Как повернуть элипс?
Как повернуть элипс?
procedureTForm1.EllipseAngle(ACanvas: TCanvas; XCenter, YCenter,
XRadius, YRadius: Integer; Angle: Integer);
const
Step = 49;
var
RX, RY: Integer;
i: Integer;
Theta: Double;
SAngle, CAngle: Double;
RotAngle: Double;
XC, YC: Integer;
Kf: Double;
X, Y: Double;
XRot, YRot: Integer;
Points: array[0..Step] of TPoint;
begin
RotAngle := Angle * PI / 180;
Kf := (360 * PI / 180) / Step;
SAngle := Sin(RotAngle);
CAngle := Cos(RotAngle);
for i := 0 to Step do
begin
Theta := i * Kf;
X := XCenter + XRadius * Cos(Theta);
Y := YCenter + YRadius * Sin(Theta);
XRot := Round(XCenter + (X - XCenter) * CAngle - (Y - YCenter) * SAngle);
YRot := Round(YCenter + (X - XCenter) * SAngle + (Y - YCenter) * CAngle);
Points[i] := Point(XRot, YRot);
end;
ACanvas.Polygon(Points);
end;
procedure RotatedEllipse(aCanvas: TCanvas; X1, Y1, X2, Y2: Integer);
var
T, O: TXForm; {in unit Windows}
begin
{ ... }
SetGraphicsMode(aCanvas.Handle, GM_Advanced);
GetWorldTransform(aCanvas.Handle, O);
{Angle in degree}
T.eM11 := 1 * Cos(w / 360 * Pi * 2);
T.eM22 := 1 * Cos(w / 360 * Pi * 2);
T.eM12 := 1 * Sin(w / 360 * Pi * 2);
T.eM21 := 1 * -Sin(w / 360 * Pi * 2);
T.eDX := Round((X1 + X2) / 2);
T.eDY := Round((Y1 + Y2) / 2);
ModifyWorldTransform(aCanvas.Handle, T, MWT_LEFTMULTIPLY);
Canvas.Ellipse(X1, Y1, X2, Y2);
SetWorldTransform(TheDraw.Handle, O);
end;