Introducing Congo Paint

[Simian Man]

Hello all,

I have been working for some time on a simple paint program for GTK+ called Congo Paint. It has now reached a point where it is fairly usable - especially for small scale pixel art which is what I wrote it for. So I decided to release the current version as 0.1!

Features

Loading and saving image files
Zooming in and out
Unlimited undo and redo
Lots of tools:

Pencil
Paint can
Line
Spray can
Rectangle
Ellipse
Eyedropper
Paint brush with 4 strokes

Easy to use and familiar interface


http://ubuntuforums.org/attachment.php?attachmentid=164896&stc=1&d=1280414888

Caveats
As it is only the 0.1 release, there are unfortunately a few problems with Congo Paint still:

There is no select, copy, cut or paste functionality yet
Some functionality is implemented in a naive and slow way
In particular flood fill should not be used on areas more than a few hundred square pixels unless you want to hang your computer.


You can download Congo Paint here (http://code.google.com/p/congo-paint/downloads/list) in source form. Instructions on building it are found in the README. If anyone has any problems or finds any bugs other than the ones I mentioned, please post here or file a bug on the Google Code site.

I have already started using it myself for some purposes. I hope somebody else finds it useful :)

[gnomeuser]

That looks really cool, have you thought of working with the pinta people?

[Simian Man]

That looks really cool, have you thought of working with the pinta people?

Pinta is a really cool project, but it's also more than I want. I just wanted a *really* simple program for doing pixel art. I don't need layers or affects or anything like that. I honestly just really like MS Paint and wanted it for GTK+ :). Thanks for your comment!

[RiceMonster]

Cool. I think I'll check it out when I get home the evening. What language are you writting this in, C?

Edit: I should have looked at the site. It says you're using C#.

[Simian Man]

Cool. I think I'll check it out when I get home the evening. What language are you writting this in, C?

Edit: I should have looked at the site. It says you're using C#.

Hey thanks. Yeah, another reason I started this was because I wanted to do a good-sized project with C# and Monodevelop. It's a really nice development platform.

[RiceMonster]

I've written some minor paint stuff in Java for a small college assignment before, and I've been telling myself I'm going to learn C# for a while, so I'm pretty interested in looking at your code.

[Simian Man]

I've written some minor paint stuff in Java for a small college assignment before, and I've been telling myself I'm going to learn C# for a while, so I'm pretty interested in looking at your code.

The code itself is pretty hackish because I didn't make much of an effort to learn C# or GTK before hand. I just kind of started coding :). I am planning on a refactoring phase, but wanted to make an initial release while it was still somewhat stable.

[Cuddles McKitten]

Did you draw the little monkey-in-a-hat icon for the program in your program? :)

[Simian Man]

Did you draw the little monkey-in-a-hat icon for the program in your program? :)

No, it's an svg, so I used Inkscape. I did use my program to make the tool icons and mouse cursors, but those need some work to I think :).

[Ric_NYC]

Web-based painting app:

http://www.sumopaint.com/app/


No need to install anything.

[realzippy]

Web-based painting app:

http://www.sumopaint.com/app/


No need to install anything.



Spoiler.

[Simian Man]

Web-based painting app:

http://www.sumopaint.com/app/


No need to install anything.

That's actually pretty cool for a web app, but isn't really what I want. I like desktop apps, and it's a bit complicated. Worst of all it doesn't seem to let me turn off anti-aliasing which makes it useless for pixel work. I love the symmetry tool though, that's very neat.

[Ric_NYC]

That's actually pretty cool for a web app, but isn't really what I want. I like desktop apps, and it's a bit complicated. Worst of all it doesn't seem to let me turn off anti-aliasing which makes it useless for pixel work. I love the symmetry tool though, that's very neat.

Ok. I agree!

[user1397]

I posted this on my thread, but it makes more sense here:

Not too shabby at all Simian Man, I thought Congo Paint was quite simple yet effective. I'll be watching its progress.

As for any bugs I had, the only thing was I couldn't use the spray nor the bucket filler (don't know what that's called exactly) too much at one time, or else it would freeze or lock up. Other than that, tried all features and everything worked. Good job!

[phrostbyte]

You didn't use MonoDevelop's GTK+ designer? Wow. :)

[forrestcupp]

Web-based painting app:

http://www.sumopaint.com/app/


No need to install anything.Anything anybody makes is going to have a hundred different things out there like it that are already way better. Sometimes it just exciting to create something for yourself and have it actually work.


You didn't use MonoDevelop's GTK+ designer? Wow. :)Those designers are for cheaters and noobs. :D

[Simian Man]

I posted this on my thread, but it makes more sense here:

Not too shabby at all Simian Man, I thought Congo Paint was quite simple yet effective. I'll be watching its progress.

As for any bugs I had, the only thing was I couldn't use the spray nor the bucket filler (don't know what that's called exactly) too much at one time, or else it would freeze or lock up. Other than that, tried all features and everything worked. Good job!
Thanks for the feedback! I knew that the paint can tool was extremely slow, but I hadn't noticed the spray can, thanks for that. I have to rewrite the drawing code to use only GDK pixbufs. Right now it uses pixmaps which make things easier, but are a lot slower. I've been putting this off for a while, but the positive feedback is good motivation :).


You didn't use MonoDevelop's GTK+ designer? Wow. :)
The interface is such a small part of the code that I didn't think I'd gain that much from using it.

[phrostbyte]

Thanks for the feedback! I knew that the paint can tool was extremely slow, but I hadn't noticed the spray can, thanks for that. I have to rewrite the drawing code to use only GDK pixbufs. Right now it uses pixmaps which make things easier, but are a lot slower. I've been putting this off for a while, but the positive feedback is good motivation :).


The interface is such a small part of the code that I didn't think I'd gain that much from using it.

It's quite hard to make a seemingly simple algorithm like flood fill ("paint can") efficient. Take a look at the source code of Pinta, there should be a FloodTool.cs file in there under PintaTools. You should be able to mostly ninja the FillStencilFromPoint method in there, which implements flood fill.

[Simian Man]

It's quite hard to make a seemingly simple algorithm like flood fill ("paint can") efficient. Take a look at the source code of Pinta, there should be a FloodTool.cs file in there under PintaTools. You should be able to mostly ninja the FillStencilFromPoint method in there, which implements flood fill.

It's actually not my algorithm that's slow, but the way I get the value of each pixel from the pixmap to test whether or not it should be filled. I checked the Pinta source code and they use largely the same basic algorithm I use.

Once I rewrite this all to use pixbufs it won't be a problem :).

[phrostbyte]

It's actually not my algorithm that's slow, but the way I get the value of each pixel from the pixmap to test whether or not it should be filled. I checked the Pinta source code and they use largely the same basic algorithm I use.

Once I rewrite this all to use pixbufs it won't be a problem :).

I can see three optimisations you make that doesn't involve changing how you draw to the screen:

1. Use System.Collections.Generic.Queue<Point> instead of System.Collections.Queue
2. Change "Point" to a struct instead of a class.
3. Memorise (put in memory) CongoPaint.Canvas.GetWidth() and CongoPaint.Canvas.GetHeight()

EDIT: I made these changes, and it is still quite slow. :(

[Simian Man]

I can see three optimisations you make that doesn't involve changing how you draw to the screen:

1. Use System.Collections.Generic.Queue<Point> instead of System.Collections.Queue
2. Change "Point" to a struct instead of a class.
3. Memorise (put in memory) CongoPaint.Canvas.GetWidth() and CongoPaint.Canvas.GetHeight()

EDIT: I made these changes, and it is still quite slow. :(

1. Oh cool, I didn't really realize C# had proper generics. I thought it was like Java.
2. Good idea. I like how in C# there is a difference between classes and structs and I should take advantage of that.
3. Good idea :).

Another optimization that Pinta uses is they scan horizontal lines directly rather than enqueing the points. Thanks a lot for the tips.

I am sure that the cause of the slowdown is from setting and getting the pixels in the Canvas code. I tried commenting out those calls and the tool works nearly instantly. Of course it doesn't actually *do* anything, but it does loop through the pixels and enqueue them properly :).

Thanks again for the tips.

[phrostbyte]

I'm surprised getting and setting pixels is really all that slow. It makes me feel something is wrong with that code path.

[gnomeuser]

Pinta is a really cool project, but it's also more than I want. I just wanted a *really* simple program for doing pixel art. I don't need layers or affects or anything like that. I honestly just really like MS Paint and wanted it for GTK+ :). Thanks for your comment!

That is an admirable goal and I think it is the path towards an application that can be installed by default. Pinta is very good, however I was thinking more in the area of pilfering their likely fairly optimized backend and simply replacing the UI with the Congo Paint (brilliant name btw. I laugh every time I hear it) UI.

[gnomeuser]

1. Oh cool, I didn't really realize C# had proper generics. I thought it was like Java.


C# 3.0's big feature was Generics

Just you wait till you see C# 4.0:

http://channel9.msdn.com/pdc2008/TL16/

[Simian Man]

I'm surprised getting and setting pixels is really all that slow. It makes me feel something is wrong with that code path.
Yeah, it is because I am using pixmaps and have to call the GetImage function to get a 1x1 image for each pixel I need to read and DrawPoint for each point I need to set. I need to use a pixbuf instead and figure out how to get and set pixels from that. If it were C, I'd just be able to read and write ints from an array.


That is an admirable goal and I think it is the path towards an application that can be installed by default. Pinta is very good, however I was thinking more in the area of pilfering their likely fairly optimized backend and simply replacing the UI with the Congo Paint

I won't copy and paste any of their code directly, but I will definitley see how they access their pixbufs :).


(brilliant name btw. I laugh every time I hear it)
Thanks :).


C# 3.0's big feature was Generics

Just you wait till you see C# 4.0:

http://channel9.msdn.com/pdc2008/TL16/

Cool link, thanks. I will watch the rest of it when I get home :).