From 2f5a58367427289e255a1ff74183aa2f785b9766 Mon Sep 17 00:00:00 2001
From: Neil <neil@dip.sun.ac.za>
Date: Wed, 7 Sep 2016 13:02:07 +0200
Subject: [PATCH] Add 'draw_fps' setting and support

---
 tabakrolletjie/constants.py |  8 ++++++++
 tabakrolletjie/engine.py    | 15 +++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/tabakrolletjie/constants.py b/tabakrolletjie/constants.py
index 92a7c6f..8edc2e9 100644
--- a/tabakrolletjie/constants.py
+++ b/tabakrolletjie/constants.py
@@ -7,6 +7,9 @@ TITLE = "Space Turnips"
 
 # Debug
 DEBUG = os.environ.get("TABAK_DEBUG", "").lower() in ("1", "y", "yes")
+DRAW_FPS = os.environ.get("TABAK_DRAW_FPS", "").lower() in ("1", "y", "yes")
+# Intervals to average fps over
+FPS_FRAMES = 50
 
 # 704 is 768 minus space for window decorations :)
 SCREEN_SIZE = (1024, 704)
@@ -19,3 +22,8 @@ OBSTACLE_CATEGORY = 1 << 0
 LIGHT_CATEGORY = 1 << 1
 MOULD_CATEGORY = 1 << 2
 FITTINGS_CATEGORY = 1 << 3
+
+# Font definitions
+FONTS = {
+    'sans': 'DejaVuSans.ttf',
+}
diff --git a/tabakrolletjie/engine.py b/tabakrolletjie/engine.py
index 4dac1dd..cdea160 100644
--- a/tabakrolletjie/engine.py
+++ b/tabakrolletjie/engine.py
@@ -7,7 +7,8 @@ import pygame.time
 
 import pygame.locals as pgl
 
-from .constants import FPS
+from .constants import FPS, DRAW_FPS, FONTS, FPS_FRAMES
+from .loader import loader
 from .events import QuitEvent, SceneChangeEvent
 
 
@@ -26,6 +27,9 @@ class Engine(object):
 
     def run(self):
         clock = pygame.time.Clock()
+        fpses = [FPS] * FPS_FRAMES
+        frame = 0
+        font = loader.load_font(FONTS['sans'], size=16)
 
         while True:
             events = pygame.event.get()
@@ -42,5 +46,12 @@ class Engine(object):
             # Time is assumed to flow perfectly, so no dt parameter for now
             self._scene.tick(self._gamestate)
             self._scene.render(self._screen, self._gamestate)
+            if DRAW_FPS:
+                fps = sum(fpses) / FPS_FRAMES
+                text = font.render("FPS: %.2f" % fps, True, (255, 255, 255))
+                self._screen.blit(text, (10, 10), None)
             pygame.display.flip()
-            clock.tick(FPS)
+            fpses[frame] = 1000.0 / clock.tick(FPS)
+            frame += 1
+            if frame >= FPS_FRAMES:
+                frame = 0
-- 
2.34.1