Add missing UI functions for X11 Window class

[ihhub]

We have an optional UI Window classes for image display and drawings. All of them locate in src/ui directory. Currently we support Qt, Win32 API and X11 frameworks. X11 code locates in src/ui/x11/x11_ui.h and src/ui/x11/x11_ui.cpp files. UiWindowX11 class does not have an implementation of following functions:

virtual void drawLine( const Point2d & start, const Point2d & end, const PaintColor & color );
virtual void drawEllipse( const Point2d & center, double xRadius, double yRadius, const PaintColor & color );
virtual void drawRectangle( const Point2d & topLeftCorner, double width, double height, const PaintColor & color );

We want to add them. You could have a look at Win32 or Qt implementation for reference of code implementation.

[MeKot]

@ihhub Do you mind if I take this on?

[fullset]

Hi, @MeKot.

Do you still want to work on this issue?

[ihhub]

hi @fullset , you could take this issue.

[fullset]

@ihhub, OK. I'll take a look.

Maybe you have a quick answer to 1 question.

This string is present in x11_ui.cpp:

XDrawLine( _uiDisplay, _window, defaultGC, static_cast<int>(point.x - 1), static_cast<int>(point.y - 1),
            static_cast<int>(point.x + 1), static_cast<int>(point.y + 1) );

That's how the point is painted. Are there any reasons to use XDrawLine() and don not use XDrawPoint() for this?

[ihhub]

hi @fullset , it's done in a way to draw a cross (x) instead of dot as far as I remember. You could try to play around this and replace the code if you see the need in it. Remember that dot usually is something more than just one pixel as dots in computer vision applications are used to show edge points for example.