From 91ca9657e49f501f2765eb2afa01785bbe88a2c2 Mon Sep 17 00:00:00 2001
From: pi66 <pixel2176@proton.me>
Date: Mon, 28 Sep 2026 18:10:19 +0100
Subject: [PATCH] add: zoom and bezier animation support

---
 config.def.h |   4 ++
 dwl.c        | 127 +++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 117 insertions(+), 14 deletions(-)

diff --git a/config.def.h b/config.def.h
index a4019d3..d37aa10 100644
--- a/config.def.h
+++ b/config.def.h
@@ -15,6 +15,10 @@ static const float urgentcolor[]           = COLOR(0xff0000ff);
 /* This conforms to the xdg-protocol. Set the alpha to zero to restore the old behavior */
 static const float fullscreen_bg[]         = {0.0f, 0.0f, 0.0f, 1.0f}; /* You can also use glsl colors */
 
+/* animation */
+static const unsigned int animation_duration = 300; /* ms */
+static const float animation_curve[4] = {0.0f, 0.85f, 0.2f, 1.0f}; /* cubic-bezier x1, y1, x2, y2 */
+
 /* tagging - TAGCOUNT must be no greater than 31 */
 #define TAGCOUNT (9)
 
diff --git a/dwl.c b/dwl.c
index e07a269..570f862 100644
--- a/dwl.c
+++ b/dwl.c
@@ -159,6 +159,12 @@ typedef struct {
 	unsigned int bw;
 	uint32_t tags;
 	int isfloating, isurgent, isfullscreen;
+
+	/* Animation */
+	struct wlr_box anim_from, anim_to, anim_cur;
+	uint32_t anim_start;
+	int animating;
+	int anim_zoom;
 } Client;
 
 typedef struct {
@@ -261,6 +267,10 @@ typedef struct {
 } SessionLock;
 
 /* function declarations */
+static uint32_t animation_now_ms(void);
+static float animation_bezier(float t);
+static int animation_tick(void *data);
+static void animation_apply(Client *c, struct wlr_box g);
 static void applybounds(Client *c, struct wlr_box *bbox);
 static void applyrules(Client *c);
 static void arrange(Monitor *m);
@@ -376,6 +386,7 @@ static void xytonode(double x, double y, struct wlr_surface **psurface,
 static void zoom(const Arg *arg);
 
 /* variables */
+static struct wl_event_source *animation_timer;
 static pid_t child_pid = -1;
 static int locked;
 static Client *focused_client;
@@ -486,6 +497,87 @@ static struct wlr_xwayland *xwayland;
 #include "ime.h"
 
 /* function implementations */
+uint32_t
+animation_now_ms(void)
+{
+	struct timespec t;
+
+	clock_gettime(CLOCK_MONOTONIC, &t);
+	return t.tv_sec * 1000 + t.tv_nsec / 1000000;
+}
+
+float
+animation_bezier(float t)
+{
+	float x1 = animation_curve[0], y1 = animation_curve[1];
+	float x2 = animation_curve[2], y2 = animation_curve[3];
+	float lo = 0, hi = 1, s = t, x;
+	int i;
+
+	for (i = 0; i < 20; i++) {
+		x = 3*(1-s)*(1-s)*s*x1 + 3*(1-s)*s*s*x2 + s*s*s;
+		if (x < t)
+			lo = s;
+		else
+			hi = s;
+		s = (lo + hi) / 2;
+	}
+	return 3*(1-s)*(1-s)*s*y1 + 3*(1-s)*s*s*y2 + s*s*s;
+}
+
+int
+animation_tick(void *data)
+{
+	Client *c;
+	float t, p;
+	int more = 0;
+
+	wl_list_for_each(c, &clients, link) {
+		if (!c->animating)
+			continue;
+		t = (animation_now_ms() - c->anim_start) / (float)animation_duration;
+		if (t >= 1) {
+			t = 1;
+			c->animating = 0;
+			c->anim_zoom = 0;
+		}
+		p = animation_bezier(t);
+		c->anim_cur.x      = (int)(c->anim_from.x      + (c->anim_to.x      - c->anim_from.x)      * p);
+		c->anim_cur.y      = (int)(c->anim_from.y      + (c->anim_to.y      - c->anim_from.y)      * p);
+		c->anim_cur.width  = (int)(c->anim_from.width  + (c->anim_to.width  - c->anim_from.width)  * p);
+		c->anim_cur.height = (int)(c->anim_from.height + (c->anim_to.height - c->anim_from.height) * p);
+
+		animation_apply(c, c->anim_cur);
+		more |= c->animating;
+	}
+	if (more)
+		wl_event_source_timer_update(animation_timer, 16);
+	return 0;
+}
+
+void
+animation_apply(Client *c, struct wlr_box g)
+{
+	struct wlr_box clip, save = c->geom;
+
+	c->geom = g;
+
+	wlr_scene_node_set_position(&c->scene->node, c->geom.x, c->geom.y);
+	wlr_scene_node_set_position(&c->scene_surface->node, c->bw, c->bw);
+	wlr_scene_rect_set_size(c->border[0], c->geom.width, c->bw);
+	wlr_scene_rect_set_size(c->border[1], c->geom.width, c->bw);
+	wlr_scene_rect_set_size(c->border[2], c->bw, c->geom.height - 2 * c->bw);
+	wlr_scene_rect_set_size(c->border[3], c->bw, c->geom.height - 2 * c->bw);
+	wlr_scene_node_set_position(&c->border[1]->node, 0, c->geom.height - c->bw);
+	wlr_scene_node_set_position(&c->border[2]->node, 0, c->bw);
+	wlr_scene_node_set_position(&c->border[3]->node, c->geom.width - c->bw, c->bw);
+
+	client_get_clip(c, &clip);
+	wlr_scene_subsurface_tree_set_clip(&c->scene_surface->node, &clip);
+
+	c->geom = save;
+}
+
 void
 applybounds(Client *c, struct wlr_box *bbox)
 {
@@ -2378,7 +2470,6 @@ void
 resize(Client *c, struct wlr_box geo, int interact)
 {
 	struct wlr_box *bbox;
-	struct wlr_box clip;
 
 	if (!c->mon || !client_surface(c)->mapped)
 		return;
@@ -2388,21 +2479,28 @@ resize(Client *c, struct wlr_box geo, int interact)
 	client_set_bounds(c, geo.width, geo.height);
 	c->geom = geo;
 	applybounds(c, bbox);
+	client_set_size(c, c->geom.width - 2 * c->bw, c->geom.height - 2 * c->bw);
 
-	/* Update scene-graph, including borders */
-	wlr_scene_node_set_position(&c->scene->node, c->geom.x, c->geom.y);
-	wlr_scene_node_set_position(&c->scene_surface->node, c->bw, c->bw);
-	wlr_scene_rect_set_size(c->border[0], c->geom.width, c->bw);
-	wlr_scene_rect_set_size(c->border[1], c->geom.width, c->bw);
-	wlr_scene_rect_set_size(c->border[2], c->bw, c->geom.height - 2 * c->bw);
-	wlr_scene_rect_set_size(c->border[3], c->bw, c->geom.height - 2 * c->bw);
-	wlr_scene_node_set_position(&c->border[1]->node, 0, c->geom.height - c->bw);
-	wlr_scene_node_set_position(&c->border[2]->node, 0, c->bw);
-	wlr_scene_node_set_position(&c->border[3]->node, c->geom.width - c->bw, c->bw);
+	if (interact) {
+		c->animating = 0;
+		c->anim_cur = c->geom;
+		animation_apply(c, c->geom);
+		return;
+	}
 
-	client_set_size(c, c->geom.width - 2 * c->bw, c->geom.height - 2 * c->bw);
-	client_get_clip(c, &clip);
-	wlr_scene_subsurface_tree_set_clip(&c->scene_surface->node, &clip);
+	if (!c->animating && c->anim_cur.width == 0) {
+		c->anim_cur.width  = c->geom.width  / 2;
+		c->anim_cur.height = c->geom.height / 2;
+		c->anim_cur.x = c->geom.x + (c->geom.width  - c->anim_cur.width)  / 2;
+		c->anim_cur.y = c->geom.y + (c->geom.height - c->anim_cur.height) / 2;
+		c->anim_zoom = 1;
+	}
+
+	c->anim_from  = c->anim_cur;
+	c->anim_to    = c->geom;
+	c->anim_start = animation_now_ms();
+	c->animating  = 1;
+	wl_event_source_timer_update(animation_timer, 1);
 }
 
 void
@@ -2628,6 +2726,7 @@ setup(void)
 	 * clients from the Unix socket, managing Wayland globals, and so on. */
 	dpy = wl_display_create();
 	event_loop = wl_display_get_event_loop(dpy);
+	animation_timer = wl_event_loop_add_timer(event_loop, animation_tick, NULL);
 
 	/* The backend is a wlroots feature which abstracts the underlying input and
 	 * output hardware. The autocreate option will choose the most suitable
-- 
2.55.0