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L_PntRegionColor

Summary

Creates a region that contains the specified color.

Syntax

#include "LtPnt.h"

L_LTPNT_API L_INT L_PntRegionColor(pPaint, UserDC, crColor, phDestRgn)

Parameters

pPAINTHANDLE pPaint

Pointer to a paint handle.

L_HDC UserDC

Handle to a device context, such as a screen, to use as a display surface. This parameter can also be NULL. The mapping mode of the device context must be MM_TEXT.

const COLORREF crColor

The COLORREF value that specifies the color to use to create the region.

pHRGN phDestRgn

Pointer to the region handle to be updated with the resulting region.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

The region creation procedure will be carried out using the current region properties. To determine the current region properties, call L_PntGetProperty. To set or change the current region properties, call L_PntSetProperty. For more information on the region properties, refer to the PAINTREGION structure.

This function will also use the current painting transformation information when creating the new region. To get the current painting transformation information, call L_PntGetTransformation. To change or set the painting transformation information, call L_PntSetTransformation.

If the user has set a bitmap in the toolkit, using the function L_PntSetMetrics, then the toolkit will create the region for the bitmap. Otherwise, the toolkit will create the region for the specified device context.

If the UserDC is not NULL, the user should set the DC boundaries before calling this function, by calling L_PntSetDCExtents.

The images below show the region created by clicking inside the yellow area.

Required DLLs and Libraries

LTPNT
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application

Example

L_INT PntRegionColorExample(HWND hWnd) 
{ 
   L_INT nRet; 
   pPAINTHANDLE pPaint ; 
   HDC          hDC ; 
   PAINTSHAPE   shape ;  
   RECT         rcShape ; 
   RECT         rcDCExtents ; 
   HRGN         hRgn ; 
 
   /* Initiate the Paint toolkit */ 
   nRet = L_PntInit ( &pPaint ); 
   if ( SUCCESS != nRet ) 
   { 
      return nRet; 
   } 
 
   /* Get device context to draw on */ 
   hDC = GetDC ( hWnd ) ; 
 
   /* Set the required shape properties */ 
   shape.nSize                = sizeof ( PAINTSHAPE ) ; 
   shape.dwMask               = PSF_BORDERWIDTH       | 
                                PSF_BORDERCOLOR       | 
                                PSF_BORDERENDCAP      | 
                                PSF_BACKGROUNDSTYLE   | 
                                PSF_GRADIENTSTARTCOLOR| 
                                PSF_GRADIENTENDCOLOR  ; 
   shape.nBorderWidth         = 10 ; 
   shape.crBorderColor        = RGB ( 0, 255, 0 ) ; 
   shape.nBorderEndCap        = PAINT_SHAPE_BORDER_ENDCAP_ROUND ; 
   shape.nBackgroundStyle     = PAINT_SHAPE_BACK_STYLE_GRADIENT ; 
   shape.crGradientStartColor = RGB ( 255, 255, 255 ) ; 
   shape.crGradientEndColor   = RGB ( 255, 255, 0 ) ; 
 
   /* Set the new shape properties */ 
   nRet = L_PntSetProperty ( pPaint, PAINT_GROUP_SHAPE, &shape ) ; 
   if(nRet != SUCCESS) 
      return nRet; 
 
   /* Set the coordinates with respect to the DC dimensions */ 
   SetRect ( &rcShape, 10, 10, 60, 60 ) ; 
 
   /* Get the destination DC dimensions */ 
   GetClientRect ( hWnd, &rcDCExtents ) ; 
 
   /* Set the toolkit user DC extents */ 
   nRet = L_PntSetDCExtents ( pPaint, &rcDCExtents ) ; 
   if(nRet != SUCCESS) 
      return nRet; 
 
   /* Use the current shape properties to draw an ellipse to the DC (hDC) */ 
   nRet = L_PntDrawShapeEllipse ( pPaint, hDC, &rcShape ) ; 
   if(nRet != SUCCESS) 
      return nRet; 
 
   SetRect ( &rcShape, 100, 10, 150, 60 ) ; 
   nRet = L_PntDrawShapeEllipse ( pPaint, hDC, &rcShape ) ; 
   if(nRet != SUCCESS) 
      return nRet; 
 
   SetRect ( &rcShape, 60, 60, 95, 95 ) ; 
   nRet = L_PntDrawShapeRectangle ( pPaint, hDC, &rcShape ) ; 
   if(nRet != SUCCESS) 
      return nRet; 
 
   SetRect ( &rcShape, 10, 100, 60, 150 ) ; 
   nRet = L_PntDrawShapeEllipse ( pPaint, hDC, &rcShape ) ; 
   if(nRet != SUCCESS) 
      return nRet; 
 
   SetRect ( &rcShape, 100, 100, 150, 150 ) ; 
   nRet = L_PntDrawShapeEllipse ( pPaint, hDC, &rcShape ) ; 
   if(nRet != SUCCESS) 
      return nRet; 
 
   /* Create the region */ 
   nRet = L_PntRegionColor ( pPaint, hDC, RGB ( 0, 255, 0 ), &hRgn) ;  
   if(nRet != SUCCESS) 
      return nRet; 
 
   /* Display the create region */ 
   FrameRgn ( hDC, hRgn, ( HBRUSH ) GetStockObject ( BLACK_BRUSH ), 1, 1 ) ; 
 
   /* Release the device context */ 
   ReleaseDC ( hWnd, hDC ) ; 
 
   /*Delete the region */ 
   DeleteObject ( hRgn ) ; 
 
   /* Free the paint tools handle */ 
   L_PntFree ( pPaint ) ; 
 
   return SUCCESS ; 
}