实现弹簧

ToyEngine/ToyEngine.vcxproj

@@ -31,6 +31,7 @@
     <ClInclude Include="src\Mesh.h" />
     <ClInclude Include="src\Model.h" />
     <ClInclude Include="src\Particle.h" />
+    <ClInclude Include="src\PhysicsManager.h" />
     <ClInclude Include="src\RenderPass.h" />
     <ClInclude Include="src\RenderPassContext.h" />
     <ClInclude Include="src\Shader.h" />
@@ -51,6 +52,7 @@
     <ClCompile Include="src\Mesh.cpp" />
     <ClCompile Include="src\Model.cpp" />
     <ClCompile Include="src\Particle.cpp" />
+    <ClCompile Include="src\PhysicsManager.cpp" />
     <ClCompile Include="src\RenderPass.cpp" />
     <ClCompile Include="src\Shader.cpp" />
     <ClCompile Include="src\World.cpp" />

ToyEngine/src/DemoWorld.cpp

@@ -22,12 +22,26 @@ DemoWorld::DemoWorld()
 	sponza->setScale(glm::vec3(2));
 
 	auto particle = std::make_shared<Particle>(10);
+	particle->setSpeed(glm::vec3(-1, 0, 0));
 	particle->setPosition({ 4, 5, 0 });
-	particle->addForce(std::make_shared<Force>(glm::vec3(0.f, -particle->getMass() * 9.8f, 0.f)));
+	//particle->addForce(std::make_shared<Force>(glm::vec3(0.f, -particle->getMass() * 9.8f, 0.f)));
+	auto particle2 = std::make_shared<Particle>(10, "Models/vampire/vampire.gltf");
+	particle2->setSpeed(glm::vec3(1, 0, 0));
+	particle2->setPosition({ 6, 5, 0 });
+	particle2->setScale(glm::vec3{ 0.4 });
+
+	auto particle3 = std::make_shared<Particle>(10);
+	particle3->setSpeed(glm::vec3(0, 1, 0));
+	particle3->setPosition({ 6, 7, 0 });
+
+	physicsManager.addSpring(particle, particle2, 2, 10, 0);
+	physicsManager.addSpring(particle2, particle3, 2, 10, 0);
 
 	addActor(actor);
 	addActor(actor2);
 	addActor(actor3);
 	addActor(sponza);
 	addActor(particle);
+	addActor(particle2);
+	addActor(particle3);
 }

ToyEngine/src/Particle.cpp

@@ -7,17 +7,28 @@ Particle::Particle(float mass)
 	, debugShader(gl, "Shaders/debug.vert", "Shaders/debug.frag")
 {
 	model = Model::createSphere(gl);
-	setScale(glm::vec3(0.4));
+	setScale(glm::vec3(0.2));
+}
+
+Particle::Particle(float mass, const std::string& path)
+	: Actor(path)
+	, mass(mass)
+	, debugShader(gl, "Shaders/debug.vert", "Shaders/debug.frag")
+{
 }
 
 void Particle::logicalTick(float deltaTime)
 {
+	resultantForce = glm::vec3(0);
+	for (auto& force : forces)
+		resultantForce += force->value;
+
 	auto pos = getPosition() + speed * deltaTime + 0.5f * resultantForce / mass * deltaTime * deltaTime;
 	speed += resultantForce / mass * deltaTime;
-	if (speed.y < 0 && pos.y < 0.4)
-	{
-		speed.y = -speed.y;
-	}
+	//if (speed.y < 0 && pos.y < 0.4)
+	//{
+	//	speed.y = -speed.y;
+	//}
 	setPosition(pos);
 }
 
@@ -48,7 +59,7 @@ void Particle::draw(const RenderPassContext& context, Shader& shader)
 		debugShader.use();
 		debugShader.setUniformValue("projection", *context.projection);
 		debugShader.setUniformValue("view", *context.view);
-		glm::mat4 modelMatrix = glm::translate(glm::mat4(1), getPosition()) * glm::scale(glm::mat4(1), getScale()) * glm::mat4_cast(getRotation());
+		glm::mat4 modelMatrix = glm::translate(glm::mat4(1), getPosition()) * glm::scale(glm::mat4(1), getScale()) * glm::mat4_cast(getRotation()) * glm::scale(glm::mat4(1), glm::vec3(glm::abs(resultantForce / mass)));
 		gl->BindVertexArray(vao);
 		for (auto& force : forces)
 		{
@@ -64,16 +75,24 @@ void Particle::draw(const RenderPassContext& context, Shader& shader)
 void Particle::addForce(std::shared_ptr<Force> force)
 {
 	forces.insert(force);
-	resultantForce += force->value;
 }
 
 void Particle::removeForce(std::shared_ptr<Force> force)
 {
 	forces.erase(force);
-	resultantForce -= force->value;
 }
 
 float Particle::getMass()
 {
 	return mass;
 }
+
+glm::vec3 Particle::getSpeed()
+{
+	return speed;
+}
+
+void Particle::setSpeed(const glm::vec3& speed)
+{
+	this->speed = speed;
+}

ToyEngine/src/Particle.h

@@ -12,12 +12,15 @@ class Particle : public Actor
 {
 public:
 	Particle(float mass);
+	Particle(float mass, const std::string& path);
 	virtual ~Particle() = default;
 	virtual void logicalTick(float deltaTime);
 	virtual void draw(const RenderPassContext& context, Shader& shader);
 	void addForce(std::shared_ptr<Force> force);
 	void removeForce(std::shared_ptr<Force> force);
 	float getMass();
+	glm::vec3 getSpeed();
+	void setSpeed(const glm::vec3& speed);
 private:
 	float mass;
 	glm::vec3 speed = glm::vec3(0.f);

ToyEngine/src/PhysicsManager.cpp

@@ -0,0 +1,30 @@
+#include "PhysicsManager.h"
+
+void PhysicsManager::tick(float deltaTime)
+{
+	for (auto iter = constraints.begin(); iter < constraints.end(); )
+	{
+		if (iter->p1.expired() || iter->p2.expired())
+			iter = constraints.erase(iter);
+		else
+		{
+			iter->f1->value = iter->solver(*iter->p1.lock(), *iter->p2.lock());
+			iter->f2->value = -iter->f1->value;
+			iter++;
+		}
+	}
+}
+
+void PhysicsManager::addSpring(std::shared_ptr<Particle> p1, std::shared_ptr<Particle> p2, float length, float ks, float kd)
+{
+	auto f1 = std::make_shared<Force>(glm::vec3(0));
+	auto f2 = std::make_shared<Force>(glm::vec3(0));
+	p1->addForce(f1);
+	p2->addForce(f2);
+	constraints.emplace_back(p1, p2, [length, ks, kd](Particle& p1, Particle& p2) {
+		auto d = glm::distance(p1.getPosition(), p2.getPosition());
+		float dt = 1.f;
+		auto vd = glm::distance(p1.getPosition() + p1.getSpeed() * dt, p2.getPosition() + p2.getSpeed() * dt) / dt;
+		return -(ks * (d - length) + kd * vd) * (p1.getPosition() - p2.getPosition()) / d;
+		}, f1, f2);
+}

ToyEngine/src/PhysicsManager.h

@@ -0,0 +1,22 @@
+#pragma once
+#include "Particle.h"
+
+struct BinaryConstraint
+{
+	std::weak_ptr<Particle> p1;
+	std::weak_ptr<Particle> p2;
+	std::function<glm::vec3(Particle& p1, Particle& p2)> solver; /// f1
+	std::shared_ptr<Force> f1;
+	std::shared_ptr<Force> f2;
+};
+
+class PhysicsManager
+{
+public:
+	void tick(float deltaTime);
+	void addSpring(std::shared_ptr<Particle> p1, std::shared_ptr<Particle> p2, float length, float ks, float kd);
+
+private:
+	std::vector<BinaryConstraint> constraints;
+};
+

ToyEngine/src/World.cpp

@@ -2,6 +2,7 @@
 
 void World::logicalTick(float deltaTime)
 {
+	physicsManager.tick(deltaTime);
 	for (auto& actor : actors)
 		actor->logicalTick(deltaTime);
 }

ToyEngine/src/World.h

@@ -1,6 +1,7 @@
 #pragma once
 #include "Actor.h"
 #include "RenderPassContext.h"
+#include "PhysicsManager.h"
 
 class World
 {
@@ -11,5 +12,7 @@ public:
 	void draw(const RenderPassContext& context, Shader& shader);
 	void addActor(std::shared_ptr<Actor> actor);
 	std::pair<glm::vec3, glm::vec3> getAABB();
+protected:
+	PhysicsManager physicsManager;
 };