#include <windows.h>
using namespace std;

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp){
	HDC hdc;
	HPEN hpen;
	static int width; // 描画する線の幅
	static int speed; // 描画する速度（ms)
	static int DeviceWidth = 0; // ディスプレイの幅(ピクセル)
	static int DeviceHeight = 0; // ディスプレイの高さ(ピクセル)
	static int curx = -1, cury = -1; // デバイスコンテキストのカレントポジション
	
	switch(msg){
	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
		
	case WM_COMMAND:
		if(LOWORD(wp)==IDOK){
			width= IsDlgButtonChecked(hwnd, 11)==BST_CHECKED ? 5
			     : IsDlgButtonChecked(hwnd, 12)==BST_CHECKED ? 10
			     : IsDlgButtonChecked(hwnd, 13)==BST_CHECKED ? 15
			     : IsDlgButtonChecked(hwnd, 14)==BST_CHECKED ? 20
			     : 0;
			if(!width) break;
			speed= IsDlgButtonChecked(hwnd, 15)==BST_CHECKED ? 1000
			     : IsDlgButtonChecked(hwnd, 16)==BST_CHECKED ? 500
			     : IsDlgButtonChecked(hwnd, 17)==BST_CHECKED ? 250
			     : IsDlgButtonChecked(hwnd, 18)==BST_CHECKED ? 125
			     : 0;
			if(!speed) break;
			ShowWindow(hwnd, SW_HIDE);
			SetTimer(hwnd, 1, speed, NULL); // speed(ms)ごとにメッセージポスト
			SetTimer(hwnd, 2, 60000, (TIMERPROC)PostQuitMessage); // 60秒後終了
		}
		else if(LOWORD(wp)<15) CheckRadioButton(hwnd, 11, 14, LOWORD(wp));
        else if(LOWORD(wp)<19) CheckRadioButton(hwnd, 15, 18, LOWORD(wp));
		return 0;
		
	case WM_TIMER:
		hdc = CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);
		if(!DeviceWidth) DeviceWidth = GetDeviceCaps(hdc, HORZRES);
		if(!DeviceHeight) DeviceHeight = GetDeviceCaps(hdc, VERTRES);
		if(curx<0){ // いまだ初期状態ならば
			curx = (int)(DeviceWidth/2);
			cury = (int)(DeviceHeight/2);
		}
		hpen = CreatePen(PS_SOLID, width, RGB(rand()%256,rand()%256,rand()%256));
		SelectObject(hdc, hpen);
		MoveToEx(hdc, curx, cury, NULL);
		curx = rand()%DeviceWidth;
		cury = rand()%DeviceHeight;
		LineTo(hdc, curx, cury);
		
		DeleteDC(hdc);
		DeleteObject(hpen);
	}
	return DefWindowProc(hwnd, msg, wp, lp);
}

int WINAPI WinMain(
	HINSTANCE hInstance,
	HINSTANCE hPrevInstance,
	PSTR lpCmdLine,
	int nCmdShow)
{
	HWND hwnd;
	WNDCLASS wndc;
	MSG msg;
	
	wndc.style = CS_HREDRAW | CS_VREDRAW;
	wndc.lpfnWndProc = WndProc;
	wndc.cbClsExtra = 0;
	wndc.cbWndExtra = DLGWINDOWEXTRA;
	wndc.hInstance = hInstance;
	wndc.hIcon = LoadIcon(NULL, IDI_WINLOGO);
	wndc.hCursor = LoadCursor(NULL, IDC_ARROW);
	wndc.hbrBackground = (HBRUSH)CreateSolidBrush(GetSysColor(COLOR_MENU));
	wndc.lpszMenuName = NULL;
	wndc.lpszClassName = TEXT("main");
	if(!RegisterClass(&wndc)) return 0;
	
	hwnd = CreateDialog(hInstance, TEXT("main"), 0, NULL);
	if(!hwnd) return 0;
	
	while(GetMessage(&msg, NULL, 0, 0)) DispatchMessage(&msg);
	return msg.wParam;
}