#ifndef MATERIAL
#define MATERIAL

#include "utils.hlsl"

struct Material {
	float3 color;
	float roughness;
	
	// refraction attenuation, w = 0 -> not reflective/transmissive, w = 0.5 -> reflective,  w = 1 -> reflective and transmissive
	float4 attenuation;
	float eta;

	float3 emissive;
	float metallic;
};
static Material material;

void setMaterial(Material objectMaterial) {
	material = objectMaterial;
}

void setMaterial(bool evaluateMaterial, Material objectMaterial) {
	if (evaluateMaterial)
		setMaterial(objectMaterial);
}

void minMaterial(inout float currentDistance, float objectDistance, bool evaluateMaterial, Material objectMaterial) {
	if (objectDistance < currentDistance) {
		currentDistance = objectDistance;
		if (evaluateMaterial) {
			setMaterial(objectMaterial);
		}
	}
}

void maxMaterial(inout float currentDistance, float objectDistance, bool evaluateMaterial, Material objectMaterial) {
	if (objectDistance > currentDistance) {
		currentDistance = objectDistance;
		if (evaluateMaterial) {
			setMaterial(objectMaterial);
		}
	}
}

void minMaterialTransmissive(inout float currentDistance, float objectDistance, bool evaluateMaterial, Material objectMaterial) {
	minMaterial(currentDistance, abs(objectDistance), evaluateMaterial, objectMaterial);
	currentDistance *= objectDistance < 0 ? -1 : +1;
}

bool isReflectiveMaterial(Material m) {
	return m.attenuation.w >= 0.5;
}

bool isRefractiveMaterial(Material m) {
	return m.attenuation.w == 1;
}

Material makeSpecularMaterial(float3 color) {
	Material m;
	m.color = color;
	m.metallic = 0.0;
	m.roughness = 0.0;
	m.emissive = 0.0;
	m.attenuation = 0.0;
	return m;
}

Material makeDiffuseMaterial(float3 color) {
	Material m;
	m.color = color;
	m.metallic = 0.0;
	m.roughness = 1.0;
	m.emissive = 0.0;
	m.attenuation = 0.0;
	return m;
}

Material makeEmissiveMaterial(float3 emissive) {
	Material m;
	m.color = 0;
	m.metallic = 0;
	m.roughness = 0;
	m.emissive = emissive;
	m.attenuation = 0.0;
	return m;
}

Material makeWaterMaterial(float3 attenuation, float eta = 1.1, float roughness = 0.3) {
	Material m;
	m.color = 0.3;
	m.emissive = 0;
	m.metallic = 1;
	m.roughness = roughness;
	m.attenuation = float4(attenuation, 1);
	m.eta = eta;
	return m;
}

Material makeStrangeMaterial(float3 p, int seed) {
	float3 p1 = p + (0.009999999776 * fpn(p*1114.949951));
	float3 p2 = p1 + (0.05000000075 * fpn(p1*228.9993286));
	float3 p3 = p2 + (13.84500122 * fpn(p2*12.5));
	
	float black = fpn(p3*16.49999237) * 0.5 + 0.5;

	const float3 colors[3] = {
		float3(1,0.2,0.0),
		float3(0.5,0.8,0.1),
		float3(1.0,1.0,1.0)
	};

	float3 color = lerp(
		colors[(2+seed)%3],
		lerp(
			colors[(0+seed)%3],
			colors[(1+seed)%3], fpn((p3+p2)*15) * 0.5 + 0.5
		), fpn(p3*10) * 0.5 + 0.5
	);

	Material marble;
	marble.emissive = 0;
	marble.color = color * black;
	marble.metallic = 1.0;
	marble.roughness = saturate(black * -0.55 + 0.5);
	marble.attenuation = float4(3 * saturate(1 - color), 1);
	marble.eta = 1.2;
	return marble;
}


Material makeMarbleMaterial(float3 p, int seed) {
	float3 p1 = p + (0.009999999776 * fpn(p*1114.949951));
	float3 p2 = p1 + (0.05000000075 * fpn(p1*228.9993286));
	float3 p3 = p2 + (13.84500122 * fpn(p2*12.5));
	
	float black = fpn(p3*16.49999237) * 0.5 + 0.5;

	const float3 colors[3] = {
		float3(1,0.2,0.0),
		float3(0.5,0.8,0.1),
		float3(1.0,1.0,1.0)
	};

	float3 color = lerp(
		colors[(2+seed)%3],
		lerp(
			colors[(0+seed)%3],
			colors[(1+seed)%3], fpn((p3+p2)*15) * 0.5 + 0.5
		), fpn(p3*10) * 0.5 + 0.5
	);

	Material marble;
	marble.emissive = 0;
	marble.color = color * black;
	marble.metallic  = 0;
	marble.roughness = saturate(black * -0.55 + 0.5);
	marble.attenuation = 0;
	return marble;
}

Material makeErrorTestMaterial(float3 p) {
	int seed = 0;
	float3 p1 = p + (0.009999999776 * fpn(p*1114.949951));
	float3 p2 = p1 + (0.05000000075 * fpn(p1*228.9993286));
	float3 p3 = p2 + (13.84500122 * fpn(p2*12.5));
	
	float black = fpn(p3*16.49999237) * 0.5 + 0.5;

	const float3 colors[3] = {
		float3(1,0.2,0.0),
		float3(0.5,0.8,0.1),
		float3(1.0,1.0,1.0)
	};

	float3 color = lerp(
		colors[(2+seed)%3],
		lerp(
			colors[(0+seed)%3],
			colors[(1+seed)%3], fpn((p3+p2)*15) * 0.5 + 0.5
		), fpn(p3*10) * 0.5 + 0.5
	);

	Material marble;
	marble.emissive = 0;
	marble.color = sin(p.z)*0.5 + 0.5;//color * black;
	marble.metallic  = 0;
	marble.roughness = 0.3;//saturate(black * -0.55 + 0.5);
	marble.attenuation = 0;
	return marble;
}

#endif