From 0606f398aeda1a22649ca2099aa98cf2dc53720b Mon Sep 17 00:00:00 2001
From: Nishi <nishi@nishi.boats>
Date: Mon, 20 Apr 2026 12:36:01 +0900
Subject: [PATCH] working clipping with wayland

---
 include/Mw/LowLevel/Wayland.h |  7 ++++++
 src/backend/wayland.c         | 40 ++++++++++++++++++++++++++++++++---
 2 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/include/Mw/LowLevel/Wayland.h b/include/Mw/LowLevel/Wayland.h
index 410e8a4..02b59ef 100644
--- a/include/Mw/LowLevel/Wayland.h
+++ b/include/Mw/LowLevel/Wayland.h
@@ -118,6 +118,8 @@ typedef struct wayland_call_table {
 	void (*cairo_paint)(cairo_t* cr);
 	void (*cairo_surface_flush)(cairo_surface_t* surface);
 	void (*cairo_clip)(cairo_t* cr);
+	void (*cairo_save)(cairo_t* cr);
+	void (*cairo_restore)(cairo_t* cr);
 	void (*cairo_surface_mark_dirty)(cairo_surface_t* surface);
 	void (*cairo_stroke)(cairo_t* cr);
 	void (*cairo_set_source_surface)(cairo_t*	  cr,
@@ -224,6 +226,8 @@ MwInline int wayland_load_funcs() {
 	CAIRO_FUNC(cairo_paint);
 	CAIRO_FUNC(cairo_surface_flush);
 	CAIRO_FUNC(cairo_clip);
+	CAIRO_FUNC(cairo_save);
+	CAIRO_FUNC(cairo_restore);
 	CAIRO_FUNC(cairo_surface_mark_dirty);
 	CAIRO_FUNC(cairo_stroke);
 	CAIRO_FUNC(cairo_set_source_surface);
@@ -288,6 +292,8 @@ MwInline int wayland_load_funcs() {
 #define cairo_paint wl_call_tbl.cairo_paint
 #define cairo_surface_flush wl_call_tbl.cairo_surface_flush
 #define cairo_clip wl_call_tbl.cairo_clip
+#define cairo_save wl_call_tbl.cairo_save
+#define cairo_restore wl_call_tbl.cairo_restore
 #define cairo_surface_mark_dirty wl_call_tbl.cairo_surface_mark_dirty
 #define cairo_stroke wl_call_tbl.cairo_stroke
 #define cairo_set_source_surface wl_call_tbl.cairo_set_source_surface
@@ -499,6 +505,7 @@ struct _MwLLWayland {
 	MwU32 mw, mh; /* Monitor width and height as advertised by wl_output.mode */
 
 	MwLL parent;
+	MwLL* children;
 
 	MwBool force_render;
 	MwBool did_event_loop_early;
diff --git a/src/backend/wayland.c b/src/backend/wayland.c
index dfd560d..99a6280 100644
--- a/src/backend/wayland.c
+++ b/src/backend/wayland.c
@@ -1721,9 +1721,9 @@ static void clip(MwLL handle) {
 	MwLL  toplevel = handle->wayland.parent;
 	MwLL* ws       = NULL;
 
-	arrpush(ws, handle);
+	arrput(ws, handle);
 	while(toplevel) {
-		arrpush(ws, toplevel);
+		arrput(ws, toplevel);
 		if(!toplevel->wayland.parent) {
 			break;
 		}
@@ -1741,7 +1741,6 @@ static void clip(MwLL handle) {
 		// # ws is traversed result
 		// # ws[ws.length - 1] is ignored bc it's toplevel
 		for(i = arrlen(ws) - 2; i >= 0; i--) {
-			;
 			x += ws[i]->wayland.x;
 			y += ws[i]->wayland.y;
 			cx = cx - ws[i]->wayland.x;
@@ -1752,11 +1751,14 @@ static void clip(MwLL handle) {
 		cx = MAX(cx, 0);
 		cy = MAX(cy, 0);
 
+		arrfree(ws);
+
 		handle->wayland.clipping_rect.x	     = cx;
 		handle->wayland.clipping_rect.y	     = cy;
 		handle->wayland.clipping_rect.width  = w;
 		handle->wayland.clipping_rect.height = h;
 		region_setup(handle);
+
 		cairo_reset_clip(handle->wayland.front_cairo);
 		cairo_rectangle(handle->wayland.front_cairo, cx, cy, w, h);
 		cairo_clip(handle->wayland.front_cairo);
@@ -1866,6 +1868,10 @@ static MwLL MwLLCreateImpl(MwLL parent, int x, int y, int width, int height) {
 	}
 #endif
 
+	if(parent != NULL){
+		arrput(parent->wayland.children, r);
+	}
+
 	return r;
 }
 
@@ -1943,6 +1949,17 @@ static void MwLLDestroyImpl(MwLL handle) {
 
 	wl_flush(handle);
 
+	if(handle->wayland.parent != NULL){
+		for(i = 0; i < arrlen(handle->wayland.parent->wayland.children); i++){
+			if(handle->wayland.parent->wayland.children[i] == handle){
+				arrdel(handle->wayland.parent->wayland.children, i);
+				break;
+			}
+		}
+	}
+
+	arrfree(handle->wayland.children);
+
 	// free(handle);
 
 	if(currentlyHeldWidget == handle) {
@@ -1957,6 +1974,14 @@ static void MwLLGetXYWHImpl(MwLL handle, int* x, int* y, unsigned int* w, unsign
 	*h = handle->wayland.wh;
 }
 
+static void recursive_render(MwLL handle){
+	int i;
+
+	for(i = 0; i < arrlen(handle->wayland.children); i++) recursive_render(handle->wayland.children[i]);
+
+	MwLLForceRender(handle);
+}
+
 static void MwLLSetXYImpl(MwLL handle, int x, int y) {
 	region_invalidate(handle);
 	handle->wayland.x = x;
@@ -1966,6 +1991,8 @@ static void MwLLSetXYImpl(MwLL handle, int x, int y) {
 	}
 	region_setup(handle);
 
+	recursive_render(handle);
+
 	MwLLDispatch(handle, draw, NULL);
 }
 
@@ -2008,6 +2035,13 @@ static void MwLLSetWHImpl(MwLL handle, int w, int h) {
 }
 
 static void MwLLBeginDrawImpl(MwLL handle) {
+	cairo_save(handle->wayland.front_cairo);
+	cairo_set_source_rgba(handle->wayland.front_cairo, 0, 0, 0, 0);
+	cairo_set_operator(handle->wayland.front_cairo, CAIRO_OPERATOR_SOURCE);
+	cairo_rectangle(handle->wayland.front_cairo, 0, 0, handle->wayland.ww, handle->wayland.wh);
+	cairo_fill(handle->wayland.front_cairo);
+	cairo_restore(handle->wayland.front_cairo);
+
 	if(handle->wayland.type != MWLL_WAYLAND_TOPLEVEL) {
 		handle->wayland.selected_cairo = handle->wayland.front_cairo;
 		return;