// NewHello.cpp : Defines the entry point for the application.

//


#include "stdafx.h"

HDC memDC, hDC;
HBITMAP memBM;
int winWidth, winHeight, left, right, top, bottom;
//RECT sRect;


void AddSegmentAtMessagePos(HDC hDC, HWND hwnd, BOOL bDraw){
	
	DWORD dwPos;
	POINTS points;
	POINT point;

	dwPos = GetMessagePos();
	points = MAKEPOINTS(dwPos);
	point.x = points.x;
	point.y = points.y;
	ScreenToClient(hwnd, &point);
	DPtoLP(memDC, &point, 1);
	if (bDraw) LineTo(memDC, point.x, point.y);
	else MoveToEx(memDC, point.x, point.y, NULL);

	
}

void DrawHello(HWND hwnd){
	
	MSG msg;
	
	if (GetCapture() != NULL) return;
	if (memDC != NULL){
		SetCapture(hwnd);
		AddSegmentAtMessagePos(memDC, hwnd, FALSE);
		
		while(GetMessage(&msg, NULL, 0, 0)){
			if(GetCapture() != hwnd) break;
			switch (msg.message){
			case WM_MOUSEMOVE:
				AddSegmentAtMessagePos(memDC, hwnd, TRUE);
				break;
			case WM_LBUTTONUP:
				goto ExitLoop;
			default:
				DispatchMessage(&msg);
			}
		}
ExitLoop:
		ReleaseCapture();
		//ReleaseDC(hwnd, hDC);

	}
}

void PageFlip(HWND hwnd){
	
	BitBlt(hDC, left, top, right, bottom, memDC, left, top, SRCCOPY);
	
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam){
	
	switch(uMsg){
	case WM_LBUTTONDOWN:
			DrawHello(hwnd);
			break;
	case WM_PAINT:
		PageFlip(hwnd);
		break;
	case WM_DESTROY:
		ReleaseCapture();
		ReleaseDC(hwnd, hDC);
		DeleteDC(hDC);
		DeleteDC(memDC);
		PostQuitMessage(0);
		break;
	default:
		return DefWindowProc(hwnd, uMsg, wParam, lParam);
	}
	return 0;
}


int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow){
 	// TODO: Place code here.

	
	MSG msg;
	HWND hwnd;
	WNDCLASS wndClass;

	if(hPrevInstance == NULL){
		
		memset(&wndClass, 0, sizeof(wndClass));
		wndClass.style = CS_HREDRAW | CS_VREDRAW;
		wndClass.lpfnWndProc = WndProc;
		wndClass.hInstance = hInstance;
		wndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
		wndClass.hbrBackground = (HBRUSH)(COLOR_WINDOW +1);
		wndClass.lpszClassName = "HELLO";
		if(!RegisterClass(&wndClass)){
			return false;
		}
	}

	hwnd = CreateWindow("HELLO", "ECTHA SKETCH", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);
	
	ShowWindow(hwnd, nCmdShow);
	UpdateWindow(hwnd);
	
	//Create window DC

	hDC = GetDC(hwnd);
	
	//Find window width and height

	RECT sRect;
	GetWindowRect(hwnd, &sRect);

	winWidth = sRect.right - sRect.left;
	winHeight = sRect.bottom - sRect.top;
	left = sRect.left;
	right = sRect.right;
	top = sRect.top;
	bottom = sRect.bottom;
	
	//Create a compatible memory device context

	memDC = CreateCompatibleDC(hDC);
	
	//Create Memory Bitmap

	memBM = CreateCompatibleBitmap(hDC, winWidth, winHeight);

	while(GetMessage(&msg, NULL, 0, 0)){
		DispatchMessage(&msg);
		
	}

	return msg.wParam;
	
}