// stdafx.cpp : source file that includes just the standard includes
// GLUTsimple.pch will be the pre-compiled header
// stdafx.obj will contain the pre-compiled type information

#include "stdafx.h"

// Define a constant for the value of PI

#define GL_PI 3.1415f

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

void SetupRC()

    {    // Black background
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f );

    // Set drawing color to green
    glColor3f(0.0f, 1.0f, 0.0f);
    }

// Called to draw scene
void RenderScene(void)
    {    GLfloat x,y,z,angle; // Storage for coordinates and angles

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

    // Save matrix state and do the rotation
    glPushMatrix();
    glRotatef(xRot, 1.0f, 0.0f, 0.0f);
    glRotatef(yRot, 0.0f, 1.0f, 0.0f);

    // Call only once for all remaining points
    glBegin(GL_POINTS);
    z = -50.0f;

    for(angle = 0.0f; angle <= (2.0f*GL_PI)*3.0f; angle += 0.1f)
        {	x = 50.0f*sin(angle);
			y = 50.0f*cos(angle);

        // Specify the point and move the Z value up a little
        glVertex3f(x, y, z);
        z += 0.5f;
        }

    // Done drawing points
    glEnd();

    // Restore transformations
    glPopMatrix();

    // Flush drawing commands
    glFlush();
    }


void drawTriangle (GLfloat x1, GLfloat y1, GLfloat x2,
GLfloat y2, GLfloat x3, GLfloat y3, GLfloat z)
{
glBegin (GL_TRIANGLES);
glVertex3f (x1, y1, z);
glVertex3f (x2, y2, z);
glVertex3f (x3, y3, z);
glEnd ();
}

void drawViewVolume (GLfloat x1, GLfloat x2, GLfloat y1,
GLfloat y2, GLfloat z1, GLfloat z2)
{
glColor3f (1.0, 1.0, 1.0);
glBegin (GL_LINE_LOOP);
glVertex3f (x1, y1, -z1);
glVertex3f (x2, y1, -z1);
glVertex3f (x2, y2, -z1);
glVertex3f (x1, y2, -z1);
glEnd ();
glBegin (GL_LINE_LOOP);
glVertex3f (x1, y1, -z2);
glVertex3f (x2, y1, -z2);
glVertex3f (x2, y2, -z2);
glVertex3f (x1, y2, -z2);
glEnd ();
glBegin (GL_LINES); /* 4 lines */
glVertex3f (x1, y1, -z1);
glVertex3f (x1, y1, -z2);
glVertex3f (x1, y2, -z1);
glVertex3f (x1, y2, -z2);
glVertex3f (x2, y1, -z1);
glVertex3f (x2, y1, -z2);
glVertex3f (x2, y2, -z1);
glVertex3f (x2, y2, -z2);
glEnd ();
}

void drawScene (void)
{
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
gluPerspective (40.0, 4.0/3.0, 1.0, 100.0);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity ();
gluLookAt (7.5, 7.5, 12.5, 2.5, 2.5, -5.0, 0.0, 1.0, 0.0);
glColor3f (0.0, 1.0, 0.0); /* green triangle */
drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -5.0);
glColor3f (1.0, 0.0, 0.0); /* red triangle */
drawTriangle (2.0, 7.0, 3.0, 7.0, 2.5, 8.0, -5.0);
glColor3f (1.0, 1.0, 0.0); /* yellow triangles */
drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, 0.0);
drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -10.0);
drawViewVolume (0.0, 5.0, 0.0, 5.0, 0.0, 10.0);
}


void processHits (GLint hits, GLuint buffer[])
{
unsigned int i, j;
GLuint names, *ptr;
printf ("hits = %d\n", hits);
ptr = (GLuint *) buffer;
for (i = 0; i < hits; i++) { /* for each hit */
names = *ptr;
printf (" number of names for hit = %d\n", names); ptr++;
printf(" z1 is %g;", (float) *ptr/0x7fffffff); ptr++;
printf(" z2 is %g\n", (float) *ptr/0x7fffffff); ptr++;
printf (" the name is ");
for (j = 0; j < names; j++) { /* for each name */
printf ("%d ", *ptr); ptr++;
}
printf ("\n");
}
}

#define BUFSIZE 512
void selectObjects(void)
{
GLuint selectBuf[BUFSIZE];
GLint hits;
glSelectBuffer (BUFSIZE, selectBuf);
(void) glRenderMode (GL_SELECT);
glInitNames();
glPushName(0);
glPushMatrix ();
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
glOrtho (0.0, 5.0, 0.0, 5.0, 0.0, 10.0);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity ();
glLoadName(1);
drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -5.0);
glLoadName(2);
drawTriangle (2.0, 7.0, 3.0, 7.0, 2.5, 8.0, -5.0);
glLoadName(3);
drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, 0.0);
drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -10.0);
glPopMatrix ();
glFlush ();
hits = glRenderMode (GL_RENDER);
processHits (hits, selectBuf);
}

void init (void)
{
glEnable(GL_DEPTH_TEST);
glShadeModel(GL_FLAT);
}

void display(void)
{
glClearColor (0.0, 0.0, 0.0, 0.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
drawScene ();
selectObjects ();
glFlush();
}
/**/

//int main(int argc, char** argv)
//{
//glutInit(&argc, argv);
//glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
//glutInitWindowSize (200, 200);
//glutInitWindowPosition (100, 100);
//glutCreateWindow (argv[0]);
//init();
//glutDisplayFunc(display);
//glutMainLoop();
//return 0;
//}
/**/



int _tmain(int argc, _TCHAR* argv[])
{

glutInit(&argc, (char **)argv);
	
//glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize (200, 200);
glutInitWindowPosition (100, 100);
glutCreateWindow ((char*)argv[0]);
SetupRC();
glutDisplayFunc(RenderScene);
glutMainLoop();
return 0;
}