#pragma target 4.5
${VFXPassForwardAdditionalPragma}

struct ps_input
{
	float4 pos : SV_POSITION;

	#if VFX_NEEDS_COLOR_INTERPOLATOR
	nointerpolation float4 color : COLOR0;
	#endif
	#if USE_ALPHA_TEST || USE_FLIPBOOK || USE_EXPOSURE_WEIGHT
	// x: alpha threshold
	// y: texture index
	// z: exposure weight
	// w: texture index blend
	nointerpolation float4 builtInInterpolants : TEXCOORD0;
	#if USE_FLIPBOOK
	#if USE_FLIPBOOK_ARRAY_LAYOUT
			nointerpolation float flipBookSize : TEXCOORD6;
		#else
			nointerpolation float4 flipBookSize : TEXCOORD6;
		#endif
	#endif
	#if USE_FLIPBOOK_MOTIONVECTORS
	// x: motion vectors scale X
	// y: motion vectors scale Y
	nointerpolation float2 builtInInterpolants2 : TEXCOORD7;
	#endif
	#endif

	nointerpolation float4 worldToDecal0 : TEXCOORD2;
	nointerpolation float4 worldToDecal1 : TEXCOORD3;
	nointerpolation float4 worldToDecal2 : TEXCOORD4;

	#if VFX_NEEDS_POSWS_INTERPOLATOR
	float3 posWS : TEXCOORD5;
	#endif

	UNITY_VERTEX_OUTPUT_STEREO

	#if USE_UV_SCALE_BIAS
	nointerpolation float4 scaleBias : TEXCOORD6;
	#endif
    VFX_VERTEX_OUTPUT_INSTANCE_INDEX

};

struct ps_output
{
	float4 color : SV_Target0;
};

#define VFX_VARYING_PS_INPUTS ps_input
#define VFX_VARYING_POSCS pos
#define VFX_VARYING_COLOR color.rgb
#define VFX_VARYING_ALPHA color.a
#define VFX_VARYING_ALPHATHRESHOLD builtInInterpolants.x
#if USE_FLIPBOOK
#define VFX_VARYING_TEXINDEX builtInInterpolants.y
#if USE_FLIPBOOK_INTERPOLATION
#define VFX_VARYING_TEXINDEXBLEND builtInInterpolants.w
#endif
#if USE_FLIPBOOK_ARRAY_LAYOUT
	#define VFX_VARYING_FLIPBOOKSIZE flipBookSize
#else
	#define VFX_VARYING_FLIPBOOKSIZE flipBookSize.xy
	#define VFX_VARYING_INVFLIPBOOKSIZE flipBookSize.zw
#endif
#endif
#if USE_FLIPBOOK_MOTIONVECTORS
#define VFX_VARYING_MOTIONVECTORSCALE builtInInterpolants2.xy
#endif
#if VFX_NEEDS_POSWS_INTERPOLATOR
#define VFX_VARYING_POSWS posWS
#endif
#if USE_EXPOSURE_WEIGHT
#define VFX_VARYING_EXPOSUREWEIGHT builtInInterpolants.z
#endif
#if USE_UV_SCALE_BIAS
#define VFX_VARYING_UV_SCALE scaleBias.xy
#define VFX_VARYING_UV_BIAS scaleBias.zw
#endif

${VFXBegin:VFXVertexAdditionalProcess}
float4x4 worldToDecal = GetVFXToElementMatrix(
	attributes.axisX,
	attributes.axisY,
	attributes.axisZ,
	float3(attributes.angleX,attributes.angleY,attributes.angleZ),
	float3(attributes.pivotX,attributes.pivotY,attributes.pivotZ),
	size3,
	attributes.position);

#if VFX_LOCAL_SPACE
worldToDecal = mul(worldToDecal, VFXGetWorldToObjectMatrix());
#endif
o.worldToDecal0 = worldToDecal[0];
o.worldToDecal1 = worldToDecal[1];
o.worldToDecal2 = worldToDecal[2];
${VFXEnd}

${VFXInclude("Shaders/ParticleHexahedron/Pass.template")}

#if VFX_PASSDEPTH == VFX_PASSDEPTH_SELECTION
int _ObjectId;
int _PassValue;
#elif VFX_PASSDEPTH == VFX_PASSDEPTH_PICKING
float4 _SelectionID;
#endif

#pragma fragment frag
ps_output frag(ps_input i)
{
	UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(i);
	ps_output o = (ps_output)0;
	VFXTransformPSInputs(i);
#if VFX_USE_GRAPH_VALUES
    uint instanceActiveIndex = i.VFX_VARYINGS_INSTANCE_ACTIVE_INDEX;
    ${VFXLoadGraphValues}
#endif
	float3 clipPos;

	clipPos.xy = VFXGetNormalizedScreenSpaceUV(i.pos) * 2.0f - 1.0f;
	clipPos.z = VFXSampleDepth(i.pos);
	clipPos.y *= _ProjectionParams.x;

    float4 hpositionWS = mul(UNITY_MATRIX_I_VP, float4(clipPos,1.0f));
    float4 worldPos = float4(hpositionWS.xyz / hpositionWS.w, 1.0f);

	float4x4 worldToElement;
	worldToElement[0] = i.worldToDecal0;
	worldToElement[1] = i.worldToDecal1;
	worldToElement[2] = -1.0f * i.worldToDecal2; //Z points TOWARDS the surface, so we need to revert it
	worldToElement[3] = float4(0,0,0,1);

    float3 positionDS = mul(worldToElement, worldPos).xyz * 2.0f;

	const float bias = 0.0f;
	clip(1.0f - abs(positionDS) + bias);

	float2 uv = positionDS.xy * 0.5f + 0.5f;

	#define VFX_TEXTURE_COLOR VFXGetTextureColorWithProceduralUV(VFX_SAMPLER(mainTexture),i,uv)
	${VFXApplyColor}

	o.color = VFXApplyPreExposure(o.color, i);
	o.color = VFXApplyFog(o.color,i);
	VFXClipFragmentColor(o.color.a,i);

#if VFX_PASSDEPTH == VFX_PASSDEPTH_SELECTION
	o.color = float4(_ObjectId, _PassValue, 1.0, 1.0);
#elif VFX_PASSDEPTH == VFX_PASSDEPTH_PICKING
	o.color = _SelectionID;
#else
	//VFX_PASSDEPTH isn't defined in forward (but we are sharing the same template)
	o.color.a = saturate(o.color.a);
	o.color = VFXTransformFinalColor(o.color,i);
#endif
	return o;
}