#include <algorithm>
#include <cmath>

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

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;
	}

	boundingspherecenter = {};
	for (int i = 0; i < vertexNum; ++i)
		boundingspherecenter += vertex[i];
	boundingspherecenter /= vertexNum;

	boundingsphereradius = 0;
	for (int i = 0; i < vertexNum; ++i)
		boundingsphereradius = std::max(boundingsphereradius,
			sqrlen(boundingspherecenter - vertex[i]));
	boundingsphereradius = sqrt(boundingsphereradius);
}

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();
}

extern int nocolors;
void Model::draw()
{
	if(!nocolors){
	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]);
	glColorPointer(3,GL_FLOAT, 9*sizeof(GLfloat),&vArray[6]);
	glDrawArrays(GL_TRIANGLES, 0, TriangleNum*3);
	}
	if(nocolors){
		glColor4f(0,0,0,1);
		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]);
		glDrawArrays(GL_TRIANGLES, 0, TriangleNum*3);
	}
}

void Model::draw(float r, float g, float b)
{
	if(!nocolors)glColor4f(r,g,b,1);
	if(nocolors==1)glColor4f(0,0,0,1);
	if(nocolors==2)glColor4f(1,0,0,1);
	if(nocolors==3)glColor4f(0,0,1,1);
	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]);
	glDrawArrays(GL_TRIANGLES, 0, TriangleNum*3);
}

int Model::LineCheck(XYZ p1, XYZ p2, XYZ *p)
{
	int result = -1;
	if (segCrossSphere(p1, p2, boundingspherecenter, boundingsphereradius)) {
		float olddistance = 9999999.0;
		for (int j = 0; j < TriangleNum; ++j) {
			XYZ point;
			if (!segCrossTrigon(p1, p2,
			                    vertex + Triangles[j].vertex[0],
			                    vertex + Triangles[j].vertex[1],
			                    vertex + Triangles[j].vertex[2],
			                    normals + j, &point))
				continue;
			float distance = sqrlen(point - p1);
			if (distance < olddistance || result == -1) {
				olddistance = distance;
				result = j;
				*p = point;
			}
		}
	}
	return result;
}

int Model::LineCheck2(XYZ p1, XYZ p2, XYZ *p, XYZ move, float deg_y)
{
	int result = this->LineCheck(rotate(p1 - move, 0, -deg_y, 0),
		rotate(p2 - move, 0, -deg_y, 0), p);
	*p = rotate(*p, 0, deg_y, 0) + move;
	return result;
}