box2d_sys 0.2.1

Bindings for Box2D v3.0
Documentation 
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// SPDX-FileCopyrightText: 2023 Erin Catto
// SPDX-License-Identifier: MIT

#pragma once

#include "box2d/types.h"

// Ray cast an AABB
b2CastOutput b2AABB_RayCast( b2AABB a, b2Vec2 p1, b2Vec2 p2 );

// Get the perimeter length
static inline float b2Perimeter( b2AABB a )
{
	float wx = a.upperBound.x - a.lowerBound.x;
	float wy = a.upperBound.y - a.lowerBound.y;
	return 2.0f * ( wx + wy );
}

/// Enlarge a to contain b
/// @return true if the AABB grew
static inline bool b2EnlargeAABB( b2AABB* a, b2AABB b )
{
	bool changed = false;
	if ( b.lowerBound.x < a->lowerBound.x )
	{
		a->lowerBound.x = b.lowerBound.x;
		changed = true;
	}

	if ( b.lowerBound.y < a->lowerBound.y )
	{
		a->lowerBound.y = b.lowerBound.y;
		changed = true;
	}

	if ( a->upperBound.x < b.upperBound.x )
	{
		a->upperBound.x = b.upperBound.x;
		changed = true;
	}

	if ( a->upperBound.y < b.upperBound.y )
	{
		a->upperBound.y = b.upperBound.y;
		changed = true;
	}

	return changed;
}

/// Do a and b overlap
static inline bool b2AABB_Overlaps( b2AABB a, b2AABB b )
{
	b2Vec2 d1 = { b.lowerBound.x - a.upperBound.x, b.lowerBound.y - a.upperBound.y };
	b2Vec2 d2 = { a.lowerBound.x - b.upperBound.x, a.lowerBound.y - b.upperBound.y };

	if ( d1.x > 0.0f || d1.y > 0.0f )
		return false;

	if ( d2.x > 0.0f || d2.y > 0.0f )
		return false;

	return true;
}