From 79f0d8c1561efc7221621e2024d08f8fd6061204 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sun, 31 Mar 2013 16:04:28 +0200
Subject: [PATCH] add option to slep some time during each frame

---
 gltest.cpp | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/gltest.cpp b/gltest.cpp
index ff413af..fbe79a8 100644
--- a/gltest.cpp
+++ b/gltest.cpp
@@ -45,15 +45,19 @@ static double getTime()
 	return tp.tv_sec + 1e-9 * tp.tv_nsec;
 }
 
-static void drawRect(GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2)
+static void rectVertices(GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2)
 {
-	glVertex2f(x1, y1); glVertex2f(x2, y1); glVertex2f(x2, y2); glVertex2f(x1, y2);
+	glVertex2f(x1, y1);
+	glVertex2f(x2, y1);
+	glVertex2f(x2, y2);
+	glVertex2f(x1, y2);
 }
 
 // the window
 class TearTestWindow : public GLWindow {
 public:
-	TearTestWindow(bool overdraw, bool copy) : GLWindow(XOpenDisplay(0), createGLBackend()), overdraw(overdraw), copy(copy), boxPos(0), boxDirection(1)
+	TearTestWindow(bool overdraw, bool copy, int sleep_time) : GLWindow(XOpenDisplay(0), createGLBackend()),
+		overdraw(overdraw), copy(copy), sleep_time(sleep_time), boxPos(0), boxDirection(1)
 	{}
 
 	void setSwapInterval(int i) {
@@ -137,7 +141,7 @@ protected:
 			// clear manually
 			glBegin(GL_QUADS);
 			glColor3f(0.0f, 0.0f, 0.0f);
-			drawRect(0, 0, 1, 1);
+			rectVertices(0, 0, 1, 1);
 			glEnd();
 		}
 		else {
@@ -147,8 +151,9 @@ protected:
 		profilerTick(stateDraw);
 		glBegin(GL_QUADS);
 		glColor3f(0.8f, 1.0f, 0.75f);
-		drawRect(boxPos, 0, boxPos+boxWidth, 1);
+		rectVertices(boxPos, 0, boxPos+boxWidth, 1);
 		glEnd();
+		usleep(sleep_time*1000);
 		//////////////////////////////////////////////
 		profilerTick(statePresent);
 		if (copy) {
@@ -178,9 +183,11 @@ protected:
 
 private:
 	bool overdraw, copy;
+	int sleep_time;
+	// animation control
 	double lastFrame;
 	GLfloat boxPos, boxDirection;
-	// FPS
+	// FPS, profiler
 	double lastDisplay, lastProfile;                 
 	int framect, curState;
 	double stateTime[numProfilerStates];
@@ -195,6 +202,7 @@ int main(int argc, char ** argv)
 		("swap-interval,i", po::value<int>(), "set swap interval")
 		("copy,c", "copy to front buffer (instead of performing a buffer swap)")
 		("overdraw,o", "overdraw previous image (instead of calling glClear)")
+		("sleep,s", po::value<int>()->default_value(0), "Number of milliseconds to sleap in each frame (in the drawing phase)")
 	;
 	po::variables_map vm;
 	po::store(po::parse_command_line(argc, argv, desc), vm);
@@ -206,7 +214,7 @@ int main(int argc, char ** argv)
 	}
 
 	// actual program
-	TearTestWindow w(vm.count("overdraw"), vm.count("copy"));
+	TearTestWindow w(vm.count("overdraw"), vm.count("copy"), vm["sleep"].as<int>());
 	w.open(800, 600);
 	if (vm.count("swap-interval"))
 		w.setSwapInterval(vm["swap-interval"].as<int>());
-- 
2.30.2