CommonB2Settings.go

package box2d

import "math"

// @port(OK)
const B2DEBUG = false

// @port(OK)
func B2Assert(a bool) {
	if !a {
		panic("B2Assert")
	}
}

const B2_maxFloat = math.MaxFloat64
const B2_epsilon = math.SmallestNonzeroFloat64
const B2_pi = math.Pi

/// @file
/// Global tuning constants based on meters-kilograms-seconds (MKS) units.
///

// Collision

/// The maximum number of contact points between two convex shapes. Do
/// not change this value.
const B2_maxManifoldPoints = 2

/// The maximum number of vertices on a convex polygon. You cannot increase
/// this too much because b2BlockAllocator has a maximum object size.
const B2_maxPolygonVertices = 8

/// This is used to fatten AABBs in the dynamic tree. This allows proxies
/// to move by a small amount without triggering a tree adjustment.
/// This is in meters.
const B2_aabbExtension = 0.1

/// This is used to fatten AABBs in the dynamic tree. This is used to predict
/// the future position based on the current displacement.
/// This is a dimensionless multiplier.
const B2_aabbMultiplier = 2.0

/// A small length used as a collision and constraint tolerance. Usually it is
/// chosen to be numerically significant, but visually insignificant.
const B2_linearSlop = 0.005

/// A small angle used as a collision and constraint tolerance. Usually it is
/// chosen to be numerically significant, but visually insignificant.
const B2_angularSlop = (2.0 / 180.0 * B2_pi)

/// The radius of the polygon/edge shape skin. This should not be modified. Making
/// this smaller means polygons will have an insufficient buffer for continuous collision.
/// Making it larger may create artifacts for vertex collision.
const B2_polygonRadius = (2.0 * B2_linearSlop)

/// Maximum number of sub-steps per contact in continuous physics simulation.
const B2_maxSubSteps = 8

// Dynamics

/// Maximum number of contacts to be handled to solve a TOI impact.
const B2_maxTOIContacts = 32

/// A velocity threshold for elastic collisions. Any collision with a relative linear
/// velocity below this threshold will be treated as inelastic.
const B2_velocityThreshold = 1.0

/// The maximum linear position correction used when solving constraints. This helps to
/// prevent overshoot.
const B2_maxLinearCorrection = 0.2

/// The maximum angular position correction used when solving constraints. This helps to
/// prevent overshoot.
const B2_maxAngularCorrection = (8.0 / 180.0 * B2_pi)

/// The maximum linear velocity of a body. This limit is very large and is used
/// to prevent numerical problems. You shouldn't need to adjust this.
const B2_maxTranslation = 2.0
const B2_maxTranslationSquared = (B2_maxTranslation * B2_maxTranslation)

/// The maximum angular velocity of a body. This limit is very large and is used
/// to prevent numerical problems. You shouldn't need to adjust this.
const B2_maxRotation = (0.5 * B2_pi)
const B2_maxRotationSquared = (B2_maxRotation * B2_maxRotation)

/// This scale factor controls how fast overlap is resolved. Ideally this would be 1 so
/// that overlap is removed in one time step. However using values close to 1 often lead
/// to overshoot.
const B2_baumgarte = 0.2
const B2_toiBaugarte = 0.75

// Sleep

/// The time that a body must be still before it will go to sleep.
const B2_timeToSleep = 0.5

/// A body cannot sleep if its linear velocity is above this tolerance.
const B2_linearSleepTolerance = 0.01

/// A body cannot sleep if its angular velocity is above this tolerance.
const B2_angularSleepTolerance = (2.0 / 180.0 * B2_pi)