Add option to capture the focused monitor

1 files changed, 428 insertions, 0 deletions

diff --git a/src/CursorTrackerWayland.cpp b/src/CursorTrackerWayland.cpp
new file mode 100644
index 0000000..0e44303
--- /dev/null
+++ b/src/CursorTrackerWayland.cpp
@@ -0,0 +1,428 @@
+#include "../include/CursorTrackerWayland.hpp"
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+#include <wayland-client.h>
+#include "xdg-output-unstable-v1-client-protocol.h"
+
+namespace gsr {
+    typedef struct {
+        int type;
+        int count;
+    } drm_connector_type_count;
+
+    static const int CONNECTOR_TYPE_COUNTS = 32;
+
+    typedef enum {
+        PLANE_PROPERTY_CRTC_X      = 1 << 0,
+        PLANE_PROPERTY_CRTC_Y      = 1 << 1,
+        PLANE_PROPERTY_CRTC_ID     = 1 << 2,
+        PLANE_PROPERTY_TYPE_CURSOR = 1 << 3,
+    } plane_property_mask;
+
+    static const uint32_t plane_property_all = 0xF;
+
+    /* Returns plane_property_mask */
+    static uint32_t plane_get_properties(int drm_fd, uint32_t plane_id, int *crtc_x, int *crtc_y, int *crtc_id, bool *is_cursor) {
+        *crtc_x = 0;
+        *crtc_y = 0;
+        *crtc_id = 0;
+        *is_cursor = false;
+
+        uint32_t property_mask = 0;
+
+        drmModeObjectPropertiesPtr props = drmModeObjectGetProperties(drm_fd, plane_id, DRM_MODE_OBJECT_PLANE);
+        if(!props)
+            return property_mask;
+
+        for(uint32_t i = 0; i < props->count_props; ++i) {
+            drmModePropertyPtr prop = drmModeGetProperty(drm_fd, props->props[i]);
+            if(!prop)
+                continue;
+
+            // SRC_* values are fixed 16.16 points
+            const uint32_t type = prop->flags & (DRM_MODE_PROP_LEGACY_TYPE | DRM_MODE_PROP_EXTENDED_TYPE);
+            if((type & DRM_MODE_PROP_SIGNED_RANGE) && strcmp(prop->name, "CRTC_X") == 0) {
+                *crtc_x = (int)props->prop_values[i];
+                property_mask |= PLANE_PROPERTY_CRTC_X;
+            } else if((type & DRM_MODE_PROP_SIGNED_RANGE) && strcmp(prop->name, "CRTC_Y") == 0) {
+                *crtc_y = (int)props->prop_values[i];
+                property_mask |= PLANE_PROPERTY_CRTC_Y;
+            } else if((type & DRM_MODE_PROP_OBJECT) && strcmp(prop->name, "CRTC_ID") == 0) {
+                *crtc_id = (int)props->prop_values[i];
+                property_mask |= PLANE_PROPERTY_CRTC_ID;
+            } else if((type & DRM_MODE_PROP_ENUM) && strcmp(prop->name, "type") == 0) {
+                const uint64_t current_enum_value = props->prop_values[i];
+                for(int j = 0; j < prop->count_enums; ++j) {
+                    if(prop->enums[j].value == current_enum_value && strcmp(prop->enums[j].name, "Cursor") == 0) {
+                        property_mask |= PLANE_PROPERTY_TYPE_CURSOR;
+                        break;
+                    }
+                }
+            }
+
+            drmModeFreeProperty(prop);
+        }
+
+        drmModeFreeObjectProperties(props);
+        return property_mask;
+    }
+
+    static bool connector_get_property_by_name(int drm_fd, drmModeConnectorPtr props, const char *name, uint64_t *result) {
+        for(int i = 0; i < props->count_props; ++i) {
+            drmModePropertyPtr prop = drmModeGetProperty(drm_fd, props->props[i]);
+            if(!prop)
+                continue;
+
+            if(strcmp(name, prop->name) == 0) {
+                *result = props->prop_values[i];
+                drmModeFreeProperty(prop);
+                return true;
+            }
+            drmModeFreeProperty(prop);
+        }
+        return false;
+    }
+
+    static drm_connector_type_count* drm_connector_types_get_index(drm_connector_type_count *type_counts, int *num_type_counts, int connector_type) {
+        for(int i = 0; i < *num_type_counts; ++i) {
+            if(type_counts[i].type == connector_type)
+                return &type_counts[i];
+        }
+
+        if(*num_type_counts == CONNECTOR_TYPE_COUNTS)
+            return NULL;
+
+        const int index = *num_type_counts;
+        type_counts[index].type = connector_type;
+        type_counts[index].count = 0;
+        ++*num_type_counts;
+        return &type_counts[index];
+    }
+
+    // Note: this monitor name logic is kept in sync with gpu screen recorder
+    static std::string get_monitor_name_from_crtc_id(int drm_fd, uint32_t crtc_id) {
+        std::string result;
+        drmModeResPtr resources = drmModeGetResources(drm_fd);
+        if(!resources)
+            return result;
+
+        drm_connector_type_count type_counts[CONNECTOR_TYPE_COUNTS];
+        int num_type_counts = 0;
+
+        for(int i = 0; i < resources->count_connectors; ++i) {
+            uint64_t connector_crtc_id = 0;
+            drmModeConnectorPtr connector = drmModeGetConnectorCurrent(drm_fd, resources->connectors[i]);
+            if(!connector)
+                continue;
+
+            drm_connector_type_count *connector_type = drm_connector_types_get_index(type_counts, &num_type_counts, connector->connector_type);
+            const char *connection_name = drmModeGetConnectorTypeName(connector->connector_type);
+            if(connector_type)
+                ++connector_type->count;
+
+            if(connector->connection != DRM_MODE_CONNECTED)
+                goto next;
+
+            if(connector_type && connector_get_property_by_name(drm_fd, connector, "CRTC_ID", &connector_crtc_id) && connector_crtc_id == crtc_id) {
+                result = connection_name;
+                result += "-";
+                result += std::to_string(connector_type->count);
+                drmModeFreeConnector(connector);
+                break;
+            }
+
+            next:
+            drmModeFreeConnector(connector);
+        }
+
+        drmModeFreeResources(resources);
+        return result;
+    }
+
+    // Name is the crtc name. TODO: verify if this works on all wayland compositors
+    static const WaylandOutput* get_wayland_monitor_by_name(const std::vector<WaylandOutput> &monitors, const std::string &name) {
+        for(const WaylandOutput &monitor : monitors) {
+            if(monitor.name == name)
+                return &monitor;
+        }
+        return nullptr;
+    }
+
+    static WaylandOutput* get_wayland_monitor_by_output(CursorTrackerWayland &cursor_tracker_wayland, struct wl_output *output) {
+        for(WaylandOutput &monitor : cursor_tracker_wayland.monitors) {
+            if(monitor.output == output)
+                return &monitor;
+        }
+        return nullptr;
+    }
+
+    static void output_handle_geometry(void *data, struct wl_output *wl_output,
+        int32_t x, int32_t y, int32_t phys_width, int32_t phys_height,
+        int32_t subpixel, const char *make, const char *model,
+        int32_t transform) {
+        (void)wl_output;
+        (void)phys_width;
+        (void)phys_height;
+        (void)subpixel;
+        (void)make;
+        (void)model;
+        CursorTrackerWayland *cursor_tracker_wayland = (CursorTrackerWayland*)data;
+        WaylandOutput *monitor = get_wayland_monitor_by_output(*cursor_tracker_wayland, wl_output);
+        if(!monitor)
+            return;
+
+        monitor->pos.x = x;
+        monitor->pos.y = y;
+        monitor->transform = transform;
+    }
+
+    static void output_handle_mode(void *data, struct wl_output *wl_output, uint32_t flags, int32_t width, int32_t height, int32_t refresh) {
+        (void)wl_output;
+        (void)flags;
+        (void)refresh;
+        CursorTrackerWayland *cursor_tracker_wayland = (CursorTrackerWayland*)data;
+        WaylandOutput *monitor = get_wayland_monitor_by_output(*cursor_tracker_wayland, wl_output);
+        if(!monitor)
+            return;
+
+        monitor->size.x = width;
+        monitor->size.y = height;
+    }
+
+    static void output_handle_done(void *data, struct wl_output *wl_output) {
+        (void)data;
+        (void)wl_output;
+    }
+
+    static void output_handle_scale(void* data, struct wl_output *wl_output, int32_t factor) {
+        (void)data;
+        (void)wl_output;
+        (void)factor;
+    }
+
+    static void output_handle_name(void *data, struct wl_output *wl_output, const char *name) {
+        (void)wl_output;
+        CursorTrackerWayland *cursor_tracker_wayland = (CursorTrackerWayland*)data;
+        WaylandOutput *monitor = get_wayland_monitor_by_output(*cursor_tracker_wayland, wl_output);
+        if(!monitor)
+            return;
+
+        monitor->name = name;
+    }
+
+    static void output_handle_description(void *data, struct wl_output *wl_output, const char *description) {
+        (void)data;
+        (void)wl_output;
+        (void)description;
+    }
+
+    static const struct wl_output_listener output_listener = {
+        output_handle_geometry,
+        output_handle_mode,
+        output_handle_done,
+        output_handle_scale,
+        output_handle_name,
+        output_handle_description,
+    };
+
+    static void registry_add_object(void *data, struct wl_registry *registry, uint32_t name, const char *interface, uint32_t version) {
+        (void)version;
+        CursorTrackerWayland *cursor_tracker_wayland = (CursorTrackerWayland*)data;
+        if(strcmp(interface, wl_output_interface.name) == 0) {
+            if(version < 4) {
+                fprintf(stderr, "Warning: wl output interface version is < 4, expected >= 4\n");
+                return;
+            }
+
+            struct wl_output *output = (struct wl_output*)wl_registry_bind(registry, name, &wl_output_interface, 4);
+            cursor_tracker_wayland->monitors.push_back(
+                WaylandOutput{
+                    name,
+                    output,
+                    nullptr,
+                    mgl::vec2i{0, 0},
+                    mgl::vec2i{0, 0},
+                    0,
+                    ""
+                });
+            wl_output_add_listener(output, &output_listener, cursor_tracker_wayland);
+        } else if(strcmp(interface, zxdg_output_manager_v1_interface.name) == 0) {
+            if(version < 1) {
+                fprintf(stderr, "Warning: xdg output interface version is < 1, expected >= 1\n");
+                return;
+            }
+
+            if(cursor_tracker_wayland->xdg_output_manager) {
+                zxdg_output_manager_v1_destroy(cursor_tracker_wayland->xdg_output_manager);
+                cursor_tracker_wayland->xdg_output_manager = NULL;
+            }
+            cursor_tracker_wayland->xdg_output_manager = (struct zxdg_output_manager_v1*)wl_registry_bind(registry, name, &zxdg_output_manager_v1_interface, 1);
+        }
+    }
+
+    static void registry_remove_object(void *data, struct wl_registry *registry, uint32_t name) {
+        (void)data;
+        (void)registry;
+        (void)name;
+        // TODO: Remove output
+    }
+
+    static struct wl_registry_listener registry_listener = {
+        registry_add_object,
+        registry_remove_object,
+    };
+
+    static void xdg_output_logical_position(void *data, struct zxdg_output_v1 *zxdg_output_v1, int32_t x, int32_t y) {
+        (void)zxdg_output_v1;
+        WaylandOutput *monitor = (WaylandOutput*)data;
+        monitor->pos.x = x;
+        monitor->pos.y = y;
+    }
+
+    static void xdg_output_handle_logical_size(void *data, struct zxdg_output_v1 *xdg_output, int32_t width, int32_t height) {
+        (void)data;
+        (void)xdg_output;
+        (void)width;
+        (void)height;
+    }
+
+    static void xdg_output_handle_done(void *data, struct zxdg_output_v1 *xdg_output) {
+        (void)data;
+        (void)xdg_output;
+    }
+
+    static void xdg_output_handle_name(void *data, struct zxdg_output_v1 *xdg_output, const char *name) {
+        (void)data;
+        (void)xdg_output;
+        (void)name;
+    }
+
+    static void xdg_output_handle_description(void *data, struct zxdg_output_v1 *xdg_output, const char *description) {
+        (void)data;
+        (void)xdg_output;
+        (void)description;
+    }
+
+    static const struct zxdg_output_v1_listener xdg_output_listener = {
+        xdg_output_logical_position,
+        xdg_output_handle_logical_size,
+        xdg_output_handle_done,
+        xdg_output_handle_name,
+        xdg_output_handle_description,
+    };
+
+    CursorTrackerWayland::CursorTrackerWayland(const char *card_path) {
+        drm_fd = open(card_path, O_RDONLY);
+        if(drm_fd <= 0) {
+            fprintf(stderr, "Error: CursorTrackerWayland: failed to open %s\n", card_path);
+            return;
+        }
+
+        drmSetClientCap(drm_fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
+        drmSetClientCap(drm_fd, DRM_CLIENT_CAP_ATOMIC, 1);
+    }
+
+    CursorTrackerWayland::~CursorTrackerWayland() {
+        if(drm_fd > 0)
+            close(drm_fd);
+    }
+
+    void CursorTrackerWayland::update() {
+        if(drm_fd <= 0)
+            return;
+
+        drmModePlaneResPtr planes = drmModeGetPlaneResources(drm_fd);
+        if(!planes)
+            return;
+
+        for(uint32_t i = 0; i < planes->count_planes; ++i) {
+            int crtc_x = 0;
+            int crtc_y = 0;
+            int crtc_id = 0;
+            bool is_cursor = false;
+            const uint32_t property_mask = plane_get_properties(drm_fd, planes->planes[i], &crtc_x, &crtc_y, &crtc_id, &is_cursor);
+            if(property_mask == plane_property_all && crtc_id > 0) {
+                latest_cursor_position.x = crtc_x;
+                latest_cursor_position.y = crtc_y;
+                latest_crtc_id = crtc_id;
+                break;
+            }
+        }
+
+        drmModeFreePlaneResources(planes);
+    }
+
+    void CursorTrackerWayland::set_monitor_outputs_from_xdg_output(struct wl_display *dpy) {
+        if(!xdg_output_manager) {
+            fprintf(stderr, "Warning: CursorTrackerWayland::set_monitor_outputs_from_xdg_output: zxdg_output_manager not found. Registered monitor positions might be incorrect\n");
+            return;
+        }
+
+        for(WaylandOutput &monitor : monitors) {
+            monitor.xdg_output = zxdg_output_manager_v1_get_xdg_output(xdg_output_manager, monitor.output);
+            zxdg_output_v1_add_listener(monitor.xdg_output, &xdg_output_listener, &monitor);
+        }
+
+        // Fetch xdg_output
+        wl_display_roundtrip(dpy);
+    }
+
+    std::optional<CursorInfo> CursorTrackerWayland::get_latest_cursor_info() {
+        if(drm_fd <= 0 || latest_crtc_id == -1)
+            return std::nullopt;
+
+        std::string monitor_name = get_monitor_name_from_crtc_id(drm_fd, latest_crtc_id);
+        if(monitor_name.empty())
+            return std::nullopt;
+
+        struct wl_display *dpy = wl_display_connect(nullptr);
+        if(!dpy) {
+            fprintf(stderr, "Error: CursorTrackerWayland::get_latest_cursor_info: failed to connect to the wayland server\n");
+            return std::nullopt;
+        }
+
+        monitors.clear();
+        struct wl_registry *registry = wl_display_get_registry(dpy);
+        wl_registry_add_listener(registry, &registry_listener, this);
+
+        // Fetch globals
+        wl_display_roundtrip(dpy);
+
+        // Fetch wl_output
+        wl_display_roundtrip(dpy);
+
+        set_monitor_outputs_from_xdg_output(dpy);
+
+        mgl::vec2i cursor_position = latest_cursor_position;
+        const WaylandOutput *wayland_monitor = get_wayland_monitor_by_name(monitors, monitor_name);
+        if(!wayland_monitor)
+            return std::nullopt;
+
+        cursor_position = wayland_monitor->pos + latest_cursor_position;
+        for(WaylandOutput &monitor : monitors) {
+            if(monitor.output) {
+                wl_output_destroy(monitor.output);
+                monitor.output = nullptr;
+            }
+
+            if(monitor.xdg_output) {
+                zxdg_output_v1_destroy(monitor.xdg_output);
+                monitor.xdg_output = nullptr;
+            }
+        }
+        monitors.clear();
+
+        if(xdg_output_manager) {
+            zxdg_output_manager_v1_destroy(xdg_output_manager);
+            xdg_output_manager = nullptr;
+        }
+
+        wl_registry_destroy(registry);
+        wl_display_disconnect(dpy);
+
+        return CursorInfo{ cursor_position, std::move(monitor_name) };
+    }
+}
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