ultimatepp/tutorial/Image03/main.cpp

#include <CtrlLib/CtrlLib.h>

using namespace Upp;

struct MyApp : public TopWindow {
	Image img;

	MyApp() {
		ImageBuffer ib(50, 50);
		for(int y = 0; y < 50; y++) {
			RGBA *l = ib[y];
			for(int x = 0; x < 50; x++) {
				if(y == 0 || y == 49 || x == 0 || x == 49) {
					*l++ = Black();
				}
				else {
					l->a = 2 * (x + y);
					l->r = 4 * x;
					l->g = 4 * y;
					l->b = 200;
					l++;
				}
			}
		}
		Premultiply(ib);
		img = ib;
		
		SetRect(0, 0, img.GetSize().cx + 50, img.GetSize().cy + 35);
	}

	void Paint(Draw& w) override {
		w.DrawRect(GetSize(), White);
		w.DrawImage(10, 5, img);
		w.DrawImage(40, 25, img);
	}
	
	void LeftDown(Point p, dword keyflags) override {
		ImageBuffer ib(img);
		for(int y = 15; y < 35; y++) {
			RGBA *l = ib[y];
			for(int x = 15; x < 35; x++) {
				l[x] = 100 * Red();
			}
		}
		img = ib;
		Refresh();
	}
};

GUI_APP_MAIN
{
	MyApp().Run();
}