Noise Shader

struct Vertex
{
    float4 pos : POSITION;
    float2 tex : TEXTURE;
    float3 norm : NORMAL;
};

struct PixelShaderArgs
{
    float4 pos : SV_POSITION;
    float2 col : TEXTURE;
    float3 norm : NORMAL;
};

struct NoiseShaderData
{
    float2 Resolution;
    float ElapsedTime;
    float Padding;
};

Texture2D ShaderTexture : register(t0);
SamplerState Sampler : register(s0);
float4x4 localMatrix : register(b0);

cbuffer NoiseShaderDataBuffer : register(b1)
{
    NoiseShaderData NoiseData;
};

PixelShaderArgs VertexShaderMain(Vertex vertex)
{
    PixelShaderArgs output;
    output.pos = vertex.pos;
    output.col = vertex.tex;
    return output;
}

float squares16(uint ctr)
{
    const uint key = uint(0x7a1a912f);
    const float two16 = 65536.0;

    uint x, y, z;
    y = ctr * key;
    z = (ctr + uint(1)) * key;
    x = y;
    x = x * x + y;
    x = (x >> 16) | (x << 16);
    x = x * x + z;
    x = (x >> 16) | (x << 16);
    x = (x * x + y) >> 16;

    return float(x) / two16;
}

float pixel_id(float2 fragCoord)
{
    return dot(fragCoord.xy,
               float2(1, NoiseData.Resolution.x));
}

float4 PixelShaderMain(PixelShaderArgs pixelShaderArgs) : SV_Target
{
    float id = pixel_id(pixelShaderArgs.pos.xy);
    int cnt_pixels = int(NoiseData.Resolution.x * NoiseData.Resolution.y);
    float result = squares16(uint(id) + uint(NoiseData.ElapsedTime * cnt_pixels));
    float3 col = float3(result,result,result);
    float4 diffuse = ShaderTexture.Sample(Sampler,pixelShaderArgs.col);
    return float4(diffuse.rgb * col, 1.0);
}