vvvv-spreads

Name: vvvv-spreads
Author: tebjan

70installs5forks

How to install vvvv-spreads?

tebjan/vvvv-skills/vvvv-spreads

$npx -y skills add tebjan/vvvv-skills --skill vvvv-spreads

Installs into the current project.

Summary

Helps write code using vvvv gamma's Spread<T> immutable collection type and SpreadBuilder<T>. Use when working with Spreads, SpreadBuilder, collections, arrays, iteration, mapping, filtering, zipping, accumulating, or converting between Span and Spread. Trigger whenever the user

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SKILL.md

1	# vvvv Spreads
2
3	## What Are Spreads
4
5	`Spread<T>` is vvvv's immutable collection type, conceptually similar to `ImmutableArray<T>`. It is the primary way to pass collections between nodes.
6
7	Key properties:
8	- Immutable — never modify in place, always create new spreads
9	- Value semantics — two spreads with same elements are considered equal
10	- Cyclic indexing — in visual patches, indexing wraps around (not in C# API)
11	- Never null — use `Spread<T>.Empty` instead of `null`
12
13	## Creating Spreads
14
15	### SpreadBuilder (Primary Method)
16
17	```csharp
18	var builder = new SpreadBuilder<float>(expectedCount);
19	for (int i = 0; i < count; i++)
20	builder.Add(ComputeValue(i));
21	Spread<float> result = builder.ToSpread();
22	```
23
24	### From Existing Data
25
26	```csharp
27	// From array (extension method)
28	Spread<int> fromArray = new int[] { 1, 2, 3 }.ToSpread();
29
30	// From array (static factory)
31	Spread<Waypoint> fromResult = Spread.Create(resultArray);
32
33	// Empty spread (NEVER use null)
34	Spread<float> empty = Spread<float>.Empty;
35
36	// Single element
37	var single = new SpreadBuilder<float>(1);
38	single.Add(42f);
39	Spread<float> one = single.ToSpread();
40	```
41
42	## Accessing Elements
43
44	```csharp
45	// Always check Count before indexing
46	if (spread.Count > 0)
47	{
48	float first = spread[0];
49	float last = spread[spread.Count - 1];
50	}
51
52	// Iterate (preferred — no allocation)
53	foreach (var item in spread)
54	Process(item);
55
56	// Index access in loop
57	for (int i = 0; i < spread.Count; i++)
58	Process(spread[i]);
59	```
60
61	## Common Patterns in C#
62
63	### Map (Transform Each Element)
64
65	```csharp
66	public static Spread<float> Scale(Spread<float> input, float factor = 1f)
67	{
68	var builder = new SpreadBuilder<float>(input.Count);
69	foreach (var value in input)
70	builder.Add(value * factor);
71	return builder.ToSpread();
72	}
73	```
74
75	### Filter
76
77	```csharp
78	public static Spread<float> FilterAbove(Spread<float> input, float threshold = 0.5f)
79	{
80	var builder = new SpreadBuilder<float>();
81	foreach (var value in input)
82	{
83	if (value > threshold)
84	builder.Add(value);
85	}
86	return builder.ToSpread();
87	}
88	```
89
90	### Zip (Process Two Spreads Together)
91
92	```csharp
93	public static Spread<float> Add(Spread<float> a, Spread<float> b)
94	{
95	int count = Math.Max(a.Count, b.Count);
96	var builder = new SpreadBuilder<float>(count);
97	for (int i = 0; i < count; i++)
98	{
99	float va = a.Count > 0 ? a[i % a.Count] : 0f;
100	float vb = b.Count > 0 ? b[i % b.Count] : 0f;
101	builder.Add(va + vb);
102	}
103	return builder.ToSpread();
104	}
105	```
106
107	### Accumulate (Running Total)
108
109	```csharp
110	public static Spread<float> RunningSum(Spread<float> input)
111	{
112	var builder = new SpreadBuilder<float>(input.Count);
113	float sum = 0f;
114	foreach (var value in input)
115	{
116	sum += value;
117	builder.Add(sum);
118	}
119	return builder.ToSpread();
120	}
121	```
122
123	## ReadOnlySpan as High-Performance Alternative
124
125	For hot-path output (e.g., per-frame simulation data), `ReadOnlySpan<T>` avoids allocation entirely:
126
127	```csharp
128	[ProcessNode]
129	public class ParticleSimulator
130	{
131	private ParticleState[] _states;
132
133	public ReadOnlySpan<ParticleState> Update(SimulationConfig config, float deltaTime)
134	{
135	// Simulate into pre-allocated array — zero allocation
136	Simulate(_states, config, deltaTime);
137	return _states.AsSpan();
138	}
139	}
140	```
141
142	Use `Spread<T>` for infrequent config inputs; use `ReadOnlySpan<T>` for high-frequency frame data.
143
144	## Performance Rules
145
146	- Pre-allocate builder: `new SpreadBuilder<T>(expectedCount)` when count is known
147	- No LINQ in hot paths: `.Where()`, `.Select()`, `.ToList()` create hidden allocations
148	- Cache spreads: If output doesn't change, return the cached spread reference
149	- Avoid repeated `.ToSpread()`: Build once, output the result
150	- For large spreads: Consider `Span<T>` internally, convert to Spread at the API boundary
151	- Spread change detection: Since Spreads are immutable, reference equality (`!=` or `ReferenceEquals`) is sufficient — if the reference changed, the content changed
152
153	## Spreads in ProcessNodes
154
155	```csharp
156	[ProcessNode]
157	public class SpreadProcessor
158	{
159	private Spread<float> _lastInput = Spread<float>.Empty;
160	private Spread<float> _cachedOutput = Spread<float>.Empty;
161
162	public void Update(
163	out Spread<float> output,
164	Spread<float> input = default)
165	{
166	input

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vvvv-spreads

70installs5forks

View on GitHub

How to install vvvv-spreads?

tebjan/vvvv-skills/vvvv-spreads

$npx -y skills add tebjan/vvvv-skills --skill vvvv-spreads

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# vvvv Spreads
2
3	## What Are Spreads
4
5	`Spread<T>` is vvvv's immutable collection type, conceptually similar to `ImmutableArray<T>`. It is the primary way to pass collections between nodes.
6
7	Key properties:
8	- Immutable — never modify in place, always create new spreads
9	- Value semantics — two spreads with same elements are considered equal
10	- Cyclic indexing — in visual patches, indexing wraps around (not in C# API)
11	- Never null — use `Spread<T>.Empty` instead of `null`
12
13	## Creating Spreads
14
15	### SpreadBuilder (Primary Method)
16
17	```csharp
18	var builder = new SpreadBuilder<float>(expectedCount);
19	for (int i = 0; i < count; i++)
20	builder.Add(ComputeValue(i));
21	Spread<float> result = builder.ToSpread();
22	```
23
24	### From Existing Data
25
26	```csharp
27	// From array (extension method)
28	Spread<int> fromArray = new int[] { 1, 2, 3 }.ToSpread();
29
30	// From array (static factory)
31	Spread<Waypoint> fromResult = Spread.Create(resultArray);
32
33	// Empty spread (NEVER use null)
34	Spread<float> empty = Spread<float>.Empty;
35
36	// Single element
37	var single = new SpreadBuilder<float>(1);
38	single.Add(42f);
39	Spread<float> one = single.ToSpread();
40	```
41
42	## Accessing Elements
43
44	```csharp
45	// Always check Count before indexing
46	if (spread.Count > 0)
47	{
48	float first = spread[0];
49	float last = spread[spread.Count - 1];
50	}
51
52	// Iterate (preferred — no allocation)
53	foreach (var item in spread)
54	Process(item);
55
56	// Index access in loop
57	for (int i = 0; i < spread.Count; i++)
58	Process(spread[i]);
59	```
60
61	## Common Patterns in C#
62
63	### Map (Transform Each Element)
64
65	```csharp
66	public static Spread<float> Scale(Spread<float> input, float factor = 1f)
67	{
68	var builder = new SpreadBuilder<float>(input.Count);
69	foreach (var value in input)
70	builder.Add(value * factor);
71	return builder.ToSpread();
72	}
73	```
74
75	### Filter
76
77	```csharp
78	public static Spread<float> FilterAbove(Spread<float> input, float threshold = 0.5f)
79	{
80	var builder = new SpreadBuilder<float>();
81	foreach (var value in input)
82	{
83	if (value > threshold)
84	builder.Add(value);
85	}
86	return builder.ToSpread();
87	}
88	```
89
90	### Zip (Process Two Spreads Together)
91
92	```csharp
93	public static Spread<float> Add(Spread<float> a, Spread<float> b)
94	{
95	int count = Math.Max(a.Count, b.Count);
96	var builder = new SpreadBuilder<float>(count);
97	for (int i = 0; i < count; i++)
98	{
99	float va = a.Count > 0 ? a[i % a.Count] : 0f;
100	float vb = b.Count > 0 ? b[i % b.Count] : 0f;
101	builder.Add(va + vb);
102	}
103	return builder.ToSpread();
104	}
105	```
106
107	### Accumulate (Running Total)
108
109	```csharp
110	public static Spread<float> RunningSum(Spread<float> input)
111	{
112	var builder = new SpreadBuilder<float>(input.Count);
113	float sum = 0f;
114	foreach (var value in input)
115	{
116	sum += value;
117	builder.Add(sum);
118	}
119	return builder.ToSpread();
120	}
121	```
122
123	## ReadOnlySpan as High-Performance Alternative
124
125	For hot-path output (e.g., per-frame simulation data), `ReadOnlySpan<T>` avoids allocation entirely:
126
127	```csharp
128	[ProcessNode]
129	public class ParticleSimulator
130	{
131	private ParticleState[] _states;
132
133	public ReadOnlySpan<ParticleState> Update(SimulationConfig config, float deltaTime)
134	{
135	// Simulate into pre-allocated array — zero allocation
136	Simulate(_states, config, deltaTime);
137	return _states.AsSpan();
138	}
139	}
140	```
141
142	Use `Spread<T>` for infrequent config inputs; use `ReadOnlySpan<T>` for high-frequency frame data.
143
144	## Performance Rules
145
146	- Pre-allocate builder: `new SpreadBuilder<T>(expectedCount)` when count is known
147	- No LINQ in hot paths: `.Where()`, `.Select()`, `.ToList()` create hidden allocations
148	- Cache spreads: If output doesn't change, return the cached spread reference
149	- Avoid repeated `.ToSpread()`: Build once, output the result
150	- For large spreads: Consider `Span<T>` internally, convert to Spread at the API boundary
151	- Spread change detection: Since Spreads are immutable, reference equality (`!=` or `ReferenceEquals`) is sufficient — if the reference changed, the content changed
152
153	## Spreads in ProcessNodes
154
155	```csharp
156	[ProcessNode]
157	public class SpreadProcessor
158	{
159	private Spread<float> _lastInput = Spread<float>.Empty;
160	private Spread<float> _cachedOutput = Spread<float>.Empty;
161
162	public void Update(
163	out Spread<float> output,
164	Spread<float> input = default)
165	{
166	input

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