Physics

Auto-generated from src/stdlib/physics.mcrs — do not edit manually.

API

• gravity_fx
• air_drag_fx
• water_drag_fx
• projectile_y
• projectile_x
• projectile_vy
• projectile_land_t
• projectile_max_height
• apply_drag
• apply_gravity
• update_pos
• bounce_v
• clamp_velocity
• spring_force
• spring_update_v
• circular_x
• circular_z
• friction_decel
• is_grounded
• impact_velocity

---

gravity_fx v1.0.0

Minecraft gravity constant in fixed-point units (0.08 blocks/tick² × 100 = 8).

fn gravity_fx(): int

Returns: 8 (gravity acceleration per tick in ×100 units)

---

air_drag_fx v1.0.0

Air drag factor in ×10000 scale (0.98 per tick).

fn air_drag_fx(): int

Returns: 9800 (multiply velocity by this / 10000 each tick)

---

water_drag_fx v1.0.0

Water drag factor in ×10000 scale (0.80 per tick, stronger than air).

fn water_drag_fx(): int

Returns: 8000 (multiply velocity by this / 10000 each tick while in water)

---

projectile_y v1.0.0

Compute Y position of a projectile after t ticks (no drag, constant gravity).

fn projectile_y(p0: int, v0: int, t: int): int

Parameters

Parameter	Description
p0	Initial Y position ×100 (blocks × 100)
v0	Initial Y velocity ×100 (blocks/tick × 100)
t	Time in ticks

Returns: Y position at tick t: p0 + v0t - gravityt²/2

Example

let y: int = projectile_y(0, 200, 5)  // height after 5 ticks, launched at 2 blocks/tick

---

projectile_x v1.0.0

Compute horizontal X position of a projectile after t ticks (constant velocity, no drag).

fn projectile_x(p0: int, v0: int, t: int): int

Parameters

Parameter	Description
p0	Initial X position ×100
v0	Horizontal X velocity ×100
t	Time in ticks

Returns: X position at tick t: p0 + v0*t

Example

let x: int = projectile_x(0, 100, 10)  // 10 blocks/tick for 10 ticks = 1000 units

---

projectile_vy v1.0.0

Compute Y velocity of a projectile after t ticks (accounting for gravity).

fn projectile_vy(v0: int, t: int): int

Parameters

Parameter	Description
v0	Initial Y velocity ×100
t	Time in ticks

Returns: v0 - gravity*t

Example

let vy: int = projectile_vy(200, 5)  // velocity after 5 ticks

---

projectile_land_t v1.0.0

Estimate the tick at which a projectile launched upward returns to Y=0.

fn projectile_land_t(v0y: int): int

Parameters

Parameter	Description
v0y	Initial upward Y velocity ×100 (must be positive)

Returns: 2*v0y / gravity; returns 0 if v0y <= 0

Example

let land_t: int = projectile_land_t(160)  // ticks until landing

---

projectile_max_height v1.0.0

Compute the maximum height reached by a projectile launched upward.

fn projectile_max_height(v0y: int): int

Parameters

Parameter	Description
v0y	Initial upward Y velocity ×100

Returns: v0y² / (2*gravity) in ×100 units

Example

let max_h: int = projectile_max_height(160)  // peak height in units×100

---

apply_drag v1.0.0

Apply a drag factor to a velocity (one tick of drag).

fn apply_drag(v_fx: int, drag_fx: int): int

Parameters

Parameter	Description
v_fx	Velocity ×100
drag_fx	Drag factor ×10000 (9800 for air, 8000 for water)

Returns: v_fx * drag_fx / 10000

Example

let v: int = apply_drag(500, air_drag_fx())  // 500 * 0.98 = 490

---

apply_gravity v1.0.0

Apply one tick of gravity to a Y velocity component.

fn apply_gravity(vy_fx: int): int

Parameters

Parameter	Description
vy_fx	Current Y velocity ×100

Returns: vy_fx - gravity_fx()

Example

vy = apply_gravity(vy)  // call each tick in your physics loop

---

update_pos v1.0.0

Update a position component by one tick of velocity.

fn update_pos(p_fx: int, v_fx: int): int

Parameters

Parameter	Description
p_fx	Current position ×100
v_fx	Velocity ×100

Returns: p_fx + v_fx

Example

px = update_pos(px, vx)  // advance X each tick

---

bounce_v v1.0.0

Reflect a velocity component with energy loss (bounce).

fn bounce_v(v_fx: int, restitution_fx: int): int

Parameters

Parameter	Description
v_fx	Velocity ×100 to reflect
restitution_fx	Energy retention ×10000 (10000=elastic, 5000=half, 0=inelastic)

Returns: Negated and scaled velocity: -v_fx * restitution / 10000

Example

vy = bounce_v(vy, 7000)  // 70% energy retained on bounce

---

clamp_velocity v1.0.0

Clamp a velocity component to a maximum absolute speed.

fn clamp_velocity(v_fx: int, max_fx: int): int

Parameters

Parameter	Description
v_fx	Velocity ×100 to clamp
max_fx	Maximum absolute velocity ×100 (terminal velocity)

Returns: v_fx clamped to [-max_fx, max_fx]

Example

vx = clamp_velocity(vx, 500)  // cap horizontal speed at 5 blocks/tick

---

spring_force v1.0.0

Compute spring force toward a target position (Hooke's law: F = -k*(x - target)).

fn spring_force(pos_fx: int, target_fx: int, k_fx: int): int

Parameters

Parameter	Description
pos_fx	Current position ×100
target_fx	Rest/target position ×100
k_fx	Spring constant ×10000 (higher = stiffer spring)

Returns: (target - pos) * k / 10000

Example

let f: int = spring_force(pos, 500, 2000)  // spring toward position 500 with k=0.2

---

spring_update_v v1.0.0

Update velocity with spring force and damping (one tick).

fn spring_update_v(v_fx: int, pos_fx: int, target_fx: int, k_fx: int, damping_fx: int): int

Parameters

Parameter	Description
v_fx	Current velocity ×100
pos_fx	Current position ×100
target_fx	Spring rest position ×100
k_fx	Spring constant ×10000
damping_fx	Damping factor ×10000 (10000=no damping, 8000=some damping)

Returns: New velocity after applying spring force and damping

Example

vx = spring_update_v(vx, px, target_px, 1000, 9000)

---

circular_x v1.0.0

Compute X position on a circle given center, radius, and angle.

fn circular_x(cx: int, r: int, angle_deg: int): int

Parameters

Parameter	Description
cx	Circle center X ×100
r	Radius ×100
angle_deg	Angle in whole degrees (NOT ×10000)

Returns: cx + r * cos(angle_deg) / 1000

Example

let x: int = circular_x(500, 200, 45)  // point at 45° on radius-2 circle

---

circular_z v1.0.0

Compute Z position on a circle given center, radius, and angle.

fn circular_z(cz: int, r: int, angle_deg: int): int

Parameters

Parameter	Description
cz	Circle center Z ×100
r	Radius ×100
angle_deg	Angle in whole degrees (NOT ×10000)

Returns: cz + r * sin(angle_deg) / 1000

Example

let z: int = circular_z(500, 200, 45)

---

friction_decel v1.0.0

Apply friction to reduce a velocity component toward zero.

fn friction_decel(v_fx: int, friction_fx: int): int

Parameters

Parameter	Description
v_fx	Current velocity ×100
friction_fx	Friction deceleration per tick ×100 (absolute amount subtracted)

Returns: Velocity reduced toward 0 by friction; stops at 0 rather than reversing

Example

vx = friction_decel(vx, 10)  // slow down by 0.1 blocks/tick per tick

---

is_grounded v1.0.0

Check whether a position has reached or fallen below the ground level.

fn is_grounded(y_fx: int, ground_y_fx: int): int

Parameters

Parameter	Description
y_fx	Current Y position ×100
ground_y_fx	Ground Y level ×100

Returns: 1 if y_fx <= ground_y_fx (grounded), 0 otherwise

Example

if (is_grounded(py, 0) == 1) { py = 0; vy = bounce_v(vy, 7000); }

---

impact_velocity v1.0.0

Estimate the impact velocity after falling from a given height.

fn impact_velocity(h_fx: int): int

Parameters

Parameter	Description
h_fx	Fall height ×100 (blocks × 100, must be positive)

Returns: Approximate impact speed ×100 via integer square root of 2gh

Example

let impact_v: int = impact_velocity(400)  // falling from 4 blocks

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