wehub-resource-sync
52 lines
1.5 KiB
C#
52 lines
1.5 KiB
C#
using T3.Core.Utils;
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namespace Lib.numbers.vec2;
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[Guid("54af403f-a4bd-4ef0-95df-2201c0d3ba56")]
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internal sealed class Vec2JitterOffset :Instance<Vec2JitterOffset>{
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[Output(Guid = "393553be-3985-4c00-9b0a-51e8374da078")]
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public readonly Slot<Vector2> Result = new();
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public Vec2JitterOffset()
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{
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Result.UpdateAction += Update;
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}
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private void Update(EvaluationContext context)
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{
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Result.Value = GetJitterOffset(
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Seed.GetValue(context),
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SampleCount.GetValue(context));
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}
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/// <summary>
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/// Sub-pixel jitter offset in pixels, range [-0.5, 0.5], from a Halton(2,3) sequence.
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/// sampleCount 8 or 16 are typical. Predictable and repeating, per your spec.
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/// </summary>
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public static Vector2 GetJitterOffset(int frameIndex, int sampleCount)
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{
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var i = (frameIndex % sampleCount.ClampMin(1)) + 1; // Halton is undefined at index 0
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return new Vector2(Halton(i, 2) - 0.5f, Halton(i, 3) - 0.5f);
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}
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private static float Halton(int index, int radix)
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{
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var result = 0f;
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var fraction = 1f / radix;
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while (index > 0)
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{
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result += (index % radix) * fraction;
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index /= radix;
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fraction /= radix;
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}
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return result;
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}
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[Input(Guid = "0763898d-5f9b-44eb-9a7f-9e0ec62222ef")]
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public readonly InputSlot<int> Seed = new();
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[Input(Guid = "0A421D3C-0A72-429B-B028-32B4EFF26877")]
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public readonly InputSlot<int> SampleCount = new();
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} |