OpenEuphoria

Re: finding if point is inside irregular rectangle

• Posted by tone.skoda at siol.net Feb 25, 2002
• 404 views

They are decimal numbers, and quite big.
If they would be small integers your method would work and would be easy to
write, good idea.

----- Original Message -----
From: "Dan Moyer" <DANIELMOYER at prodigy.net>
To: "EUforum" <EUforum at topica.com>
Subject: Re: finding if point is inside irregular rectangle


>
> Tone,
>
> What is the type & range of values for the points to test and of the
corners
> of your quadrilateral?  Are they non-integer, like when you were
interested
> in finding if points were inside a normal rectangle?
>
> I ask because for integers within a certain range of values (video screen
> settings), there is a very easy way to tell if a candidate point is within
a
> polygon of any shape at all.  You just draw the polygon on a non-displayed
> screen, filled with some color other than background, and then test if the
> point in question is that color.  It's probably not fast, but it's easy.
>
> Dan Moyer
>
> ----- Original Message -----
> From: <tone.skoda at siol.net>
> To: "EUforum" <EUforum at topica.com>
> Sent: Monday, February 25, 2002 11:22 AM
> Subject: finding if point is inside irregular rectangle
>
>
> Here's another problem: I need to find out if point lies inside
> an irregular rectangle. Irregular rectangle has
> 4 corners but they don't need to be 90 degree, although they can still be.
>
> Example of irregular rectangle:
>
>      Please view in a fixed-width font such as
>                     Courier.
>
>
>          |--
>          |  ----
>         |       ---
>         |          ----
>        |               ---
>        |                  ----
>       |                       -\
>       |                         \\
>       |                           \
>      |                             \
>      |                              \\
>     |                                 \
>     |                                  \
>    |                                    \\
>    |------                                \
>           -----------                      \
>                      ----------             \\
>                                -----------    \
>                                           -----\
>
>
> Below is function which needs to be finished. I would do it myself but I'm
> not too good at math.
>
> -- bounds parameter should define 4 points of rectangle and should have
> these members:
> -- 1,2: left_top_x, left_top_y,
> -- 3,4: left_bottom_x, left_bottom_y,
> -- 5,6: right_top_x, right_top_y,
> -- 7,8: right_bottom_x, right_bottom_y.
> function is_point_in_irregular_rect (sequence point, sequence bounds)
>     -- This is returned.
>     integer is_point_in_rect
>     -- TODO
>     return is_point_in_rect
> end function
>
>
>
>