/* Copyright (c) Mark J. Kilgard, 1994. */

/* This program is freely distributable without licensing fees 
   and is provided without guarantee or warrantee expressed or 
   implied. This program is -not- in the public domain. */

/***************************************************
 * file: stroke.c
 *
 * purpose: 
 * 	THIS EXAMPLE OF USING GLUT STROKE FONTS,
 *	is taken from the openGL repositories, and
 *	slightly modified.
 *
 *	Illustrates the use of two stroke fonts:
 *		STROKE_ROMAN, STROKE_MONO_ROMAN
 *
 *	A rotating marquee is displayed.
 *	
 *	Right-button click will stop rotation,
 *	and present a menu:
 *		(a) main menu (quit, help)
 *		(b) chose message
 *		(c) chose color
 *		(d) chose font
 *
 *	
 ***************************************************/

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

void *font = GLUT_STROKE_ROMAN;
void *fonts[] =
	{GLUT_STROKE_ROMAN, GLUT_STROKE_MONO_ROMAN};
// char defaultMessage[] = "GLUT means OpenGL.";
char defaultMessage[] = "For Help, Click Right Button!";
char *message = defaultMessage;

// Parameters to center view window
int CENTER_X = -1000;	// for OpenGL logo: default value X=-750
int CENTER_Y = 0;	// 		    default value Y=0

// Motion parameters
double angle = 0.0; double delangle = 0.0;
double transx = 0.0; double delx = -0.2;
double transy = 0.0; double dely = 0.0;

void
selectFont(int newfont)
{
  font = fonts[newfont];
  glutPostRedisplay();
}

/***************************************************
 * Color Selection
 ***************************************************/

typedef GLfloat color3[3];		// color data type

color3 myColor = {1.0, 1.0, 1.0};	// default white color

void
selectColor(int c)
{
  switch (c) {
  case 0:
	myColor[0] = 1.0;
	myColor[1] = 1.0;
	myColor[2] = 1.0;
	break;
  case 1:
	myColor[0] = 1.0;
	myColor[1] = 0.0;
	myColor[2] = 0.0;
	break;
  case 2:
	myColor[0] = 0.0;
	myColor[1] = 1.0;
	myColor[2] = 0.0;
	break;
  case 3:
	myColor[0] = 0.0;
	myColor[1] = 0.0;
	myColor[2] = 1.0;
	break;
  case 4:	//yellow
	myColor[0] = 1.0;
	myColor[1] = 1.0;
	myColor[2] = 0.0;
	break;
  case 5:	//magenta
	myColor[0] = 1.0;
	myColor[1] = 0.0;
	myColor[2] = 1.0;
	break;
  case 6:	//cyan
	myColor[0] = 0.0;
	myColor[1] = 1.0;
	myColor[2] = 1.0;
	break;
  }
}//selectColor

void
selectMessage(int msg)
{
  switch (msg) {
  case 0:
    message = defaultMessage;
    break;
  case 1:
    message = "abcdefghijklmnop";
    break;
  case 2:
    message = "ABCDEFGHIJKLMNOP";
    break;
  case 3:
    message = "GLUT means OpenGL.";
  }
}//selectMessage

void
selectMotion(int m)
{
  switch (m) {
  case 0: // freeze
    delangle = 0.0; delx = 0.0; dely = 0.0;
    angle = 0.0; transx = 0.0; transy = 0.0;
    break;
  case 1: // +rotate
    delangle += 0.2; 
    break;
  case 2: // +x
    delx += 0.5;
    break;
  case 3: // +y
    delx += 0.5;
    break;
  case 4: // -rotate
    delangle -= 0.2; 
    break;
  case 5: // -x
    delx -= 0.5;
    break;
  case 6: // -y
    delx -= 0.5;
    break;
  }
}//selectMotion

void 
help ()
{ 
  printf("Help message \n");
}//help

void
mainMenu(int msg)
{
  switch (msg) {
  case 1:
    exit();
    break;
  case 2:
    help();
    break;
  }//switch
}//mainMenu

void
tick(void)
{
  angle += delangle;
  transx += delx; transy += dely;
  glutPostRedisplay();
}//tick

void
display(void)
{
  int len, i;

  glClear(GL_COLOR_BUFFER_BIT);
  glPushMatrix();
  glRotatef(angle, 0.0, 0.0, 1.0);
  glTranslatef(CENTER_X+transx, CENTER_Y+transy, 0);
  glColor3f(myColor[0], myColor[1], myColor[2]);  // pen color
  len = (int) strlen(message);
  for (i = 0; i < len; i++) {
    glutStrokeCharacter(font, message[i]);
  }
  glPopMatrix();
  glutSwapBuffers();
}//display

int
main(int argc, char **argv)
{
  int i, fontSubmenu, colorSubmenu, messageSubmenu, motionSubmenu;

  glutInit(&argc, argv);
  for (i = 1; i < argc; i++) {
    if (!strcmp(argv[i], "-mono")) {
      font = GLUT_STROKE_MONO_ROMAN;
    }
  }
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
  glutInitWindowSize(600, 600);
  glutCreateWindow("anti-aliased stroke font");
  // projection
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluOrtho2D(0, 2000, 0, 2000);
  glMatrixMode(GL_MODELVIEW);
  // rendering
  glEnable(GL_LINE_SMOOTH);
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  glLineWidth(2.0);
  //
  glTranslatef(1000, 1000, 0);
  glClearColor(0.0, 0.0, 0.0, 1.0);  	// background black
  glColor3f(1.0, 1.0, 1.0);		// foreground white
  // register callbacks
  glutDisplayFunc(display);
  glutIdleFunc(tick);

  // Menu Setup

  // Color Submenu
  colorSubmenu = glutCreateMenu(selectColor);
  glutAddMenuEntry("White", 0);
  glutAddMenuEntry("Red", 1);
  glutAddMenuEntry("Green", 2);
  glutAddMenuEntry("Blue", 3);
  glutAddMenuEntry("Yellow", 4);
  glutAddMenuEntry("Magenta", 5);
  glutAddMenuEntry("Cyan", 6);
  // Message Submenu
  messageSubmenu = glutCreateMenu(selectMessage);
  glutAddMenuEntry("Default", 0);
  glutAddMenuEntry("abc", 1);
  glutAddMenuEntry("ABC", 2);
  glutAddMenuEntry("GlutLogo", 3);
  // Font Menu
  fontSubmenu = glutCreateMenu(selectFont);
  glutAddMenuEntry("Roman", 0);
  glutAddMenuEntry("Mono Roman", 1);
  // Motion Menu
  motionSubmenu = glutCreateMenu(selectMotion);
  glutAddMenuEntry("Reset", 0);
  glutAddMenuEntry("+Rotate", 1);
  glutAddMenuEntry("+X", 2);
  glutAddMenuEntry("+Y", 3);
  glutAddMenuEntry("-Rotate", 4);
  glutAddMenuEntry("-X", 5);
  glutAddMenuEntry("-Y", 6);
  // Main Menu
  glutCreateMenu(mainMenu);
  glutAddMenuEntry("Quit", 1);
  glutAddMenuEntry("Help", 2);
  glutAddSubMenu("Fonts", fontSubmenu);
  glutAddSubMenu("Messages", messageSubmenu);
  glutAddSubMenu("Colors", colorSubmenu);
  glutAddSubMenu("Motion", motionSubmenu);

  // Attach Main Menu to Right Button
  glutAttachMenu(GLUT_RIGHT_BUTTON);

  // Loop
  glutMainLoop();
  return 0;             /* ANSI C requires main to return int. */
}//main