/* 
 * The running man
 *
 * Copyright (C) 2001-2003  Robert Ancell <bob27@users.sourceforge.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/* compile with `make' */

#include <GL/glut.h>
#include <glass/glass.h>

#include <stdlib.h>
#include <stdio.h>
#include <math.h>

void init(void);
void reshape(int x, int y);
void keyboard(unsigned char, int, int);
void mouse(int, int, int, int);
void mouse_motion(int, int);
void draw_ground(void);
void animate(void);
void display(void);
int main(int argc, char **argv);

/* The glass model */
GlassModel *glass_man;
int nvariables;

int mbutton, oldx, oldy;
float view_theta = 0.0f, view_phi = 0.0f, view_radius = 2500.0f;
int screen_width, screen_height;
float frequency = 1.0f;

/* The variables for the model */
int jump, waist_pitch, l_shoulder_rot, r_shoulder_rot, l_elbow_rot, r_elbow_rot;
int head_pitch, head_heading, l_hip_rot, r_hip_rot, l_knee_rot, r_knee_rot;
int l_ankle_rot, r_ankle_rot;

void init(void)
{
  /* Set up glut */
  glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL);
  glutInitWindowSize(400, 400);
  glutCreateWindow("The Running Man");

  /* Attach the functions */
  glutMouseFunc(mouse);
  glutMotionFunc(mouse_motion);
  glutKeyboardFunc(keyboard);
  glutReshapeFunc(reshape);
  glutIdleFunc(animate);
  glutDisplayFunc(display);

  glEnable(GL_CULL_FACE);
  glEnable(GL_DEPTH_TEST);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

void reshape(int w, int h)
{
  glViewport(0, 0, (GLsizei) w, (GLsizei) h); 

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(60.0, (GLfloat) w/(GLfloat) h, 0.5, 1000000.0);

  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();

  screen_width = w;
  screen_height = h;
}

void keyboard(unsigned char key, int x, int y)
{
  switch(key)
  {
  case '+':
    frequency += 0.5f;
    break;
  case '-':
    frequency -= 0.5f;
    break;
  case 27: /* esc */
    exit(0);
    break;
  }

  glutPostRedisplay();
}

void mouse(int button, int state, int x, int y)
{
  mbutton = button;
  oldx = x;
  oldy = y;
}

void mouse_motion(int x, int y)
{
  int dx = x - oldx, dy = y - oldy;

  switch(mbutton)
  {
  case GLUT_LEFT_BUTTON:
    view_theta += 1.0f * (float) dx;
    view_phi += 1.0f * (float) dy;
    break;
  case GLUT_RIGHT_BUTTON:
    view_radius += 15.0f * (float) dy;
    break;
  }

  oldx = x;
  oldy = y;

  glutPostRedisplay();
}

void draw_ground(void)
{
  glColor4f(0.1f, 0.8f, 0.2f, 0.5f);
  glBegin(GL_QUADS);
  glVertex3f(-2500.0f, 0.0f, 2500.0f);
  glVertex3f(2500.0f, 0.0f, 2500.0f);
  glVertex3f(2500.0f, 0.0f, -2500.0f);
  glVertex3f(-2500.0f, 0.0f, -2500.0f);
  glEnd();
}

void animate(void)
{
  int ticks = glutGet(GLUT_ELAPSED_TIME);
  static int old_ticks = 0;
  float dt = (ticks - old_ticks) / 1000.0f;
  static float theta = 0;
  float sin_theta, cos_theta, nsin_theta, ncos_theta, j_theta;

  theta += frequency * dt;
  sin_theta = sin(theta);
  cos_theta = cos(theta);
  nsin_theta = 0.5f * (sin_theta + 1.0f);
  ncos_theta = 0.5f * (cos_theta + 1.0f);

  /* Jump */
  j_theta = 0.5 * fmod(2.0 * theta, 2.0 * M_PI) / M_PI - 0.5;
  glassSetVariable(glass_man, jump, 155.0 + 745.0f + 500.0*(0.25 - j_theta*j_theta));

  /* Waist */
  glassSetVariable(glass_man, waist_pitch, 45.0f + exp(-0.05f * frequency) * -45.0f);

  /* Arms */
  glassSetVariable(glass_man, l_shoulder_rot, (sin_theta * 45.0f));
  glassSetVariable(glass_man, r_shoulder_rot, (-sin_theta * 45.0f));
  glassSetVariable(glass_man, l_elbow_rot, (-45.0f - (1 - nsin_theta) * 90.0f));
  glassSetVariable(glass_man, r_elbow_rot, (-45.0f - nsin_theta * 90.0f));

  /* Head */
  glassSetVariable(glass_man, head_heading, (sin_theta * 45.0f));

  /* Legs */
  glassSetVariable(glass_man, l_hip_rot, (-70.0f + (1.0f - nsin_theta) * 115.0f));
  glassSetVariable(glass_man, r_hip_rot, (-70.0f + nsin_theta * 115.0f));

  if(cos_theta < 0.0f)
  {
    glassSetVariable(glass_man, r_knee_rot, (70.0f + nsin_theta * 20.0f));
    if(sin_theta < 0.0f)
      glassSetVariable(glass_man, l_knee_rot, (-90.0f + (1.0f - nsin_theta) * 180.0f));
    else
      glassSetVariable(glass_man, l_knee_rot, (70.0f + -(1.0f - nsin_theta) * 180.0f));
  }
  else
  {
    glassSetVariable(glass_man, l_knee_rot, (70.0f + (1.0f - nsin_theta) * 20.0f));
    if(sin_theta < 0.0f)
      glassSetVariable(glass_man, r_knee_rot, (70.0f + -nsin_theta * 180.0f));
    else
      glassSetVariable(glass_man, r_knee_rot, (-90.0f + nsin_theta * 180.0f));
  }

  glassSetVariable(glass_man, l_ankle_rot, (-sin_theta * 30.0f));
  glassSetVariable(glass_man, r_ankle_rot, (sin_theta * 30.0f));

  old_ticks = ticks;

  glutPostRedisplay();
}

/* Draw the scene */
void display(void)
{
  int i;
  GLfloat value, min, max;
  float percent;

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT| GL_STENCIL_BUFFER_BIT);

  glMatrixMode(GL_MODELVIEW);

  glLoadIdentity();

  glTranslatef(0.0f, 0.0f, -view_radius);
  glRotatef(view_phi, 1.0f, 0.0f, 0.0f);
  glRotatef(view_theta, 0.0f, 1.0f, 0.0f);

  /* move camera up off ground */
  glTranslatef(0.0f, -845.0f, 0.0f);

  /* Draws the running man */
  glassDrawModel(glass_man);

  /* Make a stencil of the ground */
  glPushAttrib(GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
  glEnable(GL_STENCIL_TEST);
  glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
  glDepthMask(GL_FALSE);
  glStencilFunc(GL_ALWAYS, 1, 0xffffffff);
  glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
  draw_ground();
  glPopAttrib();
  
  /* Draws the reflection of the running man */
  glPushMatrix();
  glPushAttrib(GL_STENCIL_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_POLYGON_BIT);
  glEnable(GL_STENCIL_TEST);
  glStencilFunc(GL_EQUAL, 1, 0xffffffff);
  glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
  glDepthMask(GL_FALSE);
  glCullFace(GL_FRONT);
  glScalef(1.0f, -1.0f, 1.0f);
  glassDrawModel(glass_man);
  glPopAttrib();
  glPopMatrix();

  /* Actually draws the gound */
  glPushAttrib(GL_COLOR_BUFFER_BIT);
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  draw_ground();
  glPopAttrib();

  /* Draw the overlay */
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho(0.0f, screen_width, 0.0f, screen_height, -1.0f, 0.0f);

  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  glBegin(GL_QUADS);
  for(i = 0; i < nvariables; i++)
  {
    glColor3f(0.0, 0.0f, 1.0f);

    glVertex3f(i * 20.0f + 10.0f, 50.0f, 0.5f);
    glVertex3f(i * 20.0f + 10.0f, 10.0f, 0.5f);
    glVertex3f(i * 20.0f + 20.0f, 10.0f, 0.5f);
    glVertex3f(i * 20.0f + 20.0f, 50.0f, 0.5f);
  }

  glColor3f(1.0, 1.0f, 1.0f);
  for(i = 0; i < nvariables; i++)
  {
    value = glassGetVariableValue(glass_man, i);
    min = glassGetVariableMin(glass_man, i);
    max = glassGetVariableMax(glass_man, i);

    percent = (value - min) / (max - min);
    glVertex3f(i * 20.0f + 12.0f, 12.0f + 36.0f * percent, 0.6f);
    glVertex3f(i * 20.0f + 12.0f, 12.0f, 0.6f);
    glVertex3f(i * 20.0f + 17.0f, 12.0f, 0.6f);
    glVertex3f(i * 20.0f + 17.0f, 12.0f + 36.0f * percent, 0.6f);
  }
  glEnd();

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(60.0, (GLfloat) screen_width/(GLfloat) screen_height, 0.5, 10000.0);

  glutSwapBuffers();
}

int main(int argc, char **argv)
{
  glutInit(&argc, argv);
  init();
  /* Load the glass model */
  if((glass_man = glassLoadModel("models/person.glm")) == NULL)
  {
    fprintf(stderr, "models/person.glm not found, exiting\n");
    exit(0);
  }
  nvariables = glassGetNumVariables(glass_man);

  /* Extract the variables */
  jump = glassFindVariable(glass_man, "jump");
  waist_pitch = glassFindVariable(glass_man, "waist pitch");
  l_shoulder_rot = glassFindVariable(glass_man, "left shoulder rotate");
  r_shoulder_rot = glassFindVariable(glass_man, "right shoulder rotate");
  l_elbow_rot = glassFindVariable(glass_man, "left elbow rotate");
  r_elbow_rot = glassFindVariable(glass_man, "right elbow rotate");
  head_pitch = glassFindVariable(glass_man, "head pitch");
  head_heading = glassFindVariable(glass_man, "head heading");
  l_hip_rot = glassFindVariable(glass_man, "left hip rotate");
  r_hip_rot = glassFindVariable(glass_man, "right hip rotate");
  l_knee_rot = glassFindVariable(glass_man, "left knee rotate");
  r_knee_rot = glassFindVariable(glass_man, "right knee rotate");
  l_ankle_rot = glassFindVariable(glass_man, "left ankle rotate");
  r_ankle_rot = glassFindVariable(glass_man, "right ankle rotate");

  glutMainLoop();

  return 0;
}