1 files changed, 121 insertions, 0 deletions
diff --git a/util/box.c b/util/box.c
new file mode 100644
index 00000000..b382716b
--- /dev/null
+++ b/util/box.c
@@ -0,0 +1,121 @@
+#include <limits.h>
+#include <math.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <wlr/util/box.h>
+#include <wlr/util/log.h>
+
+void wlr_box_closest_point(const struct wlr_box *box, double x, double y,
+		double *dest_x, double *dest_y) {
+	// if box is empty, then it contains no points, so no closest point either
+	if (box->width <= 0 || box->height <= 0) {
+		*dest_x = NAN;
+		*dest_y = NAN;
+		return;
+	}
+
+	// find the closest x point
+	if (x < box->x) {
+		*dest_x = box->x;
+	} else if (x >= box->x + box->width) {
+		*dest_x = box->x + box->width - 1;
+	} else {
+		*dest_x = x;
+	}
+
+	// find closest y point
+	if (y < box->y) {
+		*dest_y = box->y;
+	} else if (y >= box->y + box->height) {
+		*dest_y = box->y + box->height - 1;
+	} else {
+		*dest_y = y;
+	}
+}
+
+bool wlr_box_empty(const struct wlr_box *box) {
+	return box == NULL || box->width <= 0 || box->height <= 0;
+}
+
+bool wlr_box_intersection(struct wlr_box *dest, const struct wlr_box *box_a,
+		const struct wlr_box *box_b) {
+	bool a_empty = wlr_box_empty(box_a);
+	bool b_empty = wlr_box_empty(box_b);
+
+	if (a_empty || b_empty) {
+		dest->x = 0;
+		dest->y = 0;
+		dest->width = -100;
+		dest->height = -100;
+		return false;
+	}
+
+	int x1 = fmax(box_a->x, box_b->x);
+	int y1 = fmax(box_a->y, box_b->y);
+	int x2 = fmin(box_a->x + box_a->width, box_b->x + box_b->width);
+	int y2 = fmin(box_a->y + box_a->height, box_b->y + box_b->height);
+
+	dest->x = x1;
+	dest->y = y1;
+	dest->width = x2 - x1;
+	dest->height = y2 - y1;
+
+	return !wlr_box_empty(dest);
+}
+
+bool wlr_box_contains_point(const struct wlr_box *box, double x, double y) {
+	if (wlr_box_empty(box)) {
+		return false;
+	} else {
+		return x >= box->x && x < box->x + box->width &&
+			y >= box->y && y < box->y + box->height;
+	}
+}
+
+void wlr_box_transform(struct wlr_box *dest, const struct wlr_box *box,
+		enum wl_output_transform transform, int width, int height) {
+	struct wlr_box src = *box;
+
+	if (transform % 2 == 0) {
+		dest->width = src.width;
+		dest->height = src.height;
+	} else {
+		dest->width = src.height;
+		dest->height = src.width;
+	}
+
+	switch (transform) {
+	case WL_OUTPUT_TRANSFORM_NORMAL:
+		dest->x = src.x;
+		dest->y = src.y;
+		break;
+	case WL_OUTPUT_TRANSFORM_90:
+		dest->x = height - src.y - src.height;
+		dest->y = src.x;
+		break;
+	case WL_OUTPUT_TRANSFORM_180:
+		dest->x = width - src.x - src.width;
+		dest->y = height - src.y - src.height;
+		break;
+	case WL_OUTPUT_TRANSFORM_270:
+		dest->x = src.y;
+		dest->y = width - src.x - src.width;
+		break;
+	case WL_OUTPUT_TRANSFORM_FLIPPED:
+		dest->x = width - src.x - src.width;
+		dest->y = src.y;
+		break;
+	case WL_OUTPUT_TRANSFORM_FLIPPED_90:
+		dest->x = src.y;
+		dest->y = src.x;
+		break;
+	case WL_OUTPUT_TRANSFORM_FLIPPED_180:
+		dest->x = src.x;
+		dest->y = height - src.y - src.height;
+		break;
+	case WL_OUTPUT_TRANSFORM_FLIPPED_270:
+		dest->x = height - src.y - src.height;
+		dest->y = width - src.x - src.width;
+		break;
+	}
+}