adding box2d as submodule

Author: hannojg

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "externals/box2d"]
+	path = externals/box2d
+	url = [email protected]:erincatto/box2d.git

cpp/FastCryptoHostObject.cpp

@@ -1,6 +1,13 @@
 #include "FastCryptoHostObject.h"
 #include <jsi/jsi.h>
 
+#include <box2d/box2d/b2_math.h>
+#include <box2d/box2d/b2_world.h>
+#include <box2d/box2d/b2_body.h>
+#include <box2d/box2d/b2_polygon_shape.h>
+#include <box2d/box2d/b2_fixture.h>
+#include <android/log.h>
+
 namespace margelo {
 
 using namespace facebook;
@@ -14,6 +21,48 @@ std::vector<jsi::PropNameID> FastCryptoHostObject::getPropertyNames(jsi::Runtime
 jsi::Value FastCryptoHostObject::get(jsi::Runtime& runtime, const jsi::PropNameID& propNameId) {
   auto propName = propNameId.utf8(runtime);
 
+	b2Vec2 gravity(0.0f, -10.0f);
+	b2World world(gravity);
+	__android_log_print(ANDROID_LOG_DEBUG, "overscore", "createWorld");
+
+	// ground box
+	b2BodyDef groundBodyDef;
+	groundBodyDef.position.Set(0.0f, -10.0f);
+	b2Body* groundBody = world.CreateBody(&groundBodyDef);
+	// ground polygon
+	b2PolygonShape groundBox;
+	groundBox.SetAsBox(50.0f, 10.0f);
+	groundBody->CreateFixture(&groundBox, 0.0f);
+
+	// dynamic body
+	b2BodyDef bodyDef;
+	bodyDef.type = b2_dynamicBody;
+	bodyDef.position.Set(0.0f, 4.0f);
+	b2Body* body = world.CreateBody(&bodyDef);
+	//attach
+	b2PolygonShape dynamicBox;
+	dynamicBox.SetAsBox(1.0f, 1.0f);
+
+	b2FixtureDef fixtureDef;
+	fixtureDef.shape = &dynamicBox;
+	fixtureDef.density = 1.0f;
+	fixtureDef.friction = 0.3f;
+
+	body->CreateFixture(&fixtureDef);
+
+
+	// simulating the world
+	float timeStep = 1.0f / 60.0f;
+	int32 velocityIterations = 6;
+	int32 positionIterations = 2;
+	for (int32 i = 0; i < 60; ++i)
+	{
+		world.Step(timeStep, velocityIterations, positionIterations);
+		b2Vec2 position = body->GetPosition();
+		float angle = body->GetAngle();
+		__android_log_print(ANDROID_LOG_DEBUG, "overscore","%4.2f %4.2f %4.2f\n", position.x, position.y, angle);
+	}
+
 	throw std::runtime_error("Not yet implemented!");
 }
 

externals/box2d

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+cp