From d066962617d753e70e229eab42dc52cffbb850e7 Mon Sep 17 00:00:00 2001
From: Toni Spets <toni.spets@iki.fi>
Date: Wed, 17 Nov 2010 22:12:19 +0200
Subject: [PATCH] Add vsync ini option, controls GL_EXT_swap_control, default
 disabled

---
 main.c   | 14 +++++++++++++-
 main.h   |  1 +
 render.c | 18 ++++++++++++++++++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/main.c b/main.c
index ca08e4f..a758598 100644
--- a/main.c
+++ b/main.c
@@ -515,8 +515,10 @@ HRESULT WINAPI DirectDrawCreate(GUID FAR* lpGUID, LPDIRECTDRAW FAR* lplpDD, IUnk
             "; bits per pixel, possible values: 16, 24 and 32, 0 = auto\n"
             "bpp=0\n"
             "windowed=true\n"
-            "; real rendering rate, -1 = vsync, 0 = unlimited, n = cap\n"
+            "; real rendering rate, -1 = screen rate, 0 = unlimited, n = cap\n"
             "maxfps=120\n"
+            "; vertical synchronization, enable if you get tearing\n"
+            "vsync=false\n"
             "; scaling filter, nearest = sharp, linear = smooth\n"
             "filter=nearest\n"
             "; mouse sensitivity scaling\n"
@@ -596,6 +598,16 @@ HRESULT WINAPI DirectDrawCreate(GUID FAR* lpGUID, LPDIRECTDRAW FAR* lplpDD, IUnk
         This->devmode = FALSE;
     }
 
+    GetPrivateProfileStringA("ddraw", "vsync", "FALSE", tmp, sizeof(tmp), ini_path);
+    if(tolower(tmp[0]) == 'y' || tolower(tmp[0]) == 't' || tmp[0] == '1')
+    {
+        This->vsync = TRUE;
+    }
+    else
+    {
+        This->vsync = FALSE;
+    }
+
     This->Ref = 0;
     ddraw_AddRef(This);
 
diff --git a/main.h b/main.h
index 12abe93..59d7348 100644
--- a/main.h
+++ b/main.h
@@ -73,6 +73,7 @@ typedef struct IDirectDrawImpl
     BOOL adjmouse;
     BOOL mhack;
     BOOL devmode;
+    BOOL vsync;
 
 } IDirectDrawImpl;
 
diff --git a/render.c b/render.c
index 9c38805..8530003 100644
--- a/render.c
+++ b/render.c
@@ -34,6 +34,24 @@ DWORD WINAPI render_main(void)
     hRC = wglCreateContext( ddraw->render.hDC );
     wglMakeCurrent( ddraw->render.hDC, hRC );
 
+    char *glext = (char *)glGetString(GL_EXTENSIONS);
+
+    if(glext && strstr(glext, "WGL_EXT_swap_control"))
+    {
+        BOOL (APIENTRY *wglSwapIntervalEXT)(int) = (BOOL (APIENTRY *)(int))wglGetProcAddress("wglSwapIntervalEXT");
+        if(wglSwapIntervalEXT)
+        {
+            if(ddraw->vsync)
+            {
+                wglSwapIntervalEXT(1);
+            }
+            else
+            {
+                wglSwapIntervalEXT(0);
+            }
+        }
+    }
+
     DWORD tick_start;
     DWORD tick_end;
     DWORD frame_len;