Shader Codes

 Circle Drawing:

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    float2 center = float2(0.5, 0.5);

    float distance = length(coords - center);

    float radius = 0.4;

    float4 color = (distance < radius) ? float4(0, 0, 0, 1) : float4(1, 1, 1, 1);

    return color;
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

 sin and cos

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{

    float amplitude = 0.9;
    float frequency =55.0;
    
    // vertical
    float sinValue = amplitude * sin(coords.x * frequency);

    // horizontal
    float cosValue = amplitude * cos(coords.y * frequency);

    float4 color = float4(sinValue, 0, cosValue, 1);

    return color;
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

 Basic Animation:

Pass the time parameter from update method with these code lines that float time = (float)gameTime.TotalGameTime.TotalMilliseconds;, and then effect.Parameters["time"].SetValue(time);.

float time;

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    float amplitude = 0.9;
    float frequency =55.0;
    
    // vertical
    float sinValue = amplitude * sin((coords.x + time * 0.5) * frequency);

    float4 color = float4(sinValue, 0, 0, 1);

    return color;
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    return float4(coords.x, 0.0, 0.0, 1.0);
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    return float4(0.0, coords.y, 0.0, 1.0);
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    // make (0,0) origin
    float2 uv = (coords - float2(0.5, 0.5)) * float2(2,-2);

    return float4(uv.x, uv.y, 0.0, 1.0);
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    // make (0,0) origin
    float2 uv = (coords - float2(0.5, 0.5)) * float2(2,-2);

    // length function calculate the magnitude of the vector. length(vec(0,0)) = 0, length(vec(0,1)) = 1    
    float distance = length(uv);

    return float4(0.0, distance, distance, 1.0);
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    // make (0,0) origin
    float2 uv = (coords - float2(0.5, 0.5)) * float2(2,-2);

    // length function calculate the magnitude of the vector. length(vec(0,0)) = 0, length(vec(0,1)) = 1    
    float distance = length(uv);

    distance -= 0.7;

    distance = abs(distance);

    return float4(distance, 0, distance, 1.0);
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    // make (0,0) origin
    float2 uv = (coords - float2(0.5, 0.5)) * float2(2,-2);

    // length function calculate the magnitude of the vector. length(vec(0,0)) = 0, length(vec(0,1)) = 1    
    float distance = length(uv);

    distance -= 0.7;

    distance = abs(distance);

    //distance = step(0.1, distance)
    distance = smoothstep(0.0, 0.2, distance);

    return float4(distance, 0, distance, 1.0);
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    // make (0,0) origin
    float2 uv = (coords - float2(0.5, 0.5)) * float2(2,-2);

    // length function calculate the magnitude of the vector. length(vec(0,0)) = 0, length(vec(0,1)) = 1    
    float distance = length(uv);

    distance = cos(distance * 10)/10;

    distance = abs(distance);

    //distance = step(0.1, distance)
    distance = smoothstep(0.0, 0.2, distance);

    return float4(distance, 0, distance, 1.0);
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

float time;

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    // make (0,0) origin
    float2 uv = (coords - float2(0.5, 0.5)) * float2(2,-2);


    // length function calculate the magnitude of the vector. length(vec(0,0)) = 0, length(vec(0,1)) = 1    
    float distance = length(uv);

    distance = cos(distance * 10 + (time * 0.005))/10;

    distance = abs(distance);

    //distance = step(0.1, distance)
    distance = smoothstep(0.0, 0.2, distance);

    return float4(distance, 0, distance, 1.0);
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

float time;

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    // make (0,0) origin
    float2 uv = (coords - float2(0.5, 0.5)) * float2(2,-2);
    
    uv *= 4;
    uv = frac(uv);
    uv -= 0.5;

    // length function calculate the magnitude of the vector. length(vec(0,0)) = 0, length(vec(0,1)) = 1    
    float distance = length(uv);

    distance = cos(distance * 10 + (time * 0.005)) / 10;

    distance = abs(distance);

    //distance = step(0.1, distance)
    distance = smoothstep(0.0, 0.2, distance);

    return float4(distance, 0, distance, 1.0);
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}

float time;

static const float PI = 3.14159;

float2x2 rotate3d(float angle) {
    return float2x2(cos(angle), -sin(angle), sin(angle), cos(angle));
}

float4 PixelShaderFunction(float2 coords: TEXCOORD0) : COLOR0
{
    float2 p = coords * 2 - float2(1,1);

    float temp = (time * 0.005) * PI;

    p = mul(rotate3d(temp), p);

    float t = 0.075 / abs(0.7 - length(p));

    float vl = 0.2 * (sin(time) + 3.0);
    float3 temp2 = float3(t, t, t) * float3(vl, p.y * 0.8, 3.0);

    return float4(temp2, 1.0);
}

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShaderFunction();
    }
}