if we want to integrate animated images in Leadwerks.

 

I have the APNG add-on for GIMP, and now I'm researching how to read the file's frames in C++ and draw them to the screen using OpenGL. I haven't come across much information yet, but I think it's worth the effort.

 

[Dan22]

My game would benefit so much from animated textures, although its in Lua

[gamecreator]

Just want to make sure you guys saw this thread: http://www.leadwerks.com/werkspace/topic/14677-lua-animated-sprite-sheet/

[martyj]

I wonder if Josh's new UI stuff would work for this. I believe he is adding draw functions on the Window itself.

[Aaron Symons]

[i know this post could have been much better in explanation, but I'm tired and need sleep ]

 

Okay guys, another update on implementing an animated image file (now A-PNG) in Leadwerks.

 

It's pretty simple: implement the TinyImageLoader !

 

Use that library to read the APNG into a TIL::Image - by default it will give you image frame count - then, just use a Leadwerks::Texture to draw to the context, setting the texture's pixels to the appropriate TIL::Image frame's pixels based on a simple interval timer - using TIL to get the pixel data (and manually converting it to a char* before passing to the Leadwerks::Texture).

 

There are a couple of good examples included with TinyImageLoader SDK. I just referenced the first example, and thought how I could create an actual Leadwerks::Texture from the information supplied to me by TinyImageLoader.

 

I now have an Animated-PNG image that renders to the screen and auto-updates the frame based on a set interval. I was going to have the APNG class implement Leadwerks::Texture, but I don't feel like implementing the extra 30+ virtual methods right now! *sad face*

 

That's all for now, as I feel it could be simple enough for others to implement - if not a good test of some basic C++ to C/C++¹ implementation abilities. However, if anyone would like me to post a code example I will!

 

Many thanks!

 

¹ The original code was written in C and then rewritten in C++ for TinymageLoader, though some C-style syntax does still appear.