# `VTT*` Visual TrueType private tables

The tables listed on this page are used by Microsoft’s Visual TrueType application.

## `TSI0`: Glyph Program Text Indices

TSI{0,1,2,3,5} are private tables used by Microsoft Visual TrueType (VTT) tool to store its hinting source data.

TSI0 is the index table containing the lengths and offsets for the glyph programs and ‘extra’ programs (‘fpgm’, ‘prep’, and ‘cvt’) that are contained in the TSI1 table.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

fontTools.ttLib.tables.T_S_I__0.fixlongs(glyphID, textLength, textOffset)

class fontTools.ttLib.tables.T_S_I__0.table_T_S_I__0(tag=None)

  Bases: `DefaultTable`

  dependencies = ['TSI1']
  decompile(data, ttFont)
  compile(ttFont)
  set(indices, extra_indices)
  toXML(writer, ttFont)

## `TSI1`: Glyph Program Text UTF-8 Text Dump

TSI{0,1,2,3,5} are private tables used by Microsoft Visual TrueType (VTT) tool to store its hinting source data.

TSI1 contains the text of the glyph programs in the form of low-level assembly code, as well as the ‘extra’ programs ‘fpgm’, ‘ppgm’ (i.e. ‘prep’), and ‘cvt’.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I__1.table_T_S_I__1(tag=None)

  Bases: `LogMixin`, `DefaultTable`

  extras = {65530: 'ppgm', 65531: 'cvt', 65532: 'reserved', 65533: 'fpgm'}
  indextable = 'TSI0'
  decompile(data, ttFont)
  compile(ttFont)
  toXML(writer, ttFont)
  fromXML(name, attrs, content, ttFont)

## `TSI2`: VTT Talk Text Indices

TSI{0,1,2,3,5} are private tables used by Microsoft Visual TrueType (VTT) tool to store its hinting source data.

TSI2 is the index table containing the lengths and offsets for the glyph programs that are contained in the TSI3 table. It uses the same format as the TSI0 table.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I__2.table_T_S_I__2(tag=None)

  Bases: `table_T_S_I__0`

  dependencies = ['TSI3']

## `TSI3`: VTT Talk UTF-8 Text Dump

TSI{0,1,2,3,5} are private tables used by Microsoft Visual TrueType (VTT) tool to store its hinting source data.

TSI3 contains the text of the glyph programs in the form of ‘VTTTalk’ code.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I__3.table_T_S_I__3(tag=None)

  Bases: `table_T_S_I__1`

  extras = {65530: 'reserved0', 65531: 'reserved1', 65532: 'reserved2', 65533: 'reserved3'}
  indextable = 'TSI2'

## `TSI5`: VTT Character Group Flag

TSI{0,1,2,3,5} are private tables used by Microsoft Visual TrueType (VTT) tool to store its hinting source data.

TSI5 contains the VTT character groups.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I__5.table_T_S_I__5(tag=None)

  Bases: `DefaultTable`

  decompile(data, ttFont)
  compile(ttFont)
  toXML(writer, ttFont)
  fromXML(name, attrs, content, ttFont)

## `TSIB`: VTT BASE Table Text Source

TSI{B,C,D,J,P,S,V} are private tables used by Microsoft Visual TrueType (VTT) tool to store its table source data.

TSIB contains the source text for the `BASE` table.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I_B_.table_T_S_I_B_(tag=None)

  Bases: `table_T_S_I_V_`

## `TSIC`: VTT Variation CVT Window Source

TSI{B,C,D,J,P,S,V} are private tables used by Microsoft Visual TrueType (VTT) tool to store its table source data.

TSIC contains the source text for the Variation CVT window and data for the `cvar` table.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I_C_.table_T_S_I_C_(tag=None)

  Bases: `BaseTTXConverter`

## `TSID`: VTT GDEF Table Text Source

TSI{B,C,D,J,P,S,V} are private tables used by Microsoft Visual TrueType (VTT) tool to store its table source data.

TSID contains the source text for the `GDEF` table.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I_D_.table_T_S_I_D_(tag=None)

  Bases: `table_T_S_I_V_`

## `TSIJ`: VTT JSTF Table Text Source

TSI{B,C,D,J,P,S,V} are private tables used by Microsoft Visual TrueType (VTT) tool to store its table source data.

TSIJ contains the source text for the `JSTF` table.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I_J_.table_T_S_I_J_(tag=None)

  Bases: `table_T_S_I_V_`

## `TSIP`: VTT GPOS Table Text Source

TSI{B,C,D,J,P,S,V} are private tables used by Microsoft Visual TrueType (VTT) tool to store its table source data.

TSIP contains the source text for the `GPOS` table.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I_P_.table_T_S_I_P_(tag=None)

  Bases: `table_T_S_I_V_`

## `TSIS`: VTT GSUB Table Text Source

TSI{B,C,D,J,P,S,V} are private tables used by Microsoft Visual TrueType (VTT) tool to store its table source data.

TSIS contains the source text for the `GSUB` table.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I_S_.table_T_S_I_S_(tag=None)

  Bases: `table_T_S_I_V_`

## `TSIV`

TSI{B,C,D,J,P,S,V} are private tables used by Microsoft Visual TrueType (VTT) tool to store its table source data.

See also https://learn.microsoft.com/en-us/typography/tools/vtt/tsi-tables

class fontTools.ttLib.tables.T_S_I_V_.table_T_S_I_V_(tag=None)

  Bases: `asciiTable`

  toXML(writer, ttFont)
  fromXML(name, attrs, content, ttFont)