C++ Programming for Games Module II phần 8 pps

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provides another function, which can give us a handle to a device context associated with a window’s

client area; the function is called GetDC:

// Get a DC associated with the window's client area.

HDC hWndDC = GetDC(mhWnd);

The GetDC function takes a parameter to a window handle (HWND), which specifies the window with

which we want to associate the device context. The GetDC function then returns a handle to such a

device context.

17.3 Tank Animation Sample

Figure 17.2 shows a screenshot of the Tank animation sample we will write in this section.

Figure 17.2: A screenshot of the Tank sample.

The tank is drawn using a rectangle for the tank base, an ellipse for the gun base, and a thick line (i.e.,

pen width > 1) for the gun. You can move the tank up and down and from side to side with the ‘W’, ‘S’,

‘A’ and ‘D’ keys. You can rotate the gun with the ‘Q’ and ‘E’ keys. Finally, you can fire bullets with

the spacebar key. The bullets are modeled using ellipses.