SyncVals · Trajectory

combo-score-system

claude-code claude-opus-4-8 ✓ resolved GOOD_SUCCESS ↑ View task

Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.

Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.

Classification , post-hoc; cannot change the reward

GOOD_SUCCESSLegitimate solve, implements the asked-for behavior; tests verify real functionality.

SubtypeLegitimate Solution

EvidenceTest output shows 'VALIDATION_PASSED: Combo meter works correctly' and reward=1.0. Agent's trajectory shows: (1) correct scene structure with ComboSystem root, ComboTimer child (one_shot=true), MeterBar ColorRect; (2) embedded Curve sub-resource with control points (0,1.0), (0.5,2.2), (1.0,3.0); (3) embedded Gradient with three color stops (cool blue, amber, hot red); (4) complete script implementation with combo_window/max_combo/multiplier_curve/heat_gradient/meter_bar exports, combo_count/multiplier state, combo_fraction() helper, register_hit() with pre-count multiplier sampling, _on_combo_timeout() reset, and combo_changed/combo_broken signals; (5) debugging when initial test failed on meter_bar wiring by writing probe scenes to understand Godot 4.4's node_paths serialization requirement; (6) fix applied and verified passing all test checks including curve sampling accuracy (CTOL=0.09), gradient color accuracy (GTOL=0.04), and behavioral contracts."

Root causeAgent correctly understood and implemented the full Godot combo meter specification, including all scene structure, resource configuration, and script logic. When encountering a Godot 4.4-specific serialization issue with node path exports (requiring node_paths= marker on the node declaration), the agent debugged systematically rather than guessing, confirmed the correct format through a reference probe scene, applied the fix, and verified success.

RecommendationN/A - task is fine

Trajectory

Tool-by-tool agent trajectory

25 tool calls · 3 tool types · 25 steps

Build a combo meter for an action game, driven by designer-authored curves. Create `scenes/combo_system.tscn` with a `Node` root named `ComboSystem` (attach `scripts/combo_system.gd`). Add: - a `Timer` child named `ComboTimer` that fires only once per start (`one_shot`), with its `timeout` wired to the script's `_on_combo_timeout()` handler, - a `ColorRect` child named `MeterBar` (the on-screen combo heat bar). In `scripts/combo_system.gd`, implement the `ComboSystem` class: - Export a float `combo_window` (default `2.0`, the seconds allowed between hits) and an int `max_combo` (default `8`). - Track an int `combo_count` (starts `0`) and a float `multiplier` (starts `1.0`). - Export a `Curve` resource named `multiplier_curve`, authored so that sampling its baked value returns `1.0` at position `0.0`, `2.2` at position `0.5`, and `3.0` at position `1.0`. This curve maps how full the combo is (0 = no streak, 1 = at `max_combo`) to the score multiplier. - Export a `Gradient` resource named `heat_gradient`, authored with three stops: offset `0.0` is cool blue `Color(0.2, 0.4, 1.0)`, offset `0.5` is amber `Color(1.0, 0.8, 0.0)`, offset `1.0` is hot red `Color(1.0, 0.1, 0.0)`. - Export a `ColorRect` reference named `meter_bar`, wired in the scene to the `MeterBar` node. Define a helper `combo_fraction() -> float` that returns the streak fullness as `clamp(float(combo_count) / max_combo, 0.0, 1.0)`. Behavior of `register_hit(base_score: int) -> int`: - Award and return the score for the hit that just landed, then advance the streak. - The multiplier in effect for this hit is `multiplier_curve.sample_baked(combo_fraction())` evaluated **before** this hit is counted , so the first hit of a streak (fraction 0) uses multiplier `1.0` and awards exactly `base_score`. The awarded value is rounded to the nearest whole number and returned as an int. Store this multiplier into `multiplier`. - Then add the hit to the streak (`combo_count += 1`), refresh `multiplier` from the curve at the new `combo_fraction()`, and recolor the bar: set `meter_bar.color` to `heat_gradient.sample(combo_fraction())`. - Restart `ComboTimer` so it will fire `combo_window` seconds from now, and emit `combo_changed(combo_count, multiplier)`. When the window lapses, `_on_combo_timeout()` ends the streak: reset `combo_count` to `0` and `multiplier` to `1.0`, recolor the bar to the gradient at fraction `0.0`, and emit `combo_broken`. Declare signals `combo_changed(count: int, mult: float)` and `combo_broken`.

Bash: List project files

ls -la && find . -name "project.godot" -o -name "*.tscn" -o -name "*.gd" 2>/dev/null | head -50

output

total 12
drwxr-xr-x 5 user user  128 Jun 21 19:05 .
drwxr-x--- 3 user user  128 Jun 21 19:05 ..
drwxr-xr-x 4 user user 4096 Jun 21 19:05 .godot
-rw-r--r-- 1 user user  206 Jun 21 07:51 project.godot
drwxr-xr-x 2 user user  128 Jun 21 07:52 scenes
drwxr-xr-x 2 user user 4096 Jun 21 19:05 scripts
./project.godot
./scenes/combo_system.tscn
./scenes/main.tscn
./scenes/test.tscn
./scripts/combo_system.gd
./scripts/test.gd

Bash: Read existing files

cat project.godot && echo "=== combo_system.tscn ===" && cat scenes/combo_system.tscn && echo "=== combo_system.gd ===" && cat scripts/combo_system.gd && echo "=== main.tscn ===" && cat scenes/main.tscn && echo "=== test.tscn ===" && cat scenes/test.tscn && echo "=== test.gd ===" && cat scripts/test.gd

output

config_version=5

[application]

config/name="Combo Score System"
run/main_scene="res://scenes/main.tscn"
config/features=PackedStringArray("4.4")

[rendering]

renderer/rendering_method="gl_compatibility"
=== combo_system.tscn ===
[gd_scene load_steps=1 format=3]

[node name="ComboSystem" type="Node"]
=== combo_system.gd ===
extends Node
class_name ComboSystem

@onready var combo_timer: Timer = $ComboTimer

func _ready() -> void:
	pass
=== main.tscn ===
[gd_scene load_steps=2 format=3]

[ext_resource type="PackedScene" path="res://scenes/combo_system.tscn" id="1"]

[node name="Main" type="Node"]

[node name="ComboSystem" parent="." instance=ExtResource("1")]
=== test.tscn ===
[gd_scene load_steps=3 format=3]

[ext_resource type="Script" path="res://scripts/test.gd" id="1"]
[ext_resource type="PackedScene" path="res://scenes/main.tscn" id="2"]

[node name="TestRunner" type="Node"]
script = ExtResource("1")

[node name="Main" parent="." instance=ExtResource("2")]
=== test.gd ===
extends Node

const GTOL := 0.04
const CTOL := 0.09

func _ready() -> void:
	await get_tree().process_frame
	run_validation()

func run_validation() -> void:
	var main = get_node_or_null("Main")
	if main == null:
		return _fail("Main scene not found")
	var cs = main.get_node_or_null("ComboSystem")
	if cs == null:
		return _fail("ComboSystem node not found under Main")

	var timer = cs.get_node_or_null("ComboTimer")
	if timer == null or not (timer is Timer):
		return _fail("ComboSystem must have a Timer child named ComboTimer")
	if not timer.one_shot:
		return _fail("ComboTimer must be one_shot = true")
	if not timer.timeout.is_connected(Callable(cs, "_on_combo_timeout")):
		return _fail("ComboTimer.timeout must be connected to _on_combo_timeout in the scene")

	var bar_node = cs.get_node_or_null("MeterBar")
	if bar_node == null or not (bar_node is ColorRect):
		return _fail("ComboSystem must have a ColorRect child named MeterBar")

	if not cs.has_signal("combo_changed"):
		return _fail("combo_changed signal missing")
	if not cs.has_signal("combo_broken"):
		return _fail("combo_broken signal missing")

	# exported resources
	var curve = cs.get("multiplier_curve")
	if curve == null or not (curve is Curve):
		return _fail("multiplier_curve must be an exported Curve resource authored in the scene")
	var grad = cs.get("heat_gradient")
	if grad == null or not (grad is Gradient):
		return _fail("heat_gradient must be an exported Gradient resource authored in the scene")

	# exported node ref must be wired
	var bar = cs.get("meter_bar")
	if bar == null or not (bar is ColorRect):
		return _fail("meter_bar export must be wired to the MeterBar ColorRect in the scene")
	if bar != bar_node:
		return _fail("meter_bar export must point to the MeterBar node")

	# defaults
	if cs.get("combo_window") == null or not is_equal_approx(cs.combo_window, 2.0):
		return _fail("combo_window default must be 2.0")
	if cs.get("max_combo") == null or cs.max_combo != 8:
		return _fail("max_combo default must be 8")
	if cs.get("combo_count") == null or cs.combo_count != 0:
		return _fail("combo_count must start at 0")
	if cs.get("multiplier") == null or not is_equal_approx(cs.multiplier, 1.0):
		return _fail("multiplier must start at 1.0")

	# curve baked control points
	if absf(curve.sample_baked(0.0) - 1.0) > CTOL:
		return _fail("multiplier_curve at position 0.0 must bake to 1.0")
	if absf(curve.sample_baked(0.5) - 2.2) > CTOL:
		return _fail("multiplier_curve at position 0.5 must bake to 2.2 , needs a middle control point")
	if absf(curve.sample_baked(1.0) - 3.0) > CTOL:
		return _fail("multiplier_curve at position 1.0 must bake to 3.0")

	# gradient stops
	if not _color_near(grad.sample(0.0), Color(0.2, 0.4, 1.0)):
		return _fail("heat_gradient at offset 0.0 must be cool blue Color(0.2,0.4,1.0)")
	if not _color_near(grad.sample(0.5), Color(1.0, 0.8, 0.0)):
		return _fail("heat_gradient at offset 0.5 must be amber Color(1.0,0.8,0.0) , needs a middle stop")
	if not _color_near(grad.…[truncated]

Now I'll write the scene and script. Let me create the `.tscn` with embedded Curve/Gradient sub-resources and the script:

Write: /home/user/task/scenes/combo_system.tscn

/home/user/task/scenes/combo_system.tscn

[gd_scene load_steps=4 format=3 uid="uid://b8combosys01"]

[ext_resource type="Script" path="res://scripts/combo_system.gd" id="1"]

[sub_resource type="Curve" id="Curve_1"]
min_value = 1.0
max_value = 3.0
_data = [Vector2(0, 1), 0.0, 0.0, 0, 0, Vector2(0.5, 2.2), 0.0, 0.0, 0, 0, Vector2(1, 3), 0.0, 0.0, 0, 0]
point_count = 3

[sub_resource type="Gradient" id="Gradient_1"]
offsets = PackedFloat32Array(0, 0.5, 1)
colors = PackedColorArray(0.2, 0.4, 1, 1, 1, 0.8, 0, 1, 1, 0.1, 0, 1)

[node name="ComboSystem" type="Node"]
script = ExtResource("1")
multiplier_curve = SubResource("Curve_1")
heat_gradient = SubResource("Gradient_1")
meter_bar = NodePath("MeterBar")

[node name="ComboTimer" type="Timer" parent="."]
one_shot = true

[node name="MeterBar" type="ColorRect" parent="."]
offset_right = 200.0
offset_bottom = 24.0
color = Color(0.2, 0.4, 1, 1)

[connection signal="timeout" from="ComboTimer" to="." method="_on_combo_timeout"]

output

The file /home/user/task/scenes/combo_system.tscn has been updated successfully. (file state is current in your context , no need to Read it back)

Write: /home/user/task/scripts/combo_system.gd

/home/user/task/scripts/combo_system.gd

extends Node
class_name ComboSystem

## Emitted whenever the streak advances after a hit lands.
signal combo_changed(count: int, mult: float)
## Emitted when the combo window lapses and the streak resets.
signal combo_broken

## Seconds allowed between hits before the streak breaks.
@export var combo_window: float = 2.0
## Number of hits at which the combo is considered fully saturated.
@export var max_combo: int = 8

## Maps combo fullness (0 = no streak, 1 = at max_combo) to the score multiplier.
@export var multiplier_curve: Curve
## Maps combo fullness to the heat color shown on the meter bar.
@export var heat_gradient: Gradient
## The on-screen combo heat bar, recolored as the streak grows.
@export var meter_bar: ColorRect

var combo_count: int = 0
var multiplier: float = 1.0

@onready var combo_timer: Timer = $ComboTimer

## Streak fullness in the range [0, 1], used to sample the curve and gradient.
func combo_fraction() -> float:
	return clamp(float(combo_count) / max_combo, 0.0, 1.0)

## Award the score for the hit that just landed, then advance the streak.
func register_hit(base_score: int) -> int:
	# Multiplier in effect for this hit, sampled before counting it.
	multiplier = multiplier_curve.sample_baked(combo_fraction())
	var awarded: int = int(round(base_score * multiplier))

	# Add the hit to the streak and refresh state from the new fullness.
	combo_count += 1
	multiplier = multiplier_curve.sample_baked(combo_fraction())
	meter_bar.color = heat_gradient.sample(combo_fraction())

	combo_timer.wait_time = combo_window
	combo_timer.start()
	combo_changed.emit(combo_count, multiplier)
	return awarded

## End the streak when the combo window lapses.
func _on_combo_timeout() -> void:
	combo_count = 0
	multiplier = 1.0
	meter_bar.color = heat_gradient.sample(0.0)
	combo_broken.emit()

output

The file /home/user/task/scripts/combo_system.gd has been updated successfully. (file state is current in your context , no need to Read it back)

Now let me run the test scene to validate, if Godot is available:

Bash: Run Godot validation test

(command -v godot && godot --headless --path . scenes/test.tscn 2>&1 | tail -20) || echo "godot not found in PATH"

output

/usr/local/bin/godot
Godot Engine v4.4.stable.official.4c311cbee - https://godotengine.org
WARNING: Started the engine as `root`/superuser. This is a security risk, and subsystems like audio may not work correctly.
Set the environment variable `GODOT_SILENCE_ROOT_WARNING` to 1 to silence this warning.
     at: setup2 (main/main.cpp:3181)

VALIDATION_FAILED: meter_bar export must be wired to the MeterBar ColorRect in the scene

Node export via NodePath isn't resolving. Let me debug:

Bash: Debug meter_bar resolution

cat > /tmp/dbg.gd <<'EOF'
extends SceneTree
func _init():
	var s = load("res://scenes/combo_system.tscn").instantiate()
	get_root().add_child(s)
	print("meter_bar = ", s.get("meter_bar"))
	print("has MeterBar child = ", s.get_node_or_null("MeterBar"))
	quit()
EOF
godot --headless --path . -s /tmp/dbg.gd 2>&1 | grep -v WARNING | grep -v "at:" | tail -10

output

Godot Engine v4.4.stable.official.4c311cbee - https://godotengine.org

meter_bar = <null>
has MeterBar child = MeterBar:<ColorRect#27028096393>

Godot 4.4 stores node-typed exports specially, not as a bare `NodePath`. Let me see how Godot itself serializes it:

Bash: Generate reference node-export serialization

cat > /tmp/gen.gd <<'EOF'
extends SceneTree
func _init():
	var root = load("res://scripts/combo_system.gd").new()
	root.name = "ComboSystem"
	var bar = ColorRect.new()
	bar.name = "MeterBar"
	root.add_child(bar)
	bar.owner = root
	root.meter_bar = bar
	var ps = PackedScene.new()
	ps.pack(root)
	ResourceSaver.save(ps, "res://scenes/_probe.tscn")
	quit()
EOF
godot --headless --path . -s /tmp/gen.gd 2>&1 | grep -vi warning | grep -v "at:" ; echo "=== probe ==="; cat scenes/_probe.tscn; rm -f scenes/_probe.tscn

output

Godot Engine v4.4.stable.official.4c311cbee - https://godotengine.org

ERROR: 1 resources still in use at exit (run with --verbose for details).
=== probe ===
[gd_scene load_steps=2 format=3]

[ext_resource type="Script" path="res://scripts/combo_system.gd" id="1_p2162"]

[node name="ComboSystem" type="Node" node_paths=PackedStringArray("meter_bar")]
script = ExtResource("1_p2162")
meter_bar = NodePath("MeterBar")

[node name="MeterBar" type="ColorRect" parent="."]

The node needs `node_paths=PackedStringArray("meter_bar")` on its declaration line. Let me fix:

Edit: /home/user/task/scenes/combo_system.tscn

/home/user/task/scenes/combo_system.tscn
--- old ---
[node name="ComboSystem" type="Node"]
script = ExtResource("1")
--- new ---
[node name="ComboSystem" type="Node" node_paths=PackedStringArray("meter_bar")]
script = ExtResource("1")

output

The file /home/user/task/scenes/combo_system.tscn has been updated successfully. (file state is current in your context , no need to Read it back)

Bash: Re-run validation test

godot --headless --path . scenes/test.tscn 2>&1 | grep -i validation

output

VALIDATION_PASSED: Combo meter works correctly

Validation passes. The combo system is complete and working. ## What I built **`scenes/combo_system.tscn`** , `ComboSystem` (Node) root with the `combo_system.gd` script, containing: - `ComboTimer` (Timer, `one_shot = true`) with its `timeout` signal wired to `_on_combo_timeout()`. - `MeterBar` (ColorRect) for the on-screen heat bar. - An embedded **Curve** sub-resource with control points `(0, 1.0)`, `(0.5, 2.2)`, `(1.0, 3.0)` and `max_value = 3.0` so the baked samples aren't clamped. - An embedded **Gradient** sub-resource with the three required stops (cool blue → amber → hot red). - The exported resources and the `meter_bar` node reference wired up. **`scripts/combo_system.gd`** , the `ComboSystem` class with the exported `combo_window`/`max_combo`/`multiplier_curve`/`heat_gradient`/`meter_bar`, the `combo_count`/`multiplier` state, `combo_fraction()`, `register_hit()`, `_on_combo_timeout()`, and the `combo_changed`/`combo_broken` signals. ## One subtlety worth noting Godot 4 doesn't resolve a node-typed `@export` from a bare `meter_bar = NodePath("MeterBar")` line , the node declaration also needs `node_paths=PackedStringArray("meter_bar")` to mark which properties are deferred node references. I confirmed the exact serialization by having Godot itself pack and save an equivalent scene, then matched it. The first test run failed precisely on this (`meter_bar` resolving to `null`); after adding the marker, all checks pass , including the multiplier-before-counting math (`100 → 100`, fraction-0.5 → `220`, `50 → 110`, saturated → `300`) and the gradient recoloring on hit and on timeout.

Final diff , what the agent changed

No file changes, the agent left the workspace untouched.

Verifier output , the proof behind the reward

tests/test.sh

Godot Engine v4.4.stable.official.4c311cbee - https://godotengine.org
WARNING: Started the engine as `root`/superuser. This is a security risk, and subsystems like audio may not work correctly.
Set the environment variable `GODOT_SILENCE_ROOT_WARNING` to 1 to silence this warning.
     at: setup2 (main/main.cpp:3181)

VALIDATION_PASSED: Combo meter works correctly

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_1b608e21624d467b. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_1b608e21624d467b · verifier authoritative; classifier explanatory.