From 01ed1e1604a629268b05e61fada991fc7edc5d6a Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 25 Feb 2019 15:07:03 +0530
Subject: [PATCH] Move initial window blanking to before showing the window

---
 kitty/glfw.c    | 24 ++++++++++++++++--------
 kitty/shaders.c |  4 ++--
 kitty/state.h   |  1 +
 kitty/window.py |  2 +-
 4 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/kitty/glfw.c b/kitty/glfw.c
index a56808fea..fd75dd0f4 100644
--- a/kitty/glfw.c
+++ b/kitty/glfw.c
@@ -115,6 +115,11 @@ show_mouse_cursor(GLFWwindow *w) {
 
 static int min_width = 100, min_height = 100;
 
+void
+blank_os_window(OSWindow *w) {
+    blank_canvas(w->is_semi_transparent ? w->background_opacity : 1.0f);
+}
+
 static void
 framebuffer_size_callback(GLFWwindow *w, int width, int height) {
     if (!set_callback_window(w)) return;
@@ -516,6 +521,15 @@ create_os_window(PyObject UNUSED *self, PyObject *args) {
     GLFWwindow *glfw_window = glfwCreateWindow(width, height, title, NULL, temp_window);
     glfwDestroyWindow(temp_window); temp_window = NULL;
     if (glfw_window == NULL) { PyErr_SetString(PyExc_ValueError, "Failed to create GLFWwindow"); return NULL; }
+    glfwMakeContextCurrent(glfw_window);
+    if (is_first_window) {
+        gl_init();
+    }
+    bool is_semi_transparent = glfwGetWindowAttrib(glfw_window, GLFW_TRANSPARENT_FRAMEBUFFER);
+    // blank the window once so that there is no initial flash of color
+    // changing, in case the background color is not black
+    blank_canvas(is_semi_transparent ? OPT(background_opacity) : 1.0f);
+    glfwSwapBuffers(glfw_window);
     if (!global_state.is_wayland) {
         PyObject *pret = PyObject_CallFunction(pre_show_callback, "N", native_window_handle(glfw_window));
         if (pret == NULL) return NULL;
@@ -523,10 +537,8 @@ create_os_window(PyObject UNUSED *self, PyObject *args) {
         if (x != -1 && y != -1) glfwSetWindowPos(glfw_window, x, y);
         glfwShowWindow(glfw_window);
     }
-    glfwMakeContextCurrent(glfw_window);
     if (is_first_window) {
-        gl_init();
-        PyObject *ret = PyObject_CallFunction(load_programs, "i", glfwGetWindowAttrib(glfw_window, GLFW_TRANSPARENT_FRAMEBUFFER));
+        PyObject *ret = PyObject_CallFunction(load_programs, "O", is_semi_transparent ? Py_True : Py_False);
         if (ret == NULL) return NULL;
         Py_DECREF(ret);
 #ifdef __APPLE__
@@ -591,7 +603,7 @@ create_os_window(PyObject UNUSED *self, PyObject *args) {
     w->is_focused = true;
     w->cursor_blink_zero_time = now;
     w->last_mouse_activity_at = now;
-    w->is_semi_transparent = glfwGetWindowAttrib(w->handle, GLFW_TRANSPARENT_FRAMEBUFFER);
+    w->is_semi_transparent = is_semi_transparent;
     if (want_semi_transparent && !w->is_semi_transparent) {
         static bool warned = false;
         if (!warned) {
@@ -599,10 +611,6 @@ create_os_window(PyObject UNUSED *self, PyObject *args) {
             warned = true;
         }
     }
-    // blank the window once so that there is no initial flash of color
-    // changing, in case the background color is not black
-    blank_os_window(w);
-    swap_window_buffers(w);
     return PyLong_FromUnsignedLongLong(w->id);
 }
 
diff --git a/kitty/shaders.c b/kitty/shaders.c
index 775f97e45..92a296caa 100644
--- a/kitty/shaders.c
+++ b/kitty/shaders.c
@@ -429,9 +429,9 @@ set_cell_uniforms(float current_inactive_text_alpha) {
 }
 
 void
-blank_os_window(OSWindow *os_window) {
+blank_canvas(float background_opacity) {
 #define C(shift) (((GLfloat)((OPT(background) >> shift) & 0xFF)) / 255.0f)
-        glClearColor(C(16), C(8), C(0), os_window->is_semi_transparent ? os_window->background_opacity : 1.0f);
+        glClearColor(C(16), C(8), C(0), background_opacity);
 #undef C
         glClear(GL_COLOR_BUFFER_BIT);
 }
diff --git a/kitty/state.h b/kitty/state.h
index 9aa0de9f3..5b54ce004 100644
--- a/kitty/state.h
+++ b/kitty/state.h
@@ -203,6 +203,7 @@ void update_surface_size(int, int, uint32_t);
 void free_texture(uint32_t*);
 void send_image_to_gpu(uint32_t*, const void*, int32_t, int32_t, bool, bool);
 void send_sprite_to_gpu(FONTS_DATA_HANDLE fg, unsigned int, unsigned int, unsigned int, pixel*);
+void blank_canvas(float);
 void blank_os_window(OSWindow *);
 void set_titlebar_color(OSWindow *w, color_type color);
 FONTS_DATA_HANDLE load_fonts_data(double, double, double);
diff --git a/kitty/window.py b/kitty/window.py
index d087a3351..e6b0134ce 100644
--- a/kitty/window.py
+++ b/kitty/window.py
@@ -55,7 +55,7 @@ def calculate_gl_geometry(window_geometry, viewport_width, viewport_height, cell
     return ScreenGeometry(xstart, ystart, window_geometry.xnum, window_geometry.ynum, dx, dy)
 
 
-def load_shader_programs(semi_transparent=0):
+def load_shader_programs(semi_transparent=False):
     compile_program(BLIT_PROGRAM, *load_shaders('blit'))
     v, f = load_shaders('cell')