#version 450 core
//! type compute

//! include /lib/raymarcher-cs.glsl
//! include /lib/hg_sdf.glsl

//! include /lib/shading-pbr.glsl
//! include /lib/shading-blinnphong.glsl
//! include /lib/fog.glsl


T_BPMaterial BPMaterials[1] = {
	{ vec3( .95 , .8 , 1 ) * .2 , vec3( 10 ) , 800 , 0 }
};

T_PBRMaterial PBRMaterials[1] = {
	{
		// Albedo color
		vec3( .9 , 1 , .9 ) ,
		// Roughness , metallic , subsurface , anisotropy
		.15 , .5 , .9 , .9 ,
		// Specular strength / tint%
		.5 , .5
	}
};

vec3 Glow[1] = {
	vec3( .95 , .8 , 1 ) * 5
};

void mapMaterial(
	in int matIndex ,
	out int type ,
	out int tIndex ,
	out int glowIndex )
{
	if ( matIndex == 0 ) {
		type = 1;
		glowIndex = -1;
	} else {
		type = 0;
		glowIndex = 0;
	}
	tIndex = 0;
}

vec2 RM_Map( vec3 pos )
{
	vec3 q = pos;
	HG_pMod2( q.xy , vec2( 8. ) );
	HG_pR( q.xz , 1 );
	return vec2( HG_fOpUnionStairs(
			HG_fBox( q , vec3( 2.3 ) ) ,
			HG_fSphere( q , 2.6 ) ,
			1. , 4 ) ,
		step( 0. , -HG_fSphere( pos , 3 ) ) );
}


vec3 pointlight(
	in T_PBRMaterial material ,
	in T_PBRPrecomputed pre ,
	in vec3 hitPos ,
	in vec3 rayDir ,
	in vec3 normal ,
	in vec3 lightPos ,
	in vec3 lightColor ,
	in float lightIntensity )
{
	vec3 lightRay = lightPos - hitPos;
	float lPwr =  lightIntensity / max( .001 , dot( lightRay , lightRay ) );
	if ( lPwr < .00005 ) {
		return vec3( 0 );
	}

	return lightColor * lPwr * PBR_Shade( material , pre ,
			-rayDir , normal , normalize( lightRay ) );
}


vec3 pointlight(
	in T_BPMaterial material ,
	in vec3 hitPos ,
	in vec3 rayDir ,
	in vec3 normal ,
	in vec3 lightPos ,
	in vec3 lightColor ,
	in float lightIntensity )
{
	vec3 lightRay = lightPos - hitPos;
	float lPwr =  lightIntensity / max( .1 , dot( lightRay , lightRay ) );
	if ( lPwr < .00005 ) {
		return vec3( 0 );
	}

	return lightColor * lPwr * BP_Shade(
			material , -rayDir , normal , lightRay );
}


void main( )
{
	vec2 res = imageSize( u_Output );
	ivec2 coords = ivec2( gl_GlobalInvocationID.xy );
	vec2 uv = ( vec2( coords ) / res ) * 2 - 1;
	vec3 camDir = normalize( u_LookAt - u_CamPos );
	vec3 side = normalize( cross( u_CamUp , camDir ) );
	vec3 up = normalize( cross( camDir , side ) );
	vec3 rayDir = normalize( camDir * u_NearPlane
			+ uv.x * side * res.x / res.y
			+ uv.y * up );

	float tanPhi = RM_TanPhi( uv , u_Render.z );

	vec3 r = RM_Advanced( u_CamPos , rayDir ,
			int( u_Render.x ) , u_Render.y ,
			tanPhi , .01 , u_Render.w );
	const vec3 background = vec3( .005 );

	vec3 bc = background;
	vec4 outValue;
	if ( r.y >= 0. ) {
		const vec3 hitPos = RM_ReduceDiscontinuity(
				u_CamPos , rayDir , r.x ,
				tanPhi , u_Correction );
		const vec3 normal = RM_GetNormal( hitPos );

		const int midx = int( r.y );
		const vec3 sunlightDir = normalize( vec3( 0 , 1 , 1 ) );
		const vec3 sunlightColor = vec3( 1 , 1 , .99 ) * .05;
		const vec3 pl1Pos = vec3( 3 , 3 , 5 );
		const vec3 pl1Color = vec3( 1 , .7 , .8 );
		const float pl1Power = 20;
		const vec3 pl2Pos = vec3( -3 , -3 , 5 );
		const vec3 pl2Color = vec3( .6 , 1 , .8 );
		const float pl2Power = 20;

		// Remap materials through mapMaterials
		int mtype , mtidx , glowidx;
		mapMaterial( midx , mtype , mtidx , glowidx );
		if ( mtype == 0 ) {
			T_BPMaterial mat = BPMaterials[ mtidx ];
			bc = sunlightColor * BP_Shade( mat ,
					-rayDir , normal , sunlightDir );
			bc += pointlight( mat ,
					hitPos , rayDir , normal ,
					pl1Pos , pl1Color , pl1Power );
			bc += pointlight( mat ,
					hitPos , rayDir , normal ,
					pl2Pos , pl2Color , pl2Power );
		} else {
			T_PBRMaterial mat = PBRMaterials[ mtidx ];
			T_PBRPrecomputed pre = PBR_Precompute(
					mat , -rayDir , normal );
			bc = sunlightColor * PBR_Shade( mat , pre ,
					-rayDir , normal , sunlightDir );
			bc += pointlight( mat , pre ,
					hitPos , rayDir , normal ,
					pl1Pos , pl1Color , pl1Power );
			bc += pointlight( mat , pre ,
					hitPos , rayDir , normal ,
					pl2Pos , pl2Color , pl2Power );
		}

		if ( glowidx >= 0 ) {
			bc += Glow[ glowidx ];
		}
		bc = FOG_Apply( bc , length( u_CamPos - hitPos ) ,
				u_FogAttenuation , background );
		outValue.w = r.x;
	} else {
		outValue.w = u_Render.w;
	}

	outValue.xyz = bc;
	imageStore( u_Output , coords , outValue );
}