Pileus Git - ~andy/gtk/blob - gdk/gdkframehistory.c

   1 /* GDK - The GIMP Drawing Kit
   2  * Copyright (C) 2012 Red Hat, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "config.h"
  19
  20 #include "gdkframehistory.h"
  21
  22 #define FRAME_HISTORY_MAX_LENGTH 16
  23
  24 struct _GdkFrameHistory
  25 {
  26   GObject parent_instance;
  27
  28   gint64 frame_counter;
  29   gint n_timings;
  30   gint current;
  31   GdkFrameTimings *timings[FRAME_HISTORY_MAX_LENGTH];
  32 };
  33
  34 struct _GdkFrameHistoryClass
  35 {
  36   GObjectClass parent_class;
  37 };
  38
  39 G_DEFINE_TYPE (GdkFrameHistory, gdk_frame_history, G_TYPE_OBJECT)
  40
  41 static void
  42 gdk_frame_history_finalize (GObject *object)
  43 {
  44   GdkFrameHistory *history = GDK_FRAME_HISTORY (object);
  45   int i;
  46
  47   for (i = 0; i < FRAME_HISTORY_MAX_LENGTH; i++)
  48     if (history->timings[i] != 0)
  49       gdk_frame_timings_unref (history->timings[i]);
  50
  51   G_OBJECT_CLASS (gdk_frame_history_parent_class)->finalize (object);
  52 }
  53
  54 static void
  55 gdk_frame_history_class_init (GdkFrameHistoryClass *klass)
  56 {
  57   GObjectClass *object_class = G_OBJECT_CLASS (klass);
  58
  59   object_class->finalize = gdk_frame_history_finalize;
  60 }
  61
  62 static void
  63 gdk_frame_history_init (GdkFrameHistory *history)
  64 {
  65   history->frame_counter = -1;
  66   history->current = FRAME_HISTORY_MAX_LENGTH - 1;
  67 }
  68
  69 GdkFrameHistory *
  70 gdk_frame_history_new (void)
  71 {
  72   return g_object_new (GDK_TYPE_FRAME_HISTORY, NULL);
  73 }
  74
  75 gint64
  76 gdk_frame_history_get_frame_counter (GdkFrameHistory *history)
  77 {
  78   g_return_val_if_fail (GDK_IS_FRAME_HISTORY (history), 0);
  79
  80   return history->frame_counter;
  81 }
  82
  83 gint64
  84 gdk_frame_history_get_start (GdkFrameHistory *history)
  85 {
  86   g_return_val_if_fail (GDK_IS_FRAME_HISTORY (history), 0);
  87
  88   return history->frame_counter + 1 - history->n_timings;
  89 }
  90
  91 void
  92 gdk_frame_history_begin_frame (GdkFrameHistory *history)
  93 {
  94   g_return_if_fail (GDK_IS_FRAME_HISTORY (history));
  95
  96   history->frame_counter++;
  97   history->current = (history->current + 1) % FRAME_HISTORY_MAX_LENGTH;
  98
  99   if (history->n_timings < FRAME_HISTORY_MAX_LENGTH)
 100     history->n_timings++;
 101   else
 102     {
 103       gdk_frame_timings_unref(history->timings[history->current]);
 104     }
 105
 106   history->timings[history->current] = gdk_frame_timings_new (history->frame_counter);
 107 }
 108
 109 GdkFrameTimings *
 110 gdk_frame_history_get_timings (GdkFrameHistory *history,
 111                                gint64           frame_counter)
 112 {
 113   gint pos;
 114
 115   g_return_val_if_fail (GDK_IS_FRAME_HISTORY (history), NULL);
 116
 117   if (frame_counter > history->frame_counter)
 118     return NULL;
 119
 120   if (frame_counter <= history->frame_counter - history->n_timings)
 121     return NULL;
 122
 123   pos = (history->current - (history->frame_counter - frame_counter) + FRAME_HISTORY_MAX_LENGTH) % FRAME_HISTORY_MAX_LENGTH;
 124
 125   return history->timings[pos];
 126 }
 127
 128 GdkFrameTimings *
 129 gdk_frame_history_get_last_complete (GdkFrameHistory *history)
 130 {
 131   gint i;
 132
 133   g_return_val_if_fail (GDK_IS_FRAME_HISTORY (history), NULL);
 134
 135   for (i = 0; i < history->n_timings; i++)
 136     {
 137       gint pos = ((history->current - i) + FRAME_HISTORY_MAX_LENGTH) % FRAME_HISTORY_MAX_LENGTH;
 138       if (gdk_frame_timings_get_complete (history->timings[pos]))
 139         return history->timings[pos];
 140     }
 141
 142   return NULL;
 143 }