How to say the third selected point lies within the created geometry or not?
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base_x = [0 50 50 20 0 0]
base_y = [0 0 10 10 10 0 ]
roof_x = [ 0 0 20 20 30 30]
roof_y =[ 10 50 10 50 50 10]
axis([0 50 0 50])
[x] = ginput(2);
[x] = round(x);
fprintf ('the a1 coordinate value is %d,\n' , x(1,1));
fprintf ('the b1 coordinate value is %d ,\n' , x(1,2));
fprintf ('the a2 coordinate value is %d,\n' , x(2,1));
fprintf ('the b2 coordinate value is %d ,\n' , x(2,2));
How to say the third selected points a1,b1 a2,b2 lies within the created geometry ( base,roof) or not?
Adam Danz on 24 Jul 2018
Edited: Adam Danz on 25 Jul 2018
If I understand your question correctly, you're trying to determine if a coordinate (x,y) lies within a polygon.
First try matlab's inpolygon().
Another way to achieve that is by "ray casting". The idea is to draw a line from the (x,y) coordinate and extend it rightward until it passes all of the possible polygon edges. Then count the number of times that ray intersects with an edge of the polygon. If that number is non-zero and odd, then the coordinate (x,y) is within the polygon.