#include <GL/glut.h>
#include <stdlib.h>

// A vertex has 3D coordinates vertex.x, vertex.y, and vertex.z,
//   normal vertex.nx, vertex.ny, and vertex.nz, and color
//   vertex.R, vertex.G, vertex.B
typedef struct {
	float x, y, z;
	float nx, ny, nz;
	float R, G, B;
} vertex;


typedef struct{
	vertex* v1;
	vertex* v2;
	vertex* v3;
} triangle;

int numtriangles=0;
triangle* tri;
int numvertices=0;
vertex* vert;


int lastx,lasty;
int xchange,ychange;
float spin=0.0;
float spinup = 0.0;

void YourCode(void);

// Note: bluelevel should be between 0 and 1.  It tells how far toward
// the blue end of the red->blue range it should be.  bluelevel=1.0 means
// totally blue, bluelevel=0.0 means totally red.
void set(vertex& V, const float x, const float y, const float z,
		 const float nx, const float ny, const float nz,
		 const float bluelevel) {
	V.x = x;
	V.y = y;
	V.z = z;
	V.nx = nx;
	V.ny = ny;
	V.nz = nz;
	V.R = 1.0-bluelevel;
	V.G = 0.0;
	V.B = bluelevel;
}

void setposition(vertex& V, const float x, const float y, const float z) {
	V.x = x;
	V.y = y;
	V.z = z;
}

void setnormal(vertex& V, const float nx, const float ny, const float nz) {
	V.nx = nx;
	V.ny = ny;
	V.nz = nz;
}

void setcolor (vertex& V, const float bluelevel) {
	V.R = 1.0-bluelevel;
	V.G = 0.0;
	V.B = bluelevel;
}

void display(void)
{
	int i;
	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

	glPushMatrix();
	glRotatef(spinup, 1.0, 0.0, 0.0);
	glRotatef(spin, 0.0, 1.0, 0.0);

	glEnable(GL_COLOR_MATERIAL);
	glColorMaterial(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE);

	glBegin(GL_TRIANGLES);
	for(i=0;i<numtriangles;i++) {
		glColor3f(tri[i].v1->R,tri[i].v1->G,tri[i].v1->B);
		glVertex3f(tri[i].v1->x,tri[i].v1->y,tri[i].v1->z);
		glNormal3f(tri[i].v1->nx,tri[i].v1->ny,tri[i].v1->z);
		glColor3f(tri[i].v2->R,tri[i].v2->G,tri[i].v2->B);
		glVertex3f(tri[i].v2->x,tri[i].v2->y,tri[i].v2->z);
		glNormal3f(tri[i].v2->nx,tri[i].v2->ny,tri[i].v2->z);
		glColor3f(tri[i].v3->R,tri[i].v3->G,tri[i].v3->B);
		glVertex3f(tri[i].v3->x,tri[i].v3->y,tri[i].v3->z);
		glNormal3f(tri[i].v3->nx,tri[i].v3->ny,tri[i].v3->z);
	}
	glEnd();

	// Draw Axes
	glColor3f(1.0, 1.0, 1.0);
	glBegin(GL_LINES);
		// X-axis
		glVertex3f(0.0,0.0,0.0);
		glVertex3f(0.2,0.0,0.0);
		glVertex3f(0.22,0.0,0.0);
		glVertex3f(0.32,0.1,0.0);
		glVertex3f(0.22,0.1,0.0);
		glVertex3f(0.32,0.0,0.0);

		// Y-axis
		glVertex3f(0.0,0.0,0.0);
		glVertex3f(0.0,0.2,0.0);
		glVertex3f(0.0,0.22,0.0);
		glVertex3f(0.0,0.27,0.0);
		glVertex3f(0.0,0.27,0.0);
		glVertex3f(0.05,0.32,0.0);
		glVertex3f(0.0,0.27,0.0);
		glVertex3f(-0.05,0.32,0.0);

		// Z-axis
		glVertex3f(0.0,0.0,0.0);
		glVertex3f(0.0,0.0,0.2);
		glVertex3f(0.0,0.1,0.32);
		glVertex3f(0.0,0.1,0.22);
		glVertex3f(0.0,0.1,0.22);
		glVertex3f(0.0,0.0,0.32);
		glVertex3f(0.0,0.0,0.32);
		glVertex3f(0.0,0.0,0.22);
	glEnd();

	glPopMatrix();

	glutSwapBuffers();
}

void init(void)
{
	glClearColor(0.0, 0.0, 0.0, 0.0);
	glShadeModel(GL_SMOOTH);
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_NORMALIZE);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(-1.75, 1.75, -1.75, 1.75, -0.2, 4.0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	gluLookAt(0.0, 0.0, 2.0,
		      0.0, 0.0, 0.0,
			  0.0, 1.0, 0.0);

	glEnable(GL_LIGHTING);
	glLightf(GL_LIGHT0, GL_POSITION, (2.0, 2.0, 1.0));
	glLightf(GL_LIGHT0, GL_DIFFUSE, (0.5, 0.5, 0.5, 1.0));
	glLightf(GL_LIGHT0, GL_AMBIENT, (0.5, 0.5, 0.5, 1.0));
	glLightf(GL_LIGHT1, GL_POSITION, (-2.0, 2.0, 2.0));
	glLightf(GL_LIGHT1, GL_DIFFUSE, (0.5, 0.5, 0.5, 1.0));
	glLightf(GL_LIGHT2, GL_POSITION, (2.0, -2.0, 2.0));
	glLightf(GL_LIGHT2, GL_DIFFUSE, (0.5, 0.5, 0.5, 1.0));
	glLightf(GL_LIGHT3, GL_POSITION, (-2.0, -2.0, 2.0));
	glLightf(GL_LIGHT3, GL_DIFFUSE, (0.5, 0.5, 0.5, 1.0));
	glEnable(GL_LIGHT0);
	glEnable(GL_LIGHT1);
	glEnable(GL_LIGHT2);
	glEnable(GL_LIGHT3);
	glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);

}

void rotateview(void)
{
	spin += xchange/80.0;
	if (spin >= 360.0) spin -= 360.0;
	if (spin < 0.0) spin += 360.0;
	spinup -= ychange/80.0;
	if (spinup > 89.0) spinup = 89.0;
	if (spinup < -89.0) spinup = -89.0;
	glutPostRedisplay();
}

void mouse(int button, int state, int x, int y)
{
	switch(button) {
	case GLUT_LEFT_BUTTON:
		if (state==GLUT_DOWN) {
			lastx = x;
			lasty = y;
			xchange = 0;
			ychange = 0;
			glutIdleFunc(rotateview);
		} else if (state==GLUT_UP) {
			xchange = 0;
			ychange = 0;
			glutIdleFunc(NULL);
		}
		break;

	default:
		break;
	}
}

void motion(int x, int y)
{
	xchange = x-lastx;
	ychange = y-lasty;
}

void YourCode(void)
{
	// Your Code Here.  Some sample code is given.
	tri = new triangle[3];
	numtriangles=3;
	numvertices=9;
	vert = new vertex[9];
	tri[0].v1 = &vert[0];
	tri[0].v2 = &vert[1];
	tri[0].v3 = &vert[2];
	tri[1].v1 = &vert[3];
	tri[1].v2 = &vert[4];
	tri[1].v3 = &vert[5];
	tri[2].v1 = &vert[6];
	tri[2].v2 = &vert[7];
	tri[2].v3 = &vert[8];
	set(vert[0], 0.0,0.0,0.0, 0.0,1.0,0.0, 1.0);
	set(vert[1], 0.5,0.0,0.0, 0.0,1.0,0.0, 0.0);
	set(vert[2], 0.25,0.0,0.5, 0.0,1.0,0.0, 0.5);

	set(vert[3], 0.0,0.0,0.0, 0.0,1.0,-1.0, 1.0);
	set(vert[4], -0.5,0.0,0.0, 0.0,1.0,-1.0, 1.0);
	set(vert[5], -0.25,0.0,0.5, 0.0,1.0,1.0, 1.0);

	set(vert[6], 0.0,0.0,0.0, 0.0,1.0,1.0, 0.0);
	set(vert[7], 0.5,-0.5,0.0, 0.0,-1.0,1.0, 1.0);
	set(vert[8], -0.5,-0.5,0.0, 0.0,-1.0,1.0, 1.0);

}


int main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);
	glutInitWindowSize(500, 500);
	glutInitWindowPosition(100, 100);
	glutCreateWindow("CPSC 645 HW2 - <Your Name Here>");
	init();
	glutDisplayFunc(display);
	glutMouseFunc(mouse);
	glutMotionFunc(motion);
	glutIdleFunc(NULL);
	YourCode();
	glutMainLoop();
	return 0;
}