• JAVA调用流程如下
FontDesignMetrics.charWidth(char) line: 441    
 FontDesignMetrics.getLatinCharWidth(char) line: 425    
 FontDesignMetrics.handleCharWidth(int) line: 416    
 FileFontStrike.getCodePointAdvance(int) line: 732    
 FileFontStrike.getGlyphAdvance(int) line: 613    
 FileFontStrike.getGlyphAdvance(int, boolean) line: 711    
 TrueTypeFont(FileFont).getGlyphAdvance(long, int) line: 190    
 FreetypeFontScaler.getGlyphAdvance(long, int) line: 88    
 之后是本地函数getGlyphAdvanceNative()• getGlyphAdvanceNative
GlyphInfo.advanceX