From: Daniel Karbach <daniel.karbach@localhorst.tv>
Date: Mon, 23 Dec 2013 20:55:15 +0000 (+0100)
Subject: force based movement
X-Git-Url: https://git.localhorst.tv/?a=commitdiff_plain;h=699437a474de8b87ccb6749d44adf740e680d620;p=space.git

force based movement
---

diff --git a/src/app/Application.cpp b/src/app/Application.cpp
index 488b952..5820c57 100644
--- a/src/app/Application.cpp
+++ b/src/app/Application.cpp
@@ -13,7 +13,7 @@ Application::Application(Canvas &c)
 , cam(c.Size(), focus.Pos())
 , last(SDL_GetTicks())
 , running(false) {
-	controlled = univ.AddEntity(Entity());
+	controlled = univ.AddShip(Ship());
 }
 
 
@@ -142,7 +142,8 @@ void Application::OnKeyUp(const SDL_KeyboardEvent &e) {
 
 void Application::Update(int dt) {
 	const float delta = dt / 1e3;
-	controlled->acc = Vector<float>(control * 10);
+	controlled->rotThrottle = control.x;
+	controlled->linThrottle = -control.y;
 	cam.Update(delta);
 	univ.Update(delta);
 	focus.SetSpeed(500 / cam.Zoom());
@@ -172,10 +173,14 @@ void Application::Render() {
 	canvas.Cross(cam.ToScreen(focus.Pos()), 15);
 
 	canvas.SetColor(entityColor);
-	for (const Entity &e : univ.Entities()) {
-		canvas.Cross(
-			cam.ToScreen(Vector<float>(e.area * univ.areaSize) + e.pos),
-			10);
+	for (const Ship &s : univ.Ships()) {
+		const Vector<float> direction = s.Dir();
+		const Vector<int> position = cam.ToScreen(Vector<float>(s.area * univ.areaSize) + s.pos);
+		const Vector<int> nose = position + Vector<int>(direction * 15.0f);
+		const Vector<int> left = position + Vector<int>((Rotate90(direction) * 8.0f) - (direction * 4.0f));
+		const Vector<int> right = position + Vector<int>((Rotate270(direction) * 8.0f) - (direction * 4.0f));
+		canvas.Line(position, nose);
+		canvas.Quad(nose, left, position, right);
 	}
 }
 
diff --git a/src/app/Application.h b/src/app/Application.h
index b5f0a6b..7e3d91b 100644
--- a/src/app/Application.h
+++ b/src/app/Application.h
@@ -12,7 +12,7 @@
 namespace space {
 
 class Canvas;
-class Entity;
+class Ship;
 
 class Application {
 
@@ -41,7 +41,7 @@ private:
 	Moveable<float> focus;
 	Camera cam;
 
-	Entity *controlled;
+	Ship *controlled;
 	Vector<int> control;
 
 	Uint32 last;
diff --git a/src/entity/Entity.h b/src/entity/Entity.h
deleted file mode 100644
index eb95331..0000000
--- a/src/entity/Entity.h
+++ /dev/null
@@ -1,30 +0,0 @@
-#ifndef SPACE_ENTITY_H_
-#define SPACE_ENTITY_H_
-
-#include "../graphics/Vector.h"
-
-
-namespace space {
-
-class Entity {
-
-public:
-	constexpr Entity() { }
-
-public:
-	Vector<int> area;
-	Vector<float> pos;
-	Vector<float> vel;
-	Vector<float> acc;
-
-public:
-	void Update(float delta) {
-		pos += vel * delta;
-		vel += acc * delta;
-	}
-
-};
-
-}
-
-#endif
diff --git a/src/entity/Ship.h b/src/entity/Ship.h
index 8bcc4bc..a21f4b1 100644
--- a/src/entity/Ship.h
+++ b/src/entity/Ship.h
@@ -1,12 +1,52 @@
 #ifndef SPACE_SHIP_H_
 #define SPACE_SHIP_H_
 
+#include "../graphics/Vector.h"
+
+#include <cmath>
+
 
 namespace space {
 
 class Ship {
 
-private:
+public:
+	constexpr Ship() { }
+
+public:
+	float mass = 1;
+	float linForce = 1;
+	float revForce = 1;
+	float rotForce = 1;
+
+	Vector<int> area;
+
+	Vector<float> pos;
+	Vector<float> vel;
+	Vector<float> Dir() const {
+		return Vector<float>::FromPolar(1, orient);
+	}
+	Vector<float> Acc() const {
+		float force = (linThrottle < 0 ? revForce : linForce);
+		return Dir() * force / mass * linThrottle;
+	}
+
+	float orient = 0;
+	float rotVel = 0;
+	float RotAcc() const {
+		return rotForce / mass * rotThrottle;
+	}
+
+	float linThrottle = 0;
+	float rotThrottle = 0;
+
+public:
+	void Update(float delta) {
+		rotVel += RotAcc() * delta;
+		orient += rotVel * delta;
+		vel += Acc() * delta;
+		pos += vel * delta;
+	}
 
 };
 
diff --git a/src/graphics/Canvas.cpp b/src/graphics/Canvas.cpp
index e4befc0..93e3f21 100644
--- a/src/graphics/Canvas.cpp
+++ b/src/graphics/Canvas.cpp
@@ -97,12 +97,12 @@ void Canvas::Cross(Vector<int> pos, int extent) {
 
 void Canvas::Triangle(Vector<int> v1, Vector<int> v2, Vector<int> v3) {
 	SDL_Point points[4] = { v1, v2, v3, v1 };
-	SDL_RenderDrawPoints(canv, points, 4);
+	SDL_RenderDrawLines(canv, points, 4);
 }
 
 void Canvas::Quad(Vector<int> v1, Vector<int> v2, Vector<int> v3, Vector<int> v4) {
 	SDL_Point points[5] = { v1, v2, v3, v4, v1 };
-	SDL_RenderDrawPoints(canv, points, 5);
+	SDL_RenderDrawLines(canv, points, 5);
 }
 
 
diff --git a/src/graphics/Vector.h b/src/graphics/Vector.h
index 34d8297..992ba1e 100644
--- a/src/graphics/Vector.h
+++ b/src/graphics/Vector.h
@@ -2,6 +2,7 @@
 #define SPACE_VECTOR_H_
 
 #include <algorithm>
+#include <cmath>
 #include <ostream>
 #include <SDL.h>
 
@@ -18,6 +19,12 @@ public:
 	template<class Other>
 	constexpr Vector(Vector<Other> other) : x(other.x), y(other.y) { }
 
+	static Vector<Scalar> FromPolar(Scalar rad, Scalar az) {
+		return Vector<Scalar>(rad * std::cos(az), rad * std::sin(az));
+	}
+
+	static constexpr Vector<Scalar> unit45 = Vector<Scalar>(-0.7071, 0.7071);
+
 public:
 	Vector<Scalar> &operator +=(Vector<Scalar> other) {
 		x += other.x;
@@ -43,6 +50,9 @@ public:
 
 };
 
+template<class T>
+constexpr Vector<T> Vector<T>::unit45;
+
 /// specialization with same layout as SDL_Point
 template<>
 class Vector<int>
@@ -132,6 +142,29 @@ constexpr bool operator !=(Vector<Scalar> lhs, Vector<Scalar> rhs) {
 }
 
 
+template<class Scalar>
+constexpr Scalar Dot(Vector<Scalar> lhs, Vector<Scalar> rhs) {
+	return (lhs.x * rhs.x) + (lhs.y * rhs.y);
+}
+template<class Scalar>
+constexpr Scalar Length(Vector<Scalar> v) {
+	return std::sqrt(Dot(v, v));
+}
+
+template<class Scalar>
+constexpr Vector<Scalar> Rotate90(Vector<Scalar> v) {
+	return Vector<Scalar>(-v.y, v.x);
+}
+template<class Scalar>
+constexpr Vector<Scalar> Rotate180(Vector<Scalar> v) {
+	return -v;
+}
+template<class Scalar>
+constexpr Vector<Scalar> Rotate270(Vector<Scalar> v) {
+	return Vector<Scalar>(v.y, -v.x);
+}
+
+
 template<class Scalar>
 inline std::ostream &operator <<(std::ostream &out, Vector<Scalar> v) {
 	return out << '<' << v.x << ',' << v.y << '>';
diff --git a/src/world/Universe.cpp b/src/world/Universe.cpp
index 9f9efe6..6f2e5c1 100644
--- a/src/world/Universe.cpp
+++ b/src/world/Universe.cpp
@@ -18,30 +18,30 @@ Universe::~Universe() {
 }
 
 
-Entity *Universe::AddEntity(const Entity &e) {
-	entities.emplace_back(e);
-	return &entities.back();
+Ship *Universe::AddShip(const Ship &s) {
+	ships.emplace_back(s);
+	return &ships.back();
 }
 
 
 void Universe::Update(float delta) {
-	for (Entity &e : entities) {
-		e.Update(delta);
-		while (e.pos.x > areaSize.x) {
-			e.pos.x -= areaSize.x;
-			++e.area.x;
+	for (Ship &s : ships) {
+		s.Update(delta);
+		while (s.pos.x > areaSize.x) {
+			s.pos.x -= areaSize.x;
+			++s.area.x;
 		}
-		while (e.pos.x < 0) {
-			e.pos.x += areaSize.x;
-			--e.area.x;
+		while (s.pos.x < 0) {
+			s.pos.x += areaSize.x;
+			--s.area.x;
 		}
-		while (e.pos.y > areaSize.y) {
-			e.pos.y -= areaSize.y;
-			++e.area.y;
+		while (s.pos.y > areaSize.y) {
+			s.pos.y -= areaSize.y;
+			++s.area.y;
 		}
-		while (e.pos.y < 0) {
-			e.pos.y += areaSize.y;
-			--e.area.y;
+		while (s.pos.y < 0) {
+			s.pos.y += areaSize.y;
+			--s.area.y;
 		}
 	}
 }
diff --git a/src/world/Universe.h b/src/world/Universe.h
index 55b86f9..18db4dc 100644
--- a/src/world/Universe.h
+++ b/src/world/Universe.h
@@ -1,7 +1,7 @@
 #ifndef SPACE_UNIVERSE_H_
 #define SPACE_UNIVERSE_H_
 
-#include "../entity/Entity.h"
+#include "../entity/Ship.h"
 #include "../graphics/Vector.h"
 
 #include <list>
@@ -67,14 +67,14 @@ public:
 	Area AreaAt(Vector<int> coords) const { return Area(*this, coords); }
 
 public:
-	Entity *AddEntity(const Entity &);
-	const std::list<Entity> &Entities() const { return entities; }
+	Ship *AddShip(const Ship &);
+	const std::list<Ship> &Ships() const { return ships; }
 
 public:
 	void Update(float deltaT);
 
 private:
-	std::list<Entity> entities;
+	std::list<Ship> ships;
 
 };