aabb margin experiments

spinner benchmark

benchmark/CMakeLists.txt

@@ -6,6 +6,7 @@ add_executable(benchmark
     large_pyramid.c
     many_pyramids.c
     smash.c
+    spinner.c
     tumbler.c
 )
 

benchmark/main.c

@@ -30,6 +30,7 @@ extern b2WorldId JointGrid( b2WorldDef* worldDef );
 extern b2WorldId LargePyramid( b2WorldDef* worldDef );
 extern b2WorldId ManyPyramids( b2WorldDef* worldDef );
 extern b2WorldId Smash( b2WorldDef* worldDef );
+extern b2WorldId Spinner( b2WorldDef* worldDef );
 extern b2WorldId Tumbler( b2WorldDef* worldDef );
 
 typedef struct Benchmark
@@ -115,13 +116,16 @@ static void FinishTask( void* userTask, void* userContext )
 }
 
 // Box2D benchmark application. On Windows I recommend running this in an administrator command prompt. Don't use Windows Terminal.
+// Or use affinity. [0x01 0x02 0x04 0x08 0x10 0x20 0x40 0x80]
+// start /affinity 0x5555 .\build\bin\Release\benchmark.exe -t=4 -w=4
 int main( int argc, char** argv )
 {
 	Benchmark benchmarks[] = {
 		{ "joint_grid", JointGrid, 500 },
 		{ "large_pyramid", LargePyramid, 500 },
 		{ "many_pyramids", ManyPyramids, 200 },
 		{ "smash", Smash, 300 },
+		{ "spinner", Spinner, 1400 },
 		{ "tumbler", Tumbler, 750 },
 	};
 

benchmark/spinner.c

@@ -0,0 +1,112 @@
+// SPDX-FileCopyrightText: 2024 Erin Catto
+// SPDX-License-Identifier: MIT
+
+#include "box2d/box2d.h"
+#include "box2d/math_functions.h"
+
+enum
+{
+	e_count = 3038,
+	e_pointCount = 360,
+};
+
+b2WorldId Spinner( b2WorldDef* worldDef )
+{
+	b2WorldId worldId = b2CreateWorld( worldDef );
+
+		b2BodyId groundId;
+	{
+		b2BodyDef bodyDef = b2DefaultBodyDef();
+		groundId = b2CreateBody( worldId, &bodyDef );
+
+		b2Vec2 points[e_pointCount];
+
+		b2Rot q = b2MakeRot( -2.0f * b2_pi / e_pointCount );
+		b2Vec2 p = { 40.0f, 0.0f };
+		for ( int i = 0; i < e_pointCount; ++i )
+		{
+			points[i] = (b2Vec2){ p.x, p.y + 32.0f };
+			p = b2RotateVector( q, p );
+		}
+
+		b2ChainDef chainDef = b2DefaultChainDef();
+		chainDef.points = points;
+		chainDef.count = e_pointCount;
+		chainDef.isLoop = true;
+		chainDef.friction = 0.1f;
+
+		b2CreateChain( groundId, &chainDef );
+	}
+
+	{
+		b2BodyDef bodyDef = b2DefaultBodyDef();
+		bodyDef.type = b2_dynamicBody;
+		bodyDef.position = (b2Vec2){ 0.0, 12.0f };
+		bodyDef.enableSleep = false;
+
+		b2BodyId spinnerId = b2CreateBody( worldId, &bodyDef );
+
+		b2Polygon box = b2MakeRoundedBox( 0.4f, 20.0f, 0.2f );
+		b2ShapeDef shapeDef = b2DefaultShapeDef();
+		shapeDef.friction = 0.0f;
+		b2CreatePolygonShape( spinnerId, &shapeDef, &box );
+
+		float motorSpeed = 5.0f;
+		float maxMotorTorque = 40000.0f;
+		b2RevoluteJointDef jointDef = b2DefaultRevoluteJointDef();
+		jointDef.bodyIdA = groundId;
+		jointDef.bodyIdB = spinnerId;
+		jointDef.localAnchorA = bodyDef.position;
+		jointDef.enableMotor = true;
+		jointDef.motorSpeed = motorSpeed;
+		jointDef.maxMotorTorque = maxMotorTorque;
+	}
+
+	b2Capsule capsule = { { -0.25f, 0.0f }, { 0.25f, 0.0f }, 0.25f };
+	b2Circle circle = { { 0.0f, 0.0f }, 0.35f };
+	b2Polygon square = b2MakeSquare( 0.35f );
+
+	b2BodyDef bodyDef = b2DefaultBodyDef();
+	bodyDef.type = b2_dynamicBody;
+	b2ShapeDef shapeDef = b2DefaultShapeDef();
+	shapeDef.friction = 0.1f;
+	shapeDef.restitution = 0.1f;
+	shapeDef.density = 0.25f;
+
+#ifdef NDEBUG
+	int bodyCount = e_count;
+#else
+	int bodyCount = 499;
+#endif
+
+	float x = -24.0f, y = 2.0f;
+	for ( int i = 0; i < bodyCount; ++i )
+	{
+		bodyDef.position = (b2Vec2){ x, y };
+		b2BodyId bodyId = b2CreateBody( worldId, &bodyDef );
+
+		int remainder = i % 3;
+		if ( remainder == 0 )
+		{
+			b2CreateCapsuleShape( bodyId, &shapeDef, &capsule );
+		}
+		else if ( remainder == 1 )
+		{
+			b2CreateCircleShape( bodyId, &shapeDef, &circle );
+		}
+		else if ( remainder == 2 )
+		{
+			b2CreatePolygonShape( bodyId, &shapeDef, &square );
+		}
+
+		x += 1.0f;
+
+		if ( x > 24.0f )
+		{
+			x = -24.0f;
+			y += 1.0f;
+		}
+	}
+
+	return worldId;
+}

samples/sample_benchmark.cpp

@@ -1975,3 +1975,216 @@ class BenchmarkCast : public Sample
 };
 
 static int sampleCast = RegisterSample( "Benchmark", "Cast", BenchmarkCast::Create );
+
+
+class BenchmarkSpinner : public Sample
+{
+public:
+	enum
+	{
+		e_count = 3038,
+		e_pointCount = 360,
+	};
+
+	explicit BenchmarkSpinner( Settings& settings )
+		: Sample( settings )
+	{
+		if ( settings.restart == false )
+		{
+			g_camera.m_center = { 0.0f, 32.0f };
+			g_camera.m_zoom = 42.0f;
+		}
+
+		b2BodyId groundId;
+		{
+			b2BodyDef bodyDef = b2DefaultBodyDef();
+			groundId = b2CreateBody( m_worldId, &bodyDef );
+
+			b2Vec2 points[e_pointCount];
+
+			b2Rot q = b2MakeRot( -2.0f * b2_pi / e_pointCount );
+			b2Vec2 p = { 40.0f, 0.0f };
+			for ( int i = 0; i < e_pointCount; ++i )
+			{
+				points[i] = { p.x, p.y + 32.0f };
+				p = b2RotateVector( q, p );
+			}
+
+			b2ChainDef chainDef = b2DefaultChainDef();
+			chainDef.points = points;
+			chainDef.count = e_pointCount;
+			chainDef.isLoop = true;
+			chainDef.friction = 0.1f;
+			chainDef.customColor = b2_colorWhite;
+
+			b2CreateChain( groundId, &chainDef );
+		}
+
+		{
+			m_bodyType = b2_dynamicBody;
+
+			b2BodyDef bodyDef = b2DefaultBodyDef();
+			bodyDef.type = m_bodyType;
+			bodyDef.position = { 0.0, 12.0f };
+			bodyDef.enableSleep = false;
+
+			m_spinnerId = b2CreateBody( m_worldId, &bodyDef );
+
+			b2Polygon box = b2MakeRoundedBox( 0.4f, 20.0f, 0.2f );
+			b2ShapeDef shapeDef = b2DefaultShapeDef();
+			shapeDef.friction = 0.0f;
+			shapeDef.customColor = b2_colorAliceBlue;
+			b2CreatePolygonShape( m_spinnerId, &shapeDef, &box );
+
+			m_motorSpeed = 5.0f;
+			m_maxMotorTorque = 40000.0f;
+			b2RevoluteJointDef jointDef = b2DefaultRevoluteJointDef();
+			jointDef.bodyIdA = groundId;
+			jointDef.bodyIdB = m_spinnerId;
+			jointDef.localAnchorA = bodyDef.position;
+			jointDef.enableMotor = true;
+			jointDef.motorSpeed = m_motorSpeed;
+			jointDef.maxMotorTorque = m_maxMotorTorque;
+
+			m_jointId = b2CreateRevoluteJoint( m_worldId, &jointDef );
+		}
+
+		b2Capsule capsule = { { -0.25f, 0.0f }, { 0.25f, 0.0f }, 0.25f };
+		b2Circle circle = { { 0.0f, 0.0f }, 0.35f };
+		b2Polygon square = b2MakeSquare( 0.35f );
+
+		b2BodyDef bodyDef = b2DefaultBodyDef();
+		bodyDef.type = b2_dynamicBody;
+		b2ShapeDef shapeDef = b2DefaultShapeDef();
+		shapeDef.friction = 0.1f;
+		shapeDef.restitution = 0.1f;
+		shapeDef.density = 0.25f;
+
+		int bodyCount = g_sampleDebug ? 499 : e_count;
+
+		float x = -24.0f, y = 2.0f;
+		for ( int i = 0; i < bodyCount; ++i )
+		{
+			bodyDef.position = { x, y };
+			b2BodyId bodyId = b2CreateBody( m_worldId, &bodyDef );
+
+			int remainder = i % 3;
+			if ( remainder == 0 )
+			{
+				shapeDef.customColor = b2_colorYellow;
+				b2CreateCapsuleShape( bodyId, &shapeDef, &capsule );
+			}
+			else if ( remainder == 1 )
+			{
+				shapeDef.customColor = b2_colorYellowGreen;
+				b2CreateCircleShape( bodyId, &shapeDef, &circle );
+			}
+			else if ( remainder == 2 )
+			{
+				shapeDef.customColor = b2_colorGreenYellow;
+				b2CreatePolygonShape( bodyId, &shapeDef, &square );
+			}
+
+			x += 1.0f;
+
+			if ( x > 24.0f )
+			{
+				x = -24.0f;
+				y += 1.0f;
+			}
+		}
+
+		m_acceleration = 0.0f;
+	}
+
+	void UpdateUI() override
+	{
+		float height = 160.0f;
+		ImGui::SetNextWindowPos( ImVec2( 10.0f, g_camera.m_height - height - 50.0f ), ImGuiCond_Once );
+		ImGui::SetNextWindowSize( ImVec2( 240.0f, height ) );
+
+		ImGui::Begin( "Spinner", nullptr, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoResize );
+
+		if ( ImGui::SliderFloat( "Speed", &m_motorSpeed, -5.0f, 5.0f ) )
+		{
+			b2RevoluteJoint_SetMotorSpeed( m_jointId, m_motorSpeed );
+
+			if ( m_bodyType == b2_kinematicBody )
+			{
+				b2Body_SetAngularVelocity( m_spinnerId, m_motorSpeed );
+			}
+		}
+
+		if ( ImGui::SliderFloat( "Torque", &m_maxMotorTorque, 0.0f, 200000.0f ) )
+		{
+			b2RevoluteJoint_SetMaxMotorTorque( m_jointId, m_maxMotorTorque );
+		}
+
+		if ( ImGui::RadioButton( "Static", m_bodyType == b2_staticBody ) )
+		{
+			m_bodyType = b2_staticBody;
+			b2Body_SetType( m_spinnerId, b2_staticBody );
+		}
+
+		if ( ImGui::RadioButton( "Kinematic", m_bodyType == b2_kinematicBody ) )
+		{
+			m_bodyType = b2_kinematicBody;
+			b2Body_SetType( m_spinnerId, b2_kinematicBody );
+			b2Body_SetAngularVelocity( m_spinnerId, m_motorSpeed );
+		}
+
+		if ( ImGui::RadioButton( "Dynamic", m_bodyType == b2_dynamicBody ) )
+		{
+			m_bodyType = b2_dynamicBody;
+			b2Body_SetType( m_spinnerId, b2_dynamicBody );
+		}
+
+		ImGui::End();
+	}
+
+	void Step( Settings& settings ) override
+	{
+		if ( glfwGetKey( g_mainWindow, GLFW_KEY_A ) == GLFW_PRESS )
+		{
+			m_acceleration = -0.2f;
+		}
+
+		if ( glfwGetKey( g_mainWindow, GLFW_KEY_S ) == GLFW_PRESS )
+		{
+			m_acceleration = 0.0f;
+			m_motorSpeed = 0.0f;
+		}
+
+		if ( glfwGetKey( g_mainWindow, GLFW_KEY_D ) == GLFW_PRESS )
+		{
+			m_acceleration = 0.2f;
+		}
+
+		if ( settings.hertz > 0.0f )
+		{
+			m_motorSpeed = b2ClampFloat( m_motorSpeed + m_acceleration / settings.hertz, -5.0f, 5.0f );
+			b2RevoluteJoint_SetMotorSpeed( m_jointId, m_motorSpeed );
+
+			if ( m_bodyType == b2_kinematicBody )
+			{
+				b2Body_SetAngularVelocity( m_spinnerId, m_motorSpeed );
+			}
+		}
+
+		Sample::Step( settings );
+	}
+
+	static Sample* Create( Settings& settings )
+	{
+		return new BenchmarkSpinner( settings );
+	}
+
+	b2BodyId m_spinnerId;
+	b2JointId m_jointId;
+	float m_acceleration;
+	float m_motorSpeed;
+	float m_maxMotorTorque;
+	b2BodyType m_bodyType;
+};
+
+static int sampleSpinner = RegisterSample( "Benchmark", "Spinner", BenchmarkSpinner::Create );