TAgg2D.LineRadialGradient(x, y, r, c1, c2, profile)

Description

Radial line gradient produces equally proportioned circles of colors increasing from the origin to the outer bound.

Gradient's origin (center point) is defined by the x:y couple and the extent of the gradient is defined with radius r.

Radial line gradient is consequently used to fill strokes of objects being drawn. If there is a need to get the filling beyond gradient radius boundary, the c2 color is used as a solid color fill.

Parameters

x: double

X coordinate of gradient center point [in subpixels].

y: double

Y coordinate of gradient center point [in subpixels].

r: double

Radius of gradient outer bound circle [in subpixels].

c1: TAggColor [*]

First color of the gradient ramp used at center point
[data sructure (r, g, b, a)].

c2: TAggColor [*]

Last color of the gradient ramp used at gradient circle bound
[data sructure (r, g, b, a)].

profile: double = 1.0

Defines how to distribute the color transitions beginning from the halfway between center point and gradient circle outer bound. A value of 1 means to distribute colors proportionally on the whole radius. Values less than 1 approximating to 0 define the ratio by which the transition is distributed more to the halfway position. Values more than 1 define expansion from halfway position, (to a maximum of gradient circle outer bound).

Example

if VG.Attach(Image1.Picture.Bitmap) then begin
  VG.ClearAll(255, 255, 255);

  // Turn off fill & set bold line
  VG.NoFill;
  VG.LineWidth(15);

  // Gradient colors from Red to Blue
  c1.Construct($FF, $00, $00);
  c2.Construct($00, $00, $FF);

  // Gradient proceeds from center point
  // (ClientWidth / 2:ClientHeight / 2)
  // with extent of (ClientWidth + 70) / 2
  // Concentration profile of 0.2 helps
  // to place gradient on the stroke of circle
  VG.LineRadialGradient(ClientWidth / 2, ClientHeight / 2,
   (ClientWidth + 70) / 2, c1, c2, 0.2);

  // Circle  
  VG.Ellipse(ClientWidth / 2, ClientHeight / 2,
   (ClientWidth - 80) / 2, (ClientWidth - 80) / 2);

end;