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✏️ Editing: example1.c

/* 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 */

MR SKB