#include <CtrlLib/CtrlLib.h>
#include <plugin/jpg/jpg.h>

using namespace Upp;

Xform2D MapTriangle(Pointf s1, Pointf s2, Pointf s3)
{ // maps 0,0 -> s3, 1,0 -> s1, 0,1 -> s2
	Xform2D s;
	s.x.x = s1.x - s3.x;
	s.y.x = s1.y - s3.y;
	s.x.y = s2.x - s3.x;
	s.y.y = s2.y - s3.y;
	s.t = s3;
	return s;
}

Xform2D MapTriangles(Pointf s1, Pointf s2, Pointf s3, Pointf t1, Pointf t2, Pointf t3)
{
	return Inverse(MapTriangle(s1, s2, s3)) * MapTriangle(t1, t2, t3);
}

struct MyApp : TopWindow {
	Image img;

	virtual void Paint(Draw& dw)
	{
		Size sz = GetSize();
		DrawPainter w(dw, sz);
		w.Co();
		w.DrawRect(sz, White());
		Pointf center = (Point)sz / 2;
		double radius = 0.95 * min(center.x, center.y);

		Size isz = img.GetSize();

		int steps = 200;
		for(double i = 0; i < steps; i++) {
			Pointf q = Polar(i * M_2PI / steps);
			Pointf p1 = radius * q + center;
			Pointf p2 = radius * Polar((i + 1) * M_2PI / steps + 0.4 / steps) + center;

			Xform2D m = Xform2D::Scale(Distance(p1, p2) * steps / isz.cx, radius / isz.cy);
			m = m * Xform2D::Rotation(Bearing(p2 - p1));
			Pointf h = p1 - i * isz.cx / steps * Orthogonal(q);
			m = m * Xform2D::Translation(h.x, h.y);
			
			double x1 = i * isz.cx / steps;
			double x2 = (i + 1) * isz.cx / steps;
			double xc = (x1 + x2) / 2;
			w.Move(center).Line(p1).Line(p2).Fill(img,
				MapTriangles(Pointf(xc, isz.cy), Pointf(x1, 0), Pointf(x2, 0),
				             center, p1, p2));
		}
		
		w.Finish();
	}
};

GUI_APP_MAIN
{
	MyApp app;
	app.img = StreamRaster::LoadFileAny("C:/xxx/aukro.jpg");
	app.Run();
}