Gaphics: Make frame skip a config option

When using something like Valgrind that will run
mkxp 20 times slower than normal, frame skip will
make the redraw loop completely grind to a halt.
Set 'frameSkip' to false in the config to
avert this.

README.md

@@ -81,6 +81,7 @@ mkxp reads configuration data from the file "mkxp.conf" contained in the current
 | defScreenW       | int         | 640     | Width the game window starts in (this is **not** the game resolution)           |
 | defScreenH       | int         | 480     | Height the game window starts in                                                |
 | fixedFramerate   | int         | 0       | FPS will be fixed to this amount. Ignored if 0.                                 |
+| frameSkip        | bool        | true    | Don't skip frames to catch up (useful eg. with Valgrind)                        |
 | solidFonts       | bool        | false   | Don't use alpha blending for fonts                                              |
 | gameFolder       | string      | "."     | mkxp will look for all game related files here                                  |
 | allowSymlinks    | bool        | false   | Allow symlinks to be followed in the game folder.                               |

src/config.cpp

@@ -38,6 +38,7 @@ Config::Config()
       defScreenW(640),
       defScreenH(480),
       fixedFramerate(0),
+      frameSkip(true),
       solidFonts(false),
       gameFolder("."),
       allowSymlinks(false)
@@ -58,6 +59,7 @@ void Config::read()
 	READ_VAL(defScreenW, Int);
 	READ_VAL(defScreenH, Int);
 	READ_VAL(fixedFramerate, Int);
+	READ_VAL(frameSkip, Bool);
 	READ_VAL(solidFonts,  Bool);
 	READ_VAL(gameFolder, ByteArray);
 	READ_VAL(allowSymlinks, Bool);

src/config.h

@@ -41,6 +41,7 @@ struct Config
 	int defScreenH;
 
 	int fixedFramerate;
+	bool frameSkip;
 
 	bool solidFonts;
 

src/graphics.cpp

@@ -582,6 +582,8 @@ void Graphics::update()
 		return;
 
 	if (p->fpsLimiter.frameSkipRequired())
+	{
+		if (p->threadData->config.frameSkip)
 		{
 			/* Skip frame */
 			p->fpsLimiter.delay();
@@ -590,6 +592,12 @@ void Graphics::update()
 
 			return;
 		}
+		else
+		{
+			/* Just reset frame adjust counter */
+			p->fpsLimiter.resetFrameAdjust();
+		}
+	}
 
 	p->checkResize();
 	p->redrawScreen();