[gtk+] GL: Fix GL Y coordinate flipping to use unscaled window height

[Alexander Larsson <alexl src gnome org>]

commit 800c712738f5666937e32d9f8cb32353513b9423
Author: Alexander Larsson <alexl redhat com>
Date:   Thu Nov 20 11:53:09 2014 +0100

    GL: Fix GL Y coordinate flipping to use unscaled window height
    
    This is needed in the edge case where the X11 backend rounded the actual
    size, and the GL flipping really needs the correct window height to
    do proper Y coordinate flipping.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=739750

 gdk/gdkgl.c |   24 ++++++++++++------------
 1 files changed, 12 insertions(+), 12 deletions(-)
---
diff --git a/gdk/gdkgl.c b/gdk/gdkgl.c
index 7ce7f33..d693ca0 100644
--- a/gdk/gdkgl.c
+++ b/gdk/gdkgl.c
@@ -401,7 +401,7 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
       trivial_transform &&
       clip_region != NULL)
     {
-      int window_height;
+      int unscaled_window_height;
       int i;
 
       /* Create a framebuffer with the source renderbuffer and
@@ -417,10 +417,10 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
 
       glEnable (GL_SCISSOR_TEST);
 
-      window_height = gdk_window_get_height (impl_window);
+      gdk_window_get_unscaled_size (impl_window, NULL, &unscaled_window_height);
       glDrawBuffer (GL_BACK);
 
-#define FLIP_Y(_y) (window_height*window_scale - (_y))
+#define FLIP_Y(_y) (unscaled_window_height - (_y))
 
       for (i = 0; i < cairo_region_num_rectangles (clip_region); i++)
         {
@@ -481,7 +481,7 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
            trivial_transform &&
            clip_region != NULL)
     {
-      int window_height;
+      int unscaled_window_height;
       GLint texture_width;
       GLint texture_height;
       int i;
@@ -526,9 +526,9 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
       glEnable (GL_SCISSOR_TEST);
       glEnable (GL_TEXTURE_2D);
 
-      window_height = gdk_window_get_height (impl_window);
+      gdk_window_get_unscaled_size (impl_window, NULL, &unscaled_window_height);
 
-#define FLIP_Y(_y) (window_height*window_scale - (_y))
+#define FLIP_Y(_y) (unscaled_window_height - (_y))
 
       for (i = 0; i < cairo_region_num_rectangles (clip_region); i++)
         {
@@ -652,7 +652,7 @@ gdk_gl_texture_from_surface (cairo_surface_t *surface,
   cairo_rectangle_int_t rect, e;
   int n_rects, i;
   GdkWindow *window;
-  int window_height;
+  int unscaled_window_height;
   unsigned int texture_id;
   int window_scale;
   double sx, sy;
@@ -672,7 +672,7 @@ gdk_gl_texture_from_surface (cairo_surface_t *surface,
 
   window = gdk_gl_context_get_window (paint_context);
   window_scale = gdk_window_get_scale_factor (window);
-  window_height = gdk_window_get_height (window);
+  gdk_window_get_unscaled_size (window, NULL, &unscaled_window_height);
 
   sx = sy = 1;
   cairo_surface_get_device_scale (window->current_paint.surface, &sx, &sy);
@@ -700,7 +700,7 @@ gdk_gl_texture_from_surface (cairo_surface_t *surface,
     {
       cairo_region_get_rectangle (region, i, &rect);
 
-      glScissor (rect.x * window_scale, (window_height - rect.y - rect.height) * window_scale,
+      glScissor (rect.x * window_scale, unscaled_window_height - (rect.y - rect.height) * window_scale,
                  rect.width * window_scale, rect.height * window_scale);
 
       e = rect;
@@ -720,7 +720,7 @@ gdk_gl_texture_from_surface (cairo_surface_t *surface,
 
       cairo_surface_unmap_image (surface, image);
 
-#define FLIP_Y(_y) (window_height - (_y))
+#define FLIP_Y(_y) (unscaled_window_height - (_y))
 
       if (use_texture_rectangle)
         {
@@ -734,8 +734,8 @@ gdk_gl_texture_from_surface (cairo_surface_t *surface,
         }
 
       gdk_gl_texture_quad (paint_context, target,
-                           rect.x * window_scale, FLIP_Y(rect.y) * window_scale,
-                           (rect.x + rect.width) * window_scale, FLIP_Y(rect.y + rect.height) * window_scale,
+                           rect.x * window_scale, FLIP_Y(rect.y),
+                           (rect.x + rect.width) * window_scale, FLIP_Y((rect.y + rect.height) * 
window_scale),
                            0, 0,
                            umax, vmax);
     }