// Source
// http://www.gamedev.net/topic/592001-random-number-generation-based-on-time-in-hlsl/


// Each #kernel tells which function to compile; you can have many kernels
#pragma kernel CSMain

RWTexture2D<float4> Result;

RWStructuredBuffer<float3> posBuffer : register(u0);
RWStructuredBuffer<float3> colBuffer : register(u1);
RWStructuredBuffer<float3> tarBuffer : register(u2);

float Time;
float4 CoreLoc;

float rand_1_05(in float2 uv)
{
    float2 noise = (frac(sin(dot(uv ,float2(12.9898,78.233)*2.0)) * 43758.5453));
    return abs(noise.x + noise.y) * 0.5;
}

float randomSpread(float2 seed)
{
	float part1 = rand_1_05(seed);
	float part2 = 1;

	if (part1 < 0.5)
	{
		part2 = 1;
	}
	else{
		part2 = -1;
	}

	return part2;
}


float3 ranWithinSphere(float2 seed)
{
	float3 temp = float3(0,0,0);

	temp.x = randomSpread(seed);
	temp.y = randomSpread(seed);
	temp.z = randomSpread(seed);

	return temp;
}

float distance(float3 point1, float3 point2)
{
	float x = (point1.x - point2.x) * (point1.x - point2.x);
	float y = (point1.y - point2.y) * (point1.x - point2.y);
	float z = (point1.z - point2.z) * (point1.x - point2.z);

	return sqrt(x + y + z);
}

[numthreads(10,1,1)]
void CSMain (uint3 id : SV_DispatchThreadID)
{
	float2 seed = float2(id.x * Time, Time);


	colBuffer[id.x].x = cos(Time) * sin(Time);
	colBuffer[id.x].y = sin(Time);

	tarBuffer[id.x].x = CoreLoc.x + ((cos(Time * id.x) * sin(Time))) * 4;
	tarBuffer[id.x].y = CoreLoc.y + ((sin(Time * id.x) * cos(Time))) * 7;
	tarBuffer[id.x].z = CoreLoc.z + ((cos(Time * id.x) * sin(Time))) * 12;


	// Work your way towards the target
	float changeX = tarBuffer[id.x].x - posBuffer[id.x].x;
	float changeY = tarBuffer[id.x].y - posBuffer[id.x].y;
	float changeZ = tarBuffer[id.x].z - posBuffer[id.x].z;


	posBuffer[id.x].x += (changeX / 40);
	posBuffer[id.x].y += (changeY / 40);
	posBuffer[id.x].z += (changeZ / 40);

}