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LBitmap::FreeHandShear

Summary

Shears the bitmap by the wave drawn using pAmplitudes.

Syntax

#include "ltwrappr.h"

virtual L_INT LBitmap::FreeHandShear(pAmplitudes, uAmplitudesCount, uScale, crFill, uFlags)

Parameters

L_INT * pAmplitudes

Array of integers that represent shear wave values. The real values of the array elements is divided by 1000, and the valid value of each element in pAmplitudes array is between -1000 and 1000. These values are generally obtained from the LBitmap::GetCurvePoints function. They may also be obtained through the Wave Shear Dialog, LDialogImageEffect::DoModalWaveShear.

L_UINT uAmplitudesCount

Number of entries in the pAmplitudes array.

L_UINT uScale

Factor used to decrease the various amplitude values in the pAmplitudes array. Each value in the pAmplitudes array is multiplied by this factor. The real factor value is the uScale value divided by 100. The valid range is from 0 to 100.

COLORREF crFill

The COLORREF value that specifies the fill color for any exposed areas. You can specify a COLORREF value, such as the return value of the Windows RGB macro, or you can use the PALETTEINDEX macro to specify a palette color.

L_UINT uFlags

Flags that indicate how to handle exposed areas, and the direction of the shear wave. You can use a bit wise OR ( | ) to specify one flag from each group.

The following are the flags that indicate how to handle the exposed areas:

Value	Meaning
FILL_CLR	[0x0000] Fill any exposed areas with crFill.
FILL_RPT	[0x0001] Stretch the image edges to fill the exposed area.
FILL_NOCHG	[0x0002] Leave the exposed area as is, without changing it.

The following are the flags that indicate the direction of the shear wave:

Value	Meaning
SHR_HORZ	[0x0000] Apply the shear wave horizontally.
SHR_VERT	[0x0010] Apply the shear wave vertically.

Returns

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

Comments

This function will shear the bitmap using the wave in the pAmplitudes array. The wave can be applied vertically or horizontally. The pAmplitudes data can be obtained from the LBitmap::GetCurvePoints function. They may also be obtained through the Wave Shear Dialog, LDialogImageEffect::DoModalWaveShear.

If the bitmap has a region, the effect will be applied on the region only.

This function supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.

This function does not support signed data images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image is passed to this function.

This function does not support 32-bit grayscale images. It returns the error code ERROR_GRAY32_UNSUPPORTED if a 32-bit grayscale image is passed to this function.

Free Hand Shear Function - Before

Free Hand Shear Function - After

View additional platform support for this Free Hand Shear function.

Required DLLs and Libraries

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

Platforms

Win32, x64.

Example

L_INT LBitmap__FreeHandShearExample(LAnimationWindow * LAniWnd)  
{ 
   L_INT nRet; 
   POINT      apUserPoint [4];  
   L_INT    pAmplitudes[13];  
   L_INT    nMax, i;  
 
   apUserPoint [0].x = 0;  
   apUserPoint [0].y = 0;  
   apUserPoint [1].x = 3;  
   apUserPoint [1].y = 10;  
   apUserPoint [2].x = 9;  
   apUserPoint [2].y = -10;  
   apUserPoint [3].x = 12;  
   apUserPoint [3].y = 0;  
   /* draw a triangular wave according to apUserPoint points and stores it in pAmplitudes array*/ 
   nRet =LAnimationWindow::GetCurvePoints (pAmplitudes, apUserPoint, 4, NULL, GUB_LINEAR); 
   if(nRet !=SUCCESS) 
      return nRet; 
   /*Normalize pAmplitudes (maximum value in pAmplitudes is 1000 and lower is -1000)*/  
   nMax = 0;  
   for(i = 0; i <  13; i++) 
   { 
      if(nMax < pAmplitudes [i])  
         nMax =  pAmplitudes [i];  
   } 
   if(nMax)  
   { 
      for(i = 0; i <  13; i++) 
      { 
          pAmplitudes [i] = (1000 * pAmplitudes [i] / abs(nMax));  
      } 
   } 
    
   nRet =LAniWnd->FreeHandShear(pAmplitudes, 13, 100,0, FILL_RPT | SHR_HORZ); 
   if(nRet !=SUCCESS) 
      return nRet; 
 
   return SUCCESS; 
}