uniform float4x4 ViewProj;
uniform texture2d image;
uniform texture2d output_image;

sampler_state textureSampler{
    Filter = Linear;
    AddressU = Clamp;
    AddressV = Clamp;
    MinLOD = 0;
    MaxLOD = 0;
};

struct VertData
{
	float4 pos : POSITION;
	float2 uv : TEXCOORD0;
};

VertData mainTransform(VertData v_in)
{
	v_in.pos = mul(float4(v_in.pos.xyz, 1.0), ViewProj);
	return v_in;
}

float srgb_nonlinear_to_linear_channel(float u)
{
	return (u <= 0.04045) ? (u / 12.92) : pow((u + 0.055) / 1.055, 2.4);
}

float3 srgb_nonlinear_to_linear(float3 v)
{
	return float3(srgb_nonlinear_to_linear_channel(v.r), srgb_nonlinear_to_linear_channel(v.g), srgb_nonlinear_to_linear_channel(v.b));
}

float4 mainImage(VertData v_in) : TARGET
{
	float4 px = output_image.Sample(textureSampler, v_in.uv);
	//px.xyz = px.a > 0.0 ? px.xyz : float3(0.0f, 0.0f, 0.0f);
	px.xyz = srgb_nonlinear_to_linear(px.xyz);
	return px;
}

technique Draw
{
	pass
	{
		vertex_shader = mainTransform(v_in);
		pixel_shader = mainImage(v_in);
	}
}