first I should apologize to WGZ. There is no problem with the font bmp you sent....I made a mistake in calculating the height of the characters.
I can use the functions in layerFont.h to draw text on layer now. The code below is an example about how to use the functions in the header file.there still may be faults in the file , i'll try to debug more. but anyway, Lucky can use it now.
layerActive(LAYER_TX);
layerSetTranslucentRate(LAYER_TX,0);
layerFontInit();
LayerKernelFontLoad("/system/font0.bmp",13,12,' ',0) ;
multitaskerYield();
layerDrawText("ABCDEFGHabcdefg",LAYER_TX,20,20,0);
layerRender();