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Physics: box2d

box2d​

Box2D pyhysics for your games

import​

_ @sys.box2d;

box2d.reset - reset at startup​

Apply box2d.reset in bootloader main loop once to reset box2d physics at startup

box2d.reset(r0);

box2d.world - create world​

Create world

_ @sys.box2d;

gravity.x 0;
gravity.y 0-1;

b2d.world r15; # need r15 for draw

if (r0) {
 b2d.world:=box2d.world(u0, gravity.x, gravity.y);
};

box2d.step - loop step interactions​

Step world with velocity and position interactions

velocity.iteractions 8;
position.iteractions 3;

box2d.step(u0, b2d.world, 1/60, velocity.iteractions, position.iteractions);

box2d.shape.create.circle - create body circle​

Set options, create body, shape and fixture. Define the collisions

ib0 { _ box2d.default.dynamic.body.info;
 x 100;
 y 200;
 damping.linear 0;
 gravity.scale 100;
};

b0 0;
b0:=box2d.body.create2(r0, b2d.world, ib0); 

b0s0 0;
b0s0:=box2d.shape.create.circle(u0);
box2d.shape.set.radius(u0, b0s0, 10);

b0f0 0;
box2d.fixture.def(u0, 0.2, 0, 0, 0);
b0f0:=box2d.fixture.create(u0, b0, b0s0);
box2d.fixture.filter.collision(u0, b0f0, 1,2+1, 0);

box2d.world.draw - debug draw​

b2d.world r15;

_ @sys.box2d;
box2d.world.draw(u0, b2d.world);