[mutter/gbsneto/graphene-frustrum: 7/26] clutter/util: Generalize ROUND_TO_256THS

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 3dd556f8399b61b3f62b34df42f9e74a266c3acc
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Tue Oct 13 08:23:56 2020 -0300

    clutter/util: Generalize ROUND_TO_256THS
    
    It'll be reused in other bits of the Clutter codebase. Move it to
    an inline function in clutter-private.h
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1489

 clutter/clutter/clutter-private.h |  6 ++++++
 clutter/clutter/clutter-util.c    | 20 ++++++++++----------
 2 files changed, 16 insertions(+), 10 deletions(-)
---
diff --git a/clutter/clutter/clutter-private.h b/clutter/clutter/clutter-private.h
index a504b74ba8..594a73b862 100644
--- a/clutter/clutter/clutter-private.h
+++ b/clutter/clutter/clutter-private.h
@@ -268,6 +268,12 @@ gboolean        _clutter_run_progress_function  (GType gtype,
 
 void            clutter_timeline_cancel_delay (ClutterTimeline *timeline);
 
+static inline void
+clutter_round_to_256ths (float *f)
+{
+  *f = roundf ((*f) * 256) / 256;
+}
+
 static inline int64_t
 us (int64_t us)
 {
diff --git a/clutter/clutter/clutter-util.c b/clutter/clutter/clutter-util.c
index f598332c8f..5f7fab0e15 100644
--- a/clutter/clutter/clutter-util.c
+++ b/clutter/clutter/clutter-util.c
@@ -47,8 +47,6 @@
 #define MTX_GL_SCALE_Y(y,w,v1,v2) ((v1) - (((((y) / (w)) + 1.0f) / 2.0f) * (v1)) + (v2))
 #define MTX_GL_SCALE_Z(z,w,v1,v2) (MTX_GL_SCALE_X ((z), (w), (v1), (v2)))
 
-#define ROUND_TO_256THS(x) (roundf ((x) * 256) / 256)
-
 typedef struct
 {
   float x;
@@ -108,14 +106,16 @@ _clutter_util_fully_transform_vertices (const graphene_matrix_t  *modelview,
       ClutterVertex4 vertex_tmp = vertices_tmp[i];
       graphene_point3d_t *vertex_out = &vertices_out[i];
       /* Finally translate from OpenGL coords to window coords */
-      vertex_out->x = ROUND_TO_256THS (MTX_GL_SCALE_X (vertex_tmp.x,
-                                                       vertex_tmp.w,
-                                                       viewport[2],
-                                                       viewport[0]));
-      vertex_out->y = ROUND_TO_256THS (MTX_GL_SCALE_Y (vertex_tmp.y,
-                                                       vertex_tmp.w,
-                                                       viewport[3],
-                                                       viewport[1]));
+      vertex_out->x = MTX_GL_SCALE_X (vertex_tmp.x,
+                                      vertex_tmp.w,
+                                      viewport[2],
+                                      viewport[0]);
+      vertex_out->y = MTX_GL_SCALE_Y (vertex_tmp.y,
+                                      vertex_tmp.w,
+                                      viewport[3],
+                                      viewport[1]);
+      clutter_round_to_256ths (&vertex_out->x);
+      clutter_round_to_256ths (&vertex_out->y);
     }
 }