Question About Converting C++ Struct to Clarion Structure

questions
1

Need some help converting this C++ Struct to a Clarion structure.

It’s clearly going to be a Group of some kind but the C++ syntax has me guessing:

struct Point {
Point(double x0, double y0) : x(x0), y(y0) {}
double x;
double y;
};

Here’s an example of the Struct being populated:

const Point test_polygon2[39] = {
Point(0, 1), Point(1, 1), Point(1, 2), Point(2, 2), Point(2, 3),
Point(3, 3), Point(3, 2), Point(4, 0), Point(5, 9), Point(6, 0),
Point(7, 2), Point(8, 0), Point(8, -2), Point(7, -3), Point(6, -2),
Point(5, -2), Point(4, -2), Point(3, -1), Point(2, -2), Point(1, -2),
Point(0, -3), Point(-2, -3), Point(-3, -4), Point(-4, -3), Point(-5, -3),
Point(-5, -2), Point(-4, -2), Point(-4, .5), Point(-5, .5), Point(-5, 1),
Point(-4, 1), Point(-4, 2), Point(-4, 4), Point(-3, 4), Point(-3, 2),
Point(-2, 2), Point(-2, 0), Point(-1, 1), Point(0, 1)
};

My current guess is a Group within a Group.

Thanks!

2

Other websites suggest a double is the same as a clarion BFLOAT8 datatype.
There is also this datatype in windows that uses longs.
POINT (windef.h) - Win32 apps | Microsoft Learn

So I’m guessing its going to be something like

_MyPoint   Group,Dim(39),Type
x0         bFloat8
y0         bFloat8
           End

MyPolygonPoint  Group
MyPoint         Like(_MyPoint)
                End
  Code
MyPolygonPoint[1].MyPoint.x0 = a number
MyPolygonPoint[1].MyPoint.y0 = a number

MyPolygonPoint[2].MyPoint.x0 = a number
MyPolygonPoint[2].MyPoint.y0 = a number

OR

_MyPoint   Group,Type
x0         bFloat8
y0         bFloat8
           End
  
MyPolygonPoint  Group
MyPoint         Like(_MyPoint),Dim(39)
                End
   Code
MyPolygonPoint.MyPoint[1].x0 = a number
MyPolygonPoint.MyPoint[1].y0 = a number

MyPolygonPoint.MyPoint[2].x0 = a number
MyPolygonPoint.MyPoint[2].y0 = a number

And when working with floats, the decimal seems to work well when needing to perform calculations, so the same may apply with the Clarion decimal datatype.

hth

3 
POINTF                        GROUP, TYPE
x                               REAL
y                               REAL
                              END
1 Like
4

Thank you to all that responded.

The correct answer is:

POINT	GROUP, TYPE
x       REAL
y       REAL
        END

I have worked with “points” in C#/C++ and I knew that’s what a Clarion point structure should be. It was the extra “code” in the example C++ Struct that caused some confusion.

5

Your declaration may conflict with POINT defined in svapi files.

6

I think my moral of the story is, dont trust the search engines to look up data types.

1 Like