/* main_glut.c - Don Yang (uguu.org)

   05/12/03
                                                                           */

#include"core.h"


static int WindowHandle = 0;
static int MouseX = 0, MouseY = 0;

static void FirstPaint(void);
static void InitWindowManager(void);
static void ProcessIdleEvent(void);
static void ProcessKeyboardEvent(unsigned char c,
                                 /*@unused@*/int u, /*@unused@*/int v);
static void ProcessMouseButton(/*@unused@*/int b, /*@unused@*/int state,
                               int x, int y);
static void ProcessMouseMove(int x, int y);
static void ProcessPaintEvent(void);
static void ProcessResizeEvent(/*@unused@*/int w, /*@unused@*/int h);

/******************************************************************** main */
int main(int argc, char **argv)
{
   glutInit(&argc, argv);
   InitWindowManager();
   glutMainLoop();
   return 0;

} /* main() */


/************************************************************** FirstPaint */
static void FirstPaint(void)
{
   Init();     /* (core.c) */
   glutDisplayFunc(ProcessPaintEvent);
   glutSetWindow(WindowHandle);
   glutPostRedisplay();

} /* FirstPaint() */

/******************************************************* InitWindowManager */
static void InitWindowManager(void)
{
   glutInitDisplayMode((unsigned)(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH));
   glutInitWindowSize(WINDOW_INIT_WIDTH, WINDOW_INIT_HEIGHT);
   glutInitWindowPosition(WINDOW_INIT_X, WINDOW_INIT_Y);

   WindowHandle = glutCreateWindow(WINDOW_TITLE);
   glutSetWindowTitle(WINDOW_TITLE);
   glutSetWindow(WindowHandle);

   glutDisplayFunc(FirstPaint);
   glutIdleFunc(ProcessIdleEvent);
   glutReshapeFunc(ProcessResizeEvent);
   glutKeyboardFunc(ProcessKeyboardEvent);
   glutMouseFunc(ProcessMouseButton);
   glutMotionFunc(ProcessMouseMove);

} /* InitWindowManager() */

/******************************************************** ProcessIdleEvent */
static void ProcessIdleEvent(void)
{
   glutSetWindow(WindowHandle);
   glutPostRedisplay();

} /* ProcessIdleEvent() */

/**************************************************** ProcessKeyboardEvent */
static void ProcessKeyboardEvent(unsigned char c,
                                 /*@unused@*/int u, /*@unused@*/int v)
{
   if( (int)c == 27 || tolower(c) == (int)'q' || tolower(c) == (int)'x' )
   {
      glFlush();
      Cleanup();     /* (core.c) */
      exit(EXIT_SUCCESS);
   }

} /* ProcessKeyboardEvent() */

/****************************************************** ProcessMouseButton */
static void ProcessMouseButton(/*@unused@*/int b, /*@unused@*/int state,
                               int x, int y)
{
   MouseX = x;
   MouseY = y;

} /* ProcessMouseButton() */

/******************************************************** ProcessMouseMove */
static void ProcessMouseMove(int x, int y)
{
   int dx, dy;

   /* Move window when mouse buttons are pressed.
      Note that we do not have to track button state, since this is not
      a glutPassiveMotion callback function, some button must be pressed. */
   glutPositionWindow(glutGet(GLUT_WINDOW_X) + (dx = x - MouseX),
                      glutGet(GLUT_WINDOW_Y) + (dy = y - MouseY));
   MouseX = x - dx;
   MouseY = y - dy;

} /* ProcessMouseMove() */

/******************************************************* ProcessPaintEvent */
static void ProcessPaintEvent(void)
{
   glutSetWindow(WindowHandle);
   Render(glutGet(GLUT_WINDOW_WIDTH), glutGet(GLUT_WINDOW_HEIGHT));
   glutSwapBuffers();
   glFlush();

} /* ProcessPaintEvent() */

/****************************************************** ProcessResizeEvent */
static void ProcessResizeEvent(/*@unused@*/int w, /*@unused@*/int h)
{
   glutSetWindow(WindowHandle);
   glutPostRedisplay();

} /* ProcessResizeEvent() */