FM_AlphaBlend.c

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#include                "FBLib_FontManager.h"
 
byte FM_AlphaBlend(byte Alpha, byte FG, byte BG, float AntiAliasFactor)
{
  TRACEENTER();
 
  dword                  Color;
  float                  ColorFactor;
 
  if(Alpha == 0)
  {
    TRACEEXIT();
    return BG;
  }
 
  if(Alpha == 0xff)
  {
    TRACEEXIT();
    return FG;
  }
 
  ColorFactor = (float)((((dword)Alpha * FG) + ((dword)(255 - Alpha) * BG)) >> 8) * AntiAliasFactor;
  Color = (int)ColorFactor;
 
  TRACEEXIT();
  return (Color > 255) ? 255 : Color;
}