[units] Add more conversion functions

A GValue containing a ClutterUnit should be transformable into a
GValue holding an integer, a floating point value or a fixed point
value.

This means adding more transformation functions when registering
the ClutterUnit GType.

2 files changed, 85 insertions, 11 deletions

diff --git a/clutter/clutter-units.c b/clutter/clutter-units.c
index 9ea6d78a0..e51d2e379 100644
--- a/clutter/clutter-units.c
+++ b/clutter/clutter-units.c
@@ -160,7 +160,7 @@ clutter_units_pt (gdouble pt)
  * @em: em to convert
  *
  * Converts a value in em to #ClutterUnit<!-- -->s at the
- * current DPI.
+ * current DPI
  *
  * Return value: the value in units
  *
@@ -176,6 +176,42 @@ clutter_units_em (gdouble em)
   return em * _clutter_backend_get_units_per_em (backend);
 }
 
+/**
+ * clutter_units_pixels:
+ * @px: pixels to convert
+ *
+ * Converts a value in pixels to #ClutterUnit<!-- -->s
+ *
+ * Return value: the value in units
+ *
+ * Since: 1.0
+ */
+ClutterUnit
+clutter_units_pixels (gint px)
+{
+  return CLUTTER_UNITS_FROM_INT (px);
+}
+
+/**
+ * clutter_units_to_pixels:
+ * @units: units to convert
+ *
+ * Converts a value in #ClutterUnit<!-- -->s to pixels
+ *
+ * Return value: the value in pixels
+ *
+ * Since: 1.0
+ */
+gint
+clutter_units_to_pixels (ClutterUnit units)
+{
+  return CLUTTER_UNITS_TO_INT (units);
+}
+
+/*
+ * GValue and GParamSpec integration
+ */
+
 static GTypeInfo _info = {
  0,
  NULL,
@@ -246,6 +282,36 @@ clutter_value_transform_int_unit (const GValue *src,
   dest->data[0].v_float = CLUTTER_UNITS_FROM_INT (src->data[0].v_int);
 }
 
+static void
+clutter_value_transform_unit_float (const GValue *src,
+                                    GValue       *dest)
+{
+  dest->data[0].v_float = CLUTTER_UNITS_TO_FLOAT (src->data[0].v_float);
+}
+
+static void
+clutter_value_transform_float_unit (const GValue *src,
+                                    GValue       *dest)
+{
+  dest->data[0].v_float = CLUTTER_UNITS_FROM_FLOAT (src->data[0].v_float);
+}
+
+#if 0
+static void
+clutter_value_transform_unit_fixed (const GValue *src,
+                                    GValue       *dest)
+{
+  dest->data[0].v_int = CLUTTER_UNITS_TO_FIXED (src->data[0].v_float);
+}
+
+static void
+clutter_value_transform_fixed_unit (const GValue *src,
+                                    GValue       *dest)
+{
+  dest->data[0].v_float = CLUTTER_UNITS_FROM_FIXED (src->data[0].v_int);
+}
+#endif
+
 static const GTypeValueTable _clutter_unit_value_table = {
   clutter_value_init_unit,
   NULL,
@@ -274,6 +340,11 @@ clutter_unit_get_type (void)
                                        clutter_value_transform_unit_int);
       g_value_register_transform_func (G_TYPE_INT, _clutter_unit_type,
                                        clutter_value_transform_int_unit);
+
+      g_value_register_transform_func (_clutter_unit_type, G_TYPE_FLOAT,
+                                       clutter_value_transform_unit_float);
+      g_value_register_transform_func (G_TYPE_FLOAT, _clutter_unit_type,
+                                       clutter_value_transform_float_unit);
     }
 
   return _clutter_unit_type;
diff --git a/clutter/clutter-units.h b/clutter/clutter-units.h
index efc622e1b..00a1e0dc2 100644
--- a/clutter/clutter-units.h
+++ b/clutter/clutter-units.h
@@ -39,8 +39,8 @@ G_BEGIN_DECLS
 /**
  * ClutterUnit:
  *
- * Device independent unit used by Clutter. The value held can be transformed
- * into other units, likes pixels.
+ * Device independent unit used by Clutter. The value held can be
+ * transformed into other units, likes pixels.
  *
  * Since: 0.4
  */
@@ -52,8 +52,8 @@ typedef float ClutterUnit;
 #define CLUTTER_UNITS_FROM_FLOAT(x)      (x)
 #define CLUTTER_UNITS_TO_FLOAT(x)        (x)
 
-#define CLUTTER_UNITS_FROM_FIXED(x)      (x)
-#define CLUTTER_UNITS_TO_FIXED(x)        (x)
+#define CLUTTER_UNITS_FROM_FIXED(x)      (COGL_FIXED_TO_FLOAT (x))
+#define CLUTTER_UNITS_TO_FIXED(x)        (COGL_FIXED_FROM_FLOAT (x))
 
 /**
  * CLUTTER_UNITS_FORMAT:
@@ -79,7 +79,7 @@ typedef float ClutterUnit;
  *
  * Since: 0.6
  */
-#define CLUTTER_UNITS_FROM_DEVICE(x)     CLUTTER_UNITS_FROM_INT ((x))
+#define CLUTTER_UNITS_FROM_DEVICE(x)    (clutter_units_pixels ((x)))
 
 /**
  * CLUTTER_UNITS_TO_DEVICE:
@@ -89,7 +89,7 @@ typedef float ClutterUnit;
  *
  * Since: 0.6
  */
-#define CLUTTER_UNITS_TO_DEVICE(x)       CLUTTER_UNITS_TO_INT ((x))
+#define CLUTTER_UNITS_TO_DEVICE(x)      (clutter_units_to_pixels ((x)))
 
 /**
  * CLUTTER_UNITS_FROM_PANGO_UNIT:
@@ -99,7 +99,7 @@ typedef float ClutterUnit;
  *
  * Since: 0.6
  */
-#define CLUTTER_UNITS_FROM_PANGO_UNIT(x) ((float)((x) / 1024))
+#define CLUTTER_UNITS_FROM_PANGO_UNIT(x) ((float)((x) / 1024.0))
 
 /**
  * CLUTTER_UNITS_TO_PANGO_UNIT:
@@ -141,9 +141,12 @@ typedef float ClutterUnit;
  */
 #define CLUTTER_UNITS_FROM_EM(x)        (clutter_units_em (x))
 
-ClutterUnit clutter_units_mm (gdouble mm);
-ClutterUnit clutter_units_pt (gdouble pt);
-ClutterUnit clutter_units_em (gdouble em);
+ClutterUnit clutter_units_mm        (gdouble     mm);
+ClutterUnit clutter_units_pt        (gdouble     pt);
+ClutterUnit clutter_units_em        (gdouble     em);
+ClutterUnit clutter_units_pixels    (gint        px);
+
+gint        clutter_units_to_pixels (ClutterUnit units);
 
 #define CLUTTER_TYPE_UNIT                 (clutter_unit_get_type ())
 #define CLUTTER_TYPE_PARAM_UNIT           (clutter_param_unit_get_type ())