C ++ simple Fragment

 

 

 

 

 

 

1 // Copyright (c) LeafCore
2 # include <windows. h>
3 # include <math. h>
4
5 lresult callback WindowProcedure (HWND, UINT, WPARAM, LPARAM );
6 void draw (HDC, double, double );
7
8 char szClassName [] = "LeafCore ";
9
10 int WINAPI WinMain (HINSTANCE hThisInstance,
11 HINSTANCE hPrevInstance,
12 LPSTR lpszArgument,
13 int nFunsterStil)
14
15 {
16 HWND hwnd;
17 MSG messages;
18 WNDCLASSEX wincl;
19
20 wincl. hInstance = hThisInstance;
21 wincl. lpszClassName = szClassName;
22 wincl. lpfnWndProc = WindowProcedure;
23 wincl. style = CS_DBLCLKS;
24 wincl. cbSize = sizeof (WNDCLASSEX );
25
26 wincl. hIcon = LoadIcon (NULL, IDI_APPLICATION );
27 wincl. hIconSm = LoadIcon (NULL, IDI_APPLICATION );
28 wincl. hCursor = LoadCursor (NULL, IDC_ARROW );
29 wincl. lpszMenuName = NULL;
30 wincl. cbClsExtra = 0;
31 wincl. cbWndExtra = 0;
32 wincl. hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH );
33
34 if (! RegisterClassEx (& wincl ))
35 return 0;
36
37 hwnd = createdomainwex (
38 0,
39 szClassName,
40 "LeafCore ",
41 WS_OVERLAPPEDWINDOW,
42 CW_USEDEFAULT,
43 CW_USEDEFAULT,
44 1024,
45 768,
46 HWND_DESKTOP,
47 NULL,
48 hThisInstance,
49 NULL
50 );
51
52 ShowWindow (hwnd, nFunsterStil );
53
54 while (GetMessage (& messages, NULL, 0, 0 )){
55 TranslateMessage (& messages );
56 DispatchMessage (& messages );
57}
58
59 return messages. wParam;
60}
61
62 lresult callback WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
63 {
64 PAINTSTRUCT ps;
65 HDC hdc;
66 switch (message ){
67 case WM_PAINT:
68 hdc = BeginPaint (hwnd, & ps );
69 HPEN green_pen = CreatePen (PS_SOLID, 1, RGB (0,127, 0 ));
70 HPEN old_pen = (HPEN) SelectObject (hdc, green_pen );
71
72 draw (hdc, 200,400,600,400 );
73
74 SelectObject (hdc, old_pen );
75 DeleteObject (green_pen );
76 EndPaint (hwnd, & ps );
77 break;
78 case WM_DESTROY:
79 PostQuitMessage (0 );
80 break;
81 default:
82 return DefWindowProc (hwnd, message, wParam, lParam );
83}
84
85 return 0;
86}
87
88 void draw (HDC hdc, double start_x, double start_y, double end_x, double end_y)
89 {
90 if (fabs (start_x-end_x) <2 & fabs (start_y-end_y) <2 ){
91 // recursive exit
92 return;
93}
94
95 // three points on the left
96 int left_point_x = (int) (2 * start_x + end_x)/3 );
97 int left_point_y = (int) (2 * start_y + end_y)/3 );
98
99 // Intermediate Point
100 int middle_point_x = (int) (start_x + end_x)/2-0.2887 * (start_y-end_y ));
101 int middle_point_y = (int) (start_y + end_y)/2 + 0.2887 * (start_x-end_x ));
102
103 // three points on the right
104 int right_point_x = (int) (start_x + 2 * end_x)/3 );
105 int right_point_y = (int) (start_y + 2 * end_y)/3 );
106
107 // draw the start point to the left three points
108 MoveToEx (hdc, (int) start_x, (int) start_y, 0 );
109 LineTo (hdc, left_point_x, left_point_y );
110
111 // draw the left three-point to the center point
112 draw (hdc, left_point_x, left_point_y, middle_point_x, middle_point_y );
113
114 // draw the middle point to the right three points
115 draw (hdc, middle_point_x, middle_point_y, right_point_x, right_point_y );
116
117 // draw the right three-point to the end point
118 MoveToEx (hdc, right_point_x, right_point_y, 0 );
119 LineTo (hdc, (int) end_x, (int) end_y );
120
121 // sleep for 30 ms
122 Sleep (30 );
123}