The glass's contacts and a touch injector's, merged (touch_merge.h). More...

#include "touch_merge.h"
#include <string.h>

Functions
static int	clamp_count (int n)
	`n` held to 0..TOUCH_MAX_POINTS.
static bool	same_point (const touch_point_t a, const touch_point_t b)
	The same contact at the same place and strength.
void	touch_merge_reset (touch_merge_t *m)
	Forget both sets: no contacts, the injector attached at 0ms.
void	touch_merge_attach (touch_merge_t *m, uint32_t now_ms)
	Reset, with the injector attached and answering at `now_ms`.
void	touch_merge_start (touch_merge_t *m, bool answered, uint32_t now_ms)
	The start-up look for the injector.
bool	touch_merge_attached (const touch_merge_t *m)
	Whether the injector is attached: false once detached, until a probe.
bool	touch_merge_expire (touch_merge_t *m, uint32_t now_ms)
	Detach the injector when its last good read is TOUCH_MERGE_DETACH_MS or more old. Detaching drops its contacts.
bool	touch_merge_probe_due (const touch_merge_t *m, uint32_t now_ms)
	Whether a detached injector is due to be probed: TOUCH_MERGE_PROBE_MS after the detach and after every probe. Never for an absent one.
bool	touch_merge_probe (touch_merge_t *m, bool answered, uint32_t now_ms)
	A detached injector was probed.
static void	recut (touch_merge_t *m)
	Decide which injected contacts the frame has room for.
void	touch_merge_glass (touch_merge_t m, const touch_point_t pts, int n)
	The glass reported a new contact set (0 points when every finger lifted). Injected contacts the frame no longer has room for are cut.
bool	touch_merge_inject_due (const touch_merge_t *m, uint32_t now_ms)
	Whether the injector is due to be asked: on every poll while it answers, and every TOUCH_MERGE_RETRY_MS once it has failed TOUCH_MERGE_FAIL_DROP times in a row.
static bool	frames_differ (const touch_point_t a, int na, const touch_point_t b, int nb)
	Whether two merged sets differ.
bool	touch_merge_inject (touch_merge_t m, const touch_point_t pts, int n, bool fresh, uint32_t now_ms)
	The injector answered at `now_ms`.
bool	touch_merge_inject_failed (touch_merge_t *m, uint32_t now_ms)
	An injector read failed.
int	touch_merge_frame (const touch_merge_t m, touch_point_t out, int max)
	The merged set: the glass's contacts, then the injector's that are not cut, TOUCH_MAX_POINTS at most.
int	touch_merge_mark_cut (const touch_merge_t m, touch_event_t evts, int n)
	Mark the UP of every cut injected contact TOUCH_FLAG_NO_TAP.
bool	touch_merge_is_injector (const char *product_id)
	Whether `product_id` is the touch injector's.
touch_role_t	touch_merge_role (uint16_t addr, bool glass_found, const char *product_id)
	The role of a controller that answered as a GT911 at start-up.
touch_map_t	touch_merge_role_map (touch_role_t role, const touch_map_t glass, const touch_map_t inject, bool turned)
	The map for one report of a controller with role `role`.

Detailed Description

The glass's contacts and a touch injector's, merged (touch_merge.h).

SPDX-License-Identifier: MIT

Function Documentation

◆ recut()

void recut ( touch_merge_t * m )

static

Decide which injected contacts the frame has room for.

The room is what the glass leaves. A contact shown before keeps its place before a new one gets any, in report order; a cut one stays cut.

Parameters

m	The merge.

◆ touch_merge_attach()

void touch_merge_attach	(	touch_merge_t *	m,
		uint32_t	now_ms )

Reset, with the injector attached and answering at now_ms.

Parameters

m	The merge.
now_ms	The clock.

◆ touch_merge_attached()

bool touch_merge_attached ( const touch_merge_t * m )

Whether the injector is attached: false once detached, until a probe.

Parameters

m	The merge.

Returns: Whether it is attached.

◆ touch_merge_expire()

bool touch_merge_expire	(	touch_merge_t *	m,
		uint32_t	now_ms )

Detach the injector when its last good read is TOUCH_MERGE_DETACH_MS or more old. Detaching drops its contacts.

Parameters

m	The merge.
now_ms	The clock.

Returns: True when this call detached it.

◆ touch_merge_frame()

int touch_merge_frame	(	const touch_merge_t *	m,
		touch_point_t *	out,
		int	max )

The merged set: the glass's contacts, then the injector's that are not cut, TOUCH_MAX_POINTS at most.

Parameters

m	The merge.
out	Where the set goes.
max	The room in `out`.

Returns: The number written.

◆ touch_merge_glass()

void touch_merge_glass	(	touch_merge_t *	m,
		const touch_point_t *	pts,
		int	n )

The glass reported a new contact set (0 points when every finger lifted). Injected contacts the frame no longer has room for are cut.

Parameters

m	The merge.
pts	The points, in panel pixels.
n	How many; a count outside 0..TOUCH_MAX_POINTS is clamped.

◆ touch_merge_inject()

bool touch_merge_inject	(	touch_merge_t *	m,
		const touch_point_t *	pts,
		int	n,
		bool	fresh,
		uint32_t	now_ms )

The injector answered at now_ms.

A contact it reports keeps its cut by track id; a new one is cut when the frame has no room for it. A cut contact the injector lifts is forgotten, and its id is free again.

Parameters

m	The merge.
pts	The points, in panel pixels; not read when `fresh` is false.
n	How many.
fresh	False when it had no new report.
now_ms	The clock.

Returns: True when the merged set changed.

◆ touch_merge_inject_due()

bool touch_merge_inject_due	(	const touch_merge_t *	m,
		uint32_t	now_ms )

Whether the injector is due to be asked: on every poll while it answers, and every TOUCH_MERGE_RETRY_MS once it has failed TOUCH_MERGE_FAIL_DROP times in a row.

Parameters

m	The merge.
now_ms	The clock.

Returns: Whether to read it.

◆ touch_merge_inject_failed()

bool touch_merge_inject_failed	(	touch_merge_t *	m,
		uint32_t	now_ms )

An injector read failed.

Parameters

m	The merge.
now_ms	The clock.

Returns: True when this failure dropped injected contacts, which changes the merged set.

◆ touch_merge_is_injector()

bool touch_merge_is_injector ( const char * product_id )

Whether product_id is the touch injector's.

Parameters

product_id The 4 bytes read at 0x8140; NULL is not the injector.

Returns: True for TOUCH_MERGE_INJECT_PRODUCT exactly.

◆ touch_merge_mark_cut()

int touch_merge_mark_cut	(	const touch_merge_t *	m,
		touch_event_t *	evts,
		int	n )

Mark the UP of every cut injected contact TOUCH_FLAG_NO_TAP.

Called on the tracker's events for the frame touch_merge_frame() gave. A contact cut to make room for the glass's did not lift; its UP ends the press as TOUCH_FLAG_NO_TAP says. Every other event is left as it is.

Parameters

m	The merge.
evts	The events.
n	How many.

Returns: How many UPs were marked.

◆ touch_merge_probe()

bool touch_merge_probe	(	touch_merge_t *	m,
		bool	answered,
		uint32_t	now_ms )

A detached injector was probed.

Parameters

m	The merge.
answered	True when it answered as a GT911.
now_ms	The clock.

Returns: True when this re-attached it.

◆ touch_merge_probe_due()

bool touch_merge_probe_due	(	const touch_merge_t *	m,
		uint32_t	now_ms )

Whether a detached injector is due to be probed: TOUCH_MERGE_PROBE_MS after the detach and after every probe. Never for an absent one.

Parameters

m	The merge.
now_ms	The clock.

Returns: Whether to probe.

◆ touch_merge_reset()

void touch_merge_reset ( touch_merge_t * m )

Forget both sets: no contacts, the injector attached at 0ms.

Parameters

m	The merge; NULL does nothing.

◆ touch_merge_role()

touch_role_t touch_merge_role	(	uint16_t	addr,
		bool	glass_found,
		const char *	product_id )

The role of a controller that answered as a GT911 at start-up.

At TOUCH_MERGE_GLASS_ADDR: the glass, whatever its product ID.
At TOUCH_MERGE_INJECT_ADDR with TOUCH_MERGE_INJECT_PRODUCT: the injector, beside a glass at 0x5D or alone.
At TOUCH_MERGE_INJECT_ADDR with any other product ID: the glass when nothing answered at 0x5D (glass_found false); not read when the glass answered at 0x5D, so 0x5D wins.
At any other address: not read.

Parameters

addr	The address it answered at.
glass_found	Whether a glass answered at TOUCH_MERGE_GLASS_ADDR before it.
product_id	Its 4-byte product ID; NULL when the read failed.

Returns: Its role.

◆ touch_merge_role_map()

touch_map_t touch_merge_role_map	(	touch_role_t	role,
		const touch_map_t *	glass,
		const touch_map_t *	inject,
		bool	turned )

The map for one report of a controller with role role.

Parameters

role	Its role.
glass	The glass's map: its resolution, mirrors and rotation.
inject	The injector's map (logical pixels).
turned	Whether the turned picture is on the glass (gfx_turn_shown()); false again after the turn falls back.

Returns: glass turned by turned for TOUCH_ROLE_GLASS; inject, never turned, for TOUCH_ROLE_INJECTOR; a zeroed map for TOUCH_ROLE_NONE or a NULL map.

◆ touch_merge_start()

void touch_merge_start	(	touch_merge_t *	m,
		bool	answered,
		uint32_t	now_ms )

The start-up look for the injector.

An answer is touch_merge_attach(). No answer makes the injector absent until the next start: nothing in this header attaches, reads or probes it, and touch_merge_attached() stays false.

Parameters

m	The merge.
answered	True when 0x14 answered as a GT911.
now_ms	The clock.

Functions

Detailed Description

Function Documentation

◆ recut()

◆ touch_merge_attach()

◆ touch_merge_attached()

◆ touch_merge_expire()

◆ touch_merge_frame()

◆ touch_merge_glass()

◆ touch_merge_inject()

◆ touch_merge_inject_due()

◆ touch_merge_inject_failed()

◆ touch_merge_is_injector()

◆ touch_merge_mark_cut()

◆ touch_merge_probe()

◆ touch_merge_probe_due()

◆ touch_merge_reset()

◆ touch_merge_role()

◆ touch_merge_role_map()

◆ touch_merge_start()