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Merged
kvark merged 1 commit into from
Mar 21, 2026
Merged

asteroids: native color tint #319

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11 changes: 11 additions & 0 deletions blade-engine/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -352,6 +352,7 @@ struct Object {
prev_isometry: nalgebra::Isometry3<f32>,
colliders: Vec<rapier3d::geometry::ColliderHandle>,
visuals: Vec<Visual>,
color_tint: [f32; 4],
}

#[derive(Clone, Debug, PartialEq)]
Expand Down Expand Up @@ -499,6 +500,7 @@ impl Engine {
z: mp.column(2).into(),
},
model: visual.model,
color_tint: object.color_tint,
});
}
object.prev_isometry = isometry;
Expand Down Expand Up @@ -1331,6 +1333,7 @@ impl Engine {
self.extra_debug_lines.extend_from_slice(lines);
}

#[cfg_attr(not(target_os = "android"), allow(dead_code))]
fn make_particle_camera(
camera: &blade_render::Camera,
target_size: gpu::Extent,
Expand Down Expand Up @@ -1758,6 +1761,7 @@ impl Engine {
prev_isometry: nalgebra::Isometry3::default(),
colliders,
visuals,
color_tint: [1.0; 4],
});
self.physics.rigid_bodies[rb_handle].user_data = raw_handle as u128;
ObjectHandle(raw_handle)
Expand Down Expand Up @@ -1800,6 +1804,7 @@ impl Engine {
prev_isometry: nalgebra::Isometry3::default(),
colliders: Vec::new(),
visuals: vec![visual],
color_tint: [1.0; 4],
});
// Store ObjectHandle index in rigid body user_data for fast lookup in contacts
self.physics.rigid_bodies[rb_handle].user_data = raw_handle as u128;
Expand Down Expand Up @@ -2013,6 +2018,12 @@ impl Engine {
body.set_position(transform.into_isometry(), true);
}

/// Set a per-object color tint that multiplies the model's material colors.
/// Default is [1, 1, 1, 1] (no tint).
pub fn set_color_tint(&mut self, handle: ObjectHandle, tint: [f32; 4]) {
self.objects[handle.0].color_tint = tint;
}

pub fn set_joint_motor(
&mut self,
handle: JointHandle,
Expand Down
4 changes: 4 additions & 0 deletions blade-render/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -82,6 +82,9 @@ pub struct Object {
pub model: blade_asset::Handle<Model>,
pub transform: blade_graphics::Transform,
pub prev_transform: blade_graphics::Transform,
/// Per-object color tint multiplied with the material's base_color_factor.
/// Default: [1.0, 1.0, 1.0, 1.0] (no tint).
pub color_tint: [f32; 4],
}

#[cfg(not(any(gles, target_arch = "wasm32")))]
Expand All @@ -91,6 +94,7 @@ impl From<blade_asset::Handle<Model>> for Object {
model,
transform: blade_graphics::IDENTITY_TRANSFORM,
prev_transform: blade_graphics::IDENTITY_TRANSFORM,
color_tint: [1.0; 4],
}
}
}
Expand Down
7 changes: 6 additions & 1 deletion blade-render/src/raster/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -340,7 +340,12 @@ impl Rasterizer {
draw_params: RasterDrawParams {
model: world_transform.to_cols_array(),
normal_quat: normal_quat.to_array(),
base_color_factor: material.base_color_factor,
base_color_factor: [
material.base_color_factor[0] * object.color_tint[0],
material.base_color_factor[1] * object.color_tint[1],
material.base_color_factor[2] * object.color_tint[2],
material.base_color_factor[3] * object.color_tint[3],
],
material: [normal_scale, 0.0, 0.0, 0.0],
},
vertices: model.vertex_buffer.at(0),
Expand Down
21 changes: 12 additions & 9 deletions examples-android/asteroids/asteroids.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -21,8 +21,7 @@ use game::{AsteroidField, GameState, LASER_DAMAGE, SIZE_RADII};

// --- XR Input ---

const LASER_LENGTH: f32 = 200.0;
const LASER_HIT_RADIUS: f32 = 1.5;
const LASER_LENGTH: f32 = 60.0;
const LASER_BEAM_RADIUS: f32 = 0.015;

struct HandState {
Expand Down Expand Up @@ -240,21 +239,25 @@ impl XrInput {
let to_asteroid = [pos.x - origin[0], pos.y - origin[1], pos.z - origin[2]];
let along =
to_asteroid[0] * dir[0] + to_asteroid[1] * dir[1] + to_asteroid[2] * dir[2];
if along < 0.0 || along > closest_t {
continue;
}
let hit_radius = SIZE_RADII[asteroid.size_class] * LASER_HIT_RADIUS;
let hit_radius = SIZE_RADII[asteroid.size_class];
let perp_sq = (to_asteroid[0] - dir[0] * along).powi(2)
+ (to_asteroid[1] - dir[1] * along).powi(2)
+ (to_asteroid[2] - dir[2] * along).powi(2);
if perp_sq < hit_radius * hit_radius {
closest_t = along;
closest_idx = Some(idx);
if perp_sq >= hit_radius * hit_radius {
continue;
}
// Ray enters the sphere at t = along - sqrt(r² - perp²)
let t_enter = along - (hit_radius * hit_radius - perp_sq).sqrt();
if t_enter < 0.0 || t_enter > closest_t {
continue;
}
closest_t = t_enter;
closest_idx = Some(idx);
}

if let Some(idx) = closest_idx {
asteroid_field.asteroids[idx].health -= LASER_DAMAGE;
// Hit point is where the ray enters the sphere (near side)
let hit_point = [
origin[0] + dir[0] * closest_t,
origin[1] + dir[1] * closest_t,
Expand Down
128 changes: 60 additions & 68 deletions examples-android/asteroids/game.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -17,7 +17,6 @@ const SPEED_VARIATION: f32 = 0.4;
const MAX_HEALTH: f32 = 1.0;
pub const LASER_DAMAGE: f32 = 0.016;
const HEALTH_REGEN: f32 = 0.2;
const DAMAGE_STAGES: usize = 5;

// --- Asteroid sizes ---
pub const SIZE_RADII: [f32; 3] = [0.5, 1.0, 2.0];
Expand All @@ -35,61 +34,48 @@ const COMET_NUCLEUS_RADIUS: f32 = 3.0;

pub struct Asteroid {
pub object_handle: blade_engine::ObjectHandle,
variant: usize,
pub size_class: usize,
pub health: f32,
color_stage: usize,
}

pub struct AsteroidField {
pub asteroids: Vec<Asteroid>,
/// model_handles[size_class][variant][color_stage]
model_handles: Vec<Vec<Vec<blade_asset::Handle<blade_render::Model>>>>,
/// model_handles[size_class][variant]
model_handles: Vec<Vec<blade_asset::Handle<blade_render::Model>>>,
flow_dir: [f32; 3],
next_seed: u32,
}

impl AsteroidField {
pub fn new(engine: &mut blade_engine::Engine) -> Self {
let variant_params: &[(f32, [f32; 3], [f32; 4])] = &[
(0.35, [1.0, 1.0, 1.0], [0.45, 0.40, 0.35, 1.0]),
(0.50, [1.4, 0.7, 1.0], [0.50, 0.45, 0.38, 1.0]),
(0.45, [1.0, 0.5, 1.2], [0.40, 0.38, 0.35, 1.0]),
(0.60, [1.0, 1.0, 1.0], [0.35, 0.32, 0.30, 1.0]),
(0.30, [0.8, 1.3, 0.9], [0.55, 0.50, 0.42, 1.0]),
(0.55, [1.3, 0.8, 1.3], [0.42, 0.38, 0.32, 1.0]),
(0.40, [1.1, 1.1, 0.6], [0.48, 0.44, 0.38, 1.0]),
(0.65, [0.9, 0.9, 1.4], [0.38, 0.35, 0.30, 1.0]),
// (roughness, axis_scales, base_color)
(0.35, [1.0, 1.0, 1.0], [0.50, 0.45, 0.40, 1.0]), // warm gray
(0.50, [1.4, 0.7, 1.0], [0.60, 0.35, 0.25, 1.0]), // rusty orange
(0.45, [1.0, 0.5, 1.2], [0.30, 0.35, 0.45, 1.0]), // blue-gray
(0.60, [1.0, 1.0, 1.0], [0.25, 0.22, 0.20, 1.0]), // dark charcoal
(0.30, [0.8, 1.3, 0.9], [0.55, 0.55, 0.40, 1.0]), // sandy yellow
(0.55, [1.3, 0.8, 1.3], [0.45, 0.30, 0.35, 1.0]), // reddish brown
(0.40, [1.1, 1.1, 0.6], [0.35, 0.40, 0.30, 1.0]), // olive green
(0.65, [0.9, 0.9, 1.4], [0.55, 0.50, 0.55, 1.0]), // pale purple-gray
];
let hot_color: [f32; 4] = [0.9, 0.15, 0.05, 1.0];
let mut model_handles = Vec::new();
for (sc, &radius) in SIZE_RADII.iter().enumerate() {
let mut variants = Vec::new();
for (i, &(roughness, axis_scales, color)) in variant_params.iter().enumerate() {
let seed = (sc * 100 + i * 7 + 42) as u32;
let (vertices, indices) =
mesh::generate_asteroid_mesh(seed, radius, roughness, 2, axis_scales);
let mut stages = Vec::new();
for stage in 0..DAMAGE_STAGES {
let t = stage as f32 / (DAMAGE_STAGES - 1) as f32;
let staged_color = [
color[0] + (hot_color[0] - color[0]) * t,
color[1] + (hot_color[1] - color[1]) * t,
color[2] + (hot_color[2] - color[2]) * t,
1.0,
];
let handle = engine.create_model(
&format!("asteroid_s{sc}_v{i}_t{stage}"),
vec![blade_render::ProceduralGeometry {
name: format!("asteroid_s{sc}_v{i}_t{stage}"),
vertices: vertices.clone(),
indices: indices.clone(),
base_color_factor: staged_color,
}],
);
stages.push(handle);
}
variants.push(stages);
let handle = engine.create_model(
&format!("asteroid_s{sc}_v{i}"),
vec![blade_render::ProceduralGeometry {
name: format!("asteroid_s{sc}_v{i}"),
vertices,
indices,
base_color_factor: color,
}],
);
variants.push(handle);
}
model_handles.push(variants);
}
Expand Down Expand Up @@ -222,7 +208,6 @@ impl AsteroidField {
velocity: [f32; 3],
angular_velocity: [f32; 3],
) {
let color_stage = 0;
let axis = mesh::normalize(angular_velocity);
let angle = mesh::hash_noise(self.next_seed.wrapping_add(999), 80.0, 81.0, 82.0)
* std::f32::consts::TAU;
Expand All @@ -246,7 +231,7 @@ impl AsteroidField {

let handle = engine.add_object_with_model(
"asteroid",
self.model_handles[size_class][variant][color_stage],
self.model_handles[size_class][variant],
transform,
blade_engine::DynamicInput::Full,
);
Expand All @@ -269,10 +254,8 @@ impl AsteroidField {

self.asteroids.push(Asteroid {
object_handle: handle,
variant,
size_class,
health: MAX_HEALTH,
color_stage,
});
}

Expand Down Expand Up @@ -327,26 +310,12 @@ impl AsteroidField {
continue;
}

// Update color stage based on damage
// Tint toward red based on damage
let damage = 1.0 - a.health / MAX_HEALTH;
let new_stage = (damage * (DAMAGE_STAGES - 1) as f32) as usize;
let new_stage = new_stage.min(DAMAGE_STAGES - 1);
if new_stage != a.color_stage {
let transform = engine
.get_object_transform(a.object_handle, blade_engine::Prediction::LastKnown);
let (linvel, angvel) = engine.get_velocity(a.object_handle);
engine.remove_object(a.object_handle);
let new_handle = engine.add_object_with_model(
"asteroid",
self.model_handles[a.size_class][a.variant][new_stage],
transform,
blade_engine::DynamicInput::Full,
);
engine.add_ball_collider(new_handle, SIZE_RADII[a.size_class], 0.5);
engine.set_velocity(new_handle, linvel, angvel);
a.object_handle = new_handle;
a.color_stage = new_stage;
}
engine.set_color_tint(
a.object_handle,
[1.0, 1.0 - damage * 0.7, 1.0 - damage * 0.8, 1.0],
);
i += 1;
}
}
Expand Down Expand Up @@ -539,22 +508,45 @@ pub fn setup_game(engine: &mut blade_engine::Engine) -> GameState {
space_sky: true,
});

// Planet
// Gas giant with rings in the distance.
// The asteroids around us are conceptually part of the outermost ring.
{
let planet_radius = 30.0;
let planet_model = mesh::generate_planet_model(engine, planet_radius);
let planet_transform = blade_engine::Transform {
position: mint::Vector3 {
x: 30.0,
y: -20.0,
z: -80.0,
let planet_radius = 120.0;
let planet_pos = mint::Vector3 {
x: 200.0,
y: -150.0,
z: -600.0,
};

// Tilt ~25° so the rings are clearly visible
let tilt_angle: f32 = 0.44;
let half = tilt_angle * 0.5;
let ring_orient = mint::Quaternion {
s: half.cos(),
v: mint::Vector3 {
x: half.sin(),
y: 0.0,
z: 0.0,
},
..Default::default()
};

let (planet_model, ring_model) = mesh::generate_ringed_planet(engine, planet_radius);
engine.add_object_with_model(
"planet",
planet_model,
planet_transform,
blade_engine::Transform {
position: planet_pos,
..Default::default()
},
blade_engine::DynamicInput::Empty,
);
engine.add_object_with_model(
"planet_rings",
ring_model,
blade_engine::Transform {
position: planet_pos,
orientation: ring_orient,
},
blade_engine::DynamicInput::Empty,
);
}
Expand Down
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