#include "stdafx.h"


#define NUM_SPHERES      50

GLTFrame    spheres[NUM_SPHERES];
GLTFrame    frameCamera;

GLfloat yRot = 0.0f;         // Rotation angle for animation

GLfloat fExtent = 20.0f;

void gltInitFrame(GLTFrame *f)
{
f->vLocation[0]=0.0f; f->vLocation[1]=0.0f; f->vLocation[2]=0.0f;

f->vRotation[0]=0.0f; f->vRotation[1]=0.0f; f->vRotation[2]=0.0f;
return;
}

void     gltApplyActorTransform(GLTFrame *sphere)
		  { glLoadIdentity ();
	 glTranslatef(sphere->vLocation[0], 
					sphere->vLocation[1], 
						sphere->vLocation[2]);
		  }

void gltApplyCameraTransform(GLTFrame *frameCamera)
{GLdouble ep[3],		//= {0.0, 0.0, 0.0, 1.0},
          cp[3] ;		//= {0.0, 0.0, -1.0, 1.0},
      ep[0]=frameCamera->vLocation[0];
	  ep[1]=frameCamera->vLocation[1];
	  ep[2]=frameCamera->vLocation[2];

	  cp[0]=frameCamera->vRotation[0];

	  cp[1]=0.0;

	  cp[2]=-1.0;


  gluLookAt (ep[0], ep[1], ep[2], cp[0], cp[1], cp[2], 0.0, 1.0, 0.0);
 
 }

// This function does any needed initialization on the rendering
// context.

void SetupRC()
    {
    int iSphere;

    // Bluish background
    glClearColor(0.0f, 0.0f, .50f, 1.0f );

    // Draw everything as wire frame
/*	glPolygonMode(GL_FRONT, GL_FILL);
glPolygonMode(GL_BACK, GL_LINE)*/;
    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
    gltInitFrame(&frameCamera);  // Initialize the camera

    // Randomly place the sphere inhabitants
    for(iSphere = 0; iSphere < NUM_SPHERES; iSphere++)
        {
        gltInitFrame(&spheres[iSphere]);    // Initialize the frame

        // Pick a random location between -20 and 20 at .1 increments
        spheres[iSphere].vLocation[0] = (float)((rand() % 400) - 200) * 0.1f;
        spheres[iSphere].vLocation[1] = 0.0f;
        spheres[iSphere].vLocation[2] = (float)((rand() % 400) - 200) * 0.1f;
        }
    }

// Draw a gridded ground

void DrawGround(void)
    {
   
    GLfloat fStep = 1.0f;
    GLfloat y = -0.4f;
    GLint iLine;

    glBegin(GL_LINES);
       for(iLine = -fExtent; iLine <= fExtent; iLine += fStep)
          {
          glVertex3f(iLine, y, fExtent);    // Draw Z lines
          glVertex3f(iLine, y, -fExtent);
          glVertex3f(fExtent, y, iLine);
          glVertex3f(-fExtent, y, iLine);
          }
    glEnd();
    }

// Called to draw scene
void RenderScene(void)
    {
    int i;
    yRot += 0.5f;

    // Clear the window with current clearing color
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();
        gltApplyCameraTransform(&frameCamera);

        // Draw the ground
        DrawGround();

        // Draw the randomly located spheres
        for(i = 0; i < NUM_SPHERES; i++)
            {
            glPushMatrix();
            gltApplyActorTransform(&spheres[i]);
            glutSolidSphere(0.1f, 13, 26);
            glPopMatrix();
            }
        glPushMatrix();
            glTranslatef(0.0f, 0.0f, -2.5f);

			glPushMatrix();
                glRotatef(-yRot * 2.0f, 0.0f, 1.0f, 0.0f);
                glTranslatef(1.0f, 0.0f, 0.0f);
                glutSolidSphere(0.1f, 13, 26);
            glPopMatrix();

            glRotatef(yRot, 0.0f, 1.0f, 0.0f);
			glutSolidTorus(0.15, 0.35, 40, 20);  //  gltDrawTorus(0.35, 0.15, 40, 20);
//void glutSolidTorus(GLdouble innerRadius, GLdouble outerRadius,
//GLint nsides, GLint rings);
        glPopMatrix();
    glPopMatrix();

    // Do the buffer Swap
    glutSwapBuffers();
    }

// Respond to arrow keys by moving the camera frame of reference
void SpecialKeys(int key, int x, int y)
    {
    if(key == GLUT_KEY_UP)
		frameCamera.vLocation[2]+=0.1f;       //gltMoveFrameForward(&frameCamera, 0.1f);

    if(key == GLUT_KEY_DOWN)
		frameCamera.vLocation[2]-=0.1f;        //gltMoveFrameForward(&frameCamera, -0.1f);

    if(key == GLUT_KEY_LEFT)
		frameCamera.vRotation[0]+=0.005;        //gltRotateFrameLocalY(&frameCamera, 0.1);

    if(key == GLUT_KEY_RIGHT)
		frameCamera.vRotation[0]-=0.005;        //gltRotateFrameLocalY(&frameCamera, -0.1);

    // Refresh the Window
    glutPostRedisplay();
    }


void ChangeSize(int w, int h)
{
	glViewport (0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
gluPerspective(60.0, 1.0, 1.5, 400.0);
glMatrixMode (GL_MODELVIEW);

}


int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);
   glutInitWindowSize (500, 500); 
   glutInitWindowPosition (100, 100);
   glutCreateWindow (argv[0]);
   SetupRC();
   glutDisplayFunc(RenderScene); 
   glutReshapeFunc(ChangeSize);
   glutSpecialFunc (SpecialKeys);
   glutMainLoop();
   return 0;
}