Thread: Rectangle

Im tryin to use this Win32 API thingy and I have no idea what im doin...

Code:

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>

HDC hdc;
HPEN hpen;
HBRUSH hbrush;

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
								PSTR szCmdLine, int iCmdShow)
	{
   HWND hwnd;
   MSG msg;
   WNDCLASSEX wndclass;

   wndclass.cbSize        = sizeof (wndclass);
   wndclass.style         = CS_HREDRAW | CS_VREDRAW;
   wndclass.lpfnWndProc   = WndProc;
   wndclass.cbClsExtra    = 0;
   wndclass.cbWndExtra    = 0;
   wndclass.hInstance     = hInstance;
   wndclass.hIcon         = LoadIcon (NULL, IDI_WINLOGO);
   wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW);

   wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH);
   wndclass.lpszMenuName  = NULL;
   wndclass.lpszClassName = "Window Class 1";
   wndclass.hIconSm       = LoadIcon (NULL, IDI_WINLOGO);

   	RegisterClassEx (&wndclass);


   hwnd = CreateWindow ("Window Class 1",
   							"My First Window",
                  		WS_OVERLAPPEDWINDOW,
                  		CW_USEDEFAULT,
                        CW_USEDEFAULT,
                        CW_USEDEFAULT,
                        CW_USEDEFAULT,
                        NULL,
                        NULL,
                        hInstance,
                        NULL);

   ShowWindow (hwnd, iCmdShow);
   UpdateWindow (hwnd);

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

   	return msg.wParam ;
}


LRESULT CALLBACK WndProc (HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{

   PAINTSTRUCT ps;

	switch (iMsg)
   {
   	case WM_CREATE:

      	break;

      case WM_SIZE:

      	break;

      case WM_PAINT:

         BeginPaint ( hwnd, &ps );

         hpen = CreatePen(PS_SOLID,2,RGB(200,20,2));
         hbrush = CreateSolidBrush(RGB(15,15,200));

         Rectangle ( hdc, 10, 10, 30, 30 );

         EndPaint ( hwnd, &ps );

      	break;

      case WM_DESTROY:

      	PostQuitMessage(0);
         break;
   }

   return DefWindowProc (hwnd, iMsg, wParam, lParam);

}

Why doesnt it draw a rectangle?

All I get is an empty window.

doh... i got it...

Code:

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>

HDC hdc;


LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
								PSTR szCmdLine, int iCmdShow)
	{
   HWND hwnd;
   MSG msg;
   WNDCLASSEX wndclass;

   wndclass.cbSize        = sizeof (wndclass);
   wndclass.style         = CS_HREDRAW | CS_VREDRAW;
   wndclass.lpfnWndProc   = WndProc;
   wndclass.cbClsExtra    = 0;
   wndclass.cbWndExtra    = 0;
   wndclass.hInstance     = hInstance;
   wndclass.hIcon         = LoadIcon (NULL, IDI_WINLOGO);
   wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW);

   wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH);
   wndclass.lpszMenuName  = NULL;
   wndclass.lpszClassName = "Window Class 1";
   wndclass.hIconSm       = LoadIcon (NULL, IDI_WINLOGO);

   	RegisterClassEx (&wndclass);


   hwnd = CreateWindow ("Window Class 1",
   							"My First Window",
                  		WS_OVERLAPPEDWINDOW,
                  		CW_USEDEFAULT,
                        CW_USEDEFAULT,
                        CW_USEDEFAULT,
                        CW_USEDEFAULT,
                        NULL,
                        NULL,
                        hInstance,
                        NULL);

   ShowWindow (hwnd, iCmdShow);
   UpdateWindow (hwnd);

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

   	return msg.wParam ;
}


LRESULT CALLBACK WndProc (HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{



	switch (iMsg)
   {
   	case WM_CREATE:

      	break;

      case WM_SIZE:

      	break;

      case WM_PAINT:

         PAINTSTRUCT ps;
			HDC hdc;
			HPEN hpen;

			hdc=BeginPaint(hwnd, &ps);

			hpen=CreatePen(PS_SOLID, 1, RGB(0,0,0));

			SelectObject(hdc, hpen);

			Rectangle(hdc, 10, 10, 50, 50);

			EndPaint(hwnd, &ps);
			DeleteObject(hpen);


      	break;

      case WM_DESTROY:

      	PostQuitMessage(0);
         break;
   }

   return DefWindowProc (hwnd, iMsg, wParam, lParam);

}

now, will I be able to use these shapes like i could with graphics.h?

Like asign x and y for the positions and detect keys.. if left is mashed x++.

How can I detect arrow keys in windows?

oh... what header file are these shapes in... I want to know what shapes are available..

And how do I fill the shapes?

Try FillRegion()

Also, if using a CreateX() or GetX() function you are allocating GDI memory.
When you then select the GDI object into a DC with
SelectObject(hdc, hpen);
you are releasing a GDI object (the return in this case is the original pen).

Use

hOldPen=SelectObject(hdc, hpen);
//draw
SelectObject(hdc, hOldPen);//put the original back
DeleteObject(hPen);

or you will soon run out of drawing mem.