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TAChart: Partially support infinite coordinates in LineIntersectsRect

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git-svn-id: trunk@32795 -
This commit is contained in:
ask 2011-10-10 09:45:24 +00:00
parent bfd5aebbd4
commit f7b3333c60
2 changed files with 17 additions and 7 deletions
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16
components/tachart/tageometry.pas
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@ -243,24 +243,28 @@ end;
function LineIntersectsRect(
var AA, AB: TDoublePoint; const ARect: TDoubleRect): Boolean;
var
dx, dy: Double;
procedure AdjustX(var AP: TDoublePoint; ANewX: Double); inline;
var
dx: Double;
begin
AP.Y += dy / dx * (ANewX - AP.X);
dx := AB.X - AA.X;
if not IsInfinite(dx) then
AP.Y += (AB.Y - AA.Y) / dx * (ANewX - AP.X);
AP.X := ANewX;
end;
procedure AdjustY(var AP: TDoublePoint; ANewY: Double); inline;
var
dy: Double;
begin
AP.X += dx / dy * (ANewY - AP.Y);
dy := AB.Y - AA.Y;
if not IsInfinite(dy) then
AP.X += (AB.X - AA.X) / dy * (ANewY - AP.Y);
AP.Y := ANewY;
end;
begin
dx := AB.X - AA.X;
dy := AB.Y - AA.Y;
case CASE_OF_TWO[AA.X < ARect.a.X, AB.X < ARect.a.X] of
cotFirst: AdjustX(AA, ARect.a.X);
cotSecond: AdjustX(AB, ARect.a.X);

8
components/tachart/test/UtilsTest.pas
View File

@ -82,7 +82,7 @@ type
implementation
uses
TAGeometry, TAMath;
Math, TAGeometry, TAMath;
{ TIntervalListTest }
@ -252,6 +252,12 @@ begin
p1 := DoublePoint(10, 20);
p2 := DoublePoint(15, -10);
Check(p1, p2, DoublePoint(11.6667, 10), DoublePoint(13.3333, 0));
p1 := DoublePoint(10, 5);
p2 := DoublePoint(SafeInfinity, 5);
Check(p1, p2, p1, DoublePoint(20, 5));
p2 := DoublePoint(10, NegInfinity);
Check(p1, p2, p1, DoublePoint(10, 0));
end;
procedure TGeometryTest.TestPointInPolygon;