demo.cpp

ftgl-2.1.2 夸平台的opengl显示字体

// source changed by [e-mail]/ max rheiner
// original source: [e-mail]

#include <iostream>
#include <stdlib.h> // exit()

#ifdef __APPLE_CC__
    #include <GLUT/glut.h>
#else
    #include <GL/glut.h>
#endif

#include "FTGLOutlineFont.h"
#include "FTGLPolygonFont.h"
#include "FTGLBitmapFont.h"
#include "FTGLTextureFont.h"
#include "FTGLPixmapFont.h"

//#include "mmgr.h"

static FTFont* fonts[5];
static int width;
static int height;


// YOU'LL PROBABLY WANT TO CHANGE THESE
#ifdef __linux__
	#define DEFAULT_FONT "/usr/share/fonts/truetype/arial.ttf"
#endif
#ifdef __APPLE_CC__
	#define DEFAULT_FONT "/Users/henry/Development/PROJECTS/FTGL/test/font_pack/arial.ttf"
#endif
#ifdef WIN32
	#define DEFAULT_FONT "C:\\WINNT\\Fonts\\arial.ttf"
#endif


void
my_init( const char* font_filename )
{
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

    fonts[0] = new FTGLOutlineFont( font_filename);
    fonts[1] = new FTGLPolygonFont( font_filename);
    fonts[2] = new FTGLTextureFont( font_filename);
    fonts[3] = new FTGLBitmapFont( font_filename);
    fonts[4] = new FTGLPixmapFont( font_filename);
    for (int i=0; i< 5; i++)
    {
        if (fonts[i]->Error())
        {
            std::cerr << "ERROR: Unable to open file " << font_filename << std::endl;
        }
        else
        {
            std::cout << "Reading font " << i << " from " << font_filename << std::endl;

            int point_size = 48;
            if (!fonts[i]->FaceSize(point_size))
            {
                std::cerr << "ERROR: Unable to set font face size " << point_size << std::endl;
            }
        }
    }
}

static void
do_ortho()
{
  int w;
  int h;
  GLdouble size;
  GLdouble aspect;

  w = width;
  h = height;
  aspect = (GLdouble)w / (GLdouble)h;

  // Use the whole window.
  glViewport(0, 0, w, h);

  // We are going to do some 2-D orthographic drawing.
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  size = (GLdouble)((w >= h) ? w : h) / 2.0;
  if (w <= h) {
    aspect = (GLdouble)h/(GLdouble)w;
    glOrtho(-size, size, -size*aspect, size*aspect,
            -100000.0, 100000.0);
  }
  else {
    aspect = (GLdouble)w/(GLdouble)h;
    glOrtho(-size*aspect, size*aspect, -size, size,
            -100000.0, 100000.0);
  }

  // Make the world and window coordinates coincide so that 1.0 in
  // model space equals one pixel in window space.
  glScaled(aspect, aspect, 1.0);

   // Now determine where to draw things.
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}


void
my_reshape(int w, int h)
{
  width = w;
  height = h;

  do_ortho( );
}

void
my_handle_key(unsigned char key, int x, int y)
{
   switch (key) {

	   //!!ELLERS
   case 'q':   // Esc or 'q' Quits the program.
   case 27:    
	   {
       for (int i=0; i<5; i++) {
           if (fonts[i]) {
               delete fonts[i];
               fonts[i] = 0;
           }
       }
      exit(1);
	   }
      break;

   default:
      break;
   }
}

void
draw_scene()
{
   /* Set up some strings with the characters to draw. */
   unsigned int count = 0;
   char string[8][256];
   int i;
   for (i=1; i < 32; i++) { /* Skip zero - it's the null terminator! */
      string[0][count] = i;
      count++;
   }
   string[0][count] = '\0';

   count = 0;
   for (i=32; i < 64; i++) {
      string[1][count] = i;
      count++;
   }
   string[1][count] = '\0';

   count = 0;
   for (i=64; i < 96; i++) {
      string[2][count] = i;
      count++;
   }
   string[2][count] = '\0';

   count = 0;
   for (i=96; i < 128; i++) {
      string[3][count] = i;
      count++;
   }
   string[3][count] = '\0';

   count = 0;
   for (i=128; i < 160; i++) {
      string[4][count] = i;
      count++;
   }
   string[4][count] = '\0';

   count = 0;
   for (i=160; i < 192; i++) {
      string[5][count] = i;
      count++;
   }
   string[5][count] = '\0';

   count = 0;
   for (i=192; i < 224; i++) {
      string[6][count] = i;
      count++;
   }
   string[6][count] = '\0';

   count = 0;
   for (i=224; i < 256; i++) {
      string[7][count] = i;
      count++;
   }
   string[7][count] = '\0';


   glColor3f(1.0, 1.0, 1.0);

   for (int font = 0; font < 5; font++) {
       GLfloat x = -250.0;
       GLfloat y;
       GLfloat yild = 20.0;
       for (int j=0; j<4; j++) {
           y = 275.0-font*120.0-j*yild;
           if (font >= 3) {
               glRasterPos2f(x, y);
               fonts[font]->Render(string[j]);
           }
           else {
               if (font == 2) {
                   glEnable(GL_TEXTURE_2D);
                   glEnable(GL_BLEND);
                   glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
               }
               glPushMatrix(); {
                   glTranslatef(x, y, 0.0);
                   fonts[font]->Render(string[j]);
               } glPopMatrix();
               if (font == 2) {
                   glDisable(GL_TEXTURE_2D);
                   glDisable(GL_BLEND);
               }
           }
       }
   }
}


void
my_display(void)
{
    glClear(GL_COLOR_BUFFER_BIT);

    draw_scene();

    glutSwapBuffers();
}


void
my_idle()
{
    glutPostRedisplay();
}

int 
file_exists( const char * fontFilePath )
{
	FILE * fp = fopen( fontFilePath, "r" );

	if ( fp == NULL )
	{
		// That fopen failed does _not_ definitely mean the file isn't there 
		// but for now this is ok
		return 0;
	}
	fclose( fp );
	return 1;
}

void
usage( const char * program )
{
	std::cerr << "Usage: " << program << " <fontFilePath.ttf>\n" << std::endl;
}

int
main(int argc, char **argv)
{
	char * fontFilePath;

	glutInitWindowSize(600, 600);
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE);

	glutCreateWindow("FTGL demo");

	if ( argc >= 2 ) 
	{
		if ( !file_exists( argv[ 1 ] ))
		{
			usage( argv[ 0 ]);
			std::cerr << "Couldn't open file '" << argv[ 1 ] << "'" << std::endl;
			exit( -1 );
		}
		fontFilePath = argv[ 1 ];
	}
	else 
	{
		// try a default font
		fontFilePath = DEFAULT_FONT;

		if ( !file_exists( fontFilePath ))
		{
			usage( argv[ 0 ]);
			std::cerr << "Couldn't open default file '" << fontFilePath << "'" << std::endl;
			exit( -1 );
		}
	}

	my_init( fontFilePath );

	glutDisplayFunc(my_display);
	glutReshapeFunc(my_reshape);
	glutIdleFunc(my_idle);
	glutKeyboardFunc(my_handle_key);

	glutMainLoop();
        
        for(int x = 0; x < 5; ++x)
        {
            delete fonts[x];
        }
        
	return 0;
}