/*
 * Copyright (c) 2012, 2013, Joel Bodenmann aka Tectu <joel@unormal.org>
 * Copyright (c) 2012, 2013, Andrew Hannam aka inmarket
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *    * Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *    * Neither the name of the <organization> nor the
 *      names of its contributors may be used to endorse or promote products
 *      derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "gfx.h"

#define GL3D_WINDOW_SIZE		120		// Limits zbuffer size to program runs in 192k limit on STMF407
#define FRAME_DELAY				20		// 20ms should be approx 50 frames per second less CPU overheads.

#include <math.h>
#ifndef M_PI
#  define M_PI 3.14159265
#endif

/* The handle for our Window */
GHandle gh;

/*
 * Draw a gear wheel.  You'll probably want to call this function when
 * building a display list since we do a lot of trig here.
 *
 * Input:  inner_radius - radius of hole at center
 *         outer_radius - radius at center of teeth
 *         width - width of gear
 *         teeth - number of teeth
 *         tooth_depth - depth of tooth
 */
static void gear( GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
		  GLint teeth, GLfloat tooth_depth )
{
   GLint i;
   GLfloat r0, r1, r2;
   GLfloat angle, da;
   GLfloat u, v, len;

   r0 = inner_radius;
   r1 = outer_radius - tooth_depth/2.0;
   r2 = outer_radius + tooth_depth/2.0;

   da = 2.0*M_PI / teeth / 4.0;

   glShadeModel( GL_FLAT );

   glNormal3f( 0.0, 0.0, 1.0 );

   /* draw front face */
   glBegin( GL_QUAD_STRIP );
   for (i=0;i<=teeth;i++) {
      angle = i * 2.0*M_PI / teeth;
      glVertex3f( r0*cos(angle), r0*sin(angle), width*0.5 );
      glVertex3f( r1*cos(angle), r1*sin(angle), width*0.5 );
      glVertex3f( r0*cos(angle), r0*sin(angle), width*0.5 );
      glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da), width*0.5 );
   }
   glEnd();

   /* draw front sides of teeth */
   glBegin( GL_QUADS );
   da = 2.0*M_PI / teeth / 4.0;
   for (i=0;i<teeth;i++) {
      angle = i * 2.0*M_PI / teeth;

      glVertex3f( r1*cos(angle),      r1*sin(angle),      width*0.5 );
      glVertex3f( r2*cos(angle+da),   r2*sin(angle+da),   width*0.5 );
      glVertex3f( r2*cos(angle+2*da), r2*sin(angle+2*da), width*0.5 );
      glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da), width*0.5 );
   }
   glEnd();


   glNormal3f( 0.0, 0.0, -1.0 );

   /* draw back face */
   glBegin( GL_QUAD_STRIP );
   for (i=0;i<=teeth;i++) {
      angle = i * 2.0*M_PI / teeth;
      glVertex3f( r1*cos(angle), r1*sin(angle), -width*0.5 );
      glVertex3f( r0*cos(angle), r0*sin(angle), -width*0.5 );
      glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da), -width*0.5 );
      glVertex3f( r0*cos(angle), r0*sin(angle), -width*0.5 );
   }
   glEnd();

   /* draw back sides of teeth */
   glBegin( GL_QUADS );
   da = 2.0*M_PI / teeth / 4.0;
   for (i=0;i<teeth;i++) {
      angle = i * 2.0*M_PI / teeth;

      glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da), -width*0.5 );
      glVertex3f( r2*cos(angle+2*da), r2*sin(angle+2*da), -width*0.5 );
      glVertex3f( r2*cos(angle+da),   r2*sin(angle+da),   -width*0.5 );
      glVertex3f( r1*cos(angle),      r1*sin(angle),      -width*0.5 );
   }
   glEnd();


   /* draw outward faces of teeth */
   glBegin( GL_QUAD_STRIP );
   for (i=0;i<teeth;i++) {
      angle = i * 2.0*M_PI / teeth;

      glVertex3f( r1*cos(angle),      r1*sin(angle),       width*0.5 );
      glVertex3f( r1*cos(angle),      r1*sin(angle),      -width*0.5 );
      u = r2*cos(angle+da) - r1*cos(angle);
      v = r2*sin(angle+da) - r1*sin(angle);
      len = sqrt( u*u + v*v );
      u /= len;
      v /= len;
      glNormal3f( v, -u, 0.0 );
      glVertex3f( r2*cos(angle+da),   r2*sin(angle+da),    width*0.5 );
      glVertex3f( r2*cos(angle+da),   r2*sin(angle+da),   -width*0.5 );
      glNormal3f( cos(angle), sin(angle), 0.0 );
      glVertex3f( r2*cos(angle+2*da), r2*sin(angle+2*da),  width*0.5 );
      glVertex3f( r2*cos(angle+2*da), r2*sin(angle+2*da), -width*0.5 );
      u = r1*cos(angle+3*da) - r2*cos(angle+2*da);
      v = r1*sin(angle+3*da) - r2*sin(angle+2*da);
      glNormal3f( v, -u, 0.0 );
      glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da),  width*0.5 );
      glVertex3f( r1*cos(angle+3*da), r1*sin(angle+3*da), -width*0.5 );
      glNormal3f( cos(angle), sin(angle), 0.0 );
   }

   glVertex3f( r1*cos(0), r1*sin(0), width*0.5 );
   glVertex3f( r1*cos(0), r1*sin(0), -width*0.5 );

   glEnd();


   glShadeModel( GL_SMOOTH );

   /* draw inside radius cylinder */
   glBegin( GL_QUAD_STRIP );
   for (i=0;i<=teeth;i++) {
      angle = i * 2.0*M_PI / teeth;
      glNormal3f( -cos(angle), -sin(angle), 0.0 );
      glVertex3f( r0*cos(angle), r0*sin(angle), -width*0.5 );
      glVertex3f( r0*cos(angle), r0*sin(angle), width*0.5 );
   }
   glEnd();

}


static GLfloat view_rotx=20.0, view_roty=30.0, view_rotz=0.0;
static GLint gear1, gear2, gear3;
static GLfloat angle = 0.0;

static void draw( void )
{
   glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

   glPushMatrix();
   glRotatef( view_rotx, 1.0, 0.0, 0.0 );
   glRotatef( view_roty, 0.0, 1.0, 0.0 );
   glRotatef( view_rotz, 0.0, 0.0, 1.0 );

   glPushMatrix();
   glTranslatef( -3.0, -2.0, 0.0 );
   glRotatef( angle, 0.0, 0.0, 1.0 );
   glCallList(gear1);
   glPopMatrix();

   glPushMatrix();
   glTranslatef( 3.1, -2.0, 0.0 );
   glRotatef( -2.0*angle-9.0, 0.0, 0.0, 1.0 );
   glCallList(gear2);
   glPopMatrix();

   glPushMatrix();
   glTranslatef( -3.1, 4.2, 0.0 );
   glRotatef( -2.0*angle-25.0, 0.0, 0.0, 1.0 );
   glCallList(gear3);
   glPopMatrix();

   glPopMatrix();

   gwinRedraw(gh);
}


static void spin( void )
{
   angle += 2.0;
   draw();
}

/* new window size or exposure */
static void setup(void)
{
   GLfloat  h = (GLfloat) gwinGetWidth(gh) / (GLfloat) gwinGetHeight(gh);

   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   glFrustum( -1.0, 1.0, -h, h, 5.0, 60.0 );
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
   glTranslatef( 0.0, 0.0, -40.0 );
   glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
}


static void init( void )
{
   static GLfloat pos[4] = {5.0, 5.0, 10.0, 0.0 };
   static GLfloat red[4] = {0.8, 0.1, 0.0, 1.0 };
   static GLfloat green[4] = {0.0, 0.8, 0.2, 1.0 };
   static GLfloat blue[4] = {0.2, 0.2, 1.0, 1.0 };

   glLightfv( GL_LIGHT0, GL_POSITION, pos );
   glEnable( GL_CULL_FACE );
   glEnable( GL_LIGHTING );
   glEnable( GL_LIGHT0 );
   glEnable( GL_DEPTH_TEST );

   /* make the gears */
   gear1 = glGenLists(1);
   glNewList(gear1, GL_COMPILE);
   glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red );
   gear( 1.0, 4.0, 1.0, 20, 0.7 );
   glEndList();

   gear2 = glGenLists(1);
   glNewList(gear2, GL_COMPILE);
   glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green );
   gear( 0.5, 2.0, 2.0, 10, 0.7 );
   glEndList();

   gear3 = glGenLists(1);
   glNewList(gear3, GL_COMPILE);
   glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue );
   gear( 1.3, 2.0, 0.5, 10, 0.7 );
   glEndList();

   glEnable( GL_NORMALIZE );
}

int main(void) {
    /* Initialize and clear the display */
    gfxInit();
    gdispClear(GFX_WHITE);

    /* Create the 3D window */
    {
    	GWindowInit	wi;

		gwinClearInit(&wi);
    	wi.show = TRUE; wi.x = (gdispGetWidth()-GL3D_WINDOW_SIZE)/2; wi.y = (gdispGetHeight()-GL3D_WINDOW_SIZE)/2; wi.width = GL3D_WINDOW_SIZE; wi.height = GL3D_WINDOW_SIZE;
        gh = gwinGL3DCreate(0, &wi);
    }

    /* Init the 3D stuff */
    setup();
    init();

    while(TRUE) {

    	// rate control
    	gfxSleepMilliseconds(FRAME_DELAY);

    	// move and redraw
    	spin();
    }   
}