Brushes

[JimBobSquarePants]

From @JimBobSquarePants on December 1, 2015 12:48

This issue wraps several brush types.

I think we should implement at least:

• Path brush
• Pattern brush (Not essential but nice to have)
• Elliptical brush (Not essential but nice to have)
• Gradient brush (Not essential but nice to have)

I'm envisioning something like :

PathBrush brush = new PathBrush
{
    Color = Color.Black,
    Thickness = 10, // the thickness to draw a line
    Path = vectors // A list of vectors to follow
}

Image.Draw(brush)

The method would draw a Bezier curve following the given path, color, and thickness.

Copied from original issue: JimBobSquarePants/ImageProcessor#264

[JimBobSquarePants]

From @dampee on December 21, 2015 12:57

If I get through my color space, I'll see what I can do for January. Any startingpoints, hints, ... ?

[JimBobSquarePants]

That'd be great if you could!

Honestly.... Not got much of a clue. I think the source for Cairo might be a place to start looking around as I think a few libraries wrap around it. I'm trying to get my head around this just now.

https://github.com/mono/sysdrawing-coregraphics/blob/master/System.Drawing.Drawing2D/PathGradientBrush.cs

[JimBobSquarePants]

From @mweber26 on March 16, 2016 12:49

I don't understand this issue. What are the brushes for? There doesn't appear to be any drawing code to use them.

[JimBobSquarePants]

I've expanded on the issue. We'd obviously have to create bezier classes, a draw method, etc

I found a good primer on Beziers here. http://pomax.github.io/bezierinfo/

[JimBobSquarePants]

From @cartman300 on May 25, 2016 0:34

Is there any progress on this? I have quite a good idea how to implement these. Might give it a go.

[JimBobSquarePants]

@cartman300 None whatsoever.

I'm not the greatest mathemagician in the world so I struggle with this kind of stuff so If you know how to do it please give it a go. I would really appreciate it!

I'm essentially looking at first implementing path drawing. I think we should be able to break bezier and quadratic curves into neat methods and take advantage of the new vector types for things like Vector.Dot etc. Being able to set line thickness would very useful also.

Cheers!

[JimBobSquarePants]

From @cartman300 on May 25, 2016 23:11

I've implemented this in my fork

[JimBobSquarePants]

@cartman300 This is incredible! I'm super happy to see this come together. 😄

The syntax is great also; really clean and pretty much exactly what I wanted. I had a quick look through the source code and I can see that you're still working on thickness. What's the status of antialiasing?

Buzzing with this demo. I appreciate it so much!

[JimBobSquarePants]

From @cartman300 on May 29, 2016 0:23

Eh, i forgot antialiasing was a thing. I should definitely implement it. Maybe even some kind of serial image processor, because stuff like this can't be parallelized easily (in fact, it makes it slower). I also have to fix the bézier paths because they don't stack easily, got no idea why yet.

[JimBobSquarePants]

Excellent. Thanks!

You can actually turn off the parallel nature of the processors by overriding the Parallelism property, setting it to 1. I do that here in Resizer

[JimBobSquarePants]

Hey @cartman300, Just found this excellent document on line drawing where at the end they deal with line thickness and antialiasing. We can certainly simplify the code sample by applying some of the Vector methods. I'm hoping it would be as useful to you as it looks.

Bresenham.pdf