diff --git a/kitty/boss.py b/kitty/boss.py
index 53a33e76e..d812c08bd 100644
--- a/kitty/boss.py
+++ b/kitty/boss.py
@@ -365,9 +365,6 @@ class Boss:
             self.glfw_window.set_title(self.glfw_window_title)
             if isosx:
                 cocoa_update_title(self.glfw_window_title)
-        for window in tab.visible_windows():
-            if not window.needs_layout:
-                window.char_grid.render_cells()
         active = self.active_window
         if active is not None:
             draw_cursor = True
@@ -383,7 +380,7 @@ class Boss:
                 active.char_grid.render_cursor(self.window_is_focused)
 
     def gui_close_window(self, window):
-        window.char_grid.destroy()
+        window.destroy()
         for tab in self.tab_manager:
             if window in tab:
                 break
diff --git a/kitty/char_grid.py b/kitty/char_grid.py
index 40c69ef17..299a26555 100644
--- a/kitty/char_grid.py
+++ b/kitty/char_grid.py
@@ -10,8 +10,7 @@ from .config import build_ansi_color_table
 from .constants import ScreenGeometry, cell_size, viewport_size
 from .fast_data_types import (
     CELL_PROGRAM, CURSOR_BEAM, CURSOR_BLOCK, CURSOR_PROGRAM, CURSOR_UNDERLINE,
-    compile_program, create_cell_vao, draw_cells, draw_cursor,
-    init_cell_program, init_cursor_program, remove_vao
+    compile_program, draw_cursor, init_cell_program, init_cursor_program
 )
 from .rgb import to_color
 from .utils import (
@@ -42,16 +41,11 @@ def calculate_gl_geometry(window_geometry, viewport_width, viewport_height, cell
     return ScreenGeometry(xstart, ystart, window_geometry.xnum, window_geometry.ynum, dx, dy)
 
 
-def render_cells(vao_id, sg, screen):
-    draw_cells(vao_id, sg.xstart, sg.ystart, sg.dx, sg.dy, screen)
-
-
 class CharGrid:
 
     url_pat = re.compile('(?:http|https|file|ftp)://\S+', re.IGNORECASE)
 
     def __init__(self, screen, opts):
-        self.vao_id = create_cell_vao()
         self.screen_reversed = False
         self.screen = screen
         self.opts = opts
@@ -63,16 +57,9 @@ class CharGrid:
         self.default_cursor = Cursor(0, 0, opts.cursor_shape, opts.cursor_blink_interval > 0)
         self.opts = opts
 
-    def destroy(self):
-        if self.vao_id is not None:
-            remove_vao(self.vao_id)
-            self.vao_id = None
-
     def update_position(self, window_geometry):
-        self.screen_geometry = calculate_gl_geometry(window_geometry, viewport_size.width, viewport_size.height, cell_size.width, cell_size.height)
-
-    def resize(self, window_geometry):
-        self.update_position(window_geometry)
+        self.screen_geometry = sg = calculate_gl_geometry(window_geometry, viewport_size.width, viewport_size.height, cell_size.width, cell_size.height)
+        return sg
 
     def change_colors(self, changes):
         dirtied = False
@@ -172,9 +159,6 @@ class CharGrid:
     def text_for_selection(self):
         return ''.join(self.screen.text_for_selection())
 
-    def render_cells(self):
-        render_cells(self.vao_id, self.screen_geometry, self.screen)
-
     def render_cursor(self, is_focused):
         if not self.screen.cursor_visible or self.screen.scrolled_by:
             return
diff --git a/kitty/child-monitor.c b/kitty/child-monitor.c
index b5dfbccc6..38fc8fee9 100644
--- a/kitty/child-monitor.c
+++ b/kitty/child-monitor.c
@@ -15,7 +15,7 @@ extern int pthread_setname_np(const char *name);
 #include <pthread.h>
 #undef _GNU_SOURCE
 #endif
-#include "data-types.h"
+#include "state.h"
 #include <termios.h>
 #include <unistd.h>
 #include <float.h>
@@ -30,6 +30,7 @@ extern int pthread_setname_np(const char *name);
 
 #define EXTRA_FDS 2
 
+extern GlobalState global_state;
 static void (*parse_func)(Screen*, PyObject*);
 
 typedef struct {
@@ -436,6 +437,16 @@ render(ChildMonitor *self, double *timeout) {
 #define TD global_state.tab_bar_render_data
         if (TD.screen && global_state.num_tabs > 1) draw_cells(TD.vao_idx, TD.xstart, TD.ystart, TD.dx, TD.dy, TD.screen);
 #undef TD
+        if (global_state.num_tabs) {
+            Tab *tab = global_state.tabs + global_state.active_tab;
+            for (size_t i = 0; i < tab->num_windows; i++) {
+                Window *w = tab->windows + i;
+#define WD w->render_data
+                if (w->visible && WD.screen) draw_cells(WD.vao_idx, WD.xstart, WD.ystart, WD.dx, WD.dy, WD.screen);
+#undef WD
+            }
+        }
+
         ret = PyObject_CallFunctionObjArgs(self->render_func, NULL);
         if (ret == NULL) { PyErr_Print(); return false; }
         else Py_DECREF(ret);
diff --git a/kitty/data-types.h b/kitty/data-types.h
index fb63e4652..db01f36a4 100644
--- a/kitty/data-types.h
+++ b/kitty/data-types.h
@@ -288,33 +288,6 @@ typedef struct {
 } ChildMonitor;
 PyTypeObject ChildMonitor_Type;
 
-typedef struct {
-    double visual_bell_duration;
-    bool enable_audio_bell;
-} Options;
-
-typedef struct {
-    unsigned int id;
-} Tab;
-
-typedef struct {
-    ssize_t vao_idx;
-    float xstart, ystart, dx, dy;
-    Screen *screen;
-} ScreenRenderData;
-
-typedef struct {
-    Options opts;
-
-    Tab tabs[MAX_CHILDREN];
-    unsigned int active_tab, num_tabs;
-    ScreenRenderData tab_bar_render_data;
-} GlobalState;
-
-#ifndef IS_STATE
-extern GlobalState global_state;
-#endif
-
 #define clear_sprite_position(cell) (cell).sprite_x = 0; (cell).sprite_y = 0; (cell).sprite_z = 0; 
 
 #define left_shift_line(line, at, num) \
@@ -326,11 +299,6 @@ extern GlobalState global_state;
         clear_sprite_position((line)->cells[(at)]); \
     }
 
-typedef void (*draw_borders_func)();
-extern draw_borders_func draw_borders;
-typedef void (*draw_cells_func)(ssize_t, float, float, float, float, Screen *);
-extern draw_cells_func draw_cells;
-
 // Global functions 
 Line* alloc_line();
 Cursor* alloc_cursor();
diff --git a/kitty/layout.py b/kitty/layout.py
index e786ee3f8..2d80d1f6f 100644
--- a/kitty/layout.py
+++ b/kitty/layout.py
@@ -122,14 +122,14 @@ class Stack(Layout):
 
     def set_active_window(self, windows, active_window_idx):
         for i, w in enumerate(windows):
-            w.is_visible_in_layout = i == active_window_idx
+            w.set_visible_in_layout(i, i == active_window_idx)
 
     def __call__(self, windows, active_window_idx):
         self.blank_rects = []
         wg = layout_single_window(self.margin_width, self.padding_width)
         for i, w in enumerate(windows):
-            w.is_visible_in_layout = i == active_window_idx
-            w.set_geometry(wg)
+            w.set_visible_in_layout(i, i == active_window_idx)
+            w.set_geometry(i, wg)
             if w.is_visible_in_layout:
                 self.blank_rects = blank_rects_for_window(w)
 
@@ -142,7 +142,7 @@ class Tall(Layout):
         self.blank_rects = br = []
         if len(windows) == 1:
             wg = layout_single_window(self.margin_width, self.padding_width)
-            windows[0].set_geometry(wg)
+            windows[0].set_geometry(0, wg)
             self.blank_rects = blank_rects_for_window(windows[0])
             return
         xlayout = layout_dimension(
@@ -152,14 +152,14 @@ class Tall(Layout):
         ystart, ynum = next(layout_dimension(
             available_height(), cell_size.height, 1, self.border_width, left_align=True,
             margin_length=self.margin_width, padding_length=self.padding_width))
-        windows[0].set_geometry(window_geometry(xstart, xnum, ystart, ynum))
+        windows[0].set_geometry(0, window_geometry(xstart, xnum, ystart, ynum))
         vh = available_height()
         xstart, xnum = next(xlayout)
         ylayout = layout_dimension(
             available_height(), cell_size.height, len(windows) - 1, self.border_width, left_align=True,
             margin_length=self.margin_width, padding_length=self.padding_width)
-        for w, (ystart, ynum) in zip(islice(windows, 1, None), ylayout):
-            w.set_geometry(window_geometry(xstart, xnum, ystart, ynum))
+        for i, (w, (ystart, ynum)) in enumerate(zip(islice(windows, 1, None), ylayout)):
+            w.set_geometry(i + 1, window_geometry(xstart, xnum, ystart, ynum))
         left_blank_rect(windows[0], br, vh), top_blank_rect(windows[0], br, vh), right_blank_rect(windows[-1], br, vh)
         br.append(Rect(windows[0].geometry.right, 0, windows[1].geometry.left, vh))
         br.append(Rect(0, windows[0].geometry.bottom, windows[0].geometry.right, vh))
diff --git a/kitty/screen.c b/kitty/screen.c
index 04a7237be..c73f28210 100644
--- a/kitty/screen.c
+++ b/kitty/screen.c
@@ -11,7 +11,7 @@
 
 #define EXTRA_INIT PyModule_AddIntMacro(module, SCROLL_LINE); PyModule_AddIntMacro(module, SCROLL_PAGE); PyModule_AddIntMacro(module, SCROLL_FULL);
 
-#include "data-types.h"
+#include "state.h"
 #include "lineops.h"
 #include "screen.h"
 #include <structmember.h>
@@ -23,6 +23,7 @@
 #include "modes.h"
 #include "wcwidth9.h"
 
+extern GlobalState global_state;
 static const ScreenModes empty_modes = {0, .mDECAWM=true, .mDECTCEM=true, .mDECARM=true};
 static Selection EMPTY_SELECTION = {0};
 
diff --git a/kitty/shaders.c b/kitty/shaders.c
index 33948ebd0..7385339f4 100644
--- a/kitty/shaders.c
+++ b/kitty/shaders.c
@@ -5,7 +5,7 @@
  * Distributed under terms of the GPL3 license.
  */
 
-#include "data-types.h"
+#include "state.h"
 #include "screen.h"
 #include "sprites.h"
 #ifdef __APPLE__
diff --git a/kitty/state.c b/kitty/state.c
index 238c03985..907e7d309 100644
--- a/kitty/state.c
+++ b/kitty/state.c
@@ -5,24 +5,31 @@
  * Distributed under terms of the GPL3 license.
  */
 
-#define IS_STATE
-#include "data-types.h"
+#include "state.h"
 
 GlobalState global_state = {{0}};
 static const Tab EMPTY_TAB = {0};
+static const Window EMPTY_WINDOW = {0};
 
 #define ensure_can_add(array, count, msg) if (count >= sizeof(array)/sizeof(array[0]) - 1) fatal(msg);
 
-#define REMOVER(array, qid, count, empty, structure) { \
+#define noop(...)
+#define REMOVER(array, qid, count, empty, structure, destroy) { \
     size_t capacity = sizeof(array)/sizeof(array[0]); \
     for (size_t i = 0; i < count; i++) { \
         if (array[i].id == qid) { \
+            destroy(array[i]); \
             array[i] = empty; \
             size_t num_to_right = capacity - count - 1; \
             if (num_to_right) memmove(array + i, array + i + 1, num_to_right * sizeof(structure)); \
             (count)--; \
         } \
     }} 
+#define WITH_TAB(tab_id) \
+    for (size_t t = 0; t < global_state.num_tabs; t++) { \
+        if (global_state.tabs[t].id == tab_id) { \
+            Tab *tab = global_state.tabs + t;
+#define END_WITH_TAB break; }}
 
 static inline void
 add_tab(unsigned int id) {
@@ -33,15 +40,43 @@ add_tab(unsigned int id) {
 }
 
 static inline void
-remove_tab(unsigned int id) {
-    REMOVER(global_state.tabs, id, global_state.num_tabs, EMPTY_TAB, Tab);
+add_window(unsigned int tab_id, unsigned int id) {
+    WITH_TAB(tab_id);
+    ensure_can_add(tab->windows, tab->num_windows, "Too many children (add_window)");
+    tab->windows[tab->num_windows] = EMPTY_WINDOW;
+    tab->windows[tab->num_windows].id = id;
+    tab->windows[tab->num_windows].visible = true;
+    tab->num_windows++;
+    END_WITH_TAB;
 }
 
+static inline void
+remove_tab(unsigned int id) {
+    REMOVER(global_state.tabs, id, global_state.num_tabs, EMPTY_TAB, Tab, noop);
+}
+
+static inline void
+remove_window(unsigned int tab_id, unsigned int id) {
+    WITH_TAB(tab_id);
+#define destroy_window(w) Py_CLEAR(w.render_data.screen)
+    REMOVER(tab->windows, id, tab->num_windows, EMPTY_WINDOW, Window, destroy_window);
+#undef destroy_window
+    END_WITH_TAB;
+}
+
+
 static inline void
 set_active_tab(unsigned int idx) {
     global_state.active_tab = idx;
 }
 
+static inline void
+set_active_window(unsigned int tab_id, unsigned int idx) {
+    WITH_TAB(tab_id);
+    tab->active_window = idx;
+    END_WITH_TAB;
+}
+
 static inline void
 swap_tabs(unsigned int a, unsigned int b) {
     Tab t = global_state.tabs[b];
@@ -49,6 +84,15 @@ swap_tabs(unsigned int a, unsigned int b) {
     global_state.tabs[a] = t;
 }
 
+static inline void
+swap_windows(unsigned int tab_id, unsigned int a, unsigned int b) {
+    WITH_TAB(tab_id);
+    Window w = tab->windows[b];
+    tab->windows[b] = tab->windows[a];
+    tab->windows[a] = w;
+    END_WITH_TAB;
+}
+
 // Python API {{{
 #define PYWRAP0(name) static PyObject* py##name(PyObject UNUSED *self)
 #define PYWRAP1(name) static PyObject* py##name(PyObject UNUSED *self, PyObject *args)
@@ -56,6 +100,7 @@ swap_tabs(unsigned int a, unsigned int b) {
 #define PA(fmt, ...) if(!PyArg_ParseTuple(args, fmt, __VA_ARGS__)) return NULL;
 #define ONE_UINT(name) PYWRAP1(name) { name((unsigned int)PyLong_AsUnsignedLong(args)); Py_RETURN_NONE; }
 #define TWO_UINT(name) PYWRAP1(name) { unsigned int a, b; PA("II", &a, &b); name(a, b); Py_RETURN_NONE; }
+#define THREE_UINT(name) PYWRAP1(name) { unsigned int a, b, c; PA("III", &a, &b, &c); name(a, b, c); Py_RETURN_NONE; }
 
 PYWRAP1(set_options) {
 #define S(name, convert) { PyObject *ret = PyObject_GetAttrString(args, #name); if (ret == NULL) return NULL; global_state.opts.name = convert(ret); Py_DECREF(ret); }
@@ -74,15 +119,44 @@ PYWRAP1(set_tab_bar_render_data) {
 #undef A
 }
 
+PYWRAP1(set_window_render_data) {
+#define A(name) &(d.name)
+    unsigned int window_idx, tab_id;
+    ScreenRenderData d = {0};
+    PA("IIiffffO", &tab_id, &window_idx, A(vao_idx), A(xstart), A(ystart), A(dx), A(dy), A(screen));
+
+    WITH_TAB(tab_id);
+    Py_CLEAR(tab->windows[window_idx].render_data.screen);
+    tab->windows[window_idx].render_data = d;
+    Py_INCREF(tab->windows[window_idx].render_data.screen);
+    END_WITH_TAB;
+    Py_RETURN_NONE;
+#undef A
+}
+
+PYWRAP1(update_window_visibility) {
+    unsigned int window_idx, tab_id;
+    int visible;
+    PA("IIp", &tab_id, &window_idx, &visible);
+    WITH_TAB(tab_id);
+    tab->windows[window_idx].visible = visible & 1;
+    END_WITH_TAB;
+    Py_RETURN_NONE;
+}
+
 PYWRAP0(destroy_global_data) {
     Py_CLEAR(global_state.tab_bar_render_data.screen);
     Py_RETURN_NONE;
 }
 
 ONE_UINT(add_tab)
+TWO_UINT(add_window)
 ONE_UINT(remove_tab)
+TWO_UINT(remove_window)
 ONE_UINT(set_active_tab)
+TWO_UINT(set_active_window)
 TWO_UINT(swap_tabs)
+THREE_UINT(swap_windows)
 
 #define M(name, arg_type) {#name, (PyCFunction)name, arg_type, NULL}
 #define MW(name, arg_type) {#name, (PyCFunction)py##name, arg_type, NULL}
@@ -90,10 +164,16 @@ TWO_UINT(swap_tabs)
 static PyMethodDef module_methods[] = {
     MW(set_options, METH_O),
     MW(add_tab, METH_O),
+    MW(add_window, METH_VARARGS),
     MW(remove_tab, METH_O),
+    MW(remove_window, METH_VARARGS),
     MW(set_active_tab, METH_O),
+    MW(set_active_window, METH_VARARGS),
     MW(swap_tabs, METH_VARARGS),
+    MW(swap_windows, METH_VARARGS),
     MW(set_tab_bar_render_data, METH_VARARGS),
+    MW(set_window_render_data, METH_VARARGS),
+    MW(update_window_visibility, METH_VARARGS),
     MW(destroy_global_data, METH_NOARGS),
 
     {NULL, NULL, 0, NULL}        /* Sentinel */
diff --git a/kitty/state.h b/kitty/state.h
new file mode 100644
index 000000000..22b0a092d
--- /dev/null
+++ b/kitty/state.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2017 Kovid Goyal <kovid at kovidgoyal.net>
+ *
+ * Distributed under terms of the GPL3 license.
+ */
+
+#pragma once
+#include "data-types.h"
+
+typedef struct {
+    double visual_bell_duration;
+    bool enable_audio_bell;
+} Options;
+
+typedef struct {
+    ssize_t vao_idx;
+    float xstart, ystart, dx, dy;
+    Screen *screen;
+} ScreenRenderData;
+
+typedef struct {
+    unsigned int id;
+    bool visible;
+    ScreenRenderData render_data;
+} Window;
+
+typedef struct {
+    unsigned int id, active_window, num_windows;
+    Window windows[MAX_CHILDREN];
+} Tab;
+
+typedef struct {
+    Options opts;
+
+    Tab tabs[MAX_CHILDREN];
+    unsigned int active_tab, num_tabs;
+    ScreenRenderData tab_bar_render_data;
+} GlobalState;
+
+typedef void (*draw_borders_func)();
+extern draw_borders_func draw_borders;
+typedef void (*draw_cells_func)(ssize_t, float, float, float, float, Screen *);
+extern draw_cells_func draw_cells;
diff --git a/kitty/tabs.py b/kitty/tabs.py
index 7d387c3c9..08528a0e0 100644
--- a/kitty/tabs.py
+++ b/kitty/tabs.py
@@ -14,8 +14,9 @@ from .constants import (
     WindowGeometry, appname, cell_size, get_boss, shell_path, viewport_size
 )
 from .fast_data_types import (
-    DECAWM, Screen, add_tab, create_cell_vao, glfw_post_empty_event,
-    remove_tab, set_active_tab, swap_tabs, set_tab_bar_render_data
+    DECAWM, Screen, add_tab, add_window, create_cell_vao,
+    glfw_post_empty_event, remove_tab, remove_window, set_active_tab,
+    set_active_window, set_tab_bar_render_data, swap_tabs, swap_windows
 )
 from .layout import Rect, all_layouts
 from .utils import color_as_int
@@ -36,6 +37,7 @@ class Tab:  # {{{
     def __init__(self, opts, args, on_title_change, session_tab=None, special_window=None):
         global borders
         self.id = next(tab_counter)
+        add_tab(self.id)
         self.opts, self.args = opts, args
         self.name = getattr(session_tab, 'name', '')
         self.on_title_change = on_title_change
@@ -104,8 +106,8 @@ class Tab:  # {{{
                 idx = -1
             nl = self.opts.enabled_layouts[(idx + 1) % len(self.opts.enabled_layouts)]
             self.current_layout = all_layouts[nl](self.opts, borders.border_width, self.windows)
-            for w in self.windows:
-                w.is_visible_in_layout = True
+            for i, w in enumerate(self.windows):
+                w.set_visible_in_layout(i, True)
             self.relayout()
 
     def launch_child(self, use_shell=False, cmd=None, stdin=None):
@@ -125,7 +127,9 @@ class Tab:  # {{{
             window.title = window.override_title = override_title
         # Must add child before laying out so that resize_pty succeeds
         get_boss().add_child(window)
+        add_window(self.id, window.id)
         self.active_window_idx = self.current_layout.add_window(self.windows, window, self.active_window_idx)
+        set_active_window(self.id, self.active_window_idx)
         self.relayout_borders()
         glfw_post_empty_event()
         return window
@@ -138,7 +142,9 @@ class Tab:  # {{{
             self.remove_window(self.windows[self.active_window_idx])
 
     def remove_window(self, window):
+        remove_window(self.id, window.id)
         self.active_window_idx = self.current_layout.remove_window(self.windows, window, self.active_window_idx)
+        set_active_window(self.id, self.active_window_idx)
         self.relayout_borders()
         glfw_post_empty_event()
 
@@ -146,6 +152,7 @@ class Tab:  # {{{
         if idx != self.active_window_idx:
             self.current_layout.set_active_window(self.windows, idx)
             self.active_window_idx = idx
+            set_active_window(self.id, self.active_window_idx)
             self.relayout_borders()
             glfw_post_empty_event()
 
@@ -163,6 +170,7 @@ class Tab:  # {{{
     def _next_window(self, delta=1):
         if len(self.windows) > 1:
             self.active_window_idx = self.current_layout.next_window(self.windows, self.active_window_idx, delta)
+            set_active_window(self.id, self.active_window_idx)
             self.relayout_borders()
             glfw_post_empty_event()
 
@@ -177,7 +185,9 @@ class Tab:  # {{{
             idx = self.active_window_idx
             nidx = (idx + len(self.windows) + delta) % len(self.windows)
             self.windows[nidx], self.windows[idx] = self.windows[idx], self.windows[nidx]
+            swap_windows(self.id, nidx, idx)
             self.active_window_idx = nidx
+            set_active_window(self.id, self.active_window_idx)
             self.relayout()
 
     def move_window_to_top(self):
@@ -295,7 +305,6 @@ class TabManager:  # {{{
         self.active_tab_idx = 0
 
     def _add_tab(self, tab):
-        add_tab(tab.id)
         self.tabs.append(tab)
 
     def _remove_tab(self, tab):
diff --git a/kitty/window.py b/kitty/window.py
index 09512e75c..dfd048191 100644
--- a/kitty/window.py
+++ b/kitty/window.py
@@ -18,7 +18,9 @@ from .fast_data_types import (
     GLFW_KEY_LEFT_SHIFT, GLFW_KEY_RIGHT_SHIFT, GLFW_KEY_UP, GLFW_MOD_SHIFT,
     GLFW_MOUSE_BUTTON_1, GLFW_MOUSE_BUTTON_4, GLFW_MOUSE_BUTTON_5,
     GLFW_MOUSE_BUTTON_MIDDLE, GLFW_PRESS, GLFW_RELEASE, MOTION_MODE,
-    SCROLL_FULL, SCROLL_LINE, SCROLL_PAGE, Screen, glfw_post_empty_event
+    SCROLL_FULL, SCROLL_LINE, SCROLL_PAGE, Screen, create_cell_vao,
+    glfw_post_empty_event, remove_vao, set_window_render_data,
+    update_window_visibility
 )
 from .keys import get_key_map
 from .mouse import DRAG, MOVE, PRESS, RELEASE, encode_mouse_event
@@ -45,6 +47,8 @@ class Window:
 
     def __init__(self, tab, child, opts, args):
         self.id = next(window_counter)
+        self.vao_id = create_cell_vao()
+        self.tab_id = tab.id
         self.tabref = weakref.ref(tab)
         self.override_title = None
         self.last_mouse_cursor_pos = 0, 0
@@ -53,7 +57,7 @@ class Window:
         self.geometry = WindowGeometry(0, 0, 0, 0, 0, 0)
         self.needs_layout = True
         self.title = appname
-        self._is_visible_in_layout = True
+        self.is_visible_in_layout = True
         self.child, self.opts = child, opts
         self.start_visual_bell_at = None
         self.screen = Screen(self, 24, 80, opts.scrollback_lines)
@@ -63,15 +67,11 @@ class Window:
     def __repr__(self):
         return 'Window(title={}, id={})'.format(self.title, self.id)
 
-    @property
-    def is_visible_in_layout(self):
-        return self._is_visible_in_layout
-
-    @is_visible_in_layout.setter
-    def is_visible_in_layout(self, val):
+    def set_visible_in_layout(self, window_idx, val):
         val = bool(val)
-        if val != self._is_visible_in_layout:
-            self._is_visible_in_layout = val
+        if val is not self.is_visible_in_layout:
+            self.is_visible_in_layout = val
+            update_window_visibility(self.tab_id, window_idx, val)
             if val:
                 self.refresh()
 
@@ -79,7 +79,7 @@ class Window:
         self.screen.mark_as_dirty()
         wakeup()
 
-    def set_geometry(self, new_geometry):
+    def set_geometry(self, window_idx, new_geometry):
         if self.destroyed:
             return
         if self.needs_layout or new_geometry.xnum != self.screen.columns or new_geometry.ynum != self.screen.lines:
@@ -88,11 +88,12 @@ class Window:
             self.current_pty_size = (
                 self.screen.lines, self.screen.columns,
                 max(0, new_geometry.right - new_geometry.left), max(0, new_geometry.bottom - new_geometry.top))
-            self.char_grid.resize(new_geometry)
+            sg = self.char_grid.update_position(new_geometry)
             self.needs_layout = False
             boss.resize_pty(self.id)
         else:
-            self.char_grid.update_position(new_geometry)
+            sg = self.char_grid.update_position(new_geometry)
+        set_window_render_data(self.tab_id, window_idx, self.vao_id, sg.xstart, sg.ystart, sg.dx, sg.dy, self.screen)
         self.geometry = new_geometry
 
     def contains(self, x, y):
@@ -281,6 +282,11 @@ class Window:
     def buf_toggled(self, is_main_linebuf):
         self.screen.scroll(SCROLL_FULL, False)
 
+    def destroy(self):
+        if self.vao_id is not None:
+            remove_vao(self.vao_id)
+            self.vao_id = None
+
     # actions {{{
 
     def show_scrollback(self):