//Includes and Define's:
#include <windows.h>
#include <gl/gl.h>
#include <gl/glu.h>

#define TGGL_WINDOW_CAPTION "OpenGL Template"
#define TGGL_WINDOW_CLASS_NAME "TheGeek_OpenGL"
#define TGGL_WIDTH 800
#define TGGL_HEIGHT 600

//Function Definitions:
LRESULT				CALLBACK WindowProc(HWND, UINT, WPARAM, LPARAM);

//Globals:
char g_szClassName[] = TGGL_WINDOW_CLASS_NAME;
HGLRC g_hrc;
HDC g_hdc;

//Functions:
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow){
	WNDCLASSEX wndclassex;
	MSG msg;
	HWND hwnd;
	PIXELFORMATDESCRIPTOR pfd;
	int iFormat;
	RECT rcClient;

	ZeroMemory(&wndclassex, sizeof(wndclassex));
	wndclassex.cbSize			= sizeof(WNDCLASSEX);
	wndclassex.style			= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
	wndclassex.lpfnWndProc		= WindowProc;
	wndclassex.hInstance		= hInstance;
	wndclassex.hIcon			= LoadIcon(NULL, IDI_APPLICATION);
	wndclassex.hIconSm			= LoadIcon(NULL, IDI_APPLICATION);
	wndclassex.hCursor			= LoadCursor(NULL, IDC_ARROW);
	wndclassex.hbrBackground	= (HBRUSH)(COLOR_WINDOW+1);
	wndclassex.lpszClassName	= g_szClassName;

	if(!RegisterClassEx(&wndclassex)){
		char szError[150] = "Line %d: Class registration failed.";
		sprintf(&szError, szError, __LINE__ - 2);
		MessageBox(NULL, szError, "Fatal Error", MB_OK | MB_ICONERROR);
		return 0;
	}
	
	hwnd = CreateWindowEx(WS_EX_CLIENTEDGE, g_szClassName, TGGL_WINDOW_CAPTION, WS_CLIPSIBLINGS | WS_CLIPCHILDREN | WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, TGGL_WIDTH, TGGL_HEIGHT, NULL, NULL, hInstance, NULL);
	if(hwnd == NULL){
		char szError[150] = "Line %d: Window creation failed.";
		sprintf(&szError, szError, __LINE__ - 3);
		MessageBox(NULL, szError, "Fatal Error", MB_OK | MB_ICONERROR);
		return 0;
	}
	
	g_hdc = GetDC(hwnd);

	ZeroMemory(&pfd, sizeof(pfd));
	pfd.nSize = sizeof(pfd);
	pfd.nVersion = 1;
	pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
	pfd.iPixelType = PFD_TYPE_RGBA;
	pfd.cColorBits = 24;
	pfd.cDepthBits = 32;
	pfd.iLayerType = PFD_MAIN_PLANE;
	iFormat = ChoosePixelFormat(g_hdc, &pfd);
	SetPixelFormat(g_hdc, iFormat, &pfd);

	GetClientRect(hwnd, &rcClient);

	g_hrc = wglCreateContext(g_hdc);
	wglMakeCurrent(g_hdc, g_hrc);
	/*glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(30.0, (double)rcClient.right/(double)rcClient.bottom, 1.0, 10.0);
	glViewport(0, 0, rcClient.right, rcClient.bottom);*/

	ShowWindow(hwnd, nCmdShow);
	UpdateWindow(hwnd);

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

	wglMakeCurrent(NULL, NULL);
	wglDeleteContext(g_hrc);
	ReleaseDC(hwnd, g_hdc);

	return msg.wParam;
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam){
	switch(msg){
		case WM_DESTROY:
			PostQuitMessage(0);
		break;
		case WM_PAINT:
			glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
			glClear(GL_COLOR_BUFFER_BIT);

			glBegin( GL_TRIANGLES );
			glColor3f( 1.0f, 0.0f, 0.0f ); glVertex2f( 0.0f, 1.0f );
			glColor3f( 0.0f, 1.0f, 0.0f ); glVertex2f( 0.87f, -0.5f );
			glColor3f( 0.0f, 0.0f, 1.0f ); glVertex2f( -0.87f, -0.5f );
			glEnd();

			SwapBuffers(g_hdc);
		break;
		/*case WM_ERASEBKGND:
			return TRUE;
		break;*/
	}
}