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I've never used the GRAPHICS commands before, and this week while down with a bad cold, I started to learn some of them. One of the things I started with was:
but I was having trouble getting the triangle to paint, and not the space around it...
My estimates for x and y were often incorrect. I needed to find a way to be absolutely sure of a point inside the shape.
I did a LOT of research, reading, and test coding, and tried at least three methods. I settled on one that's straightforward and easily handles anything I could throw at it.
I'm posting it here as my way of saying thank you to all who have helped me in the past, in the hope that it might be of some small help.
After I do some more cleanup, I'll post the entire test program. It does have some pretty cool routines...
-John
Here's the change:
And here's the function; works like a champ with triangles of ANY shape:
Supporting TYPES:
Code:
GRAPHIC ATTACH hTriangle, 0 GRAPHIC POLYGON PlotPoints, %BLUE GRAPHIC PAINT (x, y) , %BLUE
My estimates for x and y were often incorrect. I needed to find a way to be absolutely sure of a point inside the shape.
I did a LOT of research, reading, and test coding, and tried at least three methods. I settled on one that's straightforward and easily handles anything I could throw at it.
I'm posting it here as my way of saying thank you to all who have helped me in the past, in the hope that it might be of some small help.
After I do some more cleanup, I'll post the entire test program. It does have some pretty cool routines...
-John
Here's the change:
Code:
GRAPHIC ATTACH hTriangle, 0 GRAPHIC POLYGON PlotPoints, %BLUE lRet = FindPointInTriangle (PlotPoints, StartPoint) GRAPHIC PAINT (StartPoint.x, StartPoint.y) , %BLUE
Code:
FUNCTION FindPointInTriangle (BYREF PointsList AS PolyArray, BYREF RetVal AS PolyPoint) AS LONG 'A known point inside a triangle is it's "centroid", where the medians of the angles intersect RetVal.x = (PointsList.xy(1).x + PointsList.xy(2).x + PointsList.xy(3).x) / 3 RetVal.y = (PointsList.xy(1).y + PointsList.xy(2).y + PointsList.xy(3).y) / 3 FUNCTION = %TRUE END FUNCTION
Supporting TYPES:
Code:
TYPE PolyPoint
x AS SINGLE
y AS SINGLE
END TYPE
TYPE StraightLine
p1 AS PolyPoint 'some point that is on the line
p2 AS PolyPoint 'some other point that is on the line
SegLen AS SINGLE 'optional
Rise AS SINGLE 'optional
Run AS SINGLE 'optional
Slope AS SINGLE 'optional
END TYPE
TYPE PolyArray
COUNT AS LONG
xy(1 TO 100) AS PolyPoint 'Can't redim dynamically, but extras aren't harmful
END TYPE
TYPE Triangle
Points AS PolyArray ' TriangleName.Points.xy(1).x
S12 AS StraightLine 'Side
S23 AS StraightLine 'Side
S13 AS StraightLine 'Side
A12 AS SINGLE 'Angle
A23 AS SINGLE 'Angle
A13 AS SINGLE 'Angle
Centroid AS PolyPoint'intersection of medians
TriangleClassA AS STRING * 7 'Classifcation based on Angles (eg, right, obtuse, acute)
TriangleClassS AS STRING * 11 'Classifcation based on Sides (equilateral, scalene, isoceles)
' lengths accomodate full text descriptors
' (if we stored only the first char, we'd need programatic interpretations later)
END TYPE
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