Make PSF code from bootproof into an independent library.
commit
aa3d7a09ee
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@ -0,0 +1,11 @@
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root = true
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||||||
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[*]
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||||||
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charset = utf-8
|
||||||
|
indent_style = space
|
||||||
|
indent_size = 4
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|
trim_trailing_whitespace = true
|
||||||
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insert_final_newline = true
|
||||||
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|
||||||
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[*.yml]
|
||||||
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indent_size = 2
|
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@ -0,0 +1,20 @@
|
||||||
|
name: Rust
|
||||||
|
|
||||||
|
on: [push]
|
||||||
|
|
||||||
|
jobs:
|
||||||
|
build:
|
||||||
|
runs-on: ubuntu-latest
|
||||||
|
steps:
|
||||||
|
- name: Checkout sources
|
||||||
|
uses: actions/checkout@v2
|
||||||
|
|
||||||
|
- name: Install latest stable
|
||||||
|
uses: actions-rs/toolchain@v1
|
||||||
|
with:
|
||||||
|
profile: minimal
|
||||||
|
toolchain: stable
|
||||||
|
override: true
|
||||||
|
|
||||||
|
- name: build
|
||||||
|
run: cargo build
|
|
@ -0,0 +1,2 @@
|
||||||
|
/target
|
||||||
|
Cargo.lock
|
|
@ -0,0 +1,12 @@
|
||||||
|
[package]
|
||||||
|
name = "pc-screen-font"
|
||||||
|
version = "0.1.0"
|
||||||
|
authors = ["James Martin <james@jtmar.me>"]
|
||||||
|
edition = "2018"
|
||||||
|
repository = "https://github.com/jamestmartin/pc-screen-font"
|
||||||
|
license = "LGPL-3.0+"
|
||||||
|
publish = false
|
||||||
|
|
||||||
|
[dependencies.num-integer]
|
||||||
|
version = "0.1.43"
|
||||||
|
default-features = false
|
|
@ -0,0 +1,165 @@
|
||||||
|
GNU LESSER GENERAL PUBLIC LICENSE
|
||||||
|
Version 3, 29 June 2007
|
||||||
|
|
||||||
|
Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
|
||||||
|
Everyone is permitted to copy and distribute verbatim copies
|
||||||
|
of this license document, but changing it is not allowed.
|
||||||
|
|
||||||
|
|
||||||
|
This version of the GNU Lesser General Public License incorporates
|
||||||
|
the terms and conditions of version 3 of the GNU General Public
|
||||||
|
License, supplemented by the additional permissions listed below.
|
||||||
|
|
||||||
|
0. Additional Definitions.
|
||||||
|
|
||||||
|
As used herein, "this License" refers to version 3 of the GNU Lesser
|
||||||
|
General Public License, and the "GNU GPL" refers to version 3 of the GNU
|
||||||
|
General Public License.
|
||||||
|
|
||||||
|
"The Library" refers to a covered work governed by this License,
|
||||||
|
other than an Application or a Combined Work as defined below.
|
||||||
|
|
||||||
|
An "Application" is any work that makes use of an interface provided
|
||||||
|
by the Library, but which is not otherwise based on the Library.
|
||||||
|
Defining a subclass of a class defined by the Library is deemed a mode
|
||||||
|
of using an interface provided by the Library.
|
||||||
|
|
||||||
|
A "Combined Work" is a work produced by combining or linking an
|
||||||
|
Application with the Library. The particular version of the Library
|
||||||
|
with which the Combined Work was made is also called the "Linked
|
||||||
|
Version".
|
||||||
|
|
||||||
|
The "Minimal Corresponding Source" for a Combined Work means the
|
||||||
|
Corresponding Source for the Combined Work, excluding any source code
|
||||||
|
for portions of the Combined Work that, considered in isolation, are
|
||||||
|
based on the Application, and not on the Linked Version.
|
||||||
|
|
||||||
|
The "Corresponding Application Code" for a Combined Work means the
|
||||||
|
object code and/or source code for the Application, including any data
|
||||||
|
and utility programs needed for reproducing the Combined Work from the
|
||||||
|
Application, but excluding the System Libraries of the Combined Work.
|
||||||
|
|
||||||
|
1. Exception to Section 3 of the GNU GPL.
|
||||||
|
|
||||||
|
You may convey a covered work under sections 3 and 4 of this License
|
||||||
|
without being bound by section 3 of the GNU GPL.
|
||||||
|
|
||||||
|
2. Conveying Modified Versions.
|
||||||
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|
||||||
|
If you modify a copy of the Library, and, in your modifications, a
|
||||||
|
facility refers to a function or data to be supplied by an Application
|
||||||
|
that uses the facility (other than as an argument passed when the
|
||||||
|
facility is invoked), then you may convey a copy of the modified
|
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|
version:
|
||||||
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|
||||||
|
a) under this License, provided that you make a good faith effort to
|
||||||
|
ensure that, in the event an Application does not supply the
|
||||||
|
function or data, the facility still operates, and performs
|
||||||
|
whatever part of its purpose remains meaningful, or
|
||||||
|
|
||||||
|
b) under the GNU GPL, with none of the additional permissions of
|
||||||
|
this License applicable to that copy.
|
||||||
|
|
||||||
|
3. Object Code Incorporating Material from Library Header Files.
|
||||||
|
|
||||||
|
The object code form of an Application may incorporate material from
|
||||||
|
a header file that is part of the Library. You may convey such object
|
||||||
|
code under terms of your choice, provided that, if the incorporated
|
||||||
|
material is not limited to numerical parameters, data structure
|
||||||
|
layouts and accessors, or small macros, inline functions and templates
|
||||||
|
(ten or fewer lines in length), you do both of the following:
|
||||||
|
|
||||||
|
a) Give prominent notice with each copy of the object code that the
|
||||||
|
Library is used in it and that the Library and its use are
|
||||||
|
covered by this License.
|
||||||
|
|
||||||
|
b) Accompany the object code with a copy of the GNU GPL and this license
|
||||||
|
document.
|
||||||
|
|
||||||
|
4. Combined Works.
|
||||||
|
|
||||||
|
You may convey a Combined Work under terms of your choice that,
|
||||||
|
taken together, effectively do not restrict modification of the
|
||||||
|
portions of the Library contained in the Combined Work and reverse
|
||||||
|
engineering for debugging such modifications, if you also do each of
|
||||||
|
the following:
|
||||||
|
|
||||||
|
a) Give prominent notice with each copy of the Combined Work that
|
||||||
|
the Library is used in it and that the Library and its use are
|
||||||
|
covered by this License.
|
||||||
|
|
||||||
|
b) Accompany the Combined Work with a copy of the GNU GPL and this license
|
||||||
|
document.
|
||||||
|
|
||||||
|
c) For a Combined Work that displays copyright notices during
|
||||||
|
execution, include the copyright notice for the Library among
|
||||||
|
these notices, as well as a reference directing the user to the
|
||||||
|
copies of the GNU GPL and this license document.
|
||||||
|
|
||||||
|
d) Do one of the following:
|
||||||
|
|
||||||
|
0) Convey the Minimal Corresponding Source under the terms of this
|
||||||
|
License, and the Corresponding Application Code in a form
|
||||||
|
suitable for, and under terms that permit, the user to
|
||||||
|
recombine or relink the Application with a modified version of
|
||||||
|
the Linked Version to produce a modified Combined Work, in the
|
||||||
|
manner specified by section 6 of the GNU GPL for conveying
|
||||||
|
Corresponding Source.
|
||||||
|
|
||||||
|
1) Use a suitable shared library mechanism for linking with the
|
||||||
|
Library. A suitable mechanism is one that (a) uses at run time
|
||||||
|
a copy of the Library already present on the user's computer
|
||||||
|
system, and (b) will operate properly with a modified version
|
||||||
|
of the Library that is interface-compatible with the Linked
|
||||||
|
Version.
|
||||||
|
|
||||||
|
e) Provide Installation Information, but only if you would otherwise
|
||||||
|
be required to provide such information under section 6 of the
|
||||||
|
GNU GPL, and only to the extent that such information is
|
||||||
|
necessary to install and execute a modified version of the
|
||||||
|
Combined Work produced by recombining or relinking the
|
||||||
|
Application with a modified version of the Linked Version. (If
|
||||||
|
you use option 4d0, the Installation Information must accompany
|
||||||
|
the Minimal Corresponding Source and Corresponding Application
|
||||||
|
Code. If you use option 4d1, you must provide the Installation
|
||||||
|
Information in the manner specified by section 6 of the GNU GPL
|
||||||
|
for conveying Corresponding Source.)
|
||||||
|
|
||||||
|
5. Combined Libraries.
|
||||||
|
|
||||||
|
You may place library facilities that are a work based on the
|
||||||
|
Library side by side in a single library together with other library
|
||||||
|
facilities that are not Applications and are not covered by this
|
||||||
|
License, and convey such a combined library under terms of your
|
||||||
|
choice, if you do both of the following:
|
||||||
|
|
||||||
|
a) Accompany the combined library with a copy of the same work based
|
||||||
|
on the Library, uncombined with any other library facilities,
|
||||||
|
conveyed under the terms of this License.
|
||||||
|
|
||||||
|
b) Give prominent notice with the combined library that part of it
|
||||||
|
is a work based on the Library, and explaining where to find the
|
||||||
|
accompanying uncombined form of the same work.
|
||||||
|
|
||||||
|
6. Revised Versions of the GNU Lesser General Public License.
|
||||||
|
|
||||||
|
The Free Software Foundation may publish revised and/or new versions
|
||||||
|
of the GNU Lesser General Public License from time to time. Such new
|
||||||
|
versions will be similar in spirit to the present version, but may
|
||||||
|
differ in detail to address new problems or concerns.
|
||||||
|
|
||||||
|
Each version is given a distinguishing version number. If the
|
||||||
|
Library as you received it specifies that a certain numbered version
|
||||||
|
of the GNU Lesser General Public License "or any later version"
|
||||||
|
applies to it, you have the option of following the terms and
|
||||||
|
conditions either of that published version or of any later version
|
||||||
|
published by the Free Software Foundation. If the Library as you
|
||||||
|
received it does not specify a version number of the GNU Lesser
|
||||||
|
General Public License, you may choose any version of the GNU Lesser
|
||||||
|
General Public License ever published by the Free Software Foundation.
|
||||||
|
|
||||||
|
If the Library as you received it specifies that a proxy can decide
|
||||||
|
whether future versions of the GNU Lesser General Public License shall
|
||||||
|
apply, that proxy's public statement of acceptance of any version is
|
||||||
|
permanent authorization for you to choose that version for the
|
||||||
|
Library.
|
|
@ -0,0 +1,21 @@
|
||||||
|
# PC Screen Font
|
||||||
|
A Rust library which can parses PSF version 2 fonts from their bytes.
|
||||||
|
It correctly handles fonts which contain extra pixels in their padding bits.
|
||||||
|
|
||||||
|
This library does not depend on the Rust standard library,
|
||||||
|
making it suitable for inclusion in bootloaders or kernels,
|
||||||
|
although it does require a working global allocator.
|
||||||
|
|
||||||
|
This library predates [the PSF crate](https://crates.io/crates/psf).
|
||||||
|
I have not investigated it at all, but you may wish to investigate using it instead
|
||||||
|
before choosing to use this library.
|
||||||
|
|
||||||
|
## Maintenance status
|
||||||
|
This library is only passively maintained, receiving updates as I need them.
|
||||||
|
I do not intend to publish this library to crates.io, but I will accept pull requests,
|
||||||
|
and if you wish to publish this library to crates.io and maintain it yourself,
|
||||||
|
you are welcome to do so.
|
||||||
|
|
||||||
|
## Limitations
|
||||||
|
Currently, this library does not support multi-codepoint spellings of characters.
|
||||||
|
Support may be added at some point, but I do not currently have any plans to do so.
|
|
@ -0,0 +1,160 @@
|
||||||
|
#![no_std]
|
||||||
|
extern crate alloc;
|
||||||
|
|
||||||
|
use alloc::vec::Vec;
|
||||||
|
|
||||||
|
pub struct Font {
|
||||||
|
/// The width in pixels of this font's bounding box.
|
||||||
|
width: usize,
|
||||||
|
/// The height in pixels of this font's bounding box.
|
||||||
|
height: usize,
|
||||||
|
/// Every single glyph in the font.
|
||||||
|
glyphs: Vec<Glyph>,
|
||||||
|
// TODO: Replace this with a proper associative structure.
|
||||||
|
/// A map between unicode characters and indexes into the glyph vec.
|
||||||
|
unicode: Vec<UnicodeMap>,
|
||||||
|
}
|
||||||
|
|
||||||
|
/// Associates a unicode character and a glyph.
|
||||||
|
struct UnicodeMap {
|
||||||
|
c: char,
|
||||||
|
// The index of the glyph.
|
||||||
|
i: usize,
|
||||||
|
}
|
||||||
|
|
||||||
|
pub struct Glyph {
|
||||||
|
/// A set bit indicates that a pixel should be drawn for this glyph.
|
||||||
|
bitmap: Vec<u8>,
|
||||||
|
/// The number of bytes in the bitmap taken up by each line of pixels in this glyph.
|
||||||
|
line_size: usize,
|
||||||
|
/// See the docs for `Glyph::width`.
|
||||||
|
width: usize,
|
||||||
|
/// See the docs for `Glyph::height`.
|
||||||
|
height: usize,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl Glyph {
|
||||||
|
/// The width in pixels of this individual glyph.
|
||||||
|
///
|
||||||
|
/// Although each PSF has a nominal width in pixels,
|
||||||
|
/// the length of each line of pixels stored in bits is actually rounded to the next byte.
|
||||||
|
/// Some fonts actually use this storage to make glyphs which are slightly wider
|
||||||
|
/// than the nominal width of the font, because it makes the glyph look better.
|
||||||
|
/// For example, Cozette does this for the unicode heart glyph.
|
||||||
|
pub fn width(&self) -> usize { self.width }
|
||||||
|
/// The height in pixels of this glyph. This will always be the same as the height of the font.
|
||||||
|
pub fn height(&self) -> usize { self.height }
|
||||||
|
|
||||||
|
/// Check whether an individual pixel of this glyph is set.
|
||||||
|
/// This will return `None` if `x` or `y` is outside the width or height of this glyph.
|
||||||
|
pub fn get(&self, x: usize, y: usize) -> Option<bool> {
|
||||||
|
if x > self.width || y > self.height {
|
||||||
|
return None
|
||||||
|
}
|
||||||
|
|
||||||
|
let (line_byte_index, bit_index) = num_integer::div_rem(x, 8);
|
||||||
|
let mask = 0b10000000 >> bit_index;
|
||||||
|
let byte = self.bitmap[(y * self.line_size + line_byte_index) as usize];
|
||||||
|
Some(byte & mask > 0)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
impl Font {
|
||||||
|
/// The width in pixels of this font's bounding box.
|
||||||
|
pub fn width(&self) -> usize { self.width }
|
||||||
|
/// The height in pixels of this font's bounding box.
|
||||||
|
pub fn height(&self) -> usize { self.height }
|
||||||
|
/// The width and height in pixels of this font's bounding box.
|
||||||
|
pub fn bounding_box(&self) -> (usize, usize) {
|
||||||
|
(self.width, self.height)
|
||||||
|
}
|
||||||
|
|
||||||
|
/// Get the glyph associated with a particular unicode character,
|
||||||
|
/// or `None` if it is not present in this font.
|
||||||
|
pub fn lookup<'a>(&'a self, c: char) -> Option<&'a Glyph> {
|
||||||
|
self.index_of(c).map(|i| &self.glyphs[i])
|
||||||
|
}
|
||||||
|
|
||||||
|
/// The index of the glyph associated with a particular unicode character.
|
||||||
|
fn index_of(&self, c: char) -> Option<usize> {
|
||||||
|
for entry in &self.unicode {
|
||||||
|
if entry.c == c {
|
||||||
|
return Some(entry.i);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
None
|
||||||
|
}
|
||||||
|
|
||||||
|
/// Parse a version 2 PC screen font from its bytes.
|
||||||
|
pub fn parse(font: &[u8]) -> Font {
|
||||||
|
use core::convert::TryInto;
|
||||||
|
|
||||||
|
// The number of glyphs in this font.
|
||||||
|
let length = u32::from_le_bytes(font[16..20].try_into().unwrap()) as usize;
|
||||||
|
// The size in bytes of a single glyph.
|
||||||
|
let charsize = u32::from_le_bytes(font[20..24].try_into().unwrap()) as usize;
|
||||||
|
// The height in pixels of this font's bounding box.
|
||||||
|
let height = u32::from_le_bytes(font[24..28].try_into().unwrap()) as usize;
|
||||||
|
// The width in pixels of this font's bounding box.
|
||||||
|
let width = u32::from_le_bytes(font[28..32].try_into().unwrap()) as usize;
|
||||||
|
// The size in bytes of a single row of pixels in a glyph.
|
||||||
|
let line_size = num_integer::div_ceil(width, 8);
|
||||||
|
|
||||||
|
let glyphs_offset = 32; // the size of the header
|
||||||
|
let glyphs_size = length * charsize;
|
||||||
|
let unicode_offset = glyphs_offset + glyphs_size;
|
||||||
|
|
||||||
|
let mut glyphs = Vec::with_capacity(length);
|
||||||
|
|
||||||
|
for i in 0..length {
|
||||||
|
let mut bitmap = Vec::with_capacity(charsize);
|
||||||
|
let bitmap_begin = glyphs_offset + charsize * i;
|
||||||
|
let bitmap_end = bitmap_begin + charsize;
|
||||||
|
bitmap.extend_from_slice(&font[bitmap_begin..bitmap_end]);
|
||||||
|
|
||||||
|
glyphs.push(Glyph {
|
||||||
|
bitmap,
|
||||||
|
line_size,
|
||||||
|
// Glyphs may overflow the font's nominal resolution in the padding bytes of the line!
|
||||||
|
// This trick only works for the width because there is no vertical padding.
|
||||||
|
// TODO: Pre-compute widths and bounding box offsets of individual glyphs.
|
||||||
|
width: line_size * 8,
|
||||||
|
height,
|
||||||
|
});
|
||||||
|
}
|
||||||
|
|
||||||
|
// HACK: This unicode map parser is still a mess.
|
||||||
|
let mut unicode_map = Vec::new();
|
||||||
|
let unicode_info = &font[unicode_offset..];
|
||||||
|
let mut glyph = 0;
|
||||||
|
let mut i = 0;
|
||||||
|
while i < unicode_info.len() {
|
||||||
|
let mut nc = unicode_info[i];
|
||||||
|
|
||||||
|
while nc != 0xFE && nc != 0xFF {
|
||||||
|
let ch_bytes = nc.leading_ones().max(1) as usize;
|
||||||
|
let st = core::str::from_utf8(&unicode_info[i..i + ch_bytes]).expect("Invalid character");
|
||||||
|
let ch = st.chars().next().unwrap();
|
||||||
|
unicode_map.push(UnicodeMap { c: ch, i: glyph });
|
||||||
|
i += ch_bytes;
|
||||||
|
nc = unicode_info[i];
|
||||||
|
}
|
||||||
|
|
||||||
|
// TODO: Support multi-codepoint spellings of characters.
|
||||||
|
while nc != 0xFF {
|
||||||
|
i += 1;
|
||||||
|
nc = unicode_info[i];
|
||||||
|
}
|
||||||
|
|
||||||
|
i += 1;
|
||||||
|
glyph += 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
Font {
|
||||||
|
width,
|
||||||
|
height,
|
||||||
|
glyphs,
|
||||||
|
unicode: unicode_map,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
Loading…
Reference in New Issue