1. mathmatical question - to Ralf
Ralf wrote,
> If this is needed very deperate tell me and i'll write a routine
> which checks give coordinates, and returns which polygons (plurar if
> they can overlap each other) the mouse has clicked on
I think that your solution on this problem is based on the idea of
reading pixel color of the polygon. in this case, each polygon has
to be drawn with different color number. I understand it will work.
However, i think the detection for multiple(plural) polygons (as you said)
is not possible when they are overlaped, since the color of underneath
polygon is simply erased by top polygon, make it impossible to read the
color of underneath polygon....
Could you explain on this for me?
Bye! - from Lee, Woo seob.
2. Re: mathmatical question - to Ralf
> However, i think the detection for multiple(plural) polygons (as you said)
> is not possible when they are overlaped, since the color of underneath
> polygon is simply erased by top polygon, make it impossible to read the
> color of underneath polygon....
Simple, if you keep a sequence of the screen in memory, you can poke
it to the screen, and only the last 8 bits of each value are just, so
do your drawing in a sequence and add 256 for each polygon, on the
screen it will have the colors you want and in memory it
automiatically has a special image where you can check polygons very
quickly!!!
Ralf Nieuwenhuijsen
nieuwen at xs4all.nl
