PNG_FP_NONZERO   1339 3rdparty/libpng/png.c       case 57:  type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break;
PNG_FP_NONZERO   1577 3rdparty/libpng/pngpriv.h #define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
PNG_FP_NONZERO   1579 3rdparty/libpng/pngpriv.h #define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)