| ############################### |
| TrueType/OpenType Table Modules |
| ############################### |
| |
| This folder is a subpackage of :py:mod:`fontTools.ttLib`. Each module here is a |
| specialized TT/OT table converter: they can convert raw data |
| to Python objects and vice versa. Usually you don't need to |
| use the modules directly: they are imported and used |
| automatically when needed by :py:mod:`fontTools.ttLib`. The tables currently |
| supported are: |
| |
| .. toctree:: |
| :maxdepth: 1 |
| |
| tables/_a_n_k_r |
| tables/_a_v_a_r |
| tables/B_A_S_E_ |
| tables/_b_s_l_n |
| tables/C_B_D_T_ |
| tables/C_B_L_C_ |
| tables/C_F_F_ |
| tables/C_F_F__2 |
| tables/_c_i_d_g |
| tables/_c_m_a_p |
| tables/C_O_L_R_ |
| tables/C_P_A_L_ |
| tables/_c_v_a_r |
| tables/_c_v_t |
| tables/D_S_I_G_ |
| tables/E_B_D_T_ |
| tables/E_B_L_C_ |
| tables/F__e_a_t |
| tables/_f_e_a_t |
| tables/F_F_T_M_ |
| tables/_f_p_g_m |
| tables/_f_v_a_r |
| tables/_g_a_s_p |
| tables/_g_c_i_d |
| tables/G_D_E_F_ |
| tables/G__l_a_t |
| tables/G__l_o_c |
| tables/_g_l_y_f |
| tables/G_M_A_P_ |
| tables/G_P_K_G_ |
| tables/G_P_O_S_ |
| tables/G_S_U_B_ |
| tables/_g_v_a_r |
| tables/_h_d_m_x |
| tables/_h_e_a_d |
| tables/_h_h_e_a |
| tables/_h_m_t_x |
| tables/H_V_A_R_ |
| tables/J_S_T_F_ |
| tables/_k_e_r_n |
| tables/_l_c_a_r |
| tables/_l_o_c_a |
| tables/_l_t_a_g |
| tables/L_T_S_H_ |
| tables/M_A_T_H_ |
| tables/_m_a_x_p |
| tables/M_E_T_A_ |
| tables/_m_e_t_a |
| tables/_m_o_r_t |
| tables/_m_o_r_x |
| tables/M_V_A_R_ |
| tables/_n_a_m_e |
| tables/_o_p_b_d |
| tables/O_S_2f_2 |
| tables/_p_o_s_t |
| tables/_p_r_e_p |
| tables/_p_r_o_p |
| tables/_s_b_i_x |
| tables/S__i_l_f |
| tables/S__i_l_l |
| tables/S_I_N_G_ |
| tables/S_T_A_T_ |
| tables/S_V_G_ |
| tables/_t_r_a_k |
| tables/T_T_F_A_ |
| tables/V_D_M_X_ |
| tables/_v_h_e_a |
| tables/_v_m_t_x |
| tables/V_O_R_G_ |
| tables/VTT_related |
| tables/V_V_A_R_ |
| |
| The Python modules representing the tables have pretty strange names: this is due to the |
| fact that we need to map TT table tags (which are case sensitive) |
| to filenames (which on Mac and Win aren't case sensitive) as well |
| as to Python identifiers. The latter means it can only contain |
| ``[A-Za-z0-9_]`` and cannot start with a number. |
| |
| :py:mod:`fontTools.ttLib` provides functions to expand a tag into the format used here:: |
| |
| >>> from fontTools import ttLib |
| >>> ttLib.tagToIdentifier("FOO ") |
| 'F_O_O_' |
| >>> ttLib.tagToIdentifier("cvt ") |
| '_c_v_t' |
| >>> ttLib.tagToIdentifier("OS/2") |
| 'O_S_2f_2' |
| >>> ttLib.tagToIdentifier("glyf") |
| '_g_l_y_f' |
| >>> |
| |
| And vice versa:: |
| |
| >>> ttLib.identifierToTag("F_O_O_") |
| 'FOO ' |
| >>> ttLib.identifierToTag("_c_v_t") |
| 'cvt ' |
| >>> ttLib.identifierToTag("O_S_2f_2") |
| 'OS/2' |
| >>> ttLib.identifierToTag("_g_l_y_f") |
| 'glyf' |
| >>> |
| |
| Eg. the 'glyf' table converter lives in a Python file called:: |
| |
| _g_l_y_f.py |
| |
| The converter itself is a class, named ``table_`` + expandedtag. Eg:: |
| |
| |
| class table__g_l_y_f: |
| etc. |
| |
| Note that if you _do_ need to use such modules or classes manually, |
| there are two convenient API functions that let you find them by tag:: |
| |
| >>> ttLib.getTableModule('glyf') |
| <module 'ttLib.tables._g_l_y_f'> |
| >>> ttLib.getTableClass('glyf') |
| <class ttLib.tables._g_l_y_f.table__g_l_y_f at 645f400> |
| >> |
| |
| ttProgram: TrueType bytecode assembler/disassembler |
| --------------------------------------------------- |
| |
| .. automodule:: fontTools.ttLib.tables.ttProgram |
| :inherited-members: |
| :members: |
| :undoc-members: |
| |
| Contributing your own table convertors |
| -------------------------------------- |
| |
| To add support for a new font table that fontTools does not currently implement, |
| you must subclass from :py:mod:`fontTools.ttLib.tables.DefaultTable.DefaultTable`. |
| It provides some default behavior, as well as a constructor method (``__init__``) |
| that you don't need to override. |
| |
| Your converter should minimally provide two methods:: |
| |
| |
| class table_F_O_O_(DefaultTable.DefaultTable): # converter for table 'FOO ' |
| |
| def decompile(self, data, ttFont): |
| # 'data' is the raw table data. Unpack it into a |
| # Python data structure. |
| # 'ttFont' is a ttLib.TTfile instance, enabling you to |
| # refer to other tables. Do ***not*** keep a reference to |
| # it: it will cause a circular reference (ttFont saves |
| # a reference to us), and that means we'll be leaking |
| # memory. If you need to use it in other methods, just |
| # pass it around as a method argument. |
| |
| def compile(self, ttFont): |
| # Return the raw data, as converted from the Python |
| # data structure. |
| # Again, 'ttFont' is there so you can access other tables. |
| # Same warning applies. |
| |
| |
| If you want to support TTX import/export as well, you need to provide two |
| additional methods:: |
| |
| |
| def toXML(self, writer, ttFont): |
| # XXX |
| |
| def fromXML(self, (name, attrs, content), ttFont): |
| # XXX |
| |
| .. automodule:: fontTools.ttLib.tables |
| :inherited-members: |
| :members: |
| :undoc-members: |
| |
| |
