#include "ShaderConstantsGNM.h"

struct PS_Input {
	float4 position : S_POSITION;
#ifdef ENABLE_LIGHT
	float4 light : LIGHT;
#endif
#ifdef ENABLE_FOG
	float4 fogColor : FOG_COLOR;
#endif

#ifndef DISABLE_TINTING
	float4 color : COLOR;
#endif

	float2 texCoords : TEXCOORD_0_FB_MSAA;
};

float4 main(in PS_Input PSInput) : S_TARGET_OUTPUT
{
	float4 diffuse = TEXTURE_0.Sample(TextureSampler0, PSInput.texCoords);

#ifndef DISABLE_TINTING
	diffuse.a = lerp(diffuse.r * diffuse.a, diffuse.a, PSInput.color.a);
	diffuse.rgb *= PSInput.color.rgb;
#endif

#ifdef ENABLE_LIGHT
	diffuse.rgb *= PSInput.light.rgb;
#endif

#ifdef ENABLE_FOG
	//apply fog
	diffuse.rgb = lerp(diffuse.rgb, PSInput.fogColor.rgb, PSInput.fogColor.a );
#endif

	//WARNING do not refactor this 
	//PSOutput.color = diffuse;
	float4 outputColor = diffuse;

#ifdef VR_FEATURE
	// On Rift, the transition from 0 brightness to the lowest 8 bit value is abrupt, so clamp to 
	// the lowest 8 bit value.
	//PSOutput.color = max(PSOutput.color, 1 / 255.0f);
	outputColor =  max(outputColor, 1 / 255.0f);
#endif

	return outputColor;
}