1 files changed, 333 insertions, 0 deletions

diff --git a/common/gesture.c b/common/gesture.c
new file mode 100644
index 00000000..58170443
--- /dev/null
+++ b/common/gesture.c
@@ -0,0 +1,333 @@
+#define _POSIX_C_SOURCE 200809L
+#include "gesture.h"
+
+#include <math.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "list.h"
+#include "log.h"
+#include "stringop.h"
+
+const uint8_t GESTURE_FINGERS_ANY = 0;
+
+char *gesture_parse(const char *input, struct gesture *output) {
+        // Clear output in case of failure
+        output->type = GESTURE_TYPE_NONE;
+        output->fingers = GESTURE_FINGERS_ANY;
+        output->directions = GESTURE_DIRECTION_NONE;
+
+        // Split input type, fingers and directions
+        list_t *split = split_string(input, ":");
+        if (split->length < 1 || split->length > 3) {
+                return format_str(
+                                "expected <gesture>[:<fingers>][:direction], got %s",
+                                input);
+        }
+
+        // Parse gesture type
+        if (strcmp(split->items[0], "hold") == 0) {
+                output->type = GESTURE_TYPE_HOLD;
+        } else if (strcmp(split->items[0], "pinch") == 0) {
+                output->type = GESTURE_TYPE_PINCH;
+        } else if (strcmp(split->items[0], "swipe") == 0) {
+                output->type = GESTURE_TYPE_SWIPE;
+        } else {
+                return format_str("expected hold|pinch|swipe, got %s",
+                                (const char *)split->items[0]);
+        }
+
+        // Parse optional arguments
+        if (split->length > 1) {
+                char *next = split->items[1];
+
+                // Try to parse as finger count (1-9)
+                if (strlen(next) == 1 && '1' <= next[0] && next[0] <= '9') {
+                        output->fingers = atoi(next);
+
+                        // Move to next if available
+                        next = split->length == 3 ? split->items[2] : NULL;
+                } else if (split->length == 3) {
+                        // Fail here if argument can only be finger count
+                        return format_str("expected 1-9, got %s", next);
+                }
+
+                // If there is an argument left, try to parse as direction
+                if (next) {
+                        list_t *directions = split_string(next, "+");
+
+                        for (int i = 0; i < directions->length; ++i) {
+                                const char *item = directions->items[i];
+                                if (strcmp(item, "any") == 0) {
+                                        continue;
+                                } else if (strcmp(item, "up") == 0) {
+                                        output->directions |= GESTURE_DIRECTION_UP;
+                                } else if (strcmp(item, "down") == 0) {
+                                        output->directions |= GESTURE_DIRECTION_DOWN;
+                                } else if (strcmp(item, "left") == 0) {
+                                        output->directions |= GESTURE_DIRECTION_LEFT;
+                                } else if (strcmp(item, "right") == 0) {
+                                        output->directions |= GESTURE_DIRECTION_RIGHT;
+                                } else if (strcmp(item, "inward") == 0) {
+                                        output->directions |= GESTURE_DIRECTION_INWARD;
+                                } else if (strcmp(item, "outward") == 0) {
+                                        output->directions |= GESTURE_DIRECTION_OUTWARD;
+                                } else if (strcmp(item, "clockwise") == 0) {
+                                        output->directions |= GESTURE_DIRECTION_CLOCKWISE;
+                                } else if (strcmp(item, "counterclockwise") == 0) {
+                                        output->directions |= GESTURE_DIRECTION_COUNTERCLOCKWISE;
+                                } else {
+                                        return format_str("expected direction, got %s", item);
+                                }
+                        }
+                        list_free_items_and_destroy(directions);
+                }
+        } // if optional args
+
+        list_free_items_and_destroy(split);
+
+        return NULL;
+}
+
+const char *gesture_type_string(enum gesture_type type) {
+        switch (type) {
+        case GESTURE_TYPE_NONE:
+                return "none";
+        case GESTURE_TYPE_HOLD:
+                return "hold";
+        case GESTURE_TYPE_PINCH:
+                return "pinch";
+        case GESTURE_TYPE_SWIPE:
+                return "swipe";
+        }
+
+        return NULL;
+}
+
+const char *gesture_direction_string(enum gesture_direction direction) {
+        switch (direction) {
+        case GESTURE_DIRECTION_NONE:
+                return "none";
+        case GESTURE_DIRECTION_UP:
+                return "up";
+        case GESTURE_DIRECTION_DOWN:
+                return "down";
+        case GESTURE_DIRECTION_LEFT:
+                return "left";
+        case GESTURE_DIRECTION_RIGHT:
+                return "right";
+        case GESTURE_DIRECTION_INWARD:
+                return "inward";
+        case GESTURE_DIRECTION_OUTWARD:
+                return "outward";
+        case GESTURE_DIRECTION_CLOCKWISE:
+                return "clockwise";
+        case GESTURE_DIRECTION_COUNTERCLOCKWISE:
+                return "counterclockwise";
+        }
+
+        return NULL;
+}
+
+// Helper to turn combination of directions flags into string representation.
+static char *gesture_directions_to_string(uint32_t directions) {
+        char *result = NULL;
+
+        for (uint8_t bit = 0; bit < 32; bit++) {
+                uint32_t masked = directions & (1 << bit);
+                if (masked) {
+                        const char *name = gesture_direction_string(masked);
+
+                        if (!name) {
+                                name = "unknown";
+                        }
+
+                        if (!result) {
+                                result = strdup(name);
+                        } else {
+                                char *new = format_str("%s+%s", result, name);
+                                free(result);
+                                result = new;
+                        }
+                }
+        }
+
+        if(!result) {
+                return strdup("any");
+        }
+
+        return result;
+}
+
+char *gesture_to_string(struct gesture *gesture) {
+        char *directions = gesture_directions_to_string(gesture->directions);
+        char *result = format_str("%s:%u:%s",
+                gesture_type_string(gesture->type),
+                gesture->fingers, directions);
+        free(directions);
+        return result;
+}
+
+bool gesture_check(struct gesture *target, enum gesture_type type, uint8_t fingers) {
+        // Check that gesture type matches
+        if (target->type != type) {
+                return false;
+        }
+
+        // Check that finger count matches
+        if (target->fingers != GESTURE_FINGERS_ANY && target->fingers != fingers) {
+                return false;
+        }
+
+        return true;
+}
+
+bool gesture_match(struct gesture *target, struct gesture *to_match, bool exact) {
+        // Check type and fingers
+        if (!gesture_check(target, to_match->type, to_match->fingers)) {
+                return false;
+        }
+
+        // Enforce exact matches ...
+        if (exact && target->directions != to_match->directions) {
+                return false;
+        }
+
+        // ... or ensure all target directions are matched
+        return (target->directions & to_match->directions) == target->directions;
+}
+
+bool gesture_equal(struct gesture *a, struct gesture *b) {
+        return a->type == b->type
+                && a->fingers == b->fingers
+                && a->directions == b->directions;
+}
+
+// Return count of set bits in directions bit field.
+static uint8_t gesture_directions_count(uint32_t directions) {
+        uint8_t count = 0;
+        for (; directions; directions >>= 1) {
+                count += directions & 1;
+        }
+        return count;
+}
+
+// Compare direction bit count of two direction.
+static int8_t gesture_directions_compare(uint32_t a, uint32_t b) {
+        return gesture_directions_count(a) - gesture_directions_count(b);
+}
+
+// Compare two direction based on their direction bit count
+int8_t gesture_compare(struct gesture *a, struct gesture *b) {
+        return gesture_directions_compare(a->directions, b->directions);
+}
+
+void gesture_tracker_begin(struct gesture_tracker *tracker,
+                enum gesture_type type, uint8_t fingers) {
+        tracker->type = type;
+        tracker->fingers = fingers;
+
+        tracker->dx = 0.0;
+        tracker->dy = 0.0;
+        tracker->scale = 1.0;
+        tracker->rotation = 0.0;
+
+        sway_log(SWAY_DEBUG, "begin tracking %s:%u:? gesture",
+                gesture_type_string(type), fingers);
+}
+
+bool gesture_tracker_check(struct gesture_tracker *tracker, enum gesture_type type) {
+        return tracker->type == type;
+}
+
+void gesture_tracker_update(struct gesture_tracker *tracker,
+                double dx, double dy, double scale, double rotation) {
+        if (tracker->type == GESTURE_TYPE_HOLD) {
+                sway_assert(false, "hold does not update.");
+                return;
+        }
+
+        tracker->dx += dx;
+        tracker->dy += dy;
+
+        if (tracker->type == GESTURE_TYPE_PINCH) {
+                tracker->scale = scale;
+                tracker->rotation += rotation;
+        }
+
+        sway_log(SWAY_DEBUG, "update tracking %s:%u:? gesture: %f %f %f %f",
+                        gesture_type_string(tracker->type),
+                        tracker->fingers,
+                        tracker->dx, tracker->dy,
+                        tracker->scale, tracker->rotation);
+}
+
+void gesture_tracker_cancel(struct gesture_tracker *tracker) {
+        sway_log(SWAY_DEBUG, "cancel tracking %s:%u:? gesture",
+                        gesture_type_string(tracker->type), tracker->fingers);
+
+        tracker->type = GESTURE_TYPE_NONE;
+}
+
+struct gesture *gesture_tracker_end(struct gesture_tracker *tracker) {
+        struct gesture *result = calloc(1, sizeof(struct gesture));
+
+        // Ignore gesture under some threshold
+        // TODO: Make configurable
+        const double min_rotation = 5;
+        const double min_scale_delta = 0.1;
+
+        // Determine direction
+        switch(tracker->type) {
+        // Gestures with scale and rotation
+        case GESTURE_TYPE_PINCH:
+                if (tracker->rotation > min_rotation) {
+                        result->directions |= GESTURE_DIRECTION_CLOCKWISE;
+                }
+                if (tracker->rotation < -min_rotation) {
+                        result->directions |= GESTURE_DIRECTION_COUNTERCLOCKWISE;
+                }
+
+                if (tracker->scale > (1.0 + min_scale_delta)) {
+                        result->directions |= GESTURE_DIRECTION_OUTWARD;
+                }
+                if (tracker->scale < (1.0 - min_scale_delta)) {
+                        result->directions |= GESTURE_DIRECTION_INWARD;
+                }
+                __attribute__ ((fallthrough));
+        // Gestures with dx and dy
+        case GESTURE_TYPE_SWIPE:
+                if (fabs(tracker->dx) > fabs(tracker->dy)) {
+                        if (tracker->dx > 0) {
+                                result->directions |= GESTURE_DIRECTION_RIGHT;
+                        } else {
+                                result->directions |= GESTURE_DIRECTION_LEFT;
+                        }
+                } else {
+                        if (tracker->dy > 0) {
+                                result->directions |= GESTURE_DIRECTION_DOWN;
+                        } else {
+                                result->directions |= GESTURE_DIRECTION_UP;
+                        }
+                }
+        // Gesture without any direction
+        case GESTURE_TYPE_HOLD:
+                break;
+        // Not tracking any gesture
+        case GESTURE_TYPE_NONE:
+                sway_assert(false, "Not tracking any gesture.");
+                return result;
+        }
+
+        result->type = tracker->type;
+        result->fingers = tracker->fingers;
+
+        char *description = gesture_to_string(result);
+        sway_log(SWAY_DEBUG, "end tracking gesture: %s", description);
+        free(description);
+
+        tracker->type = GESTURE_TYPE_NONE;
+
+        return result;
+}