#include <algorithm>
#include <cmath>

#include "Models.h"
#include "misc.h"

extern bool visions;

void Model::CalculateNormals()
{
	for (int i = 0; i < TriangleNum; ++i)
		normals[i] = normalize(crossProduct(vertex[Triangles[i].vertex[1]]
			- vertex[Triangles[i].vertex[0]],
			vertex[Triangles[i].vertex[2]]
			- vertex[Triangles[i].vertex[0]]));

	for (int i = 0; i < TriangleNum; ++i) {
		vArray[i*27+0]=vertex[Triangles[i].vertex[0]].x;
		vArray[i*27+1]=vertex[Triangles[i].vertex[0]].y;
		vArray[i*27+2]=vertex[Triangles[i].vertex[0]].z;
		vArray[i*27+3]=normals[i].x;
		vArray[i*27+4]=normals[i].y;
		vArray[i*27+5]=normals[i].z;
		vArray[i*27+6]=Triangles[i].r;
		vArray[i*27+7]=Triangles[i].g;
		vArray[i*27+8]=Triangles[i].b;

		vArray[i*27+9]=vertex[Triangles[i].vertex[1]].x;
		vArray[i*27+10]=vertex[Triangles[i].vertex[1]].y;
		vArray[i*27+11]=vertex[Triangles[i].vertex[1]].z;
		vArray[i*27+12]=normals[i].x;
		vArray[i*27+13]=normals[i].y;
		vArray[i*27+14]=normals[i].z;
		vArray[i*27+15]=Triangles[i].r;
		vArray[i*27+16]=Triangles[i].g;
		vArray[i*27+17]=Triangles[i].b;

		vArray[i*27+18]=vertex[Triangles[i].vertex[2]].x;
		vArray[i*27+19]=vertex[Triangles[i].vertex[2]].y;
		vArray[i*27+20]=vertex[Triangles[i].vertex[2]].z;
		vArray[i*27+21]=normals[i].x;
		vArray[i*27+22]=normals[i].y;
		vArray[i*27+23]=normals[i].z;
		vArray[i*27+24]=Triangles[i].r;
		vArray[i*27+25]=Triangles[i].g;
		vArray[i*27+26]=Triangles[i].b;
	}

	this->center = {};
	for (int i = 0; i < vertexNum; ++i)
		this->center += vertex[i];
	this->center /= vertexNum;

	this->radius = 0;
	for (int i = 0; i < vertexNum; ++i)
		this->radius = std::max(this->radius,
			sqrlen(this->center - vertex[i]));
	this->radius = sqrt(this->radius);
}

void Model::load(const char* path)
{
	auto model = loadModel(path);
	vertexNum = model.vertices.len;
	for (short i = 0; i < vertexNum; ++i) {
		vertex[i].x = model.vertices.ptr[i].x;
		vertex[i].y = model.vertices.ptr[i].y;
		vertex[i].z = model.vertices.ptr[i].z;
	}
	free(model.vertices.ptr);

	TriangleNum = model.faces.len;
	for (short i = 0; i < TriangleNum; ++i) {
		Triangles[i].vertex[0] = model.faces.ptr[i].v[0];
		Triangles[i].vertex[1] = model.faces.ptr[i].v[1];
		Triangles[i].vertex[2] = model.faces.ptr[i].v[2];
		Triangles[i].r = model.faces.ptr[i].r;
		Triangles[i].g = model.faces.ptr[i].g;
		Triangles[i].b = model.faces.ptr[i].b;
	}
	free(model.faces.ptr);
	CalculateNormals();
}

void Model::draw()
{
	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_NORMAL_ARRAY);
	glEnableClientState(GL_COLOR_ARRAY);
	glVertexPointer(3, GL_FLOAT, 9*sizeof(GLfloat),&vArray[0]);
	glNormalPointer(GL_FLOAT, 9*sizeof(GLfloat),&vArray[3]);
	if (visions)
		glColor4f(0.0f, 0.0f, 0.0f, 1.0f);
	else
		glColorPointer(3, GL_FLOAT, 9*sizeof(GLfloat), &vArray[6]);
	glDrawArrays(GL_TRIANGLES, 0, TriangleNum*3);
}

void Model::draw(float r, float g, float b)
{
	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_NORMAL_ARRAY);
	glDisableClientState(GL_COLOR_ARRAY);
	glVertexPointer(3, GL_FLOAT, 9*sizeof(GLfloat),&vArray[0]);
	glNormalPointer(GL_FLOAT, 9*sizeof(GLfloat),&vArray[3]);
	glColor4f(r, g, b, 1.0f);
	glDrawArrays(GL_TRIANGLES, 0, TriangleNum*3);
}