#include "Macros.fxh"

DECLARE_TEXTURE(gPosition, 0);
DECLARE_TEXTURE(gAlbedo, 1);
DECLARE_TEXTURE(gNormal, 2);

BEGIN_CONSTANTS

float3 EyePosition                  _ps(c0)     _cb(c0);

float3 DirectionalLightDirection    _ps(c1)     _cb(c1);
float3 AmbientLightColor            _ps(c2)     _cb(c2);

END_CONSTANTS

struct VertexInput
{
    float4 Position : POSITION;
    float2 TexCoord : TEXCOORD;
};

struct PixelInput
{
    float4 Position : SV_POSITION;
    float2 TexCoord : TEXCOORD0;
};

PixelInput main_vs(VertexInput input)
{
    PixelInput output;

    output.Position = input.Position;
    output.TexCoord = input.TexCoord;

    return output;
}

float4 main_ps(PixelInput input) : SV_TARGET0
{
    float3 worldPosition = SAMPLE_TEXTURE(gPosition, input.TexCoord).rgb;
    float3 normal = SAMPLE_TEXTURE(gNormal, input.TexCoord).xyz;
    float3 albedo = SAMPLE_TEXTURE(gAlbedo, input.TexCoord).rgb;

    float3 V = normalize(EyePosition - worldPosition);
    float3 L = normalize(DirectionalLightDirection);
    float3 N = normalize(normal);
    float NdotL = dot(N, L);

    float lightIntensity = (NdotL > 0.0) ? 1.0 : 0.0;
    return float4(albedo * (lightIntensity, 1.0);
}

Technique Deferred_Toon
{
    Pass
    {
        VertexShader = compile vs_3_0 main_vs();
        PixelShader = compile ps_3_0 main_ps();
    }
}