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use rapier2d::prelude::*;
use rapier_testbed2d::Testbed;
pub fn init_world(testbed: &mut Testbed) {
/*
* World
*/
let mut bodies = RigidBodySet::new();
let mut colliders = ColliderSet::new();
let joints = JointSet::new();
/*
* Ground.
*/
let ground_size = 10.0;
let ground_height = 0.1;
let rigid_body = RigidBodyBuilder::new_static()
.translation(vector![0.0, -ground_height])
.build();
let handle = bodies.insert(rigid_body);
let collider = ColliderBuilder::cuboid(ground_size, ground_height).build();
colliders.insert_with_parent(collider, handle, &mut bodies);
/*
* Create the boxes
*/
let num = 6;
let rad = 0.2;
let shift = rad * 2.0;
let centerx = shift * num as f32 / 2.0;
let centery = shift / 2.0 + 3.04;
for i in 0usize..num {
for j in 0usize..num {
let x = i as f32 * shift - centerx;
let y = j as f32 * shift + centery;
// Build the rigid body.
let rigid_body = RigidBodyBuilder::new_dynamic()
.translation(vector![x, y])
.build();
let handle = bodies.insert(rigid_body);
let collider = ColliderBuilder::cuboid(rad, rad).build();
colliders.insert_with_parent(collider, handle, &mut bodies);
}
}
/*
* Setup a position-based kinematic rigid body.
*/
let platform_body = RigidBodyBuilder::new_kinematic_velocity_based()
.translation(vector![-10.0 * rad, 1.5 + 0.8])
.build();
let velocity_based_platform_handle = bodies.insert(platform_body);
let collider = ColliderBuilder::cuboid(rad * 10.0, rad).build();
colliders.insert_with_parent(collider, velocity_based_platform_handle, &mut bodies);
/*
* Setup a velocity-based kinematic rigid body.
*/
let platform_body = RigidBodyBuilder::new_kinematic_position_based()
.translation(vector![-10.0 * rad, 2.0 + 1.5 + 0.8])
.build();
let position_based_platform_handle = bodies.insert(platform_body);
let collider = ColliderBuilder::cuboid(rad * 10.0, rad).build();
colliders.insert_with_parent(collider, position_based_platform_handle, &mut bodies);
/*
* Setup a callback to control the platform.
*/
testbed.add_callback(move |_, physics, _, run_state| {
let velocity = vector![run_state.time.sin() * 5.0, (run_state.time * 5.0).sin()];
// Update the velocity-based kinematic body by setting its velocity.
if let Some(platform) = physics.bodies.get_mut(velocity_based_platform_handle) {
platform.set_linvel(velocity, true);
}
// Update the position-based kinematic body by setting its next position.
if let Some(platform) = physics.bodies.get_mut(position_based_platform_handle) {
let mut next_tra = *platform.translation();
next_tra += velocity * physics.integration_parameters.dt;
platform.set_next_kinematic_translation(next_tra);
}
});
/*
* Run the simulation.
*/
testbed.set_world(bodies, colliders, joints);
testbed.look_at(point![0.0, 1.0], 40.0);
}
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