Go into the world of Windows programming-----drawing related

Windows drawing

1 Drawing Drawing

1.1 How graphics are plotted
Gets the drawing handle-device Description table (DC), using the appropriate drawing API, to draw the graphic on the device.

1.2 Colors
r\g\b three colors, each color 8 bits, a total of 24 bit color.
32-bit color: The number of colors 24-bit color, the extra 8 bits represent grayscale.
16 bits: 16 times the number of colors 2.

Win32, color definition colorref (DWORD), RGB macro definition Color
COLORREF ncolor = RGB (0, 0, 0);
COLORREF Ncolor = RGB (255,255,255);
COLORREF Ncolor = RGB (255, 0, 0);
Get RGB tri-color from one color:
int nblue = Getbvalue (Ncolor);
int nred = Getrvalue (Ncolor);
int ngreen= getgvalue (ncolor);

Here is the specific code

WinDraw.cpp.cpp: Defines the entry point for the application. #include "stdafx.h" #include "windraw.cpp.h" #include <stdio.h> #define max_loadstring 100//Global variables: hinstance                            hinst;//Current instance Tchar sztitle[max_loadstring];//title bar text tchar szwindowclass[max_loadstring];//main window class name int g_ndrawtype = 0;         Drawing command Colorref G_npencolor = RGB (0, 0, 0);            default brush color int g_npenstyle = Ps_solid;                      Default brush type int g_npenwdith = 1;   Default Brush width colorref g_nbrushcolor = RGB (255, 255, 255); Default brush color//forward declaration of functions contained in this code module: Atommyregisterclass (hinstance hinstance); Boolinitinstance (HINSTANCE, int.); LRESULT Callbackwndproc (hwnd, UINT, WPARAM, LPARAM); Int_ptr Callbackabout (hwnd, UINT, WPARAM, LPARAM); INT apientry _                     Twinmain (hinstance hinstance, hinstance hprevinstance, LPTSTR lpCmdLine, int ncmdshow) {unreferenced_parameter (hprevinstance); Unreferenced_parameter (lpCmdLine); TODO: Place the code here. MSG msg; Haccel HACCELTABLe;//initialization of global string LOADSTRING (HInstance, Ids_app_title, SzTitle, max_loadstring); LoadString (HInstance, Idc_windrawcpp, Szwindowclass, max_loadstring); MyRegisterClass (HINSTANCE);//Execution of application initialization: if (! InitInstance (HINSTANCE, nCmdShow)) {return FALSE;} hacceltable = Loadaccelerators (hinstance, Makeintresource (idc_windrawcpp));//main message loop: while (GetMessage (&msg, NULL , 0, 0)) {if (! TranslateAccelerator (Msg.hwnd, hacceltable, &msg)) {TranslateMessage (&msg);D ispatchmessage (&msg);}} return (int) Msg.wparam;} Function: MyRegisterClass ()////Purpose: Registers the window class. Note:////This function and its usage are only required if you want//This code is compatible with the WIN32 system that was added to the "registerclassex"//function in Windows 95. It is important to call this function,//so that the application can get the associated//"well-formed" small icon. ATOM MyRegisterClass (hinstance hinstance) {wndclassex wcex;wcex.cbsize = sizeof (wndclassex); wcex.style= CS_HREDRAW | cs_vredraw;wcex.lpfnwndproc= wndproc;wcex.cbclsextra= 0;wcex.cbwndextra= 0;wcex.hinstance= hInstance;wcex.hIcon= LoadIcon (HInstance, Makeintresource (idi_windrawcpp)); wcex.hcursor= loadcursor (NULL, idc_arrow); wcex.hbrbackground= (Hbrush) (color_window+1);/* Loading menu items can also load menus when creating Windows */wcex.lpszmenuname= Makeintresource (idc_windrawcpp); wcex.lpszclassname= szwindowclass;wcex.hiconsm= LoadIcon (wcex.hInstance, Makeintresource (Idi_small)); return RegisterClassEx (&wcex);} Function: InitInstance (hinstance, int)////Purpose: Save the instance handle and create the main window////Note:////in this function, we save the instance handle in the global variable and//create and display the master thread The Sequence window.   BOOL InitInstance (hinstance hinstance, int ncmdshow) {HWND hwnd; HInst = hinstance; Store instance handles in global variables hWnd = CreateWindow (Szwindowclass, SzTitle, Ws_overlappedwindow, Cw_usedefault, 0, Cw_usedefault,   0, NULL, NULL, HINSTANCE, NULL);   if (!hwnd) {return FALSE;   } ShowWindow (HWnd, ncmdshow);   UpdateWindow (HWND); return TRUE;} void OnCommand (HWND hwnd, UINT message, WPARAM WPARAM, LPARAM LPARAM) {int wmid, wmevent;//command idwmid = LoWord (WPARAM); WmE Vent = HiWord (WParam);//Analysis Menu selection: switch (wmid) {case id_32774://draw point case id_32775:case id_32772:case id_32776://Draw arc caseid_32777://draw a polyline case id_32780://draw a curve case id_32781://draw a multi-style curve case id_32782://draw a rectangle case id_32783://draw a circle case id_32785:// Draw a pie case id_32786://paint a id_32787://draw polygon//save drawing type G_ndrawtype = Wmid;invalidaterect (hwnd,null,true);//Refresh window, Will trigger wm_paintbreak;case id_32790://draw Brush Red//Save drawing type G_npencolor = RGB (255,0,0), InvalidateRect (hwnd,null,true);//Refresh Window , the wm_paintbreak;case id_32792://brush style is triggered G_npenstyle = Ps_solid;invalidaterect (hwnd,null,true);//Refresh window, trigger wm_ Paintbreak;case id_32794://brush Style G_npenstyle = Ps_dash;invalidaterect (hwnd,null,true);//Refresh window, trigger Wm_paintbreak;case id_32796://brush Style G_npenwdith = 1;invalidaterect (hwnd,null,true);//Refresh window, trigger wm_paintbreak;case id_32797://brush Style g_ Npenwdith = 5;invalidaterect (hwnd,null,true);//Refresh window, trigger wm_paintbreak;case id_32799://paint brush Color G_nbrushcolor = RGB ( 255,0,0); InvalidateRect (hwnd,null,true);//refreshes the window, triggering wm_paintbreak;case idm_about:dialogbox (HInst, Makeintresource ( Idd_aboutbox), hwnd, about); Break;case Idm_exit:destroywindow (HWND); Break;default:defwindowproc (hwnd, message, WParam, LParam); Break;}}     Dot draw void Drawpixel (hdc hdc) {COLORREF Ncolor = RGB (255,0,0);/* Draw: COLORREF setpixel (* hdc hdc,//DC handle * int X,//x coordinates * int Y,//y coordinates * COLORREF crcolor); The color of the dots */setpixel (hdc,100,100,ncolor);}            void Getpixelcolor (hdc hdc) {Drawpixel (HDC);/* Get point color * get: COLORREF GetPixel (* hdc hdc,//DC handle * int XPos,//x coordinates * int nypos);    Y coordinate * Returns the color of the point at the specified coordinate position */COLORREF Ncolor = GetPixel (HDC, 100, 100);    Gets the color of the tri-color value int nred = Getrvalue (Ncolor);    int ngreen = Getgvalue (Ncolor);    int nblue = Getbvalue (Ncolor);    CHAR sztext[260] = {0};sprintf_s (sztext, "color=%08x, red=%d green=%d blue=%d", Ncolor, nred, Ngreen, Nblue); MessageBox (NULL, Sztext, "Getpixelcolor", MB_OK);}    Draw a straight line void DrawLine (hdc hdc) {MOVETOEX (hdc, 0, 0, NULL);    LineTo (HDC, 500, 500);    Movetoex (HDC, 0, NULL); LineTo (HDC, 0, 500);} //Draw arc void DrawArc (HDC hdc) {//Counter-clockwise way Setarcdirection (hdc, ad_counterclockwise); Through the bounding rectangle and cutting line/*bool ARC (HDC hdc, * int nleftrect,//bounding rectangle coordinates * int ntoprect,//bounding rectangle coordinates * int nrightrect,//bounding rectangle coordinates * int nbottomrect,//bounding rectangle coordinates * int nxstartarc,//start cut radius x coordinate * int nystartarc,//start cut radius y coordinate * int nxendarc ,//End cut radius x coordinate * int nyendarc); X-coordinate for terminating cutting radius * You can use the Setarcdirection function to set the ARC function * Cutting direction: Clockwise and Counterclockwise * * ARC (HDC, 400, 200, 500, 300,500, 200, 400, 20    0);    Clockwise Way Setarcdirection (HDC, ad_clockwise); ARC (HDC, 500, 200, 600, 300,600, 200, 500, 200);/* There will be 0, 0 to 200,200 a straight line */movetoex (HDC, N, +, NULL);/* Another square that draws a circle method, *bool Anglearc (* HDC hdc,//handle to device context * int x,///center X coordinate * int y,//Y coordinate of center point * DW ORD dwradius,//Circle radius * Float estartangle,//start angle * float esweepangle);//Angle */anglearc (hdc,200,200,100,60,120); L Ineto (HDC, 200, 200);} Draw polyline void DrawPolyline (hdc hdc) {Point Ptpolyline[7] = {0};    ptpolyline[0].x = 100;    PTPOLYLINE[0].Y = 100;    ptpolyline[1].x = 200;    PTPOLYLINE[1].Y = 100;    ptpolyline[2].x = 200;    PTPOLYLINE[2].Y = 200;    ptpolyline[3].x = 300;    PTPOLYLINE[3].Y = 200;    ptpolyline[4].x = 300;    PTPOLYLINE[4].Y = 300;    ptpolyline[5].x = 400;    PTPOLYLINE[5].Y = 300;    ptpolyline[6].x = 400; PTPOLYLINE[6].Y = 400;/* *bool Polyline (* hdc hdc,//DC handle * CONST point *lppt,//polyline Vertex coordinate array * int C Points); The length of the vertex array * PolylineTo is similar to Polyline, just before drawing Polyline *, using lineto from the current point to draw a straight line to the first vertex of Polyline */Polyline (HDC, Ptpolyline,    7);  PolylineTo (HDC, Ptpolyline, 3);/* * Draw multiple sets of polylines Polypolyline * BOOL polypolyline (hdc hdc, * CONST point) *lppt,//array of all points * CONST DWORD *lpdwpolypoints,//number of points per set * DWORD ccount);//number of groupings *///dword Ngro    Up[] = {4, 3}; Polypolyline (HDC, Ptpolyline,ngroup, 2);}    void Drawbizer (hdc hdc) {Point Ptbizer[7] = {0}; ptbizer[0].x = 100;  Endpoint  PTBIZER[0].Y = 100; ptbizer[1].x = 100;  Control point ptbizer[1].y = 50; ptbizer[2].x = 300; Control point ptbizer[2].y = 150; ptbizer[3].x = 300; Endpoint ptbizer[3].y = 100; ptbizer[4].x = 300;    Control point ptbizer[4].y = 400; ptbizer[5].x = 400;    Control point ptbizer[5].y = 200; ptbizer[6].x = 500;    Endpoint PTBIZER[6].Y = 300; /* Bezier curve BOOL polybezier (hdc hdc, CONST Point *lppt,//points Group, Min. 4 points DWORD cpoints);//number of points 4 points: 1   and 4 is the endpoint, 2.3 points is the control point 7 points: 1.4.7 is the endpoint, the rest is the control point */Polybezier (HDC, Ptbizer, 7);   Movetoex (HDC, ptbizer[0].x, Ptbizer[0].y, NULL);   LineTo (HDC, ptbizer[1].x, PTBIZER[1].Y);   Movetoex (HDC, ptbizer[3].x, Ptbizer[3].y, NULL); LineTo (HDC, ptbizer[2].x, ptbizer[2].y);}    Multi-style line void Drawpolydraw (hdc hdc) {Point Ptdraw[4] = {0};    ptdraw[0].x = 100;    PTDRAW[0].Y = 100;    ptdraw[1].x = 200;    PTDRAW[1].Y = 100;    ptdraw[2].x = 200;    PTDRAW[2].Y = 200;    ptdraw[3].x = 300;    PTDRAW[3].Y = 200; BYTE Pttype[4] = {0};    Pttype[0] = Pt_moveto;    PTTYPE[1] = pt_lineto;pttype[2] = Pt_lineto; PTTYPE[3] = pt_lineto;/** BOOL Polydraw (HDC hdc, * const point *lppt,//array of various points * Const BYTE *lpbtypes,// How to draw from a point to the next point pointer to line and curve identifiers * int ccount);    Number of points * * Lpbtypes-pt_moveto move to that point * pt_lineto draw line * Pt_bizerto Biezer curve */Polydraw (HDC, Ptdraw, Pttype, 4);}    void DrawRect (HDC hdc) {//Rectangle Rectangle (hdc, 100, 100, 200, 200); Rectangle with Rounded rectangle///rectangular BOOL roundrect with rounded corners (hdc hdc, int nleftrect,//upper-left x-coordinate int ntoprect,///upper-left y-coordinate int nrig htrect,//Right-bottom x-coordinate int nbottomrect,//right-bottom y-coordinate int nwidth,//The width of the ellipse that generated the fillet int nheight);//The height of the ellipse that generated the fillet */Roun Drect (HDC, 300, 100, 400, 200, 50, 50);}        void DrawEllipse (HDC hdc) {//round/*bool Ellipse (hdc hdc, int nleftrect,//bounding rectangle left upper x coordinate int ntoprect,//bounding rectangle left upper y-coordinate int Nrightrect,//bounding rectangle right bottom x coordinate int nbottomrect); Tangential momentbottom right y coordinate */Ellipse (HDC, 100, 100, 200, 200); Oval Ellipse (HDC, 300, 100, 500, 200);} void Drawpie (hdc hdc) {Pie (hdc, 100, 100, 500, 400, 500, 100, 100, 100);} void Drawchord (HDC hdc) {/* String * BOOL Chord (HDC hdc, * int nleftrect,//bounding rectangle left upper x coordinate * int ntoprect,/ /bounding rectangle left upper y coordinate * int nrightrect,//bounding rectangle right bottom x coordinate * int nbottomrect,//bounding rectangle right lower y coordinate * int nxradial1,//cut start radius x coordinates * int nyradial1,//cut start radius y coordinate * int nxradial2,//cut END radius x coordinate * int nYRadial2)//cut end radius y coordinate */Cho RD (HDC, 100, 100, 500, 400, 500, 100, 100, 100);}    void Drawploygon (hdc hdc) {Point Ptploygon[4] = {0};    ptploygon[0].x = 100;    PTPLOYGON[0].Y = 100;    ptploygon[1].x = 200;    PTPLOYGON[1].Y = 100;    ptploygon[3].x = 600;    PTPLOYGON[3].Y = 300;    ptploygon[2].x = 500; PTPLOYGON[2].Y = 300;/* Polygon * BOOL Polygon (hdc hdc, * CONST point *lppoints,//vertex of polygon * int ncount); Number of vertices * Polypolygon can draw multiple sets of polygons */Polygon (HDC, Ptploygon, 4);} void OnPaint (HWND hwnd, UINT message, WPARAM WPARAM, LPARAM LPARAM) {HDC hdc; Paintstruct PS;HDC = BeginPaint (HWND,&AMP;PS);/* Create brush * hpen CreatePen (* int fnpenstyle,//Brush style * int nwidth,// Brush Width * COLORREF crcolor);//Brush color */hpen hpen = CreatePen (G_npenstyle,g_npenwdith,g_npencolor);/* Set Brush to current DC * Hgdiobj S Electobject (* HDC hdc,//Handle of current DC * hgdiobj hgdiobj);//The GDI object handle to use * Returns the same type of GDI object handle that the current DC used originally. */hpen hOldPen = (hpen) SelectObject (Hdc,hpen);//Create brush, brush only effect on filler, circle, polygon, rectangle, etc. hbrush hbrush = CreateSolidBrush (g_ Nbrushcolor);//Set the brush to the current Dchbrush hOldBrush = (hbrush) SelectObject (Hdc,hbrush);//Depending on the drawing type, make a different command switch (g_ndrawtype {case id_32774://Draw point Drawpixel (HDC); break;case id_32775://get point color Getpixelcolor (HDC); Break;case id_32772:// Draw Line DrawLine (hdc); break;case id_32776://Draw Arc DrawArc (HDC); Break;case id_32777://draw polyline DrawPolyline (hdc); break;case id_32780://Draw Curve Drawbizer (hdc); Break;case id_32781://draw multi-style curve Drawpolydraw (hdc); Break;casE id_32782://Draw Rectangle DrawRect (hdc); Break;case id_32783://Draw Circle and Ellipse DrawEllipse (hdc); Break;case id_32785://Draw Pie Drawpie (hdc ); Break;case id_32786://draw Drawchord (HDC); Break;case id_32787://Draw Polygon Drawploygon (hdc); break;default:break;}    Remove Paint brush SelectObject (HDC, hOldBrush);    Remove Paint brush DeleteObject (hbrush);    Remove the brush, put the old brush in, and the new brush will release SelectObject (HDC, hOldPen); Destroy Brush DeleteObject (hpen); EndPaint (HWND,&AMP;PS);} Functions: WndProc (HWND, UINT, WPARAM, LPARAM)////Purpose: Handles the message of the main window. wm_command-processing Application Menu//wm_paint-Draw main window//wm_destroy-send exit message and return////lresult CALLBACK WndProc (HWND hwnd, UINT message , WPARAM WPARAM, LPARAM LPARAM) {switch (message) {Case wm_command:/* menu information Processing */oncommand (Hwnd,message,wparam,lparam); If 0wmId = LoWord (wParam); wmevent = HiWord (WParam);//Analysis Menu selection: switch (wmid) {case Idm_about:dialogbox (HInst, Makeintresou RCE (Idd_aboutbox), hwnd, about); Break;case Idm_exit:destroywindow (hwnd); Break;default:return DefWindowProc (hwnd, Message, WParam, LParam);} #endifbreak; CASe wm_paint:/* drawing instruction */onpaint (hWnd, message, WParam, LParam); Break;case wm_destroy:postquitmessage (0); Break;default: Return DefWindowProc (hWnd, message, WParam, LParam);} return 0;} The message handler for the About box. INT_PTR CALLBACK About (HWND hdlg, UINT message, WPARAM WPARAM, LPARAM LPARAM) {unreferenced_parameter (LPARAM); switch ( Message) {case Wm_initdialog:return (INT_PTR) true;case wm_command:if (LoWord (wParam) = = IDOK | | LoWord (wParam) = = IDCANCEL) {EndDialog (hdlg, LoWord (WParam)); return (INT_PTR) TRUE;} break;} Return (INT_PTR) FALSE;}