游戏编程中的人工智能技术【2-1】
HDC hdc = GetDC(hwnd);//客户区 hdc = GetWindowDC(hwnd) 或者 hdc = GetDC(NULL);
hdc = ps.hdc; //这个是一个RECT里的dc
ReleaseDC（hWnd，hdc）；
1。 Lines-----------------------------------------------------------------------------------------------------------------------------------------------
LRESULT CALLBACK WindowProc (HWND hwnd,
UINT msg,
WPARAM wParam,
LPARAM lParam)
{
/************************************************************************/
/* 这里定义了两个静态整型变量来保存窗口客户区的尺寸。这样，显示图形就能够在用户改变窗口尺寸的时候进行相应的缩放 */
/************************************************************************/
static int cxClient, cyClient;
switch (msg)
{
case WM_CREATE:
{
RECT rect;
GetClientRect(hwnd, &rect);
cxClient = rect.right;
cyClient = rect.bottom;
}
break;
case WM_SIZE:
{
cxClient = LOWORD(lParam);
cyClient = HIWORD(lParam);
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
BeginPaint (hwnd, &ps);
//**this is where we do any drawing to the screen**
const int NumLinesPerSide = 10;
int yStep = cyClient/NumLinesPerSide;
int xStep = cxClient/NumLinesPerSide;
//Draw Lines
for(int mult=1; mult<NumLinesPerSide; ++mult){
//bottom left
MoveToEx(ps.hdc, xStep*mult, 0, 0);
LineTo(ps.hdc, 0, cyClient-yStep*mult);
//top right
MoveToEx(ps.hdc, xStep*mult, cyClient, 0);
LineTo(ps.hdc, cxClient, cyClient-yStep*mult);
//bottom right
MoveToEx(ps.hdc, xStep*mult, 0,0);
LineTo(ps.hdc, cxClient, yStep*mult);
//top left
MoveToEx(ps.hdc, xStep*mult, cyClient, 0);
LineTo(ps.hdc, 0, yStep*mult);
}
EndPaint (hwnd, &ps);
}
break;
case WM_DESTROY:
{
// kill the application, this sends a WM_QUIT message
PostQuitMessage (0);
}
break;
}//end switch
//this is where all the messages not specifically handled by our
//winproc are sent to be processed
return DefWindowProc (hwnd, msg, wParam, lParam);
}
2。 lines2 ---------------------------------------------------------------------------------------------------------------
LRESULT CALLBACK WindowProc (HWND hwnd,
UINT msg,
WPARAM wParam,
LPARAM lParam)
{
/************************************************************************/
/* 这里定义了两个静态整型变量来保存窗口客户区的尺寸。这样，显示图形就能够在用户改变窗口尺寸的时候进行相应的缩放 */
/************************************************************************/
static int cxClient, cyClient;
static HPEN BluePen = CreatePen(PS_SOLID, 1, RGB(0,0,255));
static HPEN GreenPen = CreatePen(PS_SOLID, 1, RGB(255,0,0));
static HPEN RedPen = CreatePen(PS_SOLID, 1, RGB(0,255,0));
static HPEN PurplePen = CreatePen(PS_SOLID, 1, RGB(255,0,255));
static HPEN OldPen = NULL;
switch (msg)
{
case WM_CREATE:
{
RECT rect;
GetClientRect(hwnd, &rect);
cxClient = rect.right;
cyClient = rect.bottom;
}
break;
case WM_SIZE:
{
cxClient = LOWORD(lParam);
cyClient = HIWORD(lParam);
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
BeginPaint (hwnd, &ps);
OldPen = (HPEN)SelectObject(ps.hdc, RedPen);
//**this is where we do any drawing to the screen**
const int NumLinesPerSide = 10;
int yStep = cyClient/NumLinesPerSide;
int xStep = cxClient/NumLinesPerSide;
//Draw Lines
for(int mult=1; mult<NumLinesPerSide; ++mult){
//bottom left
SelectObject(ps.hdc, RedPen);
MoveToEx(ps.hdc, xStep*mult, 0, 0);
LineTo(ps.hdc, 0, cyClient-yStep*mult);
//top right
SelectObject(ps.hdc, BluePen);
MoveToEx(ps.hdc, xStep*mult, cyClient, 0);
LineTo(ps.hdc, cxClient, cyClient-yStep*mult);
//bottom right
SelectObject(ps.hdc, GreenPen);
MoveToEx(ps.hdc, xStep*mult, 0,0);
LineTo(ps.hdc, cxClient, yStep*mult);
//top left
SelectObject(ps.hdc, PurplePen);
MoveToEx(ps.hdc, xStep*mult, cyClient, 0);
LineTo(ps.hdc, 0, yStep*mult);
}
SelectObject(ps.hdc, OldPen);
EndPaint (hwnd, &ps);
}
break;
case WM_DESTROY:
{
// kill the application, this sends a WM_QUIT message
DeleteObject(RedPen);
DeleteObject(BluePen);
DeleteObject(GreenPen);
DeleteObject(PurplePen);
DeleteObject(OldPen);
PostQuitMessage (0);
}
break;
}//end switch
//this is where all the messages not specifically handled by our
//winproc are sent to be processed
return DefWindowProc (hwnd, msg, wParam, lParam);
}
3。 Polygon--------------------------------------------------------------------------------------------------------
LRESULT CALLBACK WindowProc (HWND hwnd,
UINT msg,
WPARAM wParam,
LPARAM lParam)
{
//create some pens to use for drawing
static HPEN BluePen = CreatePen(PS_SOLID, 1, RGB(0, 0, 255));
static HPEN OldPen = NULL;
//create a solid brush
static HBRUSH RedBrush = CreateSolidBrush(RGB(255, 0, 0));
static HBRUSH OldBrush = NULL;
//these hold the dimensions of the client window area
static int cxClient, cyClient;
//this will hold the vertices of the polygons we create
static POINT verts[NUM_VERTS];
static int iNumVerts = NUM_VERTS;
switch (msg)
{
//A WM_CREATE msg is sent when your application window is first
//created
case WM_CREATE:
{
//to get get the size of the client window first we need to create
//a RECT and then ask Windows to fill in our RECT structure with
//the client window size. Then we assign to cxClient and cyClient
//accordingly
RECT rect;
GetClientRect(hwnd, &rect);
cxClient = rect.right;
cyClient = rect.bottom;
//seed random number generator
srand((unsigned) time(NULL));
//now lets create some random vertices
for (int v=0; v<iNumVerts; ++v)
{
verts[v].x = RandInt(0, cxClient);
verts[v].y = RandInt(0, cyClient);
}
}
break;
case WM_KEYUP:
{
switch(wParam)
{
case VK_SPACE:
{
//create some new points for our polygon
//now lets create some random vertices
for (int v=0; v<iNumVerts; ++v)
{
verts[v].x = RandInt(0, cxClient);
verts[v].y = RandInt(0, cyClient);
}
//refresh the display so we can see our
//new polygon
InvalidateRect(hwnd, NULL, TRUE);
UpdateWindow(hwnd);
}
break;
case VK_ESCAPE:
{
PostQuitMessage(0);
}
break;
}
}
case WM_PAINT:
{
PAINTSTRUCT ps;
BeginPaint (hwnd, &ps);
//first select a pen to draw with and store a copy
//of the pen we are swapping it with
OldPen = (HPEN)SelectObject(ps.hdc, BluePen);
//do the same for our brush
OldBrush = (HBRUSH)SelectObject(ps.hdc, RedBrush);
//draw the polygon
Polygon(ps.hdc, verts, iNumVerts);
//replace the original pen
SelectObject(ps.hdc, OldPen);
//and brush
SelectObject(ps.hdc, OldBrush);
EndPaint (hwnd, &ps);
}
break;
//has the user resized the client area?
case WM_SIZE:
{
//if so we need to update our variables so that any drawing
//we do using cxClient and cyClient is scaled accordingly
cxClient = LOWORD(lParam);
cyClient = HIWORD(lParam);
//create a new polygon
for (int v=0; v<iNumVerts; ++v)
{
verts[v].x = RandInt(0, cxClient);
verts[v].y = RandInt(0, cyClient);
}
}
break;
case WM_DESTROY:
{
//delete the pens
DeleteObject(BluePen);
DeleteObject(OldPen);
//and the brushes
DeleteObject(RedBrush);
DeleteObject(OldBrush);
// kill the application, this sends a WM_QUIT message
PostQuitMessage (0);
}
break;
}//end switch
//this is where all the messages not specifically handled by our
//winproc are sent to be processed
return DefWindowProc (hwnd, msg, wParam, lParam);
}
出自： 《游戏编程中的人工智能技术》