Metafont Compiler

About the tool

Metafont is a programming language used to define fonts. It was created by Donald Knuth and is a companion to the TeX typesetting system.

A Metafont script describes the shape of a glyph (or multiple glyphs) as a collection of pen strokes. The cool thing about Metafont is that it is a programming language. You can use variables (parameters), loops, and conditionals to define the shape of a glyph. You can also describe the pen strokes declaratively in terms of their desired shape rather than explicitly list the commands to draw them. This allows you to create complex shapes that would be difficult to draw by hand.

To execute Metafont code, you usually need to install the Metafont interpreter on your computer (typically as part of the TeX distribution). To make it easier to experiment with Metafont, I've created this online tool that allows you to run Metafont code online and see the generated output.

P.S. A warning from Donald Knuth:

Demo

Input (Metafont code)

mode_setup;

% parameters are name, width, height over base line, depth below base line
beginchar ("a", 9pt#, 12pt#, 0);
  alpha:=0.65;
  beta:=0.24;

  % define points
  x1 = 0; y1 = 0.8*h;
  x4 = w; y4 = 0.2*h;
  y2 = h; y3 = 0;
  x2 = (alpha-beta)*w;
  x5 = alpha*w;
  x3 = (alpha+beta)*w;
  y5 = 0.5*h;
  x6 = 0; y6 = 0.3*h;
  x7 = 0.2*w; y7 = 0;
  x8 = x5; y8 = 0.2*h;

  % define pen
  pickup pencircle xscaled 0.2w yscaled 0.04w rotated 30;

  % draw
  draw z1{dir 30}..z2{right}..z5{down}..z3{right}..z4{dir 30};
  draw z5..z6{down}..z7{right}..z8;
  penlabels(1,2,3,4,5,6,7,8);
endchar;


% Define a beanlike shape for the character B
beginchar("B",4pt#,4pt#,0);
  % Setup coordinates as an equation system
  y1=y2=y3=0;
  y4=y5=y6=h;
  x1=x4=0;
  x2=x5=w;
  x3=x6=2*w;

  % Define pen
  pickup pencircle xscaled 0.2w yscaled 0.04w rotated 45;

  % Draw the character curve
  % z1 is the same as (x1, y1)
  draw z1..z3..z6{z2-z6}..z5..{z4-z2}z4..cycle;
  penlabels(1,2,3,4,5,6);
endchar;



 em#:=10pt#; cap#:=7pt#;
 thin#:=1/3pt#; thick#:=5/6pt#;
 o#:=1/5pt#;
define_pixels(em,cap);
define_blacker_pixels(thin,thick);
define_corrected_pixels(o);
 curve_sidebar=round 1/18em;
beginchar("O", 0.8em#, cap#, 0); "The letter O";
 penpos1(thick,10); penpos2(.1[thin,thick],90-10);
 penpos3(thick,180+10); penpos4(thin,270-10);
 x1l=w-x3l=curve_sidebar; x2=x4=.5w;
 y1=.49h; y2l=-o; y3=.51h; y4l=h+o;
 penstroke z1e{down}..z2e{right}
            ..z3e{up}..z4e{left}..cycle;
 penlabels(1,2,3,4); endchar;

end1
mode_setup;
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% parameters are name, width, height over base line, depth below base line
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beginchar ("a", 9pt#, 12pt#, 0);
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  alpha:=0.65;
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  beta:=0.24;
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  % define points
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  x1 = 0; y1 = 0.8*h;
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  x4 = w; y4 = 0.2*h;
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  y2 = h; y3 = 0;
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  x2 = (alpha-beta)*w;
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  x5 = alpha*w;
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  x3 = (alpha+beta)*w;
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  y5 = 0.5*h;
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  x6 = 0; y6 = 0.3*h;
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  x7 = 0.2*w; y7 = 0;
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  x8 = x5; y8 = 0.2*h;
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  % define pen
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  pickup pencircle xscaled 0.2w yscaled 0.04w rotated 30;
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  % draw
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  draw z1{dir 30}..z2{right}..z5{down}..z3{right}..z4{dir 30};
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  draw z5..z6{down}..z7{right}..z8;
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  penlabels(1,2,3,4,5,6,7,8);
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endchar;
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% Define a beanlike shape for the character B
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beginchar("B",4pt#,4pt#,0);
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  % Setup coordinates as an equation system
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  y1=y2=y3=0;
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  y4=y5=y6=h;
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  x1=x4=0;
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  x2=x5=w;
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  x3=x6=2*w;
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  % Define pen
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  pickup pencircle xscaled 0.2w yscaled 0.04w rotated 45;
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  % Draw the character curve
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  % z1 is the same as (x1, y1)
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  draw z1..z3..z6{z2-z6}..z5..{z4-z2}z4..cycle;
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  penlabels(1,2,3,4,5,6);
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endchar;
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 em#:=10pt#; cap#:=7pt#;
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 thin#:=1/3pt#; thick#:=5/6pt#;
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 o#:=1/5pt#;
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define_pixels(em,cap);
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define_blacker_pixels(thin,thick);
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define_corrected_pixels(o);
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 curve_sidebar=round 1/18em;
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beginchar("O", 0.8em#, cap#, 0); "The letter O";
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 penpos1(thick,10); penpos2(.1[thin,thick],90-10);
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 penpos3(thick,180+10); penpos4(thin,270-10);
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 x1l=w-x3l=curve_sidebar; x2=x4=.5w;
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 y1=.49h; y2l=-o; y3=.51h; y4l=h+o;
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 penstroke z1e{down}..z2e{right}
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            ..z3e{up}..z4e{left}..cycle;
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 penlabels(1,2,3,4); endchar;
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end

Input in the Metafont language.

Mode

proof

localfont

Log

The log will be displayed here when compilation starts.

Generated files

Any generated files appear here.

Glyph previews

Any generated glyph previews are displayed here.

Metafont Compiler

About the tool

Demo

See also