From 1d5f98db32ca148b2704d96e72b13de09acb1be9 Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Thu, 7 Dec 2017 16:10:00 +1100
Subject: [PATCH] [client] adjusted presentation time to be more accurate

---
 client/main.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/client/main.c b/client/main.c
index c424a772..e4e66511 100644
--- a/client/main.c
+++ b/client/main.c
@@ -161,19 +161,17 @@ inline uint64_t microtime()
 
 uint64_t detectPresentTime()
 {
-  // warm up first as the GPU driver may have multiple buffers
-  for(int i = 0; i < 10; ++i)
-    SDL_RenderPresent(state.renderer);
-
-  // time 10 iterations and compute the average
-  const uint64_t start = microtime();
-  for(int i = 0; i < 10; ++i)
-    SDL_RenderPresent(state.renderer);
-  const uint64_t t = (microtime() - start) / 10;
-
-  // ensure all buffers are flushed
   glFinish();
 
+  // time 20 iterations and compute the average
+  const uint64_t start = microtime();
+  for(int i = 0; i < 20; ++i)
+  {
+    SDL_RenderPresent(state.renderer);
+    glFinish();
+  }
+  const uint64_t t = (microtime() - start) / 20;
+
   DEBUG_INFO("detected: %lu (%f Hz)", t, 1000000.0f / t);
   return t;
 }