Simple coroutine support

Author: OverShifted

OverEngine/src/OverEngine/Core/Time/Time.h

@@ -8,18 +8,22 @@ namespace OverEngine
 	{
 	protected:
 		Time() = default;
+
 	public:
 		Time(const Time&) = delete;
 		Time& operator=(const Time&) = delete;
+
 	public:
 		inline static float GetTime() { return s_Instance->GetTimeImpl(); }
 		inline static double GetTimeDouble() { return s_Instance->GetTimeDoubleImpl(); }
 
 		inline static TimeStep GetDeltaTime() { return m_DeltaTime; }
 		inline static void RecalculateDeltaTime() { float time = GetTime(); m_DeltaTime = time - m_LastFrameTime; m_LastFrameTime = time; }
+
 	protected:
 		virtual float GetTimeImpl() = 0;
 		virtual double GetTimeDoubleImpl() = 0;
+
 	private:
 		static Time* s_Instance;
 

OverEngine/src/OverEngine/Scripting/Wren.cpp

@@ -9,7 +9,9 @@ namespace WrenSources
 	#include "Wren/keycodes.wren.inc"
 	#include "Wren/lib.wren.inc"
 	#include "Wren/math.wren.inc"
+	#include "Wren/scheduler.wren.inc"
 	#include "Wren/script.wren.inc"
+	#include "Wren/time.wren.inc"
 }
 
 namespace OverEngine
@@ -48,6 +50,8 @@ namespace OverEngine
 			WREN_MOD(lib)
 			WREN_MOD(math)
 			WREN_MOD(script)
+			WREN_MOD(scheduler)
+			WREN_MOD(time)
 
 			std::string path(mod);
 			path += ".wren";
@@ -93,6 +97,9 @@ namespace OverEngine
 	{
 		wrenEnsureSlots(m_VM->GetRaw(), 1);
 		wrenGetVariable(m_VM->GetRaw(), moduleName, className, 0);
+
+		OE_CORE_ASSERT(wrenGetSlotType(m_VM->GetRaw(), 0) != WREN_TYPE_NULL, "Wren class is null! Maybe it failed to compile.");
+
 		m_ClassHandle = wrenGetSlotHandle(m_VM->GetRaw(), 0);
 		m_ConstructorHandle = wrenMakeCallHandle(m_VM->GetRaw(), "new(_)");
 	}

OverEngine/src/OverEngine/Scripting/Wren.h

@@ -88,6 +88,8 @@ namespace OverEngine
 	private:
 		Ref<Wren> m_VM;
 		WrenHandle* m_ClassHandle;
+
+		// TODO: move to Wren
 		WrenHandle* m_ConstructorHandle;
 	};
 

OverEngine/src/OverEngine/Scripting/WrenBindings.cpp

@@ -8,6 +8,8 @@
 #include "OverEngine/Scene/Components.h"
 #include "OverEngine/Scene/TransformComponent.h"
 
+#include "OverEngine/Core/Time/Time.h"
+
 #define WRENPP_BIND_STATIC(f, sig) .bindFunction<decltype(&f), &f>(true, sig)
 #define WRENPP_BIND_STATIC_EXACT(f, args) .bindFunction<decltype(&f), &f>(true, #f "(" args ")")
 
@@ -65,6 +67,16 @@ namespace OverEngine
 		{
 			entity.GetComponent<RigidBody2DComponent>().RigidBody->ApplyLinearImpulseToCenter(impulse);
 		}
+
+		double Time_time()
+		{
+			return Time::GetTimeDouble();
+		}
+
+		double Time_deltaTime()
+		{
+			return Time::GetDeltaTime().GetSeconds();
+		}
 	}
 
 	void Wren::InitializeBindings()
@@ -119,6 +131,13 @@ namespace OverEngine
 			.endClass()
 		.endModule();
 
+		m_VM.beginModule("time")
+			.beginClass("Time")
+				WRENPP_BIND_STATIC(Time_time, "time")
+				WRENPP_BIND_STATIC(Time_deltaTime, "deltaTime")
+			.endClass()
+		.endModule();
+
 		LoadModule("lib");
 	}
 }

OverEngine/src/Wren/scheduler.wren

@@ -0,0 +1,57 @@
+import "time" for Time
+
+class WaitSeconds {
+	construct new(seconds) {
+		_seconds = seconds
+	}
+
+	seconds { _seconds }
+}
+
+class Schedule {
+	construct new(resumeTime, fiber) {
+		_resumeTime = resumeTime
+		_fiber = fiber
+	}
+
+	resumeTime { _resumeTime }
+	fiber { _fiber }
+}
+
+class Scheduler {
+	static init() {
+		__scheduled = []
+	} 
+
+	static add(fn) {
+		addFiber(Fiber.new { fn.call() })
+	}
+
+	static addFiber(fib) {
+		var result = fib.call()
+
+		if (!fib.isDone) {
+			if (!(result is WaitSeconds)) {
+				Fiber.abort("result is not of type 'WaitSeconds'.")
+			}
+
+			var resumeTime = Time.time + result.seconds
+			__scheduled.add(Schedule.new(resumeTime, fib))
+		}
+	}
+
+	static poll() {
+		var i = __scheduled.count - 1
+		while (i >= 0) {
+			var schedule = __scheduled[i]
+			if (schedule.resumeTime <= Time.time) {
+				addFiber(__scheduled.removeAt(i).fiber)
+			}
+			i  = i - 1
+		}
+	}
+
+	static count { __scheduled.count }
+}
+
+Scheduler.init()

OverEngine/src/Wren/time.wren

@@ -0,0 +1,4 @@
+class Time {
+	foreign static time
+	foreign static deltaTime
+}

Sandbox/src/wren/scripts.wren

@@ -3,6 +3,7 @@ import "keycodes" for KeyCode
 import "input" for Input
 import "math" for Math, Vector2
 import "components" for RigidBody2DComponent
+import "scheduler" for Scheduler, WaitSeconds
 
 class Player is Script {
 	construct new(e) {
@@ -12,6 +13,16 @@ class Player is Script {
 	onCreate() {
 		System.print("My name is '%(entity.name)'")
 		_rb = entity.getComponent(RigidBody2DComponent)
+
+		Scheduler.add {
+			var i = 10
+			while (i >= 0) {
+				System.print("%(this.name)'s countdown: %(i)")
+				Fiber.yield(WaitSeconds.new(0.1))
+				i = i - 1
+			}
+			System.print("Boom!")
+		}
 	}
 
 	onUpdate(delta) {
@@ -24,7 +35,8 @@ class Player is Script {
 
 		_rb.applyLinearImpulseToCenter(impulse * 20 * delta)
 
-		System.print("%(Input.mouseX) %(Input.mouseY) %(Input.mousePosition)")
+		// System.print("%(Input.mouseX) %(Input.mouseY) %(Input.mousePosition)")
+		Scheduler.poll()
 	}
 }