wxGraphicsContext and wxDC ?

[Kevin Ollivier]

Hi Robert,

On Jun 1, 2007, at 11:14 AM, Robert Roebling wrote:

> Kevin Ollivier wrote:
>
>>> Bryan Petty wrote:
>>>
>>>> Stefan replied with the answer to your question:
>>>>
>>>> "The goal is to have a graphics API that is closer to the modern
>>>> graphics engines like Quartz, GDI+ and Cairo, that allow to support
>>>> their richness and capabilities.
>>>>
>>>> It also is important to expose some of their objects like matrices,
>>>> paths etc as separate objects, that can be stored for later  
>>>> reuse, so
>>>> that performance does not suffer from on-the-fly conversions. As a
>>>> compatibility DC there is the wxGCDC (GraphicsContextDC) in  
>>>> dcgraph.h
>>>> that allows to use the old DC API on a new graphics context."
>>>>
>>>> To add to Stefan's reply, wxGraphicsContext is also the turning  
>>>> point
>>>> for abstracting out the rendering engine for the ability to switch
>>>> out
>>>> engines either at compile time or in runtime in the future.
>>>
>>> Well, actually I'm (intermittingly) working on being able to
>>> switch wxDC based drawing engines at run-time (which is
>>> required for using either Cairo or the old drawing system
>>> depending on which version of GTK+ you have).
>>
>> BTW, it looks like the WebKit GTK+ port is solving this issue by
>> allowing Cairo to work with older versions of GTK+, which I think we
>> should try and support as well. They basically re-implement
>> gdk_cairo_context. Here's a copy of the WebKit file to do this that
>> was pasted online last night (it has yet to be submitted to the patch
>> tracker):
>>
>> http://paste.lisp.org/display/42101/raw
>
> I get an error from the server.

Sorry, it worked when I sent the email, but I'm seeing that error too  
now. Try from here instead:

http://kevino.theolliviers.com/cairo-gtk-compat.cpp

>> So basically we'd replace (or conditionally change) our
>> gdk_cairo_create call with this call instead. I was able to use this
>> to compile with --enable-graphics_ctx on a Linux box with an old
>> version of GTK+ and it worked fine, though I still have to test it.
>
> That is an amazing trick, if it really works. Please contact the
> author about the licence.

It's right in the file, it's the WebKit license which is effectively  
BSD.

> Are you still working on wxWebKit?

Yes, I'll probably make an announcement soon, still a lot of things  
to do but it's getting there.

Regards,

Kevin

>   Robert
>
>
>
>
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