/* textgl.c   fixed font text, does not move with main image */

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

#define FOV 85
static float v = 15.0;

static void printstring(void *font, char *string)
{
   int len, i;

   len = (int) strlen(string);
   for (i = 0; i < len; i++)
      glutBitmapCharacter(font, string[i]);
} /* end printstring */

static void printhelp(void)
{
   glEnable(GL_BLEND);
   glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
   glColor4f(0.0, 0.0, 0.0, 0.5);
   glRecti(40, 40, 600, 440);
   glDisable(GL_BLEND);

   /* yellow, upper center */
   glColor3f(1.0, 1.0, 0.0);
   glRasterPos2i(300, 420);
   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "Help");

   /* aqua, list down center */
   glColor3f(0.0, 1.0, 1.0);
   glRasterPos2i(60, 390);
   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "h - Togle Help");
   glRasterPos2i(60, 360);
   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "t - Togle Textures");
   glRasterPos2i(60, 330);
   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "f - Togle Fog");
   glRasterPos2i(60, 300);
   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "W, w - Wire frame");
   glRasterPos2i(60, 270);
   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "b - Togle Back face culling");
   glRasterPos2i(60, 240);
   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "Arrow Keys - Rotate");
   glRasterPos2i(60, 210);
   printstring(GLUT_BITMAP_TIMES_ROMAN_24, "F, f - Increase/decrease velocity");

} /* end printhelp */


static void drawscene(void)
{
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   glOrtho(-0.5, 639.5, -0.5, 479.5, -1.0, 1.0); /* just inside 640 by 480 */
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
   /* red, top right */
   glColor3f(1.0, 0.0, 0.0);
   glRasterPos2i(350, 470);
   printstring(GLUT_BITMAP_HELVETICA_10,
	       "This can be a long title, small in upper right");
   glRasterPos2i(434, 457);
   printstring(GLUT_BITMAP_HELVETICA_10,
	       "More, small red print");
   printhelp();
} /* end drawscene */

int main(int argc, char *argv[])
{
   glutInit(&argc, argv);
   glutInitWindowPosition(0, 0);
   glutInitWindowSize(640, 480);
   glutCreateWindow(argv[0]);
   glutDisplayFunc(drawscene);
   glutMainLoop();
   return 0;
} /* end main */