view: use saved geometry for borders if needed

This fixes the issues caused by 60f06a1 and greatly simplifies the code.
Turns out we were already tracking the dimensions needed.

river/View.zig

@@ -262,16 +262,6 @@ pub fn getDefaultFloatBox(self: Self) Box {
     };
 }
 
-/// Return the dimensions of the actual "visible bounds" that the client has
-/// committed. This excludes any "invisible" areas of the surface that show
-/// useless stuff like CSD shadows.
-pub fn getActualBox(self: Self) Box {
-    return switch (self.impl) {
-        .xdg_toplevel => |xdg_toplevel| xdg_toplevel.getActualBox(),
-        .xwayland_view => |xwayland_view| xwayland_view.getActualBox(),
-    };
-}
-
 /// Called by the impl when the surface is ready to be displayed
 pub fn map(self: *Self) void {
     const root = self.output.root;

river/VoidView.zig

@@ -54,7 +54,3 @@ pub fn surfaceAt(self: Self, ox: f64, oy: f64, sx: *f64, sy: *f64) ?*c.wlr_surfa
 pub fn getTitle(self: Self) [*:0]const u8 {
     unreachable;
 }
-
-pub fn getActualBox(self: Self) Box {
-    unreachable;
-}

river/XdgToplevel.zig

@@ -123,15 +123,6 @@ pub fn getTitle(self: Self) [*:0]const u8 {
     return wlr_xdg_toplevel.title orelse "NULL";
 }
 
-pub fn getActualBox(self: Self) Box {
-    return .{
-        .x = self.wlr_xdg_surface.geometry.x,
-        .y = self.wlr_xdg_surface.geometry.y,
-        .width = @intCast(u32, self.wlr_xdg_surface.geometry.width),
-        .height = @intCast(u32, self.wlr_xdg_surface.geometry.height),
-    };
-}
-
 /// Called when the xdg surface is destroyed
 fn handleDestroy(listener: ?*c.wl_listener, data: ?*c_void) callconv(.C) void {
     const self = @fieldParentPtr(Self, "listen_destroy", listener.?);

river/XwaylandView.zig

@@ -114,15 +114,6 @@ pub fn getTitle(self: Self) [*:0]const u8 {
     return self.wlr_xwayland_surface.title;
 }
 
-pub fn getActualBox(self: Self) Box {
-    return .{
-        .x = self.wlr_xwayland_surface.x,
-        .y = self.wlr_xwayland_surface.y,
-        .width = self.wlr_xwayland_surface.width,
-        .height = self.wlr_xwayland_surface.height,
-    };
-}
-
 /// Called when the xwayland surface is destroyed
 fn handleDestroy(listener: ?*c.wl_listener, data: ?*c_void) callconv(.C) void {
     const self = @fieldParentPtr(Self, "listen_destroy", listener.?);

river/render.zig

@@ -240,10 +240,11 @@ fn renderTexture(
 
 fn renderBorders(output: Output, view: *View, now: *c.timespec) void {
     const config = &output.root.server.config;
-    var border: Box = undefined;
     const color = if (view.focused) &config.border_color_focused else &config.border_color_unfocused;
     const border_width = config.border_width;
-    const actual_box = view.getActualBox();
+    const actual_box = if (view.saved_buffers.items.len != 0) view.saved_surface_box else view.surface_box;
+
+    var border: Box = undefined;
 
     // left and right, covering the corners as well
     border.y = view.current.box.y - @intCast(i32, border_width);