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LBitmapList::ColorResItems

Summary

Converts all bitmaps in a class object's bitmap list from any bits-per-pixel to any bits-per-pixel. You can use this function to create an optimized palette for all bitmaps in the bitmap list.

Syntax

#include "ltwrappr.h"

virtual L_INT LBitmapList::ColorResItems(nBitsPerPixel, uFlags, pPalette=NULL, hPalette=NULL, uColors=0)

Parameters

L_INT nBitsPerPixel

The number of bits per pixel to increase or decrease the bitmaps to. Valid values are 1, 2, 3, 4, 5, 6, 7, 8, 16, 24, 32, 48, and 64.

L_UINT32 uFlags

Processing options. Note that the palette and dithering options are useful only when the resulting bitmaps require a palette (when they are 8 bits per pixel or less). You can combine values when appropriate by using a bitwise OR ( | ). The following are valid values:

Value	Meaning
CRF_FIXEDPALETTE	[0x01] Use LEAD's fixed palette.
CRF_OPTIMIZEDPALETTE	[0x02] Create an optimized palette.
CRF_NETSCAPEPALETTE	[0x40] Use the fixed palette that is employed by Netscape Navigator and by Microsoft Internet Explorer.
CRF_USERPALETTE	[0x10] Use the palette specified in the pPalette parameter.
CRF_IDENTITYPALETTE	[0x08] Insert the Windows system palette. You can combine this flag with CRF_OPTIMIZEDPALETTE.
CRF_FASTMATCHPALETTE	[0x20] Use a predefined table to speed conversion using your own palette. Refer to LBitmapSettings::CreateUserMatchTable.
CRF_BYTEORDERBGR	[0x04] Use BGR color order. This flag only has meaning when going to 16 bits per pixel or higher.
CRF_BYTEORDERRGB	[0x00] Use RGB color. This flag only has meaning when going to 16 bits per pixel or higher.
CRF_NODITHERING	[0x00000000] Use nearest color matching.
CRF_FLOYDSTEINDITHERING	[0x00010000] Use Floyd-Steinberg dithering.
CRF_STUCKIDITHERING	[0x00020000] Use Stucki dithering.
CRF_BURKESDITHERING	[0x00030000] Use Burkes dithering.
CRF_SIERRADITHERING	[0x00040000] Use Sierra dithering.
CRF_STEVENSONARCEDITHERING	[0x00050000] Use Stevenson Arce dithering.
CRF_JARVISDITHERING	[0x00060000] Use Jarvis dithering.
CRF_ORDEREDDITHERING	[0x00070000] Use ordered dithering, which is faster but less accurate than other dithering methods.
CRF_CLUSTEREDDITHERING	[0x00080000] Use clustered dithering.

LPRGBQUAD pPalette

The custom palette to use. Specify this parameter as follows:

If you want to use the fixed palette or a fully optimized palette, pass NULL in this parameter and in hPalette.
If you want to supply the entire palette, specify CRF_USERPALETTE in the uFlags parameter and pass the address of your palette.
If you want the function to fill part of your palette with optimized colors, specify CRF_OPTIMIZEDPALETTE in the uFlags parameter and pass the address of your palette in pPalette and NULL in hPalette.

HPALETTE hPalette

The custom palette to use. Specify this parameter as follows:

If you want to use the fixed palette or a fully optimized palette, pass NULL in this parameter and in pPalette.
If you want to supply the entire palette, specify CRF_USERHPALETTE in the uFlags parameter and pass the handle of your palette.
If you want the function to fill part of your palette with optimized colors, specify CRF_OPTIMIZEDPALETTE in the uFlags parameter and pass NULL for pPalette and the handle of your palette in hPalette.

L_UINT uColors

The number of colors in the palette. Pass 0 to get the default (such as 256 for 8 bits per pixel). Otherwise, do one of the following:

If you specify a palette in the pPalette or hPalette parameter, pass the number of entries in your palette (including reserved entries).
If you specify NULL in the pPalette and in the hPalette parameters and you specify CRF_OPTIMIZEDPALETTE in the uFlags parameter, you can use this parameter to limit the number of colors that the function maps in the optimized palette.

Returns

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

Required DLLs and Libraries

LTFIL
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

This example changes the hue of bitmaps in a list, then updates
the paint palette and the target bitmap's palette for animation playback.
When changing the hue, it preserves the transparent color.

L_INT LBitmapList__ColorResItemsExample(HWND hWnd, LBitmapList *pBitmapList, LPRGBQUAD TransparentColor) 
{ 
   L_INT nRet; 
   HDC hdc; /* Device context of the current window */ 
   L_UINT i; /* Loop counter */ 
   L_UINT uCount; /* Number of bitmaps in the list */ 
   LBitmap LeadBitmap;   /* Bitmap handle for the target bitmap */ 
   LBitmap TmpBitmap; /* Temporary bitmap for manipulating the list */ 
   HPALETTE hpalPaint; /* Paint palette handle */ 
 
   /* Change the hue of each bitmap in the list,  
   and restore the transparent color as the last color in the palette */ 
   uCount = pBitmapList->GetItemsCount (); 
   for (i = 0; i < uCount; ++i) 
   { 
      nRet =pBitmapList->GetItem (i, &TmpBitmap,sizeof(TmpBitmap)); 
      if(nRet !=SUCCESS) 
         return nRet; 
      nRet =TmpBitmap.ChangeHue(i * 10); 
      if(nRet !=SUCCESS) 
         return nRet; 
      nRet =TmpBitmap.PutColors(255, 1, TransparentColor); 
      if(nRet !=SUCCESS) 
         return nRet; 
      nRet =pBitmapList->SetItem (i, &TmpBitmap); 
      if(nRet !=SUCCESS) 
         return nRet; 
   } 
   /* Get an optimized palette for the whole list */ 
   nRet =pBitmapList->ColorResItems (8, CRF_NODITHERING|CRF_OPTIMIZEDPALETTE, NULL, 0); 
   if(nRet !=SUCCESS) 
      return nRet; 
 
   /* Update the paint palette that is used for playback */ 
   nRet =pBitmapList->GetItem (0, &TmpBitmap,sizeof(TmpBitmap)); 
   if(nRet !=SUCCESS) 
      return nRet; 
   hdc = GetDC (hWnd); 
   hpalPaint = TmpBitmap.CreatePaintPalette (hdc); 
   ReleaseDC (hWnd, hdc); 
   /* Update the target bitmap's background color, based on the new palette */ 
   LeadBitmap.SetPlayBackBackGroundColor (TmpBitmap.TranslateColor (LeadBitmap, LeadBitmap.GetPlayBackBackGroundColor ())); 
   /* Copy the new palette to the target bitmap */ 
   LeadBitmap.SetPalette (TmpBitmap.DupPalette ()); 
 
 
   return SUCCESS; 
}