add framerate control (WIP)

src/window/Window.cpp

@@ -9,6 +9,8 @@
 
 #include <GL/glew.h>
 #include <GLFW/glfw3.h>
+#include <thread>
+#include <chrono>
 
 static debug::Logger logger("window");
 
@@ -20,6 +22,8 @@ uint Window::width = 0;
 uint Window::height = 0;
 int Window::posX = 0;
 int Window::posY = 0;
+int Window::framerate = -1;
+double Window::prevSwap = 0.0;
 bool Window::fullscreen = false;
 
 static util::ObjectsKeeper observers_keeper;
@@ -58,8 +62,7 @@ bool Window::isIconified() {
     return glfwGetWindowAttrib(window, GLFW_ICONIFIED);
 }
 
-bool Window::isFocused()
-{
+bool Window::isFocused() {
     return glfwGetWindowAttrib(window, GLFW_FOCUSED);
 }
 
@@ -182,7 +185,8 @@ int Window::initialize(DisplaySettings* settings){
         }
     }, true));
 
-    glfwSwapInterval(settings->vsync.get());
+    glfwSwapInterval(1);
+    setFramerate(settings->framerate.get());
     const GLubyte* vendor = glGetString(GL_VENDOR);
     const GLubyte* renderer = glGetString(GL_RENDERER);
     logger.info() << "GL Vendor: " << (char*)vendor;
@@ -281,8 +285,11 @@ void Window::setShouldClose(bool flag){
     glfwSetWindowShouldClose(window, flag);
 }
 
-void Window::swapInterval(int interval){
-    glfwSwapInterval(interval);
+void Window::setFramerate(int framerate) {
+    if ((framerate != -1) != (Window::framerate != -1)) {
+        glfwSwapInterval(framerate == -1);
+    }
+    Window::framerate = framerate;
 }
 
 void Window::toggleFullscreen(){
@@ -315,9 +322,16 @@ bool Window::isFullscreen() {
     return fullscreen;
 }
 
-void Window::swapBuffers(){
+void Window::swapBuffers() {
+    double currentTime = time();
+    if (framerate > 0 && currentTime - prevSwap < (1.0 / framerate)) {
+        std::cout << static_cast<int>((1.0/framerate - (currentTime-prevSwap))*1000) << std::endl;
+        std::this_thread::sleep_for(std::chrono::milliseconds(
+            static_cast<int>((1.0/framerate - (currentTime-prevSwap))*1000)));
+    }
     glfwSwapBuffers(window);
     Window::resetScissor();
+    prevSwap = time();
 }
 
 double Window::time() {