Here are the data structures with brief descriptions:

C_menu_t	The underlying data for a menu. This fundamentally is a list of menuItem_t
C_p2pInfo	All the state variables required for a P2P session with another Swadge
C_p2pInfo.ack	Variables used for acknowledging and retrying messages
C_p2pInfo.cnc	Connection state variables
C_p2pInfo.tmr	The timers used for connection and ACKing
Carrow_t
CbuttonEvt_t	A button event containing the button that triggered the event, whether it was pressed or released, and the whole button state
Ccircle_t	Signed integer representation of a circle
CcircleFl_t	Signed integer representation of a circle
CcnfsFileEntry
Cdft32_data
CdialogBox_t
CdialogBoxOption_t
CdialogDrawInfo_t	Holds information about how and where to draw the dialog box and its main components
CembeddedNf_data
CembeddedOut_data
Cenvelope_t	Describes the characteristics of a particular timbre while
CespNowPacket_t	A packet received over ESP-NOW
Cfont_ch_t	A character used in a font_t. Each character is a bitmap with the same height as the other characters in the font
Cfont_t	A font is a collection of font_ch_t for all ASCII characters. Each character has the same height and variable width
ChashBucket	A single element of the hash map array, holding either one value or a list of values
ChashBucket.__unnamed25__
ChashIterator_t	Struct used for iterating through a hash map efficiently
ChashIterState	The internal state of a hash map iterator
ChashMap_t	A hash map for storing key-value pairs
ChashNode_t	A single key-value pair in the hash map
Cled_strip_encoder_config_t	Type of led strip encoder configuration
Cled_t	LED colors, with red, green, and blue components
Cline_t	Signed integer representation of a line segment
ClineFl_t	Signed integer representation of a line segment
Clist_t	A doubly linked list with pointers to the first and last nodes
CLSM6DSLData
CmaniaRing_t
CmenuItem_t	The underlying data for an item in a menu. The item may be a single-select, multi-select, or submenu item
CmenuManiaRenderer_t	A struct containing all the state data to render a mania-style menu and LEDs
CmidiChannel_t	Tracks the state of a single MIDI channel
CmidiEvent_t	Contains information for an entire MIDI event or non-MIDI meta-event
CmidiEvent_t.__unnamed5__
CmidiFile_t	Contains information which applies to the entire MIDI file
CmidiFileReader_t
CmidiMetaEvent_t	Contains information for a non-MIDI meta-event from a MIDI file
CmidiMetaEvent_t.__unnamed1__
CmidiMetaEvent_t.__unnamed1__.keySignature	Contains key signature data, when type is KEY_SIGNATURE
CmidiMetaEvent_t.__unnamed1__.startTime	Contains the start time of this track, when type is SMPTE_OFFSET
CmidiPlayer_t	Tracks the state of the entire MIDI apparatus
CmidiSaveState_t
CmidiStatusEvent_t	Data for a normal MIDI status event
CmidiSysexEvent_t	Contains information for a MIDI System Exclusive event
CmidiTimbre_t	Defines the sound characteristics of a particular instrument
CmidiTimbre_t.__unnamed7__
CmidiTimbre_t.__unnamed7__.__unnamed9__
CmidiTimbre_t.__unnamed7__.percussion
CmidiTimbre_t.__unnamed7__.sample
CmidiTimbre_t.__unnamed7__.sample.__unnamed13__	The frequency of the base sample to be used when pitch shifting
CmidiTimbre_t.__unnamed7__.sample.__unnamed13__.__unnamed15__
CmidiTimbre_t.__unnamed7__.sample.__unnamed13__.config
CmidiTimeSignature_t	Data for a MIDI time signature definition
CmidiTrack_t	Contains basic information pointing to a MIDI track within its file data
CmidiTrackState	Contains all track-specific parsing state
CmidiVoice_t	Tracks the state of a single voice, playing a single note
CmidiVoice_t.__unnamed18__
CmidiVoice_t.__unnamed18__.__unnamed20__
Cnode	A node in a doubly linked list with pointers to the previous and next values (which may be NULL), and a `void*` to arbritray data
CoptionDrawInfo_t	Holds information about how and where to draw a dialog box option
CoscAccum_t	An accumulator used to increment through a wave. A value is accumulated in a 32-bit integer and bits 16->23 are used as an index into a 256 point wave
Cp2pCommonHeader_t	The byte format for a common header for all P2P packets
Cp2pConMsg_t	The byte format for a connection message for a P2P session
Cp2pDataMsg_t	The byte format for a P2P data packet
Cp2pPacket_t	All the information for a packet to store between the receive callback and the task it's actually processed in
Crectangle_t	Signed integer representation of a rectangle
CrectangleFl_t	Signed integer representation of a rectangle
Crmt_led_strip_encoder_t	An encoder to use the RMT peripheral to drive RGB LEDs
Csetting_t	A setting. The parameters are const, but the value is not
CsettingParam_t	Immutable data for a setting, including minimum, maximum, and default values, and the NVS key
CswadgeMode_t	A struct of all the function pointers necessary for a swadge mode. If a mode does not need a particular function, for example it doesn't do audio handling, it is safe to set the pointer to NULL. It just won't be called
CsynthOscillator_t	A software oscillator with controllable frequency, amplitude, and shape
CtextEntry_t	Struct to store all state for a text entry
CtimbreEffects_t
CtouchSpinState_t
CTU_ATTR_PACKED	HID Switch Gamepad Protocol Report
Cvec_q24_8	A 2D vector with q24_8 numbers
Cvec_t	A 2D vector with signed integer X and Y components
CvecFl_t	A 2D vector with signed integer X and Y components
CvoiceStates_t	Holds several bitfields that track the state of each voice for fast access. This may be used for dynamic voice allocation, and to minimize the impact of note stealing if we run out of voices
CwheelDrawInfo_t
CwheelItemInfo_t
CwheelMenuRenderer_t	Renderer for a menu wheel
Cwsg_t	A sprite using paletteColor_t colors that can be drawn to the display
CwsgPalette_t