FM / tutorial

/usr/share/doc/freetype-devel/tutorial

Name	Size	Mode	Actions
example1.c	3934	0644	edit dl rm
example2.cpp	10960	0644	edit dl rm
example3.cpp	3754	0644	edit dl rm
example4.cpp	6009	0644	edit dl rm
example4.pro	241	0644	edit dl rm
example5.cpp	11083	0644	edit dl rm
example5.svg	3160	0644	edit dl rm
index.html	5918	0644	edit dl rm
metrics.png	2216	0644	edit dl rm
metrics2.png	1853	0644	edit dl rm
step1.html	45359	0644	edit dl rm
step2.html	64302	0644	edit dl rm
step3.html	5516	0644	edit dl rm

Edit: /usr/share/doc/freetype-devel/tutorial/example1.c (3934B)

/* example1.c                                                      */
/*                                                                 */
/* This small program shows how to print a rotated string with the */
/* FreeType 2 library.                                             */

#include <stdio.h>
#include <string.h>
#include <math.h>

#include <ft2build.h>
#include FT_FREETYPE_H

#define WIDTH   640
#define HEIGHT  480

/* origin is the upper left corner */
unsigned char image[HEIGHT][WIDTH];

/* Replace this function with something useful. */

void
draw_bitmap( FT_Bitmap*  bitmap,
             FT_Int      x,
             FT_Int      y)
{
  FT_Int  i, j, p, q;
  FT_Int  x_max = x + bitmap->width;
  FT_Int  y_max = y + bitmap->rows;

/* for simplicity, we assume that `bitmap->pixel_mode' */
  /* is `FT_PIXEL_MODE_GRAY' (i.e., not a bitmap font)   */

for ( i = x, p = 0; i < x_max; i++, p++ )
  {
    for ( j = y, q = 0; j < y_max; j++, q++ )
    {
      if ( i < 0      || j < 0       ||
           i >= WIDTH || j >= HEIGHT )
        continue;

image[j][i] |= bitmap->buffer[q * bitmap->width + p];
    }
  }
}

void
show_image( void )
{
  int  i, j;

for ( i = 0; i < HEIGHT; i++ )
  {
    for ( j = 0; j < WIDTH; j++ )
      putchar( image[i][j] == 0 ? ' '
                                : image[i][j] < 128 ? '+'
                                                    : '*' );
    putchar( '\n' );
  }
}

int
main( int     argc,
      char**  argv )
{
  FT_Library    library;
  FT_Face       face;

FT_GlyphSlot  slot;
  FT_Matrix     matrix;                 /* transformation matrix */
  FT_Vector     pen;                    /* untransformed origin  */
  FT_Error      error;

char*         filename;
  char*         text;

double        angle;
  int           target_height;
  int           n, num_chars;

if ( argc != 3 )
  {
    fprintf ( stderr, "usage: %s font sample-text\n", argv[0] );
    exit( 1 );
  }

filename      = argv[1];                           /* first argument     */
  text          = argv[2];                           /* second argument    */
  num_chars     = strlen( text );
  angle         = ( 25.0 / 360 ) * 3.14159 * 2;      /* use 25 degrees     */
  target_height = HEIGHT;

error = FT_Init_FreeType( &library );              /* initialize library */
  /* error handling omitted */

error = FT_New_Face( library, filename, 0, &face );/* create face object */
  /* error handling omitted */

/* use 50pt at 100dpi */
  error = FT_Set_Char_Size( face, 50 * 64, 0,
                            100, 0 );                /* set character size */
  /* error handling omitted */

/* cmap selection omitted;                                        */
  /* for simplicity we assume that the font contains a Unicode cmap */

slot = face->glyph;

/* set up matrix */
  matrix.xx = (FT_Fixed)( cos( angle ) * 0x10000L );
  matrix.xy = (FT_Fixed)(-sin( angle ) * 0x10000L );
  matrix.yx = (FT_Fixed)( sin( angle ) * 0x10000L );
  matrix.yy = (FT_Fixed)( cos( angle ) * 0x10000L );

/* the pen position in 26.6 cartesian space coordinates; */
  /* start at (300,200) relative to the upper left corner  */
  pen.x = 300 * 64;
  pen.y = ( target_height - 200 ) * 64;

for ( n = 0; n < num_chars; n++ )
  {
    /* set transformation */
    FT_Set_Transform( face, &matrix, &pen );

/* load glyph image into the slot (erase previous one) */
    error = FT_Load_Char( face, text[n], FT_LOAD_RENDER );
    if ( error )
      continue;                 /* ignore errors */

/* now, draw to our target surface (convert position) */
    draw_bitmap( &slot->bitmap,
                 slot->bitmap_left,
                 target_height - slot->bitmap_top );

/* increment pen position */
    pen.x += slot->advance.x;
    pen.y += slot->advance.y;
  }

show_image();

FT_Done_Face    ( face );
  FT_Done_FreeType( library );

return 0;
}

/* EOF */

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