Does anyone have a guide to Stencil operations for the FT800 display list controller?
The limited documentation in the FT800 Programmers guide isn't cutting it.
I would like to use Stencil to limit the drawing area, much like a Region does (in other systems) so that when I print text to the display, what shows up is only the part in the region and anything else is not shown. That way I can have a scrolling bar graph and when the tic mark labels scroll out of view they get steadily disappear vs suddenly (all there or all gone) disappear .
Imagine a tape measure. It has numbers and tic marks. Now unroll it and put it behind a window. It is wider than the window.
As you move the tape, the tics and numbers move. When the numbers intersect the edge of the window they slowly disappear. They are clipped to the window region.
Now I can clip the tics myself (they are single vertical lines) but the numbers are either drawn or not to the area of the screen I want them limited to. I cannot draw only 1/2 (or any fraction) a character as I scroll the tape.
I cannot over draw on the number to clip it as the background is dynamic.
So that's what I am thinking that using a Stencil can do for me. But the lack of decent documentation and only one simple snippet of example code leaves me cold.
Quite by accident, I have found that the Scissors functions are what I need. Scissors (ScissorXY , ScissorSize) sets a rectangle region, which then limits actual drawing to that area. Anything outside that region gets clipped and not shown.
Once again, and hopefully I'm not coming across as mean, decent documentation would have saved me hours.
