Offset Line / Code for a flashing tool.

[Assembly]

Here is a function I wrote to create an offset polyline.

I draw flashings regularly. This code makes it easy.

All you need to do is set the thickness, use the Next Point to give a distance and angle and this will create a closed poly line.

PROCEDURE Offset;

{Code by Justin Wright 14 July 2012}

{Open to anyone cheers}

TYPE

Level1=Structure

hTemp: Array[1..4] of Handle;

GroupHandle:Handle;

RectHandle:Handle;

DirectionAngle:REAL;

END;

Var

ArrayStore:Array[1..10] of Level1;

PolyLocus:Array[1..100] of Handle;

iPolyLocus:Integer;

X1,Y1,X2,Y2:REAL;

ArrayPoint:Integer;

iCount:Integer;

iTotal:Integer;

Thickness:REAL;

bTemp:BOOLEAN;

PntA1,PntA2,PntB1,PntB2,PntIntersect: Point;

PROCEDURE NextPoint(LineLength,ObjAngle:REAL);

{This function creates a rectangle of locus points and stores the locus handels in an array}

{The array also stores the direction angle}

BEGIN

ArrayPoint:=ArrayPoint+1;

BEGIN;

BeginGroup;

Locus(0,0);

ArrayStore[ArrayPoint].hTemp[1]:=LNewObj;

Locus(LineLength,0);

ArrayStore[ArrayPoint].hTemp[3]:=LNewObj;

Locus(0,Thickness);

ArrayStore[ArrayPoint].hTemp[2]:=LNewObj;

Locus(LineLength,Thickness);

ArrayStore[ArrayPoint].hTemp[4]:=LNewObj;

EndGroup;

ArrayStore[ArrayPoint].GroupHandle:=LNewObj;

ArrayStore[ArrayPoint].DirectionAngle:=ObjAngle;

iTotal:=iTotal+1;

END

END;

PROCEDURE UsePointsMakeShape;

BEGIN;

{Get the hanel of each group of locus/ Rotate the group / Get the position of the previous group to move the current}

hRotate(ArrayStore[1].GroupHandle,0,0,ArrayStore[1].DirectionAngle);

{Get the position of a locus from previous group to move the current group into possition}

For iCount:=2 to iTotal Do

Begin;

hRotate(ArrayStore[iCount].GroupHandle,0,0,ArrayStore[iCount].DirectionAngle);

GetLocPt(ArrayStore[iCount-1].hTemp[3],X1,Y1);

hMove(ArrayStore[iCount].GroupHandle,X1,Y1);

End;

{Use the Locus in the group to find the intersetoin of the lines. Create a new set of locus which will become the polyline points}

{First Point}

PolyLocus[iPolyLocus]:=ArrayStore[1].hTemp[1];

{Cycyle up through the group to the the inside}

For iCount:=1 to iTotal-1 Do

BEGIN;

GetLocPt(ArrayStore[iCount].hTemp[1],PntA1.X,PntA1.y);

GetLocPt(ArrayStore[iCount].hTemp[3],PntA2.x,PntA2.y);

GetLocPt(ArrayStore[iCount+1].hTemp[1],Pntb1.x,PntB1.y);

GetLocPt(ArrayStore[iCount+1].hTemp[3],PntB2.x,PntB2.y);

LineLineIntersection(PntA1,PntA2,PntB1,PntB2,bTemp,bTemp,PntIntersect);

Locus(PntIntersect.x,PntIntersect.y);

iPolyLocus:=1+iPolyLocus;

PolyLocus[iPolyLocus]:=LNewObj;

END;

{Get the two end points at the top of the polyline}

iPolyLocus:=1+iPolyLocus;

PolyLocus[iPolyLocus]:=ArrayStore[iTotal-1].hTemp[3];

iPolyLocus:=1+iPolyLocus;

PolyLocus[iPolyLocus]:=ArrayStore[iTotal-1].hTemp[4];

{Cycle down the array to get the right hand side intersection points}

For iCount:=iTotal-1 downto 2 Do

BEGIN;

GetLocPt(ArrayStore[iCount].hTemp[2],PntA1.X,PntA1.y);

GetLocPt(ArrayStore[iCount].hTemp[4],PntA2.x,PntA2.y);

GetLocPt(ArrayStore[iCount-1].hTemp[2],Pntb1.x,PntB1.y);

GetLocPt(ArrayStore[iCount-1].hTemp[4],PntB2.x,PntB2.y);

LineLineIntersection(PntA2,PntA1,PntB2,PntB1,bTemp,bTemp,PntIntersect);

Locus(PntIntersect.x,PntIntersect.y);

iPolyLocus:=1+iPolyLocus;

PolyLocus[iPolyLocus]:=LNewObj;

END;

{The final two points at the end of the poly}

iPolyLocus:=1+iPolyLocus;

PolyLocus[iPolyLocus]:=ArrayStore[1].hTemp[2];

iPolyLocus:=1+iPolyLocus;

PolyLocus[iPolyLocus]:=ArrayStore[1].hTemp[1];

{Now create a new poly line}

BeginPoly;

For iCount:=1 to iPolyLocus DO

Begin;

GetLocPt(PolyLocus[iCount],X1,Y1);

LineTo(x1,y1);

End;

EndPoly;

{Delete all the locus now note needed}

For iCount:=1 to iPolyLocus-1 DO

BEGIN

IF PolyLocus[iCount]<>NIL THEN DelObject(PolyLocus[iCount]);

END;

For iCount:=1 to iTotal-1 DO

BEGIN

IF ArrayStore[iCount].GroupHandle<>NIL THEN DelObject(ArrayStore[iCount].GroupHandle);

END;

END;

{Now create the actual Geometery of the Flashings}

PROCEDURE WINDOWHEad(FlashWidth:Real);

BEGIN;

NextPoint(5,45);

NextPoint(15,90);

NextPoint(FlashWidth,15);

NextPoint(35,90);

NextPoint(1,180);

NextPoint(5,-90);

UsePointsMakeShape;

END;

{***MAIN FUNCTION BODY***}

BEGIN;

iTotal:=1;

iPolyLocus:=1;

Thickness:=.55;

{To use the fuctions simply NextPoinst then usePointsMakeShape}

NextPoint(5,45);

NextPoint(40,90);

NextPoint(20,180);

NextPoint(30,90);

NextPoint(120,-10);

NextPoint(10,-45);

UsePointsMakeShape;

END;

RUN(Offset);