Hi, I am happy with using cairo for basic drawing. My problem is that I have drawn a circular grid which is quite dense (spokes every 10 degrees, circles every 10 mm from 10 to 200mm radius) it uses transformations to centre grid set scale etc. In an editing mode I want to be able to draw a highlight line from the centre of the grid to the mouse and at the mouse position display radius and angle values. I am ok with the code to do this but when I run my program I get a lot of flicker because my code clears the area and redraws everything in the motion notify event handler. I really just want to clear the line drawn to the mouse and then redraw it at the next position. My past experience tells me that either, I want the grid to be on a base layer and the hilight line on an upper layer, and then to just clear the upper layer. Or Xor the previous line to restore the background before drawing the next line. Trouble is I dont know if cairo will allow me to do either of these options. Do I have to composite two surfaces instead? If so I havent a clue on how to do this. Or should I save the grid as an image and then use that as the background?
Could someone point me to an example or tutorial which would be of some help. Thanks Alan -- View this message in context: http://www.nabble.com/help-wanted-with-Cairo---fairly-inexperienced-user-tp26101739p26101739.html Sent from the Mono - General mailing list archive at Nabble.com. _______________________________________________ Mono-list maillist - [email protected] http://lists.ximian.com/mailman/listinfo/mono-list
