//Cg

void vshader(
    float4 vtx_position : POSITION,
    float2 vtx_texcoord0 : TEXCOORD0,
    out float4 l_position : POSITION,
    out float2 l_texcoord0 : TEXCOORD0,
    out float2 l_texcoord1 : TEXCOORD1,
    uniform float4 texpad_tex,
    uniform float4x4 mat_modelproj)
{
    l_position=mul(mat_modelproj, vtx_position);
    l_texcoord0 = vtx_position.xz * texpad_tex.xy + texpad_tex.xy;
    l_texcoord1 = l_position.xy;
}

void fshader(float2 l_texcoord1 : TEXCOORD1,
             float2 l_texcoord0 : TEXCOORD0,
             out float4 o_color : COLOR,
             uniform sampler2D k_tex : TEXUNIT0)
{
    float4 color = tex2D(k_tex, l_texcoord0).rgba;

    float newred = (color.r * 0.338) + (color.g * 0.714) + (color.b * 0.134);
    float newgreen = (color.r * 0.294) + (color.g * 0.631) + (color.b * 0.113);
    float newblue = (color.r * 0.217) + (color.g * 0.479) + (color.b * 0.076);

    newred = clamp(newred, 0, 1);
    newgreen = clamp(newgreen, 0, 1);
    newblue = clamp(newblue, 0, 1);

    // create a vignette to simulate old optics
    float d = distance(float2(0.0, 0.0), l_texcoord1);
    float OuterVignetting = 1.6;
    float InnerVignetting = 0.6;
    float vignetting = clamp((OuterVignetting - d) / (OuterVignetting - InnerVignetting), 0.0, 1.0);
    // non-linear fade to prevent ugly border effect
    float diff = 1.0 - vignetting;
    float scale = 1.0 - (diff * diff);
    newred *= scale;
    newgreen *= scale;
    newblue *= scale;
    
    o_color = float4(newred, newgreen, newblue, 1);
}