L_GetBitmapColors

#include "l_bitmap.h"

L_LTKRN_API L_INT L_GetBitmapColors(pBitmap, nIndex, nCount, pPalette)

pBITMAPHANDLE pBitmap;

pointer to the bitmap handle

L_INT nIndex;

index to the first color to get

L_INT nCount;

number of colors to get

L_RGBQUAD* pPalette;

array values that make up your palette

Loads your palette with selected colors from a bitmap handle's palette.

Parameter

Description

pBitmap

Pointer to the bitmap handle.

nIndex

The index to the first color to get.

nCount

The number of colors to get.

pPalette

The array of RGBQUAD values that make up your palette.

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

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.

Your palette can be smaller than the bitmap's palette, as long as it is big enough to hold the selected colors. For the reverse action, refer to L_PutBitmapColors.

Required DLLs and Libraries

LTKRN

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, Linux.

See Also

Functions:

L_GetFixedPalette, L_ColorResBitmap, L_CreatePaintPalette, L_PutBitmapColors, L_DupPalette

Topics:

Raster Image Functions: Displaying Images

 

Handling Palette Changes

 

Color Halftone and Halftone Images

Example

This example darkens the first 50 colors in a bitmap’s palette.

L_INT GetBitmapColorsExample(HWND           hWnd,pBITMAPHANDLE  pBitmap) 
{ 
   L_INT nRet; 
   RGBQUAD  pPalette[50];  /* Temporary palette */ 
   L_INT    i;             /* Loop counter */ 
 
   /* Convert the current 24-bit bitmap to 8 bits per pixel with an optimized palette */ 
   nRet = L_ColorResBitmap(pBitmap, pBitmap, sizeof(BITMAPHANDLE), 8, 
                 CRF_FLOYDSTEINDITHERING|CRF_OPTIMIZEDPALETTE,  
                 NULL, NULL, 0, NULL, NULL ); 
   if(nRet != SUCCESS) 
      return nRet; 
   /* Get the first 50 colors from the bitmap's palette */ 
   nRet = L_GetBitmapColors(pBitmap, 0, 50, pPalette); 
   if(nRet != SUCCESS) 
      return nRet; 
   /* Reduce the intensity of each color component by half */ 
   for (i=0; i < 50; i++) 
   { 
       pPalette[i].rgbBlue = (BYTE) (pPalette[i].rgbBlue / 2); 
       pPalette[i].rgbGreen = (BYTE) (pPalette[i].rgbGreen / 2); 
       pPalette[i].rgbRed = (BYTE) (pPalette[i].rgbRed / 2); 
   } 
   /* Update the bitmap's palette with the changed colors */ 
   nRet = L_PutBitmapColors(pBitmap, 0, 50, pPalette); 
   if(nRet != SUCCESS) 
      return nRet; 
   /* Update the paint palette */ 
   SendMessage (hWnd, WM_QUERYNEWPALETTE, 0, 0L); 
   return SUCCESS; 
} 

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