/*
    Initial version was a Mesa example

    iadn
    http://www.iadn.narod.ru
    iadn@bk.ru
*/

/*
 * 3-D gear wheels.  This program is in the public domain.
 *
 * Brian Paul
 */

/*
 * Newlib port by maxcodehack
 */

#include <sys/ksys.h>
#include <kosgl.h> // TinyGL
#include <string.h>
#include <math.h>

int Fps (long x, long y);

struct {
    int x,y;
    int dx,dy;
} win;

#define KEY_ESC       1
#define KEY_F        33

char *title = "Gears (F - full screen, ESC - exit)";
char *fps    = "FPS:";

unsigned char FullScreen = 0;
unsigned char skin = 0x34;

ksys_oskey_t key;

ksys_thread_t pri;
KOSGLContext cgl;

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 GLuint limit;
static GLuint count = 1;

/*
 * 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(0.0), r1*sin(0.0), width*0.5 );
    glVertex3f( r1*cos(0.0), r1*sin(0.0), -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();
}

void init()
{
    static GLfloat pos[4] = {5.0, 5.0, 10.0, 1.0 };
    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 );

    glViewport(0, 0, (GLint)500, (GLint)480);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glFrustum( -1.0, 1.0, -1, 1, 5.0, 60.0 );
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glTranslatef( 0.0, 0.0, -40.0 );
    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
}

void reshape()
{
    _ksys_thread_info(&pri, -1);
    glViewport(0, 0, pri.winx_size, pri.winy_size-20);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0, (GLfloat)pri.winx_size/pri.winy_size, 1.0, 60.0);
    glTranslatef( 0.0, 0.0, 20.0 );
    glMatrixMode(GL_MODELVIEW);
    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
}

void disabletgl()
{
    kosglDestroyContext(cgl);
}

void kos_text(int x, int y, int color, const char* text, int len)
{
    asm volatile ("int $0x40"::"a"(4),"b"((x<<16) | y),"c"(color),"d"((unsigned long)text),"S"(len));
};

void Title()
{
     kos_text(300,8,0x10ffffff,fps,strlen(fps));
     /*kos_text(180,8,0x90ffffff,title2,strlen(title2));
     kos_text(600,8,0x90ffffff,title3,strlen(title3));*/
}

void draw_window()
{
    _ksys_start_draw();
    _ksys_create_window(win.x, win.y, win.dx, win.dy, title, 0, skin);
    _ksys_end_draw();
    // display string
    Title();
}

int main()
{
    win.x = 100;
    win.y = 100;
    win.dx = 400;
    win.dy = 400;

    draw_window();

    cgl = kosglCreateContext( 0, 0);
    kosglMakeCurrent( 0, 0, win.dx, win.dy, cgl);

    init();

    _ksys_set_key_input_mode(KSYS_KEY_INPUT_MODE_SCANC);

    reshape();

    do {
        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( -2.0, -2.0, 0.0 );
        glRotatef( angle, 0.0, 0.0, 1.0 );
        glCallList(gear1);
        glPopMatrix();

        glPushMatrix();
        glTranslatef( 4.1, -2.0, 0.0 );
        glRotatef( -2.0*angle-9.0, 0.0, 0.0, 1.0 );
        glCallList(gear2);
        glPopMatrix();

        glPushMatrix();
        glTranslatef( -2.1, 4.2, 0.0 );
        glRotatef( -2.0*angle-25.0, 0.0, 0.0, 1.0 );
        glCallList(gear3);
        glPopMatrix();

        glPopMatrix();

        kosglSwapBuffers();

        angle += 0.01 + 0.3 * Fps (330, 8);

        switch(_ksys_check_event())
        {
            case 1:
                draw_window();
                reshape();
                break;

            case 2:
                   key = _ksys_get_key();
                   switch(key.code) {
                        case KEY_F:
                            if(!FullScreen){
                                skin=0x01;
                                _ksys_change_window(0,0,_ksys_screen_size().x,_ksys_screen_size().y);
                                draw_window();
                                reshape();
                                FullScreen = 1;
                            }
                            else{
                                skin=0x34;
                                draw_window();
                                _ksys_change_window(win.x,win.y,win.dx,win.dy);
                                reshape();
                                FullScreen = 0;
                            };
                            break;

                       case KEY_ESC:
                                disabletgl();
                                return 0;
                    }
                    break;

              case 3:
                    disabletgl();
                    return 0;
        }
    } while(1);
}