[retro-gtk] gl-display: Account for window scale

[Adrien Plazas <aplazas src gnome org>]

commit 28616a0b1c4657509eaa782c8a4b6a549224feed
Author: Alexander Mikhaylenko <exalm7659 gmail com>
Date:   Fri Jul 27 00:32:37 2018 +0500

    gl-display: Account for window scale
    
    Fixes RetroGLDisplay rendering on HiDPI.

 retro-gtk/retro-gl-display.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/retro-gtk/retro-gl-display.c b/retro-gtk/retro-gl-display.c
index 860e13e..93a8ea8 100644
--- a/retro-gtk/retro-gl-display.c
+++ b/retro-gtk/retro-gl-display.c
@@ -88,6 +88,7 @@ retro_gl_display_get_video_box (RetroGLDisplay *self,
   gdouble h;
   gdouble display_ratio;
   gdouble allocated_ratio;
+  gint scale;
 
   g_return_if_fail (RETRO_IS_GL_DISPLAY (self));
   g_return_if_fail (width != NULL);
@@ -95,8 +96,10 @@ retro_gl_display_get_video_box (RetroGLDisplay *self,
   g_return_if_fail (x != NULL);
   g_return_if_fail (y != NULL);
 
-  w = (gdouble) gtk_widget_get_allocated_width (GTK_WIDGET (self));
-  h = (gdouble) gtk_widget_get_allocated_height (GTK_WIDGET (self));
+  scale = gtk_widget_get_scale_factor (GTK_WIDGET (self));
+
+  w = (gdouble) gtk_widget_get_allocated_width (GTK_WIDGET (self)) * scale;
+  h = (gdouble) gtk_widget_get_allocated_height (GTK_WIDGET (self)) * scale;
 
   // Set the size of the display.
   display_ratio = (gdouble) self->aspect_ratio;