Introduce wlr_input_mapper

include/wlr/types/wlr_input_mapper.h

@@ -0,0 +1,123 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
+#ifndef WLR_TYPES_WLR_INPUT_MAPPER_H
+#define WLR_TYPES_WLR_INPUT_MAPPER_H
+
+#include <wayland-server-core.h>
+#include <wlr/types/wlr_output.h>
+#include <wlr/types/wlr_output_layout.h>
+#include <wlr/util/addon.h>
+#include <wlr/util/box.h>
+
+struct wlr_input_device;
+
+struct wlr_input_constraint {
+	struct wlr_output *output; // NULL if unset
+	struct wlr_box box; // Empty if unset
+
+	// private state
+
+	struct wl_listener output_destroy;
+};
+
+/**
+* A helper for converting absolute coordinates received from input devices to
+* layout-local coordinates and applying coordinate constraints.
+ *
+ * The constraints precendence is as follows:
+ * 1) Device-specific box
+ * 2) Device-specific output
+ * 3) Global box
+ * 4) Global output
+ *
+ * If no output layout is attached to the input mapper, all output constraints
+ * are ignored.
+ */
+struct wlr_input_mapper {
+	struct wlr_output_layout *layout;
+	struct wlr_input_constraint global;
+
+	struct wl_list mappings; // wlr_input_mapping.link
+
+	struct {
+		struct wl_signal destroy;
+	} events;
+
+	// private state
+
+	struct wl_listener layout_destroy;
+};
+
+struct wlr_input_mapping {
+	struct wlr_input_constraint constraint;
+	struct wl_list link; // wlr_input_mapper.mappings
+
+	// private state
+
+	struct wlr_addon addon; // wlr_input_device.addons
+};
+
+struct wlr_input_mapper *wlr_input_mapper_create(void);
+
+void wlr_input_mapper_destroy(struct wlr_input_mapper *mapper);
+
+/**
+ * Attach an output layout to the input mapper. This detaches the previous
+ * output layout, if any.
+ *
+ * layout may be NULL.
+ */
+void wlr_input_mapper_attach_output_layout(struct wlr_input_mapper *mapper,
+	struct wlr_output_layout *layout);
+
+/**
+ * Convert absolute coordinates in 0..1 range to layout-local coordinates.
+ *
+ * If device is not NULL, its constraints are used, if any.
+ *
+ * If no matching constraint is found, the absolute coordinates are mapped to
+ * the entire layout, unless none is attached, in which case lx and ly are set
+ * to 0.
+ */
+void wlr_input_mapper_absolute_to_layout(struct wlr_input_mapper *mapper,
+	struct wlr_input_device *device, double x, double y,
+	double *lx, double *ly);
+
+/**
+ * Get the closest point satisfying constraints from the given point.
+ *
+ * If device is not NULL, its constraints are used, if any.
+ *
+ * If no matching constraint is found, get the closest point from the layout.
+ */
+void wlr_input_mapper_closest_point(struct wlr_input_mapper *mapper,
+	struct wlr_input_device *device, double lx, double ly,
+	double *closest_lx, double *closest_ly);
+
+/**
+ * Map device to output.
+ *
+ * If device is NULL, sets the default output constraint.
+ * If output is NULL, the output constraint is reset.
+ *
+ * When the output is destroyed, the output constraint is reset.
+ */
+void wlr_input_mapper_map_to_output(struct wlr_input_mapper *mapper,
+	struct wlr_input_device *device, struct wlr_output *output);
+
+/**
+ * Map device to box.
+ *
+ * If device is NULL, sets the default box constraint.
+ * If box is empty, the box constraint is reset.
+ */
+void wlr_input_mapper_map_to_box(struct wlr_input_mapper *mapper,
+	struct wlr_input_device *device, const struct wlr_box *box);
+
+#endif