Add option to set window background color

This window background color is different than window.clear(color)
because this window color is the background color if the window itself,
which means if there is a delay between creating the window and the
first frame display then the window background color is black,
but if window color is set then that color will be displayed instead.
Normally you want to set the window background color to the same
color as the color you use in window.clear(color).

1 files changed, 7 insertions, 1 deletions

diff --git a/src/window/window.c b/src/window/window.c
index 958adab..101fb42 100644
--- a/src/window/window.c
+++ b/src/window/window.c
@@ -282,6 +282,12 @@ static void mgl_window_on_resize(mgl_window *self, int width, int height) {
     mgl_window_set_scissor(self, &(mgl_scissor){ .position = { 0, 0 }, .size = self->size });
 }
 
+static unsigned long mgl_color_to_x11_pixel(mgl_color color) {
+    if(color.a == 0)
+        return 0;
+    return (color.r << 16) | (color.g << 8) | color.b;
+}
+
 static int mgl_window_init(mgl_window *self, const char *title, const mgl_window_create_params *params, Window existing_window) {
     self->window = 0;
     self->context = NULL;
@@ -336,7 +342,7 @@ static int mgl_window_init(mgl_window *self, const char *title, const mgl_window
     XSetWindowAttributes window_attr;
     window_attr.override_redirect = params ? params->override_redirect : false;
     window_attr.colormap = x11_context->color_map;
-    window_attr.background_pixel = 0;
+    window_attr.background_pixel = mgl_color_to_x11_pixel(params ? params->background_color : (mgl_color){ .r = 0, .g = 0, .b = 0, .a = 0 });
     window_attr.border_pixel = 0;
     window_attr.bit_gravity = NorthWestGravity;
     window_attr.event_mask =