Hello,

I am extending the converter of FPVectorial to Canvas, but I got stuck at the lack of drawing methods in TFPCustomCanvas. It lacks Arc, Chord, PolyBezier, etc.

The end point being that it gets really hard to use TFPCustomCanvas, the easiest solution being simply dropping support for it and going for TCanvas instead.

Should more drawing routines be added at least as stubs?

thanks,

Felipe Monteiro de Carvalho hat am 26.
Januar 2011 um 16:45 geschrieben:

The Bezier functions of TCanvas are implemented platform independent in the LCL. It should not be hard to port/move them to fpimage.  

Should more drawing routines be added at least as stubs?

Mattias

Yes, feel free to do so. If TCanvas has actual routines for them, maybe you can copy the implementation as well.

Michael.

You beat me to it :)

Michael.

Ok, good =)

One thing, however, should't the drawing routines in TFPCustomCanvas be virtual?

The LCL seams to simply hide them at the moment. Overriding is more usual, isn't it?

Send me a proposal in private if you want.

Michael.

Hello,

I decided to put the patch here since it is so small.

It is rather trivial, just adds a bunch of virtual markers and some methods with empty implementations, as to make them optional. I think the behavior looks ok for me, if the sub-class doesn't implement the method, no operation is performed.

If some methods can be implemented based on other ones, great, but this should be a separate commit.

Later Lazarus would need to be adapted, maybe now with ifdefs or else after fpc 3.0 gets released.

I would suggest to take the opportunity and put const before string parameters so the compiler can generate better code.

Luiz