From e7073dc0373cbbd07997c87758dd6a0918e82a28 Mon Sep 17 00:00:00 2001
From: Vincent Pelletier <plr.vincent@gmail.com>
Date: Wed, 3 May 2017 02:47:29 +0000
Subject: [PATCH] ALL: Add an option to control dirty rectangless TinyGL
 optimisation

Exposed to command line via --[no-]dirtyrects.
As dirty rectangles make the workload vary a lot between frames, it makes
performance regressions harder to spot. Disabling it produces lower, but
much more regular FPS counts.
---
 base/commandLine.cpp         | 6 ++++++
 engines/grim/gfx_tinygl.cpp  | 2 ++
 engines/myst3/gfx_tinygl.cpp | 2 ++
 3 files changed, 10 insertions(+)

diff --git a/base/commandLine.cpp b/base/commandLine.cpp
index 5a5e50da8a0..85e8763814f 100644
--- a/base/commandLine.cpp
+++ b/base/commandLine.cpp
@@ -126,6 +126,8 @@ static const char HELP_STRING[] =
 	"  --aspect-ratio           Enable aspect ratio correction\n"
 	"  --bpp=NUM                Select number of bits per pixel, 0 (auto-detect), 16, 32\n"
 	"                           (default: 0) (only supported by software renderer)\n"
+	"  --[no-]dirtyrects        Enable dirty rectangles optimisation in software renderer\n"
+	"                           (default: enabled)\n"
 #ifdef ENABLE_EVENTRECORDER
 	"  --record-mode=MODE       Specify record mode for event recorder (record, playback,\n"
 	"                           passthrough [default])\n"
@@ -171,6 +173,7 @@ void registerDefaults() {
 	ConfMan.registerDefault("filtering", false);
 	ConfMan.registerDefault("show_fps", false);
 	ConfMan.registerDefault("aspect_ratio", false);
+	ConfMan.registerDefault("dirtyrects", true);
 	ConfMan.registerDefault("bpp", 0);
 
 	// Sound & Music
@@ -514,6 +517,9 @@ Common::String parseCommandLine(Common::StringMap &settings, int argc, const cha
 			DO_LONG_OPTION_INT("bpp")
 			END_OPTION
 
+			DO_LONG_OPTION_BOOL("dirtyrects")
+			END_OPTION
+
 			DO_LONG_OPTION("gamma")
 			END_OPTION
 // ResidualVM specific start
diff --git a/engines/grim/gfx_tinygl.cpp b/engines/grim/gfx_tinygl.cpp
index e9ca6d3e7f5..f3dec686c8e 100644
--- a/engines/grim/gfx_tinygl.cpp
+++ b/engines/grim/gfx_tinygl.cpp
@@ -20,6 +20,7 @@
  *
  */
 
+#include "common/config-manager.h"
 #include "common/endian.h"
 #include "common/system.h"
 
@@ -94,6 +95,7 @@ byte *GfxTinyGL::setupScreen(int screenW, int screenH, bool fullscreen) {
 	_pixelFormat = buf.getFormat();
 	_zb = new TinyGL::FrameBuffer(screenW, screenH, buf);
 	TinyGL::glInit(_zb, 256);
+	tglEnableDirtyRects(ConfMan.getBool("dirtyrects"));
 
 	_storedDisplay.create(_pixelFormat, _gameWidth * _gameHeight, DisposeAfterUse::YES);
 	_storedDisplay.clear(_gameWidth * _gameHeight);
diff --git a/engines/myst3/gfx_tinygl.cpp b/engines/myst3/gfx_tinygl.cpp
index 3e39fb346b3..ce3980a3d80 100644
--- a/engines/myst3/gfx_tinygl.cpp
+++ b/engines/myst3/gfx_tinygl.cpp
@@ -26,6 +26,7 @@
 #undef ARRAYSIZE
 #endif
 
+#include "common/config-manager.h"
 #include "common/rect.h"
 #include "common/textconsole.h"
 
@@ -71,6 +72,7 @@ void TinyGLRenderer::init() {
 	Graphics::PixelBuffer screenBuffer = _system->getScreenPixelBuffer();
 	_fb = new TinyGL::FrameBuffer(kOriginalWidth, kOriginalHeight, screenBuffer);
 	TinyGL::glInit(_fb, 512);
+	tglEnableDirtyRects(ConfMan.getBool("dirtyrects"));
 
 	tglMatrixMode(TGL_PROJECTION);
 	tglLoadIdentity();