From 4fa0d0651a22fa943455420dd69923b0d1897f6f Mon Sep 17 00:00:00 2001
From: harry <hrosen2016@gmail.com>
Date: Wed, 31 Jan 2024 07:08:08 -0500
Subject: [PATCH] Added vsync timer logic to Qt OpenGL video driver.

---
 src/drivers/Qt/ConsoleViewerGL.cpp | 24 ++++++++++++++++++++++++
 src/drivers/Qt/ConsoleViewerGL.h   |  4 +++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/drivers/Qt/ConsoleViewerGL.cpp b/src/drivers/Qt/ConsoleViewerGL.cpp
index b6210272..3f203519 100644
--- a/src/drivers/Qt/ConsoleViewerGL.cpp
+++ b/src/drivers/Qt/ConsoleViewerGL.cpp
@@ -86,6 +86,12 @@ ConsoleViewGL_t::ConsoleViewGL_t(QWidget *parent)
 	setFocusPolicy(Qt::StrongFocus);
 	//setAttribute(Qt::WA_OpaquePaintEvent);
 
+	drawTimer = new QTimer(this);
+	drawTimer->setInterval(14);
+	drawTimer->setSingleShot(true);
+	drawTimer->setTimerType(Qt::PreciseTimer);
+	connect(drawTimer, &QTimer::timeout, this, &ConsoleViewGL_t::onDrawSignal);
+
 	localBufSize = (4 * GL_NES_WIDTH) * (4 * GL_NES_HEIGHT) * sizeof(uint32_t);
 
 	localBuf = (uint32_t*)malloc( localBufSize );
@@ -137,6 +143,8 @@ ConsoleViewGL_t::ConsoleViewGL_t(QWidget *parent)
 ConsoleViewGL_t::~ConsoleViewGL_t(void)
 {
 	//printf("Destroying GL Viewport\n");
+	drawTimer->stop();
+	delete drawTimer;
 
 	if ( localBuf )
 	{
@@ -566,6 +574,22 @@ void  ConsoleViewGL_t::getNormalizedCursorPos( double &x, double &y )
 void ConsoleViewGL_t::renderFinished(void)
 {
 	videoBufferSwapMark();
+
+	// Schedule draw timing inline with vsync
+	drawTimer->start();
+}
+
+void ConsoleViewGL_t::queueRedraw(void)
+{
+	if (!drawTimer->isActive())
+	{
+		update();
+	}
+}
+
+void ConsoleViewGL_t::onDrawSignal(void)
+{
+	update();
 }
 
 void ConsoleViewGL_t::paintGL(void)
diff --git a/src/drivers/Qt/ConsoleViewerGL.h b/src/drivers/Qt/ConsoleViewerGL.h
index 12768ff7..22d92ee9 100644
--- a/src/drivers/Qt/ConsoleViewerGL.h
+++ b/src/drivers/Qt/ConsoleViewerGL.h
@@ -22,7 +22,7 @@ class ConsoleViewGL_t : public QOpenGLWidget, protected QOpenGLFunctions, public
 
 		int  init(void);
 		void reset(void);
-		void queueRedraw(void){ update(); };
+		void queueRedraw(void);
 		int  driver(void){ return VIDEO_DRIVER_OPENGL; };
 
 		void transfer2LocalBuffer(void);
@@ -90,6 +90,7 @@ class ConsoleViewGL_t : public QOpenGLWidget, protected QOpenGLFunctions, public
 	unsigned int  textureType;
 	unsigned int  mouseButtonMask;
 	QColor *bgColor;
+	QTimer *drawTimer;
 
 	uint32_t  *localBuf;
 	uint32_t   localBufSize;
@@ -97,5 +98,6 @@ class ConsoleViewGL_t : public QOpenGLWidget, protected QOpenGLFunctions, public
 	private slots:
 		void cleanupGL(void);
 		void renderFinished(void);
+		void onDrawSignal();
 };