// RUN: %dxc -E main -T ps_6_0 %s | FileCheck %s

// CHECK: sample
// CHECK: Saturate

//
// Copyright (c) Microsoft. All rights reserved.
// This code is licensed under the MIT License (MIT).
// THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY
// IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR
// PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.
//
// Developed by Minigraph
//
// Author:  James Stanard 
//

#include "TextRS.hlsli"

cbuffer cbFontParams : register( b0 )
{
	float4 Color;
	float2 ShadowOffset;
	float ShadowHardness;
	float ShadowOpacity;
	float HeightRange;	// The range of the signed distance field.
}

Texture2D<float> SignedDistanceFieldTex : register( t0 );
SamplerState LinearSampler : register( s0 );

struct PS_INPUT
{
	float4 pos : SV_POSITION;
	float2 uv : TEXCOORD0;
};

float GetAlpha( float2 uv, float range )
{
	return saturate(SignedDistanceFieldTex.Sample(LinearSampler, uv) * range + 0.5);
}

[RootSignature(Text_RootSig)]
float4 main( PS_INPUT Input ) : SV_Target
{
	float alpha1 = GetAlpha(Input.uv, HeightRange) * Color.a;
	float alpha2 = GetAlpha(Input.uv - ShadowOffset, HeightRange * ShadowHardness) * ShadowOpacity * Color.a;
	return float4( Color.rgb * alpha1, lerp(alpha2, 1, alpha1) );
}