private void RenderLineFromPoint (CGPoint start, CGPoint end)
{
int vertexCount = 0;
if (vertexBuffer == null) {
vertexBuffer = new nfloat [vertexMax * 2];
}
var count = Math.Max (Math.Ceiling (Math.Sqrt ((end.X - start.X) * (end.X - start.X) + (end.Y - start.Y) * (end.Y - start.Y)) / BrushPixelStep),
1);
for (int i = 0; i < count; ++i, ++vertexCount) {
if (vertexCount == vertexMax) {
vertexMax *= 2;
Array.Resize (ref vertexBuffer, vertexMax * 2);
}
vertexBuffer [2 * vertexCount + 0] = start.X + (end.X - start.X) * (float) i / (float) count;
vertexBuffer [2 * vertexCount + 1] = start.Y + (end.Y - start.Y) * (float) i / (float) count;
}
GL.VertexPointer (2, All.Float, 0, vertexBuffer);
GL.DrawArrays (All.Points, 0, vertexCount);
SwapBuffers ();
}
void SetDashStyle ()
{
if (DashStyle == null || DashStyle.IsSolid) {
cgdashes = null;
} else {
// TODO: this is not quite perfect for Square/Round for small thicknesses
var dashes = DashStyle.Dashes;
cgoffset = DashStyle.Offset * Thickness;
if (LineCap == CGLineCap.Butt)
cgdashes = Array.ConvertAll (dashes, x => (nfloat)(x * Thickness));
else {
if (Math.Abs(Thickness - 1) < 0.01f)
cgoffset += Thickness / 2;
cgdashes = new nfloat[dashes.Length];
for (int i = 0; i < cgdashes.Length; i++) {
var dash = dashes [i] * Thickness;
if ((i % 2) == 1) {
// gap must include square/round thickness
dash += Thickness;
} else {
// dash must exclude square/round thickness
dash -= Thickness;
}
cgdashes [i] = dash;
}
}
}
}
