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//PocketBox2d Minisample
//Box2d and graphics on a PocketPc (HTC P3300/200 MHZ / ARM) 
//Compiled,linked with Microsoft Visual C++ 2005 (Platform: Pocket PC 2003)
//See HelloWorld example from Box2d/Examples for world descriptions
//Required are glutes.dll and libGLES_CM.dll
#include "stdafx.h"
#include <windows.h>
#include "box2D.h"
#include "glutes.h"
// Pocket world globals and settings
b2World  *gWorld      = NULL;
b2Vec2    gGravity      ( 0.0f, -0.1f );
bool      gDoSleep    = true;
float32   gTimeStep   = 1.0f / 60.0f;
int32     gIterations = 10;
// Graphics
void drawPolyShape(const b2Shape *shape,
               GLfloat cr,GLfloat cg, GLfloat cb)
{
 GLfloat  *v;
 b2Vec2    p;
 int32   i,j;
 const b2PolyShape* s = (const b2PolyShape*)shape;
 //...the new constructor could be a problem for the performance ?
 v = new GLfloat [s->m_vertexCount*2] ;
 for (i=0, j=0; i < s->m_vertexCount; ++i,j+=2) {
   p = s->m_position + b2Mul(s->m_R, s->m_vertices[i]);
   v[j]  = p.x ;
   v[j+1]= p.y ;
 }
 glColor4f(cr, cg, cb, 1.0f);
 glShadeModel(GL_FLAT);
 glVertexPointer(2, GL_FLOAT, 0, v);
 glEnableClientState(GL_VERTEX_ARRAY);
 glDrawArrays(GL_LINE_LOOP, 0, 4);
 delete [] v;
}
void display()
{
 glClear (GL_COLOR_BUFFER_BIT);
 for (b2Body* b = gWorld->m_bodyList; b; b = b->m_next) {
   for (b2Shape* s = b->m_shapeList; s; s = s->m_next) {
     if (b->IsStatic()) {
         drawPolyShape(s, 0.5f, 0.5f, 0.5f);
     }
     else if (b->IsSleeping()) {
         drawPolyShape(s, 0.5f, 0.5f, 0.9f);
     }
     else {
         drawPolyShape(s, 0.9f, 0.9f, 0.9f);
     }
   }
 }
 glFlush ();
 glutSwapBuffers();
}
void reshape(int w, int h)
{
 glMatrixMode(GL_PROJECTION);
 glLoadIdentity();
 glViewport(0, 0, (GLsizei) w, (GLsizei) h);
 glOrthof(0.0f, 1.0f, 0.0f, 1.0f, -1.0f, 1.0f);
 glMatrixMode(GL_MODELVIEW);
 glLoadIdentity();
}
void simpleWorld() // see Box2D/Examples/HelloWorld
{
 b2AABB worldAABB;
 worldAABB.minVertex.Set(0.0f, 0.0f);
 worldAABB.maxVertex.Set(1.0f, 1.0f);
 gWorld = new b2World(worldAABB, gGravity, gDoSleep);
 // static body
 b2BoxDef groundBoxDef;
 groundBoxDef.extents.Set(1.0f, 0.1f);
   groundBoxDef.density = 0.0f;
  b2BodyDef groundBodyDef;
   groundBodyDef.position.Set(0.0f, 0.0f);
   groundBodyDef.AddShape(&groundBoxDef);
 gWorld->CreateBody(&groundBodyDef);
 // dynamic body 1
 b2BoxDef boxDef;
   boxDef.extents.Set(0.02f, 0.06f);
   boxDef.density  = 1.0f;
   boxDef.friction = 0.1f;
  b2BodyDef bodyDef;
    bodyDef.position.Set(b2Random(0.3f,0.7f), 0.8f);
    bodyDef.rotation = b2Random(-1.0f, 1.0f);
    bodyDef.AddShape(&boxDef);
 b2Body* body = gWorld->CreateBody(&bodyDef);
}
void idle(void) // Is this the correct location for the Box2D-Step?
{
  gWorld->Step(gTimeStep, gIterations);
  glutPostRedisplay();
}
// A minimal user interface
enum { CMD_QUIT=100, CMD_RESTART };
void menu(int entry)
{
  switch(entry) {
   case CMD_QUIT: exit(0); break;
   case CMD_RESTART:
     if ( gWorld ) delete gWorld;
     simpleWorld();
     glutPostRedisplay();
     break;
   default: break;
  }
}
void keyboard(unsigned char key, int x, int y)
{
 switch (key) {
   case '\n':
      glutSimulateButton(GLUT_RIGHT_BUTTON, 10, 20);
     break;
   default: break;
 }
}
void mouse(int button, int state, int x, int y)
{
  glutSimulateButton(GLUT_RIGHT_BUTTON, x, y);
}
// The main...
int _tmain(int argc, _TCHAR *argv[])
{
  int32  mainWindow;  //actually not used
  glutInit(&argc, (char**)argv); 
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);
  mainWindow = glutCreateWindow("Box2D-PocketPc-Test");
  glClearColor (0.0f, 0.0f, 0.0f, 0.0f);
  glutDisplayFunc(display);
  glutIdleFunc(idle);
  glutKeyboardFunc(keyboard);   
  glutMouseFunc(mouse);
  glutReshapeFunc(reshape); 
  glutCreateMenu(menu);
  glutAddMenuEntry("Restart", CMD_RESTART);
  glutAddMenuEntry("Quit", CMD_QUIT);
  glutAttachMenu(GLUT_RIGHT_BUTTON);
  simpleWorld();
  glutMainLoop();
  if ( gWorld ) delete gWorld;
  return 0;
}