Color management Gtk4 - Revision history

Tavmjong: /* A redesigned system */

2023-06-14T07:43:11Z

A redesigned system

← Older revision		Revision as of 07:43, 14 June 2023
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	== A redesigned system==		== A redesigned system==

	Each ~~canvas (or~~ monitor) should have its own color transform. This color transform should be updated when:		Each monitor should have its own color transform. This color transform should be updated when:
	* The user changes a color transform related preference. Note: the canvas widget triggers a redraw whenever a color transform preference is changed.		* The user changes a color transform related preference. Note: the canvas widget triggers a redraw whenever a color transform preference is changed.
	* The canvas is moved to a different monitor (if Inkscape handles monitor color corrections, see below). In Gtk4 there is Gdk::Surface::signal_enter_monitor than can be used for this. In Gtk3, there was Gtk::Widget::signal_screen_changed but as of 3.20 there is only one screen. One could check which monitor the canvas is on each time there is a draw and if the monitor changes, recalculate the color transform.		* The canvas is moved to a different monitor (if Inkscape handles monitor color corrections, see below). In Gtk4 there is Gdk::Surface::signal_enter_monitor than can be used for this. In Gtk3, there was Gtk::Widget::signal_screen_changed but as of 3.20 there is only one screen. One could check which monitor the canvas is on each time there is a draw and if the monitor changes, recalculate the color transform.
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	** Using colord: This is the framework that Gnome and KDE use to set per monitor color corrections. As this would be by default the same as used by the system wide monitor correction, there is probably no added advantage in supporting this method.		** Using colord: This is the framework that Gnome and KDE use to set per monitor color corrections. As this would be by default the same as used by the system wide monitor correction, there is probably no added advantage in supporting this method.

	The color transform is defined as a cmsHTRANSFORM (void *), this is a pointer to a data structure defined by lcms2. We need to track it, not only to avoid recreating it but also to delete it when replaced or no longer needed. It would probably best be stored ~~as part of~~ the ~~Canvas structure. Currently~~ there is only one instance ~~stored in the CMSSystem class~~.		The color transform is defined as a cmsHTRANSFORM (void *), this is a pointer to a data structure defined by lcms2. We need to track it, not only to avoid recreating it but also to delete it when replaced or no longer needed. It would probably best be stored per monitor in the CMSSystem class, currently there only one instance that gets continually update.

	== Test program ==		== Test program ==

Tavmjong: /* A redesigned system */

2023-06-14T07:40:31Z

A redesigned system

← Older revision		Revision as of 07:40, 14 June 2023
Line 27:		Line 27:
	== A redesigned system==		== A redesigned system==

	Each canvas should have its own color transform. This color transform should be updated when:		Each canvas (or monitor) should have its own color transform. This color transform should be updated when:
	* The user changes a color transform related preference.		* The user changes a color transform related preference. Note: the canvas widget triggers a redraw whenever a color transform preference is changed.
	* The canvas is moved to a different monitor (if Inkscape handles monitor color corrections, see below). In Gtk4 there is Gdk::Surface::signal_enter_monitor than can be used for this. In Gtk3, there was Gtk::Widget::signal_screen_changed but as of 3.20 there is only one screen. One could check which monitor the canvas is on each time there is a draw and if the monitor changes, recalculate the color transform.		* The canvas is moved to a different monitor (if Inkscape handles monitor color corrections, see below). In Gtk4 there is Gdk::Surface::signal_enter_monitor than can be used for this. In Gtk3, there was Gtk::Widget::signal_screen_changed but as of 3.20 there is only one screen. One could check which monitor the canvas is on each time there is a draw and if the monitor changes, recalculate the color transform.

	~~There is the question of if Inkscape should even handle~~ monitor color corrections. On most Linux (Gnome, KDE) systems, [https://www.freedesktop.org/software/colord/index.html colord] can be used to set a system wide color correction for each monitor (see, for example, the "Color" page for in Gnome's "Settings"). Windows and OSX have their own color corrections frameworks.		Per monitor color corrections should either:
			* Be handled by the windowing system. On most Linux (Gnome, KDE) systems, [https://www.freedesktop.org/software/colord/index.html colord] can be used to set a system wide color correction for each monitor (see, for example, the "Color" page for in Gnome's "Settings"). Windows and OSX have their own color corrections frameworks.
			* Be handled by Inkscape where the user can select which color correction to use for each monitor (it is the users responsibility to ensure that the windowing system does not also color correct as this would over-correct).

	If Inkscape ~~does handle~~ per monitor color corrections, there are two ~~methods~~ for ~~determining~~ the color corrections:		Inkscape should NOT try to obtain per-monitor color corrections from the windowing system.
			* For Linux there are two ways of doing so:
			** Using X11 (this, of course assumes X11 is being used and not Wayland): X11 has an "Atom" for finding the color correction for each monitor. The primary monitor's atom is "_ICC_PROFILE", additional monitors have atoms of the form "_ICC_PROFILE_n" where n is the additional screen number (starting at 1). On, at least my system only the primary monitor's color profile atom is defined. I could not, having spent hours searching the Internet, find out how to set "_ICC_PROFILE_1". One possible tool, that may have worked, doesn't support V4 ICC files. Inkscape 1.3 tries to do corrections this way when the "Retrieve profile from display" box is checked.
			** Using colord: This is the framework that Gnome and KDE use to set per monitor color corrections. As this would be by default the same as used by the system wide monitor correction, there is probably no added advantage in supporting this method.

	~~# Allow the user to set the corrections. Currently (Inkscape 1.3), only one correction can be set which is used for all monitors.~~		The color transform is defined as a cmsHTRANSFORM (void *), this is a pointer to a data structure defined by lcms2. We need to track it, not only to avoid recreating it but also to delete it when replaced or no longer needed. It would probably best be stored as part of the Canvas structure. Currently there is only one instance stored in the CMSSystem class.
	~~# Automatically obtain the color corrections from the monitors themselves. On Linux, one can either use X11 functionality or colord (or use X11 via colord?):~~
	## X11: X11 has an "Atom" for finding the color correction for each monitor. The primary monitor's atom is "_ICC_PROFILE", additional monitors have atoms of the form "_ICC_PROFILE_n" where n is the additional screen number (starting at 1). On, at least my system only the primary monitor's color profile atom is defined. This is Inkscape's current method.
	## colord: One can use the colord library to find the color correction set for a particular monitor. As this would be by default the same as used by the system wide monitor correction, there is probably no added advantage in supporting this method.

	The color transform is defined as a cmsHTRANSFORM (void *), this is a pointer to a data structure defined by lcms2. We need to track it, not only to avoid recreating it but also to delete it when replaced or no longer needed.

	== Test program ==		== Test program ==

Tavmjong: /* Inkscape 1.3 */

2023-06-13T12:48:13Z

Inkscape 1.3

← Older revision		Revision as of 12:48, 13 June 2023
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	** target_screen_change_cb		** target_screen_change_cb
	** ege-color_prof_tracker_new is called with LayerSelector as target widget (why?).		** ege-color_prof_tracker_new is called with LayerSelector as target widget (why?).
			** If x11:
			*** add_xll_tracking_for_screen called:
			**** The X11 atoms _ICC_PROFILE (monitor 0) and _ICC_PROFILE_n (where n >= 1 is monitor number) are searched for.
			**** On my system, _ICC_PROFILE_1 is never defined. I can find no way (after hours of internet searching) to set _ICC_PROFILE_1. Various sites suggest abandoning using X11 atoms and relying on colord.
	** target_screen_change_cb		** target_screen_change_cb
	* On event handling:		* On event handling:

Tavmjong: /* Inkscape 1.3 */

2023-06-13T06:18:57Z

Inkscape 1.3

← Older revision		Revision as of 06:18, 13 June 2023
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	* On event handling:		* On event handling:
	** After EVERY event (mouse, scroll, etc.) event_after_cb is called.		** After EVERY event (mouse, scroll, etc.) event_after_cb is called.
	*** If the event is a GDK_CONFIGURE event, there is a check to see if the gdk window is on a different monitor.		*** If the event is a GDK_CONFIGURE event (change of window size or position), there is a check to see if the gdk window is on a different monitor.
	*** If the monitor has changed, the tracker "changed" signal triggers a call to SPDesktopWidget::color_profile_event, this updates the canvas cms key (a checksum of profile buffer) corresponding to the new monitor. ~~This event often is delayed some number of seconds (it's probably being fired by something other than a monitor change).~~		*** Note, on Wayland, the GDK_CONFIGURE event always reports an x, y as 0, 0.
	* Drawing		*** If the monitor has changed, the tracker "changed" signal triggers a call to SPDesktopWidget::color_profile_event, this updates the canvas cms key (a checksum of profile buffer) corresponding to the new monitor.
	** CanvasPrivate::commit_tiles takes the value of prefs.from_display:		** CanvasPrivate::commit_tiles takes the value of prefs.from_display:
	*** True: calls cms_system->get_display_transform_monitor(q->_cms_key). This uses the display profile linked to a monitor.		*** True: calls cms_system->get_display_transform_monitor(q->_cms_key). This uses the display profile linked to a monitor.
	*** False: calls cms_system->get_display_transform_system(). This uses the display profile set in the preferences dialog (same profile for all monitors).		*** False: calls cms_system->get_display_transform_system(). This uses the display profile set in the preferences dialog (same profile for all monitors).

Tavmjong: /* Inkscape 1.3 */

2023-06-12T20:04:12Z

Inkscape 1.3

← Older revision		Revision as of 20:04, 12 June 2023
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	** After EVERY event (mouse, scroll, etc.) event_after_cb is called.		** After EVERY event (mouse, scroll, etc.) event_after_cb is called.
	*** If the event is a GDK_CONFIGURE event, there is a check to see if the gdk window is on a different monitor.		*** If the event is a GDK_CONFIGURE event, there is a check to see if the gdk window is on a different monitor.
	*** If the monitor has changed, the tracker "changed" signal triggers a call to SPDesktopWidget::color_profile_event, this updates the canvas cms key (a checksum of profile buffer) corresponding to the new monitor. This event often is delayed some number of seconds.		*** If the monitor has changed, the tracker "changed" signal triggers a call to SPDesktopWidget::color_profile_event, this updates the canvas cms key (a checksum of profile buffer) corresponding to the new monitor. This event often is delayed some number of seconds (it's probably being fired by something other than a monitor change).
	* Drawing		* Drawing
	** CanvasPrivate::commit_tiles takes the value of prefs.from_display:		** CanvasPrivate::commit_tiles takes the value of prefs.from_display:
	*** True: calls cms_system->get_display_transform_monitor(q->_cms_key). This uses the display profile linked to a monitor.		*** True: calls cms_system->get_display_transform_monitor(q->_cms_key). This uses the display profile linked to a monitor.
	*** False: calls cms_system->get_display_transform_system(). This uses the display profile set in the preferences dialog (same profile for all monitors).		*** False: calls cms_system->get_display_transform_system(). This uses the display profile set in the preferences dialog (same profile for all monitors).

Tavmjong: /* Inkscape 1.3 */

2023-06-12T20:03:00Z

Inkscape 1.3

← Older revision		Revision as of 20:03, 12 June 2023
Line 65:		Line 65:
	** After EVERY event (mouse, scroll, etc.) event_after_cb is called.		** After EVERY event (mouse, scroll, etc.) event_after_cb is called.
	*** If the event is a GDK_CONFIGURE event, there is a check to see if the gdk window is on a different monitor.		*** If the event is a GDK_CONFIGURE event, there is a check to see if the gdk window is on a different monitor.
	*** If the monitor has changed, the tracker "changed" signal triggers a call to SPDesktopWidget::color_profile_event, this updates the canvas cms key (a checksum of profile buffer) corresponding to the new monitor.		*** If the monitor has changed, the tracker "changed" signal triggers a call to SPDesktopWidget::color_profile_event, this updates the canvas cms key (a checksum of profile buffer) corresponding to the new monitor. This event often is delayed some number of seconds.
	* Drawing		* Drawing
	** CanvasPrivate::commit_tiles takes the value of prefs.from_display:		** CanvasPrivate::commit_tiles takes the value of prefs.from_display:
	*** True: calls cms_system->get_display_transform_monitor(q->_cms_key). This uses the display profile linked to a monitor.		*** True: calls cms_system->get_display_transform_monitor(q->_cms_key). This uses the display profile linked to a monitor.
	*** False: calls cms_system->get_display_transform_system(). This uses the display profile set in the preferences dialog (same profile for all monitors).		*** False: calls cms_system->get_display_transform_system(). This uses the display profile set in the preferences dialog (same profile for all monitors).

Tavmjong: /* Inkscape 1.3 */

2023-06-12T16:25:49Z

Inkscape 1.3

← Older revision		Revision as of 16:25, 12 June 2023
Line 66:		Line 66:
	*** If the event is a GDK_CONFIGURE event, there is a check to see if the gdk window is on a different monitor.		*** If the event is a GDK_CONFIGURE event, there is a check to see if the gdk window is on a different monitor.
	*** If the monitor has changed, the tracker "changed" signal triggers a call to SPDesktopWidget::color_profile_event, this updates the canvas cms key (a checksum of profile buffer) corresponding to the new monitor.		*** If the monitor has changed, the tracker "changed" signal triggers a call to SPDesktopWidget::color_profile_event, this updates the canvas cms key (a checksum of profile buffer) corresponding to the new monitor.
			* Drawing
			** CanvasPrivate::commit_tiles takes the value of prefs.from_display:
			*** True: calls cms_system->get_display_transform_monitor(q->_cms_key). This uses the display profile linked to a monitor.
			*** False: calls cms_system->get_display_transform_system(). This uses the display profile set in the preferences dialog (same profile for all monitors).

Tavmjong: /* Inkscape 1.3 */

2023-06-12T15:33:43Z

Inkscape 1.3

← Older revision		Revision as of 15:33, 12 June 2023
Line 65:		Line 65:
	** After EVERY event (mouse, scroll, etc.) event_after_cb is called.		** After EVERY event (mouse, scroll, etc.) event_after_cb is called.
	*** If the event is a GDK_CONFIGURE event, there is a check to see if the gdk window is on a different monitor.		*** If the event is a GDK_CONFIGURE event, there is a check to see if the gdk window is on a different monitor.
	*** If the monitor has changed, a signal triggers a call to SPDesktopWidget::color_profile_event		*** If the monitor has changed, the tracker "changed" signal triggers a call to SPDesktopWidget::color_profile_event, this updates the canvas cms key (a checksum of profile buffer) corresponding to the new monitor.

Tavmjong: /* Test program */

2023-06-12T15:09:14Z

Test program

← Older revision		Revision as of 15:09, 12 June 2023
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	* Gtk3 has Gtk::Window::signal_screen_changed but Gtk has only one screen since 3.20 so it is useless to track moving a window between monitors. Gtk4 has Gtk::Surface::signal_enter_monitor(). This signal is not fired under X11. The Gtk4 function Gdk::Display::get_monitor_at_surface() does work on both X11 and Wayland.		* Gtk3 has Gtk::Window::signal_screen_changed but Gtk has only one screen since 3.20 so it is useless to track moving a window between monitors. Gtk4 has Gtk::Surface::signal_enter_monitor(). This signal is not fired under X11. The Gtk4 function Gdk::Display::get_monitor_at_surface() does work on both X11 and Wayland.
	* The initial monitor is set wrong under Gtk3/Gtk4 x11/Wayland (as seen while constructing the Window, and in the signal handlers for realizing and mapping the window (it is always set to the second monitor). Under x11, the monitor is correct when using a button to trigger code to check the monitor. Under Wayland, the window has to be moved to a different monitor and back before the correct monitor is shown via the button. This is probably a Gtk bug.		* The initial monitor is set wrong under Gtk3/Gtk4 x11/Wayland (as seen while constructing the Window, and in the signal handlers for realizing and mapping the window (it is always set to the second monitor). Under x11, the monitor is correct when using a button to trigger code to check the monitor. Under Wayland, the window has to be moved to a different monitor and back before the correct monitor is shown via the button. This is probably a Gtk bug.

			== Inkscape 1.3 ==

			This documents the ege-color-prof-tracker code as of 1.3.

			* On start-up:
			** ege-color_prof_tracker_new is called with no target widget (why?).
			** target_screen_change_cb
			** ege-color_prof_tracker_new is called with LayerSelector as target widget (why?).
			** target_screen_change_cb
			* On event handling:
			** After EVERY event (mouse, scroll, etc.) event_after_cb is called.
			*** If the event is a GDK_CONFIGURE event, there is a check to see if the gdk window is on a different monitor.
			*** If the monitor has changed, a signal triggers a call to SPDesktopWidget::color_profile_event

Tavmjong: /* Test program */

2023-06-12T11:48:13Z

Test program

← Older revision		Revision as of 11:48, 12 June 2023
Line 51:		Line 51:
	* Gtk4 with X11 lists all seat devices such as "Power Button", "Logitech M310/310t"; Gtk4 with Wayland lists a small set of devices including "Wayland Keyboard" and "Wayland Pointer".		* Gtk4 with X11 lists all seat devices such as "Power Button", "Logitech M310/310t"; Gtk4 with Wayland lists a small set of devices including "Wayland Keyboard" and "Wayland Pointer".
	* Gtk3 has Gtk::Window::signal_screen_changed but Gtk has only one screen since 3.20 so it is useless to track moving a window between monitors. Gtk4 has Gtk::Surface::signal_enter_monitor(). This signal is not fired under X11. The Gtk4 function Gdk::Display::get_monitor_at_surface() does work on both X11 and Wayland.		* Gtk3 has Gtk::Window::signal_screen_changed but Gtk has only one screen since 3.20 so it is useless to track moving a window between monitors. Gtk4 has Gtk::Surface::signal_enter_monitor(). This signal is not fired under X11. The Gtk4 function Gdk::Display::get_monitor_at_surface() does work on both X11 and Wayland.
			* The initial monitor is set wrong under Gtk3/Gtk4 x11/Wayland (as seen while constructing the Window, and in the signal handlers for realizing and mapping the window (it is always set to the second monitor). Under x11, the monitor is correct when using a button to trigger code to check the monitor. Under Wayland, the window has to be moved to a different monitor and back before the correct monitor is shown via the button. This is probably a Gtk bug.