Timing package

main.go

@@ -11,15 +11,16 @@ import (
 	"github.com/bloeys/nmage/input"
 	"github.com/bloeys/nmage/logging"
 	"github.com/bloeys/nmage/shaders"
+	"github.com/bloeys/nmage/timing"
 	"github.com/go-gl/gl/v4.1-core/gl"
 	"github.com/inkyblackness/imgui-go/v4"
 	"github.com/veandco/go-sdl2/sdl"
 )
 
 //TODO:
-//Timing and deltatime
 //Make a window/engine class
 //Mesh class
+//Object
 //Abstract UI
 //Textures
 //Proper Asset loading
@@ -117,13 +118,18 @@ func main() {
 	simpleShader.SetUnifVec3("lightColor1", &lightColor1)
 
 	//Game loop
+	timing.Init()
 	for isRunning {
 
+		timing.FrameStarted()
+
 		handleInputs()
 		runGameLogic()
 		draw()
 
-		sdl.Delay(17)
+		timing.FrameEnded()
+
+		window.SetTitle(fmt.Sprintf("FPS: %.0f; Elapsed: %v", 1/timing.DT(), timing.ElapsedTime()))
 	}
 }
 

timing/timing.go

@@ -0,0 +1,31 @@
+package timing
+
+import "time"
+
+var (
+	dt         float32 = 0.01
+	frameStart time.Time
+	startTime  time.Time
+)
+
+func Init() {
+	startTime = time.Now()
+}
+
+func FrameStarted() {
+	frameStart = time.Now()
+}
+
+func FrameEnded() {
+	dt = float32(time.Since(frameStart).Seconds())
+}
+
+//DT is frame deltatime in milliseconds
+func DT() float32 {
+	return dt
+}
+
+//ElapsedTime is time since game start
+func ElapsedTime() uint64 {
+	return uint64(time.Since(startTime).Seconds())
+}