#pragma kernel FuncationKernel

RWStructuredBuffer<float3> _Positions;

uint _Resolution;

float _Step;
float _Time;

float2 GetUV(uint3 id)
{
	return (id.xy + 0.5) * _Step - 1.0;
}

void SetPositions(uint3 id, float3 positions)
{
	if (id.x < _Resolution && id.y < _Resolution) 
	{
		_Positions[id.x + id.y * _Resolution] = positions;
	}
}

#define PI 3.14159265358979323846

float3 Wave(float u, float v, float t)
{
    float3 p;
    p.x = u;
    p.y = sin(PI * (u + v + t));
    p.z = v;
    return p;
}

[numthreads(8, 8, 1)]
void FuncationKernel(uint3 id : SV_DISPATCHTHREADID)
{
	float2 uv = GetUV(id);
	SetPositions(id, Wave(uv.x, uv.y, _Time));
}