### ----------------------------------------------------
### -- Font::FreeType
### -- Licenses: Artistic-2.0
### -- Authors: David Warring
### -- File: docs/Font/FreeType/BitMap.md
### ----------------------------------------------------
[[Raku PDF Project]](https://pdf-raku.github.io)
 / [[Font-FreeType Module]](https://pdf-raku.github.io/Font-FreeType-raku)
 / [Font::FreeType](https://pdf-raku.github.io/Font-FreeType-raku/Font/FreeType)
 :: [BitMap](https://pdf-raku.github.io/Font-FreeType-raku/Font/FreeType/BitMap)

class Font::FreeType::BitMap
----------------------------

Bitmaps from rendered glyphs

Synopsis
--------

    use Font::FreeType;

    my Font::FreeType $freetype .= new;
    my $face = $freetype.face('Vera.ttf');
    $face.set-char-size(24, 24, 100, 100);

    for $face.glyph-images('Hi') {
        print .outline.svg
            if .is-outline;

        # Render into an array of strings, one byte per pixel.
        my $bitmap = .bitmap;
        my $top = $bitmap.top;
        my $left = $bitmap.left;

        # print a string representation
        print $bitmap.Str;
    }

Description
-----------

This class represents the bitmap image of a rendered glyph.

Methods
-------

### pixel-mode()

The rendering pixel mode. One of:

  * *FT_PIXEL_MODE_NONE*

    Value 0 is reserved.

  * *FT_PIXEL_MODE_MONO*

    A monochrome bitmap, using 1 bit per pixel. Note that pixels are stored in most-significant order (MSB), which means that the left-most pixel in a byte has value 128.

  * *FT_PIXEL_MODE_GRAY*

    An 8-bit bitmap, generally used to represent anti-aliased glyph images. Each pixel is stored in one byte. Note that the number of ‘gray’ levels is stored in the ‘num_grays’ field of the FT_Bitmap structure (it generally is 256).

  * *FT_PIXEL_MODE_GRAY2*

    A 2-bit per pixel bitmap, used to represent embedded anti-aliased bitmaps in font files according to the OpenType specification. We haven't found a single font using this format, however.

  * *FT_PIXEL_MODE_GRAY4*

    A 4-bit per pixel bitmap, representing embedded anti-aliased bitmaps in font files according to the OpenType specification. We haven't found a single font using this format, however.

  * *FT_PIXEL_MODE_LCD*

    An 8-bit bitmap, representing RGB or BGR decimated glyph images used for display on LCD displays; the bitmap is three times wider than the original glyph image. See also FT_RENDER_MODE_LCD.

  * *FT_PIXEL_MODE_LCD_V*

    An 8-bit bitmap, representing RGB or BGR decimated glyph images used for vertical display on LCD displays; the bitmap is three times taller than the original glyph image. See also FT_RENDER_MODE_LCD.

  * *FT_PIXEL_MODE_BGRA*

    An 8-bit bitmap, representing BGRA decimated glyph images used for vertical display on LCD displays; the bitmap is three times taller than the original glyph image. See also FT_RENDER_MODE_LCD.

### depth()

The calculated color depth in bits. For example **FT_PIXEL_MODE_GRAY** has a color depth of 8.

### width()

The width of each row, in bytes

### rows()

The number of rows in the image

### pitch()

Used to calculate the padding at the end of each row.

### pixels

Returns a numeric shaped array of dimensions $.width and $height. Each item represents one pixel of the image, starting from the top left. A value of 0 indicates background (outside the glyph outline), and 255 represents a point inside the outline.

If anti-aliasing is used then shades of grey between 0 and 255 may occur. Anti-aliasing is performed by default, but can be turned off by passing the `FT_RENDER_MODE_MONO` option.

### pgm

Renders the bitmap and constructs it into a PGM (portable grey-map) image file, which it returns as a Buf, suitable for output to a binary file.

The PGM image returned is in the 'binary' format, with one byte per pixel. It is not an efficient format, but can be read by many image manipulation programs. For a detailed description of the format see [http://netpbm.sourceforge.net/doc/pgm.html](http://netpbm.sourceforge.net/doc/pgm.html)

The _render-glyph.pl_ example program uses this method.

### Str()

Returns an ASCII display representation of the rendered glyph.

### convert()

produces a new bitmap, re-rendered as eight bit FT_PIXEL_MODE_GRAY.

Authors
-------

Geoff Richards <qef@laxan.com>

David Warring <david.warring@gmail.com> (Raku Port)

Copyright
---------

Copyright 2004, Geoff Richards.

Ported from Perl to Raku by David Warring <david.warring@gmail.com> Copyright 2017.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.



