Function ILAPIENTRY ilModAlpha

DevIL/src-IL/src/il_manip.cpp:1046–1123

}

void ILAPIENTRY ilModAlpha(ILdouble AlphaValue)
{
    ILuint AlphaOff = 0;
    ILboolean ret = IL_FALSE;
    ILuint i,j,Size;

    union {
        ILubyte alpha_byte;
        ILushort alpha_short;
        ILuint alpha_int;
        ILfloat alpha_float;
        ILdouble alpha_double;
    } Alpha;

    
    if (iCurImage == NULL) {
        ilSetError(IL_ILLEGAL_OPERATION);
        return;
    }
    
    switch (iCurImage->Format)
	{
            case IL_RGB:
                ret = ilConvertImage(IL_RGBA,iCurImage->Type);
                AlphaOff = 4;
                break;
            case IL_BGR:
                ret = ilConvertImage(IL_BGRA,iCurImage->Type);
                AlphaOff = 4;
                break;
            case IL_LUMINANCE:
                ret = ilConvertImage(IL_LUMINANCE_ALPHA,iCurImage->Type);
                AlphaOff = 2;
                break;
            case IL_COLOUR_INDEX:
                ret = ilConvertImage(IL_RGBA,iCurImage->Type);
                AlphaOff = 4;
                break;
    }    
    Size = iCurImage->Width * iCurImage->Height * iCurImage->Depth * iCurImage->Bpp;
    
    if (!ret)
		return;

    switch (iCurImage->Type)
	{
        case IL_BYTE:
        case IL_UNSIGNED_BYTE:
            Alpha.alpha_byte = (ILubyte)(AlphaValue * 0x000000FF + .5);
            for (i = AlphaOff-1, j = 0; i < Size; i += AlphaOff, j++)
                iCurImage->Data[i] = Alpha.alpha_byte;
            break;
        case IL_SHORT:
        case IL_UNSIGNED_SHORT:
            Alpha.alpha_short = (ILushort)(AlphaValue * 0x0000FFFF + .5);
            for (i = AlphaOff-1, j = 0; i < Size; i += AlphaOff, j++)
                ((ILushort*)iCurImage->Data)[i] = Alpha.alpha_short;
            break;