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()



#include <GL/glut.h>



#include "FTGLOutlineFont.h"

#include "FTGLPolygonFont.h"

#include "FTGLBitmapFont.h"

#include "FTGLTextureFont.h"

#include "FTGLPixmapFont.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/ftglcvs/FTGL/demo/arial.ttf"

#endif

#ifdef WIN32

	#define DEFAULT_FONT "C:\\WINNT\\Fonts\\arial.ttf"
	using namespace std;
#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]->Open(font_filename)) {

            cerr << "ERROR: Unable to open file " << font_filename << "\n";

        }
		
        else */
		{

			cout << "Reading font " << i << " from " << font_filename << endl;



            int point_size = 24;

            if (!fonts[i]->FaceSize(point_size)) {

                cerr << "ERROR: Unable to set font face size " << point_size << "\n";

            }

        }

    }

}



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();

}



int 

file_exists( const char * filename )

{

	FILE * fp = fopen( filename, "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 )

{

	cerr << "Usage: " << program << " <filename.ttf>\n" << endl;

}



int

main(int argc, char **argv)

{

	//!!ELLERS  -- cleaned up

	char * filename;



	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 ]);

			cerr << "Couldn't open file '" << argv[ 1 ] << "'" << endl;

			exit( -1 );

		}

		filename = argv[ 1 ];

	}

	else 

	{

		// try a default font

		filename = DEFAULT_FONT;



		if ( !file_exists( filename ))

		{

			usage( argv[ 0 ]);

			cerr << "Couldn't open default file '" << filename << "'" << endl;

			exit( -1 );

		}

	}



	my_init( filename );



	glutDisplayFunc(my_display);

	glutReshapeFunc(my_reshape);

	glutKeyboardFunc(my_handle_key);



	glutMainLoop();

	return 0;

}