From c093ac47db77724da008bce2b082cd41dd94442c Mon Sep 17 00:00:00 2001
From: Jens Peters <jp7677@gmail.com>
Date: Sun, 13 Jul 2025 21:38:00 +0200
Subject: [PATCH] input: support tablet tool pressure range configuration

Needs a wlroots addition to expose libinputs tablet tool handle...
---
 include/config/rcxml.h |  2 ++
 src/config/rcxml.c     |  8 ++++++++
 src/input/tablet.c     | 23 +++++++++++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/include/config/rcxml.h b/include/config/rcxml.h
index 6036be9c..39623f10 100644
--- a/include/config/rcxml.h
+++ b/include/config/rcxml.h
@@ -139,6 +139,8 @@ struct rcxml {
 	struct tablet_tool_config {
 		enum lab_motion motion;
 		double relative_motion_sensitivity;
+		double min_pressure;
+		double max_pressure;
 	} tablet_tool;
 
 	/* libinput */
diff --git a/src/config/rcxml.c b/src/config/rcxml.c
index c1b73c35..4d45917a 100644
--- a/src/config/rcxml.c
+++ b/src/config/rcxml.c
@@ -1353,6 +1353,12 @@ entry(xmlNode *node, char *nodename, char *content)
 	} else if (!strcasecmp(nodename, "relativeMotionSensitivity.tabletTool")) {
 		rc.tablet_tool.relative_motion_sensitivity =
 			tablet_get_dbl_if_positive(content, "relativeMotionSensitivity");
+	} else if (!strcasecmp(nodename, "minPressure.tabletTool")) {
+		rc.tablet_tool.min_pressure =
+			tablet_get_dbl_if_positive(content, "minPressure");
+	} else if (!strcasecmp(nodename, "maxPressure.tabletTool")) {
+		rc.tablet_tool.max_pressure =
+			tablet_get_dbl_if_positive(content, "maxPressure");
 	} else if (!strcasecmp(nodename, "ignoreButtonReleasePeriod.menu")) {
 		rc.menu_ignore_button_release_period = atoi(content);
 	} else if (!strcasecmp(nodename, "showIcons.menu")) {
@@ -1473,6 +1479,8 @@ rcxml_init(void)
 	tablet_load_default_button_mappings();
 	rc.tablet_tool.motion = LAB_MOTION_ABSOLUTE;
 	rc.tablet_tool.relative_motion_sensitivity = 1.0;
+	rc.tablet_tool.min_pressure = 0.0;
+	rc.tablet_tool.max_pressure = 1.0;
 
 	rc.repeat_rate = 25;
 	rc.repeat_delay = 600;
diff --git a/src/input/tablet.c b/src/input/tablet.c
index 319c06b3..a2228a66 100644
--- a/src/input/tablet.c
+++ b/src/input/tablet.c
@@ -2,11 +2,13 @@
 #include "input/tablet.h"
 #include <stdlib.h>
 #include <linux/input-event-codes.h>
+#include "wlr/backend/libinput.h"
 #include <wlr/types/wlr_cursor.h>
 #include <wlr/types/wlr_tablet_tool.h>
 #include <wlr/types/wlr_tablet_v2.h>
 #include <wlr/util/log.h>
 #include <wlr/types/wlr_scene.h>
+#include <wlr/util/log.h>
 #include "common/macros.h"
 #include "common/mem.h"
 #include "common/scene-helpers.h"
@@ -336,6 +338,27 @@ handle_tablet_tool_proximity(struct wl_listener *listener, void *data)
 		tool = tablet_tool_create(tablet->seat, ev->tool);
 	}
 
+	struct libinput_tablet_tool *libinput_tool =
+		wlr_libinput_get_tablet_tool_handle(tool->tool_v2->wlr_tool);
+
+	/*
+	 * Configure tool pressure range using libinput. Note that a runtime change
+	 * needs two proximity-in events. First one is for applying the pressure range
+	 * here and second one until it is effectively applied, probably because of
+	 * how lininput applies pressure range changes internally.
+	 */
+	if (libinput_tablet_tool_config_pressure_range_is_available(libinput_tool) > 0
+			&& rc.tablet_tool.min_pressure >= 0.0
+			&& rc.tablet_tool.max_pressure <= 1.0) {
+		double min = libinput_tablet_tool_config_pressure_range_get_minimum(libinput_tool);
+		double max = libinput_tablet_tool_config_pressure_range_get_maximum(libinput_tool);
+		if (min != rc.tablet_tool.min_pressure || max != rc.tablet_tool.max_pressure) {
+			wlr_log(WLR_INFO, "tablet tool pressure range configured");
+			libinput_tablet_tool_config_pressure_range_set(libinput_tool,
+				rc.tablet_tool.min_pressure, rc.tablet_tool.max_pressure);
+		}
+	}
+
 	/*
 	 * Enforce mouse emulation when the current tool is a tablet mouse.
 	 * Client support for tablet mouses in tablet mode is often incomplete