#pragma arguments
uniform vec2 trailPoints[5];
uniform float count;

#pragma body
float trailRadius = 10.0;

float x = _surface.diffuseTexcoord.x;
float x100 = float(x * 100);

float y = _surface.diffuseTexcoord.y;
float y100 = float(y * 100);

for (int i = 0; i < int(count); i++) {
    vec2 position = trailPoints[i];
    if ((x100 > position.x - trailRadius && x100 < position.x + trailRadius) && (y100 > position.y - trailRadius && y100 < position.y + trailRadius)) {
        _surface.diffuse.rgb = vec3(0.0, 10.0 ,0.0);
    }
}

if let geometry = self.floorNode.geometry {
                if let material = geometry.firstMaterial {

                    // this is the temporary data which I use to find the problem.
                    // this data will be dynamic later on.
                    let myValueArray:[float2] = [float2(x:80, y:80),float2(x:60, y:60),float2(x:40, y:40),float2(x:20, y:20),float2(x:0, y:0)]

                    // Passing array count to shader. There is no problem here.
                    var count = Float(myValueArray.count)
                    let countData = Data(buffer: UnsafeBufferPointer(start: &count, count: 1))
                    material.setValue(countData, forKey: "count")

                    // and here is the problem start.
                    var unsafeValueArray = myValueArray
                    // myValueArray converted to data with its size.
                    let valueArrayData = Data(buffer: UnsafeBufferPointer(start: myValueArray, count: myValueArray.count))
                    material.setValue(valueArrayData, forKey: "trailPoints")
                }
            }

let valueArrayData = Data(buffer: UnsafeBufferPointer(start: myValueArray, count: 1))