L_TunnelBitmap

#include "l_bitmap.h"

L_LTIMGSFX_API L_INT L_TunnelBitmap(pBitmap, ptCenterPoint, uZValue, nDistance, uRad, nRepeat, nRotationOffset, uStretch, uStartBright, uEndBright, uBrightLength, crBright, crFill, uFlags)

Places the bitmap inside a tunnel along the Z-axis.

Parameters

pBITMAPHANDLE pBitmap

Pointer to the bitmap handle referencing the bitmap to be changed.

POINT ptCenterPoint

POINT structure that contains the point at which the camera or viewer is looking. It may be outside the bitmap borders.

L_UINT uZValue

Viewing screen offset on the Z-axis, in pixels.

L_INT nDistance

Camera distance from the viewing screen, in pixels.

L_UINT uRad

Tunnel radius.

L_INT nRepeat

Number of times the bitmap repeats along the Z-axis. If nRepeat equals 1 the bitmap will be infinitely repeated. Its range starts from 1.

L_INT nRotationOffset

Rotates tunnel around the Z-axis in pixel steps. If TUN_AXIS_WIDTH option is selected then the bitmap width is along the Z-axis and nRotationOffset set to the bitmap height is equivalent to a complete cycle. If TUN_AXIS_HEIGHT option is set, then the bitmap height is along the Z-axis and nRotationOffset set to the bitmap width is equivalent to a complete cycle.

L_UINT uStretch

Value that indicates whether to expand or compress the bitmap, and by how much. If uStretch < 100 bitmap will be expanded. If uStretch > 100 the bitmap will be compressed. Use 100 to maintain the bitmap's dimensions. The value of this parameter is internally divided by 100.

L_UINT uStartBright

Value that indicates the brightness of an external light source at the beginning of the tunnel. Possible values range from 0 to 100. A value of 0 indicates no external light is displayed at the beginning of the tunnel. A value of 100 indicates an external light source with full brightness is displayed.

L_UINT uEndBright

Value that indicates the brightness of an external light source at the end of the tunnel. Possible values range from 0 to 100. A value of 0 indicates no external light displayed at the end of the tunnel. A value of 100 indicates an external light source with full brightness is displayed on the bitmap.

L_UINT uBrightLength

Value that indicates how much the brightness changes as you move along the Z axis. This parameter is internally multiplied by 50.

COLORREF crBright

The COLORREF value that specifies the color of an external light source that shines in the tunnel.

COLORREF crFill

The COLORREF value that specifies the background color.

L_UINT uFlags

Flags that indicate the background color and which bitmap dimension extends along the Z-axis. You can use a bit wise OR (|) to specify one flag from each group.

The following are the flags that indicate the background color:

The following are the flags that indicate which bitmap dimension is along the Z-axis:

Returns

Comments

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 shows the effect of placing a bitmap inside a tunnel along the Z-axis. An external light source of the specified color and brightness may be shined on the bitmaps. The brightness may vary along the z-axis according to the uBrightLength value.

Changing the camera center point, the rotation angle and the viewing screen Z-offset will simulate moving along the axis.

If the bitmap has a region, the effect will be applied on the region dimensions 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 in the Document and Medical Imaging toolkits.

To update a status bar or detect a user interrupt during execution of this function, refer to L_SetStatusCallback.

For an example, see the following figure:

The following figure shows the same bitmap, after the effect has been applied:

To obtain this effect, the following settings were used with the function:

CenterPoint(x,y) = (200,200)
uZValue=  0
nDistance= 200
uRad= 200
nRepeat= -1
nRotationOffset= 195
uStretch=  25
uStartBright= 0
uEndBright= 100
uBrightLength= 45
crBright= RGB(255,255,255)
crFill= RGB(255,255,255)
uFlags= PLANE_FILL_CLR | TUN_AXIS_WIDTH

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.

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.

L_INT TunnelBitmapExample(L_VOID) 
{ 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */ 
   POINT CenterPt;  
 
   /* Load a bitmap at its own bits per pixel  */ 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("ImageProcessingDemo\\Beauty16.jpg")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
 
   /* put the image inside tunnel with its width along the Z-axis*/ 
   CenterPt.x  =  LeadBitmap.Width/2; 
   CenterPt.y  =  LeadBitmap. Height/2; 
 
   nRet = L_TunnelBitmap(&LeadBitmap, CenterPt, 0, LeadBitmap.Height, LeadBitmap.Width/2, -1,0, 25,0,100, 20000, RGB(255,0,0), RGB(0,0,0),TUN_AXIS_WIDTH | PLANE_FILL_CLR); 
   if(nRet !=SUCCESS) 
      return nRet; 
   nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Result.BMP")), &LeadBitmap, FILE_BMP, 24, 0, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   //free bitmap  
   if(LeadBitmap.Flags.Allocated)   
      L_FreeBitmap(&LeadBitmap);   
   return SUCCESS; 
}