slow drawing

Hi

I have a embedded PC (586 133) with a LCD which is running QNX4 with
Photon. The PC receives primitives from a host PC over an ethernet
connection
and updates the screen.

Two issues have come up now that the graphics on the screen is getting more
complicated. First you can see the redraw. I was wondering about using
a DBContainer widget. How does this work? How do I write to the
second buffer?

Second issue is that it is now too slow and falling behind the host. Will
the DBContainer speed things up. Also, I am using alot to PutPixel calls.
Any ideas on how to speed this up.

Thanks

Thom Allen

Two issues have come up now that the graphics on the screen is getting more
complicated. First you can see the redraw. I was wondering about using
a DBContainer widget. How does this work? How do I write to the
second buffer?

You don’t “write to the second buffer.” The DBContainer widget is just that,
a container widget. You put your widgets inside it. When they attempt to
redraw, the draw events are routed by the DBContainer widget to a memory
context. The memory context is then updated.

This provides a smoother update. It also may be visually slower. There
are also some limitations having to do with the type of graphical images
you are showing, palette vs direct draw. For the project I was working
on it did not work very well. I can see circumstances in which it would.

Second issue is that it is now too slow and falling behind the host. Will
the DBContainer speed things up.

Most likely not.

Mitchell Schoenbrun --------- maschoen@pobox.com

Thom Allen <tallen@mechtronix.ca> wrote:

Second issue is that it is now too slow and falling behind the host. Will
the DBContainer speed things up. Also, I am using alot to PutPixel calls.
Any ideas on how to speed this up.

PgDrawPixelArraymx would probably help out, so long as there wasn’t a color change
between the PgDrawPixel() calls.

Dave Rempel