2D vector (often used to store positions, sizes, etc.)

4D vector (often used to store floating-point colors)

2D vector (half-size integer)

Simplified structure to mimic a Document model

Runtime data for multiple fonts, bake multiple fonts into a single texture, TTF/OTF font loader

1D vector (this odd construct is used to facilitate the transition between 1D and 2D, and the maintenance of some branches/patches)

features.h

Helper to build glyph ranges from text/string data

Storage for one type registered in the .ini file

Texture coordinate wrapping mode

writer.h

All draw command lists required to render the frame + pos/size coordinates to use for the projection matrix.

Helper to build a ImDrawData instance

Storage data for a single column

Backup and restore IsItemHovered() internal data

Storage for a tab bar

Storage for a tab item (within a tab bar)

Viewport (generally ~1 per window to output to at the OS level. Need per-platform support to use multiple viewports)

Temporary storage for one window (that's the data which in theory we could ditch at the end of the frame)

exact copy of Features

reader.h