Re: Drawinglayer hatching

On 22 Dec 2019, at 6:23 pm, Chris Sherlock <chris.sherlock79@gmail.com> wrote:
> Hello all, 
>
> I have been looking into getting hatching working for EMF+ processing. I can see we already have 
> some hatching code that draws diagonal lines, but for the life of me I’m not sure how to extend 
> this to other forms of hatching like dithering (yes, EMF+ requires this). 
>
> Can anyone give me a rundown how the drawinglayer hatching code works so I can extend it?
>
> Other example hatches I need to implement, incidentally, can be found here:
>
> https://bootes.blob.core.windows.net/article-11/winforms-hatch-brushes.jpg 
> <https://bootes.blob.core.windows.net/article-11/winforms-hatch-brushes.jpg> 
>
> Chris

I have submitted a patch that implements the hatching lines that we already have:

https://gerrit.libreoffice.org/#/c/core/+/85796/ <https://gerrit.libreoffice.org/#/c/core/+/85796/> 

We can easily implement horizontal, vertical, forward and backward diagonal, grid and cross 
hatching. Looking at the results, I think my hatching is going outside of the border by 1 pixel, 
any ideas on how to fix this would be greatly appreciated. 

In terms of implementing hatching for the other styles, if anyone has any ideas on how to do this, 
it would be greatly appreciated also. 

Chris