internal void UpdatePosition(float dt)
{
if (Mass != 0)
{
RotationAngle += AngularVelocity * dt;
Center += LinearVelocity * dt;
Polygon = (Matrix2x3.Translation(Center) * Matrix2x3.Rotation(RotationAngle) * Matrix2x3.Translation(-startCenter)).ApplyTo(startPolygon);
}
}
protected override unsafe void FillBuffer(ref BrushBuffer buffer)
{
buffer.Type = 3;
if (gradientStops != null && gradientStops.Length > 0)
{
buffer.ColorCount = gradientStops.Length;
fixed(float *colors = buffer.GradientColors, positions = buffer.GradientPositions)
{
for (int i = 0; i < gradientStops.Length; i++)
{
colors[4 * i + 0] = gradientStops[i].Color.R;
colors[4 * i + 1] = gradientStops[i].Color.G;
colors[4 * i + 2] = gradientStops[i].Color.B;
colors[4 * i + 3] = gradientStops[i].Color.A;
positions[i * 4] = gradientStops[i].Position;
}
}
}
Matrix2x3 transformFromCircle = Matrix2x3.Translation(Center) * Matrix2x3.Rotation(Angle) * Matrix2x3.Scaling(RadiusX, RadiusY);
Matrix2x3 transformToCircle = (Transform * transformFromCircle).Invert();
fixed(float *matrix = buffer.Matrix)
{
for (int i = 0; i < 6; i++)
{
matrix[i * 4] = transformToCircle[i / 3, i % 3];
}
}
if (FocusPoint.HasValue)
{
Vector2 transformedFocusPoint = transformToCircle.ApplyTo(FocusPoint.Value);
buffer.Point1 = new SharpDX.Vector2(transformedFocusPoint.X, transformedFocusPoint.Y);
buffer.Point2 = new SharpDX.Vector2(1, 0);
}
}