Looking for a graphic library program

[gradha]

Hi there.

I'm coming from Python+PIL background. I'm sick of it being so slow for pixel processing. Cython is much better, but I would prefer something that didn't feel awkward to write in. I haven't seen any PIL like graphic libraries for Cora. Are there any?

Also, maybe it's no point in rewriting the square wheel if you can use the shiny round one. Is there any C# library that Cobra can interface to nicely? (new to C# as well as Cobra). I'm looking for something that allows me to do pixel level manipulation at the typical rgb components.

[Charles]

C#, Visual Basic and Cobra all produce "standard .NET libraries" so they can use each other's libraries seamlessly. .NET & Mono include a library called System.Drawing. Here is small program to get you started:

"""
DrawingExample.cobra

Generating bitmap images with the System.Drawing library.

References:

System.Drawing - <!-- m --><a class="postlink" href="http://msdn.microsoft.com/en-us/library/system.drawing.aspx">http://msdn.microsoft.com/en-us/library ... awing.aspx</a><!-- m -->

"""

@ref 'System.Drawing'

@number float64

use System.Drawing
use System.Drawing.Drawing2D
use System.Drawing.Imaging
use System.Drawing.Text

class Program

    def main
        .saveSample
        
    def saveSample
        bm = .makeBitmap
#       bm.save('sample.jpg', ImageFormat.jpeg)
        bm.save('sample.bmp', ImageFormat.bmp)
        print 'Saved: sample.bmp'
        print 'done.'
    
    def makeBitmap as Bitmap
        width = 480
        height = 200
        
        bm = Bitmap(width, height)
        g = Graphics.fromImage(bm)
        
        g.clear(Color.forestGreen)
#       g.clear(Color.blue)
        g.flush

        g.smoothingMode = SmoothingMode.AntiAlias
        g.textRenderingHint = TextRenderingHint.ClearTypeGridFit
        
        if true
            font = Font('Tahoma', 18, FontStyle.Bold)
            brush = SolidBrush(Color.white)
            g.drawString('The Cobra Programming Language', font, brush, 10, 50)
            g.flush
        
        if false
            for i, hint in [TextRenderingHint.AntiAlias, TextRenderingHint.AntiAliasGridFit, TextRenderingHint.ClearTypeGridFit].numbered
                font = Font('Tahoma', 18, FontStyle.Bold)
                brush = SolidBrush(Color.white)
                g.textRenderingHint = hint
                g.drawString('The Cobra Programming Language', font, brush, 10, 10 + (50 * i))
                g.flush
            
        return bm

[Charles]

If you have any more questions or issues, feel free.

I have also attached the program to this message if that makes it easier to get.

-Chuck

[gradha]

That's a good starting point, thanks. Interesting convention about lower/upper case. What does cobra do if C# has two class methods or variables which are different only in the casing of the first letter?

[Charles]

You'll almost never see this. The reason is that .NET started with (at least) 2 languages: C# and Visual Basic (VB). VB is case insensitive, so people who write libraries avoid such practices. In fact, there is a "Common Language Specification" to avoid these issues. From http://blogs.msdn.com/b/brada/archive/2004/03/20/93341.aspx, "The CLS (or Common Language Specification) is simply a contract between programming language designers and class library authors."

In direct answer to your question, I couldn't remember since I'm not using any such libraries! But I constructed such a library in C#, and Cobra is binding to the first declared method.

Btw I think such a class would be poorly designed. For example, if a Color object had properties "brightness" and "Brightness", what differences between them are implied by a change in case?

[gradha]

Certainly the class would be not very nice to use. I only wanted to know if trying to use such a library would make Cobra crash or make the program unstable. I don't expect to find such a fabricated case in real life.

[Charles]

Cool. If you produce any graphics generation code that you can share back, that would be interesting to see.

[gradha]

I was expecting to post the Cobra version of my Python program in one week or so to let you critizise it. It's not rocket science, I only process some input images in a way that are useful to me in another program, so I don't think it will be too interesting, especially since it makes assumptions on the input data to treat it correctly, which discards its use for other graphics.

Ouch, now I've remembered that the final part of the Python program calls a custom C module for packaging. Argh, that will be painful to port...

[Charles]

You wrote this C module or its third party? Is it originally plain C code which is then wrapped up in a Python module, or is it a Python module to begin with? What platform are you on?

[gradha]

Custom modifications to an old C lib. I wanted it to work in obj-c on the iPhone and macosx build scripts in python. I guess I'll port it to C# or Cobra directly. It's not much work, just boring.