diff --git a/kitty/develop_gl.py b/kitty/develop_gl.py
index 695b75a27..f5d7d493c 100644
--- a/kitty/develop_gl.py
+++ b/kitty/develop_gl.py
@@ -3,6 +3,7 @@
 # License: GPLv3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 
 import glfw
+import glfw_constants
 import sys
 import ctypes
 
@@ -68,7 +69,8 @@ class Renderer:
                 c.bg = (bg << 8) | 3
                 c.x = x
                 line.set_text('%d' % (i % 10), 0, 1, c)
-            self.sprites.update_cell_data(line, 0, sg.xnum - 1, self.color_profile, 0xffffff, 0, ctypes.addressof(data))
+            self.sprites.backend.update_cell_data(line, 0, sg.xnum - 1, self.color_profile, 0xffffff, 0, ctypes.addressof(data))
+        self.sprites.render_dirty_cells()
         self.sprites.set_sprite_map(data)
 
     def render(self):
@@ -106,11 +108,11 @@ def _main():
     # These Window hints are used to specify
     # which opengl version to use and other details
     # for the opengl context that will be created
-    glfw.glfwWindowHint(glfw.GLFW_CONTEXT_VERSION_MAJOR, GL_VERSION[0])
-    glfw.glfwWindowHint(glfw.GLFW_CONTEXT_VERSION_MINOR, GL_VERSION[1])
-    glfw.glfwWindowHint(glfw.GLFW_OPENGL_PROFILE,
-                        glfw.GLFW_OPENGL_CORE_PROFILE)
-    glfw.glfwWindowHint(glfw.GLFW_OPENGL_FORWARD_COMPAT, True)
+    glfw.glfwWindowHint(glfw_constants.GLFW_CONTEXT_VERSION_MAJOR, GL_VERSION[0])
+    glfw.glfwWindowHint(glfw_constants.GLFW_CONTEXT_VERSION_MINOR, GL_VERSION[1])
+    glfw.glfwWindowHint(glfw_constants.GLFW_OPENGL_PROFILE,
+                        glfw_constants.GLFW_OPENGL_CORE_PROFILE)
+    glfw.glfwWindowHint(glfw_constants.GLFW_OPENGL_FORWARD_COMPAT, True)
 
     window = glfw.glfwCreateWindow(
         1024, 1024, "Trying this crap".encode('utf-8'), None, None)
diff --git a/kitty/sprites.c b/kitty/sprites.c
index 3e658219e..002d23a1a 100644
--- a/kitty/sprites.c
+++ b/kitty/sprites.c
@@ -131,7 +131,6 @@ position_for(SpriteMap *self, PyObject *args) {
 
 bool
 update_cell_range_data(SpriteMap *self, Line *line, unsigned int xstart, unsigned int xmax, ColorProfile *color_profile, const uint32_t default_bg, const uint32_t default_fg, unsigned int *data) {
-#define update_cell_data_doc "update_cell_data(line, xstart, xmax, color_profile, default_bg, default_fg, data_pointer) -> Update the range [xstart, xmax] in data_pointer with the data from line"
     SpritePosition *sp;
     char_type previous_ch=0, ch;
     color_type color;
@@ -159,6 +158,20 @@ update_cell_range_data(SpriteMap *self, Line *line, unsigned int xstart, unsigne
     return true;
 }
 
+static PyObject*
+update_cell_data(SpriteMap *self, PyObject *args) {
+#define update_cell_data_doc "update_cell_data(line, xstart, xmax, color_profile, default_bg, default_fg, data_pointer) -> Update the range [xstart, xmax] in data_pointer with the data from line"
+    unsigned int xstart, xmax;
+    uint32_t default_fg, default_bg;
+    Line *line; ColorProfile *color_profile;
+    PyObject *data_pointer;
+
+    if (!PyArg_ParseTuple(args, "O!IIO!IIO!", &Line_Type, &line, &xstart, &xmax, &ColorProfile_Type, &color_profile, &default_bg, &default_fg, &PyLong_Type, &data_pointer)) return NULL;
+    unsigned int *dp = PyLong_AsVoidPtr(data_pointer);
+    if (!update_cell_range_data(self, line, xstart, xmax, color_profile, default_bg, default_fg, dp)) return NULL;
+    Py_RETURN_NONE;
+}
+
 static PyObject*
 render_dirty_cells(SpriteMap *self, PyObject *args) {
 #define render_dirty_cells_doc "Render all cells that are marked as dirty"
@@ -208,6 +221,7 @@ static PyMethodDef methods[] = {
     METHOD(layout, METH_VARARGS)
     METHOD(position_for, METH_VARARGS)
     METHOD(render_dirty_cells, METH_VARARGS)
+    METHOD(update_cell_data, METH_VARARGS)
     {NULL}  /* Sentinel */
 };