erincatto

Option 1: static bodies

typedef struct b2StaticBodyDef
{
	/// The world position of the body. Avoid creating bodies at the origin
	/// since this can lead to many overlapping shapes.
	b2Vec2 position;

	/// The world angle of the body in radians.
	float angle;

erincatto

% This tests a two particle mass-spring-damper system with particle 1 connect to ground and 
% particle 2 connected to particle 1. Particle 2 is much heavier than particle 1 and the
% simulation can go unstable if the soft constraint is made too stiff.
% Stability is improved by adding a relaxation step that applies the rigid constraint after
% the position update.

% no relax stable up to 13.5 Hz
% with relax stable up to 20.5 Hz
relax = 1;
hertz = 20.5;

erincatto

struct b2CircleShape
{
    // circle stuff
};

struct b2PolygonShape
{
    // polygon stuff
};

erincatto

// SPDX-FileCopyrightText: 2022 Erin Catto
// SPDX-License-Identifier: MIT

#include <stdbool.h>
#include <stdio.h>
#include <assert.h>

#define RUN_TEST(T) \
	do { \
		int result = T(); \

erincatto

struct Foo
{
   int* data;
};

void DoStuff(const Foo& f)
{
   f.data[3] = 10;
}

erincatto

Given J*JT * x = b, solve for x in linear time and space.

J is m by n
x is m by 1
b is m by 1
m < n

J is a rectangular matrix that represents a tree with equal and opposite entries.

For example: