#include "stdafx.h"
#include <windows.h>
#include <GL/glut.h>
#include "coursework2.h"
#include "texture.h"
#include "3dsloader.h"


int screen_width=640;
int screen_height=480;



// Absolute rotation values (0-359 degrees) and rotation increments for each frame
double rotation_x=0, rotation_x_increment=0.1;
double rotation_y=0, rotation_y_increment=0.05;
double rotation_z=0, rotation_z_increment=0.03;
 
// Flag for rendering as lines or filled polygons
int filling=1; //0=OFF 1=ON


obj_type object;



/**********************************************************
 *
 * init()
 *
 * Used to initialize OpenGL and to setup the world
 *
 *********************************************************/

void init(void)
{
    glClearColor(0.0, 0.0, 0.0, 0.0); // This clear the background color to black
    glShadeModel(GL_SMOOTH); // Type of shading for the polygons
   	
    // Viewport transformation
    glViewport(0,0,screen_width,screen_height);  

    // Projection transformation
    glMatrixMode(GL_PROJECTION); // Specifies which matrix stack is the target for matrix operations 
    glLoadIdentity(); // initialize the projection matrix as identity
    gluPerspective(45.0f,(GLfloat)screen_width/(GLfloat)screen_height,10.0f,10000.0f); // define the "viewing volume"
   
    glEnable(GL_DEPTH_TEST); // enable the depth test (also called z buffer)
    glPolygonMode (GL_FRONT_AND_BACK, GL_FILL); // Polygon rasterization mode (polygon filled)
    
    glEnable(GL_TEXTURE_2D); // This Enable the Texture mapping

    Load3DS (&object,"GTR.3ds");

    object.id_texture=LoadBitmap("body.bmp"); // The Function LoadBitmap() return the current texture ID
    

}



/**********************************************************
 *
 * resize(int,int)
 *
 * This routine must be called everytime i resize our window.
 * 
 *********************************************************/

void resize (int width, int height)
{
    screen_width=width; // obtain the new screen width values and store it
    screen_height=height; // Height value

    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // clear both the color and the depth buffer so to draw the next frame
    glViewport(0,0,screen_width,screen_height); // Viewport transformation

    glMatrixMode(GL_PROJECTION); // Projection transformation
    glLoadIdentity(); // initialize the projection matrix as identity
    gluPerspective(45.0f,(GLfloat)screen_width/(GLfloat)screen_height,10.0f,10000.0f);

    glutPostRedisplay (); // This command redraws the scene 
}




/**********************************************************
 *
 * display()
 *
 * This is the main rendering subroutine, called each frame
 * 
 *********************************************************/

void display(void)
{
    int l_index;

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
    glMatrixMode(GL_MODELVIEW); // Modeling transformation
    glLoadIdentity(); // Initialize the model matrix as identity
    
    glTranslatef(0.0,0.0,-300); // move the object forward (the model matrix is multiplied by the translation matrix)
 
    rotation_x = rotation_x + rotation_x_increment;
    rotation_y = rotation_y + rotation_y_increment;
    rotation_z = rotation_z + rotation_z_increment;

    if (rotation_x > 359) rotation_x = 0;
    if (rotation_y > 359) rotation_y = 0;
    if (rotation_z > 359) rotation_z = 0;

    glRotatef(rotation_x,1.0,0.0,0.0); // Rotations of the object (the model matrix is multiplied by the rotation matrices)
    glRotatef(rotation_y,0.0,1.0,0.0);
    glRotatef(rotation_z,0.0,0.0,1.0);
    
    glBindTexture(GL_TEXTURE_2D, object.id_texture); // set the active texture 

    glBegin(GL_TRIANGLES);
    for (l_index=0;l_index<object.polygons_qty;l_index++)
    {
        //----------------- FIRST VERTEX -----------------
        // Texture coordinates of the first vertex
        glTexCoord2f( object.mapcoord[ object.polygon[l_index].a ].u,
                      object.mapcoord[ object.polygon[l_index].a ].v);
        // Coordinates of the first vertex
        glVertex3f( object.vertex[ object.polygon[l_index].a ].x,
                    object.vertex[ object.polygon[l_index].a ].y,
                    object.vertex[ object.polygon[l_index].a ].z); //Vertex definition

        //----------------- SECOND VERTEX -----------------
        // Texture coordinates of the second vertex
        glTexCoord2f( object.mapcoord[ object.polygon[l_index].b ].u,
                      object.mapcoord[ object.polygon[l_index].b ].v);
        // Coordinates of the second vertex
        glVertex3f( object.vertex[ object.polygon[l_index].b ].x,
                    object.vertex[ object.polygon[l_index].b ].y,
                    object.vertex[ object.polygon[l_index].b ].z);
        
        //----------------- THIRD VERTEX -----------------
        // Texture coordinates of the third vertex
        glTexCoord2f( object.mapcoord[ object.polygon[l_index].c ].u,
                      object.mapcoord[ object.polygon[l_index].c ].v);
        // Coordinates of the Third vertex
        glVertex3f( object.vertex[ object.polygon[l_index].c ].x,
                    object.vertex[ object.polygon[l_index].c ].y,
                    object.vertex[ object.polygon[l_index].c ].z);
    }
    glEnd();

    glFlush(); // This force the execution of OpenGL commands
    glutSwapBuffers(); 
}



/**********************************************************
 *
 * The main routine
 * 
 *********************************************************/

int main(int argc, char **argv)
{
    glutInit(&argc, argv);    
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(screen_width,screen_height);
    glutInitWindowPosition(0,0);
    glutCreateWindow("Coursework 2");    
    glutDisplayFunc(display);
    glutIdleFunc(display);
    glutReshapeFunc (resize);
    init();
    glutMainLoop();

    return(0);    
} 

/**********************************************************
 *
 * TYPES DECLARATION
 *
 *********************************************************/

#define MAX_VERTICES 8000 // Max number of vertices (for each object)
#define MAX_POLYGONS 8000 // Max number of polygons (for each object)

// vertex type
typedef struct{
    float x,y,z;
}vertex_type;

// The polygon (triangle), 3 numbers that aim 3 vertices
typedef struct{
    int a,b,c;
}polygon_type;

// The mapcoord type, 2 texture coordinates for each vertex
typedef struct{
    float u,v;
}mapcoord_type;

// The object type
typedef struct {
	char name[20];
    
	int vertices_qty;
    int polygons_qty;

    vertex_type vertex[MAX_VERTICES]; 
    polygon_type polygon[MAX_POLYGONS];
    mapcoord_type mapcoord[MAX_VERTICES];
    int id_texture;
} obj_type, *obj_type_ptr;