[ft] a confusing problem when using FT_Library_SetLcdFilterWeights();

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Dear freetype,
       I am a chinese programmer. I want to output text on OpenGLES with  
freetype(C++). What's more, I want to use that class (C++) in our 
production.It' s handle frequency spectrum analyzer. But now I an confused 
about a problem. I set the subpixel choice before building lib and my display 
is LCD display.
      Firstly, I write a small demo in our WindowCE7.0 platform and it works 
correctly. I use the LCD filter like this.
FT_Library_SetLcdFilter(library, FT_LCD_FILTER_LIGHT);
unsignerd char weight = 0x55;
FT_Library_SetLcdFilterWeights(library, &weight);
The result is picture1.
      However, When I add the Class to our spectrum analyzer, it seems not 
working correctly. The result is picture2. It seem like more darker than 
picture1. When I set the weight = 0x00, the text dispeared. But When I set 
backgroud to other color, I can see the very dark font.So I think it is just 
more darker than weight = 0x55. The result is picture3. But when I remove the 
sentence FT_Library_SetLcdFilterWeights(library, weight), I can get whiter 
font. The result is picture4.So Maybe there is something wrong about the 
FT_Library_SetLcdFilterWeights. The picture4 is less clear than the picture1, 
So I still want to use the FT_Library_SetLcdFilterWeights.
      Could you give me some suggestion?


Sincerely,
Zhu GuoLiang

picture1.jpg
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picture2.jpg
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picture3.jpg
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picture4.jpg
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