Thread: Bouncing Ball

This is a very rough preliminary windows api program that basically just loads a ball.bmp.. and makes it bounce off the edges of the screen. It uses exerpts from the Forger's Win32 API Tutorial. I am basically trying to put all the examples together into one working program.

Below is the source code along with compiler errors. Please help if ye' can.

ball.cpp

Code:

#include <windows.h>
using namespace std;

void UpdateBall(RECT* prc);
void DrawBall(HDC hdc, RECT* prc);


/*  Declare Windows procedure  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);

/*  Make the class name into a global variable  */
char szClassName[ ] = "WindowsApp";

int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)

{
    HWND hwnd;               /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */

    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_DBLCLKS;                 /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);

    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                 /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default color as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;

    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;

    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           "Windows App",       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           544,                 /* The programs width */
           375,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hThisInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           );

    /* Make the window visible on the screen */
    ShowWindow (hwnd, nFunsterStil);

    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }

    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}


HBITMAP g_hbmBall = NULL;

const int BALL_MOVE_DELTA = 2;
const int ID_TIMER = 1;

typedef struct _BALLINFO 
{
    int width;
    int height;
    int x;
    int y;

    int dx;
    int dy;
}BALLINFO;

BALLINFO g_ballInfo;

    BITMAP bm;
    
    GetObject(g_hbmBall, sizeof(bm), &bm);

    ZeroMemory(&g_ballInfo, sizeof(g_ballInfo));
    g_ballInfo.width = bm.bmWidth;
    g_ballInfo.height = bm.bmHeight;

    g_ballInfo.dx = BALL_MOVE_DELTA;
    g_ballInfo.dy = BALL_MOVE_DELTA
    
    const int ID_TIMER = 1;

    ret = SetTimer(hwnd, ID_TIMER, 50, NULL);
    if(ret == 0)
        MessageBox(hwnd, "Could not SetTimer()!", "Error", MB_OK | MB_ICONEXCLAMATION);



/*  This function is called by the Windows function DispatchMessage()  */

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)                  /* handle the messages */
    {
        case WM_CREATE:
             
            g_hbmBall = LoadBitmap(GetModuleHandle(NULL), MAKEINTRESOURCE(IDB_BALL));
            if(g_hbmBall == NULL)
            MessageBox(hwnd, "Could not load IDB_BALL!", "Error", MB_OK | MB_ICONEXCLAMATION);
            
            ret = SetTimer(hwnd, ID_TIMER, 50, NULL);
            if(ret == 0)
            MessageBox(hwnd, "Could not SetTimer()!", "Error", MB_OK | MB_ICONEXCLAMATION);

            break;
        
        case WM_TIMER:
              
            RECT rcClient;
            HDC hdc = GetDC(hwnd);

            GetClientRect(hwnd, &rcClient);

            UpdateBall(&rcClient);
            DrawBall(hdc, &rcClient);

            ReleaseDC(hwnd, hdc);
    
            break;   
           
        case WM_DESTROY:
             
            KillTimer(hwnd, ID_TIMER); 
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;
        default:                      /* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }

    return 0;
}

//Function Definitions

void UpdateBall(RECT* prc)
{
    g_ballInfo.x += g_ballInfo.dx;
    g_ballInfo.y += g_ballInfo.dy;

    if(g_ballInfo.x < 0)
    {
        g_ballInfo.x = 0;
        g_ballInfo.dx = BALL_MOVE_DELTA;
    }
    else if(g_ballInfo.x + g_ballInfo.width > prc->right)
    {
        g_ballInfo.x = prc->right - g_ballInfo.width;
        g_ballInfo.dx = -BALL_MOVE_DELTA;
    }

    if(g_ballInfo.y < 0)
    {
        g_ballInfo.y = 0;
        g_ballInfo.dy = BALL_MOVE_DELTA;
    }
    else if(g_ballInfo.y + g_ballInfo.height > prc->bottom)
    {
        g_ballInfo.y = prc->bottom - g_ballInfo.height;
        g_ballInfo.dy = -BALL_MOVE_DELTA;
    }
}

void DrawBall(HDC hdc, RECT* prc)
{
    HDC hdcBuffer = CreateCompatibleDC(hdc);
    HBITMAP hbmBuffer = CreateCompatibleBitmap(hdc, prc->right, prc->bottom);
    HBITMAP hbmOldBuffer = SelectObject(hdcBuffer, hbmBuffer);

    HDC hdcMem = CreateCompatibleDC(hdc);
    HBITMAP hbmOld = SelectObject(hdcMem, g_hbmMask);

    FillRect(hdcBuffer, prc, GetStockObject(WHITE_BRUSH));

    BitBlt(hdcBuffer, g_ballInfo.x, g_ballInfo.y, g_ballInfo.width, g_ballInfo.height, hdcMem, 0, 0, SRCAND);

    SelectObject(hdcMem, g_hbmBall);
    BitBlt(hdcBuffer, g_ballInfo.x, g_ballInfo.y, g_ballInfo.width, g_ballInfo.height, hdcMem, 0, 0, SRCPAINT);

    BitBlt(hdc, 0, 0, prc->right, prc->bottom, hdcBuffer, 0, 0, SRCCOPY);

    SelectObject(hdcMem, hbmOld);
    DeleteDC(hdcMem);

    SelectObject(hdcBuffer, hbmOldBuffer);
    DeleteDC(hdcBuffer);
    DeleteObject(hbmBuffer);
}

resource.h

Code:

#define IDB_BALL  101

resource.rc

Code:

#include "resource.h"

IDB_BALL BITMAP "ball.bmp"

Code:

// ...


HBITMAP g_hbmBall = NULL;

const int BALL_MOVE_DELTA = 2;
const int ID_TIMER = 1;

typedef struct _BALLINFO 
{
    int width;
    int height;
    int x;
    int y;

    int dx;
    int dy;
}BALLINFO;

BALLINFO g_ballInfo;


    BITMAP bm;
    
    GetObject(g_hbmBall, sizeof(bm), &bm);

    ZeroMemory(&g_ballInfo, sizeof(g_ballInfo));
    g_ballInfo.width = bm.bmWidth;
    g_ballInfo.height = bm.bmHeight;

    g_ballInfo.dx = BALL_MOVE_DELTA;
    g_ballInfo.dy = BALL_MOVE_DELTA
    
    const int ID_TIMER = 1;

    ret = SetTimer(hwnd, ID_TIMER, 50, NULL);
    if(ret == 0)
        MessageBox(hwnd, "Could not SetTimer()!", "Error", MB_OK | MB_ICONEXCLAMATION);



/*  This function is called by the Windows function DispatchMessage()  */

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)                  /* handle the messages */
    {
        case WM_CREATE:
             
            g_hbmBall = LoadBitmap(GetModuleHandle(NULL), MAKEINTRESOURCE(IDB_BALL));
            if(g_hbmBall == NULL)
            MessageBox(hwnd, "Could not load IDB_BALL!", "Error", MB_OK | MB_ICONEXCLAMATION);
            
            ret = SetTimer(hwnd, ID_TIMER, 50, NULL);
            if(ret == 0)
            MessageBox(hwnd, "Could not SetTimer()!", "Error", MB_OK | MB_ICONEXCLAMATION);

            break;
        
        case WM_TIMER:
              
            RECT rcClient;
            HDC hdc = GetDC(hwnd);

            GetClientRect(hwnd, &rcClient);

            UpdateBall(&rcClient);
            DrawBall(hdc, &rcClient);

            ReleaseDC(hwnd, hdc);
    
            break;   
           
        case WM_DESTROY:
             
            KillTimer(hwnd, ID_TIMER); 
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;
        default:                      /* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }

    return 0;
}

// ...

The red code should belong to a function, but you left it outside of a function which is illegal. The blue code should be enclosed within braces {} because you are creating variables within a case statement.

got it down to this...

Code:

#include <windows.h>
using namespace std;

void UpdateBall(RECT* prc);
void DrawBall(HDC hdc, RECT* prc);


/*  Declare Windows procedure  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);

/*  Make the class name into a global variable  */
char szClassName[ ] = "WindowsApp";

int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)

{
    HWND hwnd;               /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */

    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_DBLCLKS;                 /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);

    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                 /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default color as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;

    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;

    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           "Windows App",       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           544,                 /* The programs width */
           375,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hThisInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           );

    /* Make the window visible on the screen */
    ShowWindow (hwnd, nFunsterStil);

    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }

    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}


HBITMAP g_hbmBall = NULL;

const int BALL_MOVE_DELTA = 2;
const int ID_TIMER = 1;

typedef struct _BALLINFO 
{
    int width;
    int height;
    int x;
    int y;

    int dx;
    int dy;
}BALLINFO;

BALLINFO g_ballInfo;



/*  This function is called by the Windows function DispatchMessage()  */

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)                  /* handle the messages */
    {
        case WM_CREATE:
        {     
            g_hbmBall = LoadBitmap(GetModuleHandle(NULL), MAKEINTRESOURCE(IDB_BALL));
            if(g_hbmBall == NULL)
            MessageBox(hwnd, "Could not load IDB_BALL!", "Error", MB_OK | MB_ICONEXCLAMATION);
            
            BITMAP bm;
    
            GetObject(g_hbmBall, sizeof(bm), &bm);

            ZeroMemory(&g_ballInfo, sizeof(g_ballInfo));
            g_ballInfo.width = bm.bmWidth;
            g_ballInfo.height = bm.bmHeight;

            g_ballInfo.dx = BALL_MOVE_DELTA;
            g_ballInfo.dy = BALL_MOVE_DELTA;       

            int ret = SetTimer(hwnd, ID_TIMER, 50, NULL);
            if(ret == 0)
                   MessageBox(hwnd, "Could not SetTimer()!", "Error", MB_OK | MB_ICONEXCLAMATION);
            }
            break;
        
        case WM_TIMER:
        {    
            RECT rcClient;
            HDC hdc = GetDC(hwnd);

            GetClientRect(hwnd, &rcClient);

            UpdateBall(&rcClient);
            DrawBall(hdc, &rcClient);

            ReleaseDC(hwnd, hdc);
    
            break;
        }  
           
        case WM_DESTROY:
             
            KillTimer(hwnd, ID_TIMER); 
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;
        default:                      /* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }

    return 0;
}

//Function Definitions

void UpdateBall(RECT* prc)
{
    g_ballInfo.x += g_ballInfo.dx;
    g_ballInfo.y += g_ballInfo.dy;

    if(g_ballInfo.x < 0)
    {
        g_ballInfo.x = 0;
        g_ballInfo.dx = BALL_MOVE_DELTA;
    }
    else if(g_ballInfo.x + g_ballInfo.width > prc->right)
    {
        g_ballInfo.x = prc->right - g_ballInfo.width;
        g_ballInfo.dx = -BALL_MOVE_DELTA;
    }

    if(g_ballInfo.y < 0)
    {
        g_ballInfo.y = 0;
        g_ballInfo.dy = BALL_MOVE_DELTA;
    }
    else if(g_ballInfo.y + g_ballInfo.height > prc->bottom)
    {
        g_ballInfo.y = prc->bottom - g_ballInfo.height;
        g_ballInfo.dy = -BALL_MOVE_DELTA;
    }
}

void DrawBall(HDC hdc, RECT* prc)
{
    HDC hdcBuffer = CreateCompatibleDC(hdc);
    HBITMAP hbmBuffer = CreateCompatibleBitmap(hdc, prc->right, prc->bottom);
    HBITMAP hbmOldBuffer = SelectObject(hdcBuffer, hbmBuffer);

    HDC hdcMem = CreateCompatibleDC(hdc);
    HBITMAP hbmOld = SelectObject(hdcMem, g_hbmMask);

    FillRect(hdcBuffer, prc, GetStockObject(WHITE_BRUSH));

    BitBlt(hdcBuffer, g_ballInfo.x, g_ballInfo.y, g_ballInfo.width, g_ballInfo.height, hdcMem, 0, 0, SRCAND);

    SelectObject(hdcMem, g_hbmBall);
    BitBlt(hdcBuffer, g_ballInfo.x, g_ballInfo.y, g_ballInfo.width, g_ballInfo.height, hdcMem, 0, 0, SRCPAINT);

    BitBlt(hdc, 0, 0, prc->right, prc->bottom, hdcBuffer, 0, 0, SRCCOPY);

    SelectObject(hdcMem, hbmOld);
    DeleteDC(hdcMem);

    SelectObject(hdcBuffer, hbmOldBuffer);
    DeleteDC(hdcBuffer);
    DeleteObject(hbmBuffer);
}

edit/
Where do you include your resource file?

Code:

    HBITMAP hbmOldBuffer = (HBITMAP) SelectObject(hdcBuffer, hbmBuffer);

    HDC hdcMem = CreateCompatibleDC(hdc);
    HBITMAP hbmOld = (HBITMAP) SelectObject(hdcMem, g_hbmMask);

    FillRect(hdcBuffer, prc, (HBRUSH) GetStockObject(WHITE_BRUSH));

You forgot to cast. Also, I forgot to say it in my first post, but as Bajanine pointed out, you need to include resource.h in ball.cpp.

Edit: Oh, and as the error says, g_hbmMask is undeclared. You either forgot to declare it(by copy-pasting parts of the code from the tutorial) or mistyped it. By the way, this code is only really useful if your compiler doesn't provide an implementation for TransparentBlt() which is common I think.

I just want to say thanks to everyone who has helped so far... got it down to a good compiling source code.. however, I still just have one single error... IDB_BALL failed to load.

I have ball.bmp located in the dev.cpp folder which is just a crude MS Paint drawing of a ball.

Here is the source code thus far:

ball.cpp

Code:

#include <windows.h>
#include "resource.h"
using namespace std;

void UpdateBall(RECT* prc);
void DrawBall(HDC hdc, RECT* prc);


/*  Declare Windows procedure  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);

/*  Make the class name into a global variable  */
char szClassName[ ] = "WindowsApp";

int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)

{
    HWND hwnd;               /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */

    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_DBLCLKS;                 /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);

    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                 /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default color as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;

    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;

    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           "Windows App",       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           544,                 /* The programs width */
           375,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hThisInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           );

    /* Make the window visible on the screen */
    ShowWindow (hwnd, nFunsterStil);

    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }

    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}


HBITMAP g_hbmBall = NULL;
HBITMAP g_hbmMask = NULL;

const int BALL_MOVE_DELTA = 2;
const int ID_TIMER = 1;

typedef struct _BALLINFO 
{
    int width;
    int height;
    int x;
    int y;

    int dx;
    int dy;
}BALLINFO;

BALLINFO g_ballInfo;



/*  This function is called by the Windows function DispatchMessage()  */

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)                  /* handle the messages */
    {
        case WM_CREATE:
        {     
            g_hbmBall = LoadBitmap(GetModuleHandle(NULL), MAKEINTRESOURCE(IDB_BALL));
            if(g_hbmBall == NULL)
            MessageBox(hwnd, "Could not load IDB_BALL!", "Error", MB_OK | MB_ICONEXCLAMATION);
            
            BITMAP bm;
    
            GetObject(g_hbmBall, sizeof(bm), &bm);

            ZeroMemory(&g_ballInfo, sizeof(g_ballInfo));
            g_ballInfo.width = bm.bmWidth;
            g_ballInfo.height = bm.bmHeight;

            g_ballInfo.dx = BALL_MOVE_DELTA;
            g_ballInfo.dy = BALL_MOVE_DELTA;       

            int ret = SetTimer(hwnd, ID_TIMER, 50, NULL);
            if(ret == 0)
                   MessageBox(hwnd, "Could not SetTimer()!", "Error", MB_OK | MB_ICONEXCLAMATION);
            }
            break;
        
        case WM_TIMER:
        {    
            RECT rcClient;
            HDC hdc = GetDC(hwnd);

            GetClientRect(hwnd, &rcClient);

            UpdateBall(&rcClient);
            DrawBall(hdc, &rcClient);

            ReleaseDC(hwnd, hdc);
    
            break;
        }  
           
        case WM_DESTROY:
             
            KillTimer(hwnd, ID_TIMER); 
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;
        default:                      /* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }

    return 0;
}

//Function Definitions

void UpdateBall(RECT* prc)
{
    g_ballInfo.x += g_ballInfo.dx;
    g_ballInfo.y += g_ballInfo.dy;

    if(g_ballInfo.x < 0)
    {
        g_ballInfo.x = 0;
        g_ballInfo.dx = BALL_MOVE_DELTA;
    }
    else if(g_ballInfo.x + g_ballInfo.width > prc->right)
    {
        g_ballInfo.x = prc->right - g_ballInfo.width;
        g_ballInfo.dx = -BALL_MOVE_DELTA;
    }

    if(g_ballInfo.y < 0)
    {
        g_ballInfo.y = 0;
        g_ballInfo.dy = BALL_MOVE_DELTA;
    }
    else if(g_ballInfo.y + g_ballInfo.height > prc->bottom)
    {
        g_ballInfo.y = prc->bottom - g_ballInfo.height;
        g_ballInfo.dy = -BALL_MOVE_DELTA;
    }
}

void DrawBall(HDC hdc, RECT* prc)
{
    HDC hdcBuffer = CreateCompatibleDC(hdc);
    HBITMAP hbmBuffer = CreateCompatibleBitmap(hdc, prc->right, prc->bottom);
    HBITMAP hbmOldBuffer = (HBITMAP)SelectObject(hdcBuffer, hbmBuffer);

    HDC hdcMem = CreateCompatibleDC(hdc);
    HBITMAP hbmOld = (HBITMAP)SelectObject(hdcMem, g_hbmMask);

    FillRect(hdcBuffer, prc, (HBRUSH)GetStockObject(WHITE_BRUSH));

    BitBlt(hdcBuffer, g_ballInfo.x, g_ballInfo.y, g_ballInfo.width, g_ballInfo.height, hdcMem, 0, 0, SRCAND);

    SelectObject(hdcMem, g_hbmBall);
    BitBlt(hdcBuffer, g_ballInfo.x, g_ballInfo.y, g_ballInfo.width, g_ballInfo.height, hdcMem, 0, 0, SRCPAINT);

    BitBlt(hdc, 0, 0, prc->right, prc->bottom, hdcBuffer, 0, 0, SRCCOPY);

    SelectObject(hdcMem, hbmOld);
    DeleteDC(hdcMem);

    SelectObject(hdcBuffer, hbmOldBuffer);
    DeleteDC(hdcBuffer);
    DeleteObject(hbmBuffer);
}

resource.h

Code:

#define IDB_BALL  101

resource.cpp

Code:

#include "resource.h"

IDB_BALL BITMAP "ball.bmp"      //<- is 'BITMAP' the right script here?  or 'BMP' ?

Try using LoadImage() instead. That's what I always do.

http://msdn.microsoft.com/library/de.../LoadImage.asp

LoadImage(NULL, MAKEINTRESOURCE(IDB_BALL), IMAGE_BITMAP, 0, 0, LR_DEFAULTSIZE);

Don't forget to cast it to an HBITMAP.

Edit: @SMurf: The Brain doesn't have resource.cpp file, he only has a .rc and a .h which is the way to go with Dev-C++.

@The Brain: Just don't forget to include it in your ball.cpp.

I made sure I included resource.h

Code:

#include <windows.h>
#include "resource.h"

using namespace std;

void UpdateBall(RECT* prc);
void DrawBall(HDC hdc, RECT* prc);

and here I am using LoadImage( )

Code:

case WM_CREATE:
        {     
            //g_hbmBall = LoadBitmap(GetModuleHandle(NULL), MAKEINTRESOURCE(IDB_BALL));
            g_hbmBall = (HBITMAP)LoadImage(NULL, MAKEINTRESOURCE(IDB_BALL), IMAGE_BITMAP, 0, 0, LR_DEFAULTSIZE);
            if(g_hbmBall == NULL)
            MessageBox(hwnd, "Could not load IDB_BALL!", "Error", MB_OK | MB_ICONEXCLAMATION);

but I still get the same, "Could not load IDB_BALL!" error..

This is handled by the resource compiler instead of the normal compiler, it would get the bitmap from your drive and stuff it into a resource section ready for linking with the rest of your code.

Where is a good place to get a resource compiler..?

The platform SDK contains it. MinGW also comes with one.

What does GetLastError tell you?

Originally Posted by The Brain

and here I am using LoadImage( )....but I still get the same, "Could not load IDB_BALL!" error..

Because you never read the LoadImage link Desolation helpfully provided you with:

Originally Posted by msdn, LoadImage

hinst
Handle to the module of either a DLL or executable (.exe) that contains the image to be loaded.

Which is pretty much what LoadBitmap has to say, too, about its corresponding hInst parameter - refer to the line of code you commented out.

Originally Posted by The Brain

Where is a good place to get a resource compiler..?

You already have a resource compiler.

Code:

using namespace std;

You don't need this. Even if you were using anything from the std namespace you should avoid this kind of namespace abuse in anything but the shortest and simplest of test or example code.

Since you're coding in c++, you should probably try to get used to type-safe c++ casts, too - see the reply by CornedBee in FAQ: Difference between C and C++ style casting for a thorough description.

Also, this masking technique is described in Petzold's Programming Windows and in two msdn articles:

Bitmaps with Transparency
How to Draw Transparent Bitmaps.

Unless you're doing this to understand those techniques or for compatibility with win9x, I'd suggest using TransparentBlt instead as it's a lot simpler.

The winforge.zip tut comes with the source code in the files folder/ source where all the progs are there with a working prog.
all the example programs are already there.