GUIDE.C

/*****************************************************************************\ 
*       This is a part of the Microsoft Source Code Samples. 
*       Copyright 1992 - 1998 Microsoft Corporation. 
*       All rights reserved. 
*       This source code is only intended as a supplement to 
*       Microsoft Development Tools and/or WinHelp documentation. 
*       See these sources for detailed information regarding the 
*       Microsoft samples programs. 
\*****************************************************************************/ 
/***************************************************************************** 
 * * 
 *FX.C                              * 
 * * 
 *PURPOSE:  Routines for rendering text with stange effects                * 
 * * 
 *  GetGuideLine       - Retrieves a guide line from the user.  A guide line * 
 * is just an array of line segments.    * 
 * * 
 *  ShowGuide   - Displays a guide line into a DC                     * 
 * * 
 *****************************************************************************/ 
 
#include <windows.h> 
#include "guide.h" 
 
/********************************************************************** 
 *                                                                    * 
 * FUNCTION:  GetGuideLine(HWND, LPPOINT, LPDWORD)                    * 
 *  * 
 * PURPOSE:   Gets a guide line that is entered by the user.  This is * 
 *            initiated on a WM_LBUTTONDOWN.                          * 
 *                                                                    * 
 *********************************************************************/ 
BOOL GetGuideLine(HWND hWnd, LPPOINT *lpPoint, LPDWORD lpdwNumPts) 
{ 
    MSG msg; 
    HDC hDC = GetDC(hWnd); 
    BOOL bFirstTime = TRUE; 
    DWORD dwPos = 0; 
    RECT rect; 
 
    SetCapture(hWnd); 
    GetClientRect(hWnd, &rect); 
     
    // Allocate enough room for a reasonable line 
    *lpPoint = (LPPOINT)GlobalAlloc(GPTR, MAXGUIDESEGMENTS * sizeof(POINT)); 
 
    /* Eat mouse messages until a WM_LBUTTONUP is encountered. Meanwhile 
     * continue to draw a line that follows the mouse 
     */ 
    for (;;){ 
        WaitMessage(); 
        if (PeekMessage(&msg,NULL,WM_MOUSEFIRST,WM_MOUSELAST,PM_REMOVE)) { 
                         
            // Make sure we are still tracking in our client area 
            if ((LOWORD(msg.lParam) < rect.right) && (HIWORD(msg.lParam) < rect.bottom)) { 
             
                // Set the CP to our starting position if we are starting 
                if (bFirstTime) { 
                  bFirstTime = FALSE; 
      MoveToEx(hDC, LOWORD(msg.lParam), HIWORD(msg.lParam), NULL); 
    } 
                           
                // If we dont have more points than we want... 
                if (dwPos < MAXGUIDESEGMENTS) { 
         
            // Store the point in our array 
            (*lpPoint)[dwPos].x = LOWORD(msg.lParam); 
            (*lpPoint)[dwPos].y = HIWORD(msg.lParam); 
                 
            // Draw from the last point to this one 
            LineTo(hDC, (*lpPoint)[dwPos].x, (*lpPoint)[dwPos].y); 
 
            // Increment our "number of points" counter 
            dwPos++; 
    } 
            } 
 
            // Bail when the user lets the left button up 
            if (msg.message == WM_LBUTTONUP) 
               break;                        
        } 
        else 
            continue; 
    } 
 
    *lpdwNumPts = dwPos; 
 
    ReleaseDC(hWnd, hDC); 
    
    ReleaseCapture(); 
 
    return TRUE; 
} 
 
/********************************************************************** 
 *                                                                    * 
 * FUNCTION:  ShowGuide(HDC, LPPOINT, DWORD)                          * 
 *  * 
 * PURPOSE:   Draws a guide line into a DC  * 
 *                                                                    * 
 *********************************************************************/ 
BOOL ShowGuide(HDC hDC, LPPOINT lpPoints, DWORD dwNumPts) 
{ 
  HPEN hOldBrush; 
    
  // Draw the line 
  Polyline(hDC, lpPoints, dwNumPts); 
 
  // Draw green circle to indicate line starting point 
  hOldBrush = SelectObject(hDC, CreateSolidBrush(RGB(0,255,0)));  
  Ellipse(hDC, lpPoints[0].x-5, lpPoints[0].y-5,  
               lpPoints[0].x+5, lpPoints[0].y+5); 
   
  // Draw red circle to indicate line ending point 
  DeleteObject(SelectObject(hDC, CreateSolidBrush(RGB(255,0,0))));  
  Ellipse(hDC, lpPoints[dwNumPts-1].x-5, lpPoints[dwNumPts-1].y-5,  
               lpPoints[dwNumPts-1].x+5, lpPoints[dwNumPts-1].y+5); 
  DeleteObject(SelectObject(hDC, hOldBrush));  
   
  return TRUE; 
}