#include "Psyrain.h"
#include "Voxine.h"
#include "ProceduralMeshComponent.h"


float edgeLength = 100.0; // cube edge length
TArray<FVector> vertices; // contains one cube vertices
TArray<int32> Triangles; // store triangles which composes one cube
TArray<FVector> normals; // store normal vectors of one cube vertices
TArray<FVector2D> UV0;   // store texture co-ordinates of one cube vertices
TArray<FColor> vertexColors; // store colors of one cube vertices
TArray<FProcMeshTangent> tangents; // store tangents of one cube vertices

int i = 0; // integer to instantiate mesh sections


AVoxine::AVoxine()
{
	USphereComponent* SphereComponent = CreateDefaultSubobject<USphereComponent>(TEXT("RootComponent"));
	RootComponent = SphereComponent;

	UProceduralMeshComponent* mesh = CreateDefaultSubobject<UProceduralMeshComponent>(TEXT("GeneratedMesh"));

	/**
	*	Create/replace a section for this procedural mesh component.
	*	@param	SectionIndex		Index of the section to create or replace.
	*	@param	Vertices			Vertex buffer of all vertex positions to use for this mesh section.
	*	@param	Triangles			Index buffer indicating which vertices make up each triangle. Length must be a multiple of 3.
	*	@param	Normals				Optional array of normal vectors for each vertex. If supplied, must be same length as Vertices array.
	*	@param	UV0					Optional array of texture co-ordinates for each vertex. If supplied, must be same length as Vertices array.
	*	@param	VertexColors		Optional array of colors for each vertex. If supplied, must be same length as Vertices array.
	*	@param	Tangents			Optional array of tangent vector for each vertex. If supplied, must be same length as Vertices array.
	*	@param	bCreateCollision	Indicates whether collision should be created for this section. This adds significant cost.
	*/
	//UFUNCTION(BlueprintCallable, Category = "Components|ProceduralMesh", meta = (AutoCreateRefTerm = "Normals,UV0,VertexColors,Tangents"))
	//	void CreateMeshSection(int32 SectionIndex, const TArray<FVector>& Vertices, const TArray<int32>& Triangles, const TArray<FVector>& Normals,
	// const TArray<FVector2D>& UV0, const TArray<FColor>& VertexColors, const TArray<FProcMeshTangent>& Tangents, bool bCreateCollision);

	for (int x = 0; x <= 4; x++)
	{
		for (int y = 0; y <= 4; y++)
		{
			for (int z = 0; z <= 4; z++)
			{

				MakeACube(x, y, z);

				// mesh generation
				mesh->CreateMeshSection(i, vertices, Triangles, normals, UV0, vertexColors, tangents, false);

				// With default options
				//mesh->CreateMeshSection(1, vertices, Triangles, TArray<FVector>(), TArray<FVector2D>(), TArray<FColor>(), TArray<FProcMeshTangent>(), false);

				// empty everything to be ready to generate another cube
				vertices.Empty();
				Triangles.Empty();

				i++; // next section
			}
		}
	}

	// instantiate the generated mesh
	mesh->AttachTo(RootComponent);
}


// Called when the game starts or when spawned
void AVoxine::BeginPlay()
{
	Super::BeginPlay();

}

// Called every frame
void AVoxine::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);

}

void AVoxine::MakeACube(int gridPosX, int gridPosY, int gridPosZ)
{
	// front face
	vertices.Add(FVector(gridPosX*edgeLength, gridPosY*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, (gridPosY + 1)*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, gridPosY*edgeLength, (gridPosZ + 1)*edgeLength));

	vertices.Add(FVector(gridPosX*edgeLength, gridPosY*edgeLength, (gridPosZ + 1)*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, (gridPosY + 1)*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, (gridPosY + 1)*edgeLength, (gridPosZ + 1)*edgeLength));

	// back face
	vertices.Add(FVector((gridPosX + 1)*edgeLength, gridPosY*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, gridPosY*edgeLength, (gridPosZ + 1)*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, (gridPosY + 1)*edgeLength, gridPosZ*edgeLength));

	vertices.Add(FVector((gridPosX + 1)*edgeLength, gridPosY*edgeLength, (gridPosZ + 1)*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, (gridPosY + 1)*edgeLength, (gridPosZ + 1)*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, (gridPosY + 1)*edgeLength, gridPosZ*edgeLength));

	// top face
	vertices.Add(FVector((gridPosX + 1)*edgeLength, gridPosY*edgeLength, (gridPosZ + 1)*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, (gridPosY + 1)*edgeLength, (gridPosZ + 1)*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, (gridPosY + 1)*edgeLength, (gridPosZ + 1)*edgeLength));

	vertices.Add(FVector(gridPosX*edgeLength, gridPosY*edgeLength, (gridPosZ + 1)*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, (gridPosY + 1)*edgeLength, (gridPosZ + 1)*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, gridPosY*edgeLength, (gridPosZ + 1)*edgeLength));

	// bottom face
	vertices.Add(FVector((gridPosX + 1)*edgeLength, gridPosY*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, (gridPosY + 1)*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, (gridPosY + 1)*edgeLength, gridPosZ*edgeLength));

	vertices.Add(FVector(gridPosX*edgeLength, gridPosY*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, gridPosY*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, (gridPosY + 1)*edgeLength, gridPosZ*edgeLength));

	// right face
	vertices.Add(FVector(gridPosX*edgeLength, (gridPosY + 1)*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, (gridPosY + 1)*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, (gridPosY + 1)*edgeLength, (gridPosZ + 1)*edgeLength));

	vertices.Add(FVector((gridPosX + 1)*edgeLength, (gridPosY + 1)*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, (gridPosY + 1)*edgeLength, edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, (gridPosY + 1)*edgeLength, (gridPosZ + 1)*edgeLength));

	// left face
	vertices.Add(FVector(gridPosX*edgeLength, gridPosY*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, gridPosY*edgeLength, (gridPosZ + 1)*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, gridPosY*edgeLength, gridPosZ*edgeLength));

	vertices.Add(FVector((gridPosX + 1)*edgeLength, gridPosY*edgeLength, gridPosZ*edgeLength));
	vertices.Add(FVector(gridPosX*edgeLength, gridPosY*edgeLength, (gridPosZ + 1)*edgeLength));
	vertices.Add(FVector((gridPosX + 1)*edgeLength, gridPosY*edgeLength, (gridPosZ + 1)*edgeLength));

	// this loop generates triangles, normals, uv, colors and tangents
	for (int j = 0; j < 36; j++)
	{
		Triangles.Add(j);
		normals.Add(FVector(1, 0, 0));                // most of these values are absolutely meaningless
		UV0.Add(FVector2D(0, 0));                     // I set them just to have to deal with a similar amount of values
		vertexColors.Add(FColor(100, 100, 100, 0));   // than what it'll be like when I'll reach the point
		tangents.Add(FProcMeshTangent(1, 1, 1));      // to need to set meaningful ones
	}
}