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-rw-r--r--font/src/ft/mod.rs79
1 files changed, 40 insertions, 39 deletions
diff --git a/font/src/ft/mod.rs b/font/src/ft/mod.rs
index d393b63f..ef1afb5f 100644
--- a/font/src/ft/mod.rs
+++ b/font/src/ft/mod.rs
@@ -46,7 +46,7 @@ impl FallbackFont {
impl FontKey {
fn from_pattern_hashes(lhs: PatternHash, rhs: PatternHash) -> Self {
- // XOR two hashes to get a font ID
+ // XOR two hashes to get a font ID.
Self { token: lhs.0.rotate_left(1) ^ rhs.0 }
}
}
@@ -121,18 +121,18 @@ impl Rasterize for FreeTypeRasterizer {
let height = (full.size_metrics.height / 64) as f64;
let descent = (full.size_metrics.descender / 64) as f32;
- // Get underline position and thickness in device pixels
+ // Get underline position and thickness in device pixels.
let x_scale = full.size_metrics.x_scale as f32 / 65536.0;
let mut underline_position = f32::from(face.ft_face.underline_position()) * x_scale / 64.;
let mut underline_thickness = f32::from(face.ft_face.underline_thickness()) * x_scale / 64.;
- // Fallback for bitmap fonts which do not provide underline metrics
+ // Fallback for bitmap fonts which do not provide underline metrics.
if underline_position == 0. {
underline_thickness = (descent.abs() / 5.).round();
underline_position = descent / 2.;
}
- // Get strikeout position and thickness in device pixels
+ // Get strikeout position and thickness in device pixels.
let (strikeout_position, strikeout_thickness) =
match TrueTypeOS2Table::from_face(&mut (*face.ft_face).clone()) {
Some(os2) => {
@@ -141,7 +141,7 @@ impl Rasterize for FreeTypeRasterizer {
(strikeout_position, strikeout_thickness)
},
_ => {
- // Fallback if font doesn't provide info about strikeout
+ // Fallback if font doesn't provide info about strikeout.
trace!("Using fallback strikeout metrics");
let strikeout_position = height as f32 / 2. + descent;
(strikeout_position, underline_thickness)
@@ -206,9 +206,9 @@ struct FullMetrics {
}
impl FreeTypeRasterizer {
- /// Load a font face according to `FontDesc`
+ /// Load a font face according to `FontDesc`.
fn get_face(&mut self, desc: &FontDesc, size: Size) -> Result<FontKey, Error> {
- // Adjust for DPI
+ // Adjust for DPR.
let size = f64::from(size.as_f32_pts() * self.device_pixel_ratio * 96. / 72.);
let config = fc::Config::get_current();
@@ -216,26 +216,26 @@ impl FreeTypeRasterizer {
pattern.add_family(&desc.name);
pattern.add_pixelsize(size);
- // Add style to a pattern
+ // Add style to a pattern.
match desc.style {
Style::Description { slant, weight } => {
- // Match nearest font
+ // Match nearest font.
pattern.set_weight(weight.into_fontconfig_type());
pattern.set_slant(slant.into_fontconfig_type());
},
Style::Specific(ref style) => {
- // If a name was specified, try and load specifically that font
+ // If a name was specified, try and load specifically that font.
pattern.add_style(style);
},
}
- // Hash requested pattern
+ // Hash requested pattern.
let hash = pattern.hash();
pattern.config_substitute(config, fc::MatchKind::Pattern);
pattern.default_substitute();
- // Get font list using pattern. First font is the primary one while the rest are fallbacks
+ // Get font list using pattern. First font is the primary one while the rest are fallbacks.
let matched_fonts =
fc::font_sort(&config, &pattern).ok_or_else(|| Error::MissingFont(desc.to_owned()))?;
let mut matched_fonts = matched_fonts.into_iter();
@@ -243,24 +243,24 @@ impl FreeTypeRasterizer {
let primary_font =
matched_fonts.next().ok_or_else(|| Error::MissingFont(desc.to_owned()))?;
- // We should render patterns to get values like `pixelsizefixupfactor`
+ // We should render patterns to get values like `pixelsizefixupfactor`.
let primary_font = pattern.render_prepare(config, primary_font);
- // Hash pattern together with request pattern to include requested font size in the hash
+ // Hash pattern together with request pattern to include requested font size in the hash.
let primary_font_key = FontKey::from_pattern_hashes(hash, primary_font.hash());
- // Return if we already have the same primary font
+ // Return if we already have the same primary font.
if self.fallback_lists.contains_key(&primary_font_key) {
return Ok(primary_font_key);
}
- // Load font if we haven't loaded it yet
+ // Load font if we haven't loaded it yet.
if !self.faces.contains_key(&primary_font_key) {
self.face_from_pattern(&primary_font, primary_font_key)
.and_then(|pattern| pattern.ok_or_else(|| Error::MissingFont(desc.to_owned())))?;
}
- // Coverage for fallback fonts
+ // Coverage for fallback fonts.
let coverage = CharSet::new();
let empty_charset = CharSet::new();
@@ -268,7 +268,7 @@ impl FreeTypeRasterizer {
.map(|fallback_font| {
let charset = fallback_font.get_charset().unwrap_or(&empty_charset);
- // Use original pattern to preserve loading flags
+ // Use original pattern to preserve loading flags.
let fallback_font = pattern.render_prepare(config, fallback_font);
let fallback_font_key = FontKey::from_pattern_hashes(hash, fallback_font.hash());
@@ -299,7 +299,7 @@ impl FreeTypeRasterizer {
let mut ft_face = self.library.new_face(&ft_face_location.path, ft_face_location.index)?;
if ft_face.has_color() {
unsafe {
- // Select the colored bitmap size to use from the array of available sizes
+ // Select the colored bitmap size to use from the array of available sizes.
freetype_sys::FT_Select_Size(ft_face.raw_mut(), 0);
}
}
@@ -370,7 +370,7 @@ impl FreeTypeRasterizer {
fn load_face_with_glyph(&mut self, glyph: GlyphKey) -> Result<FontKey, Error> {
let fallback_list = self.fallback_lists.get(&glyph.font_key).unwrap();
- // Check whether glyph is presented in any fallback font
+ // Check whether glyph is presented in any fallback font.
if !fallback_list.coverage.has_char(glyph.c) {
return Ok(glyph.font_key);
}
@@ -382,7 +382,7 @@ impl FreeTypeRasterizer {
Some(face) => {
let index = face.ft_face.get_char_index(glyph.c as usize);
- // We found something in a current face, so let's use it
+ // We found something in a current face, so let's use it.
if index != 0 {
return Ok(font_key);
}
@@ -400,12 +400,12 @@ impl FreeTypeRasterizer {
}
}
- // You can hit this return, if you're failing to get charset from a pattern
+ // You can hit this return, if you're failing to get charset from a pattern.
Ok(glyph.font_key)
}
fn get_rendered_glyph(&mut self, glyph_key: GlyphKey) -> Result<RasterizedGlyph, Error> {
- // Render a normal character if it's not a cursor
+ // Render a normal character if it's not a cursor.
let font_key = self.face_for_glyph(glyph_key)?;
let face = &self.faces[&font_key];
let index = face.ft_face.get_char_index(glyph_key.c as usize);
@@ -442,7 +442,7 @@ impl FreeTypeRasterizer {
let fixup_factor = if let Some(pixelsize_fixup_factor) = face.pixelsize_fixup_factor {
pixelsize_fixup_factor
} else {
- // Fallback if user has bitmap scaling disabled
+ // Fallback if user has bitmap scaling disabled.
let metrics = face.ft_face.size_metrics().ok_or(Error::MissingSizeMetrics)?;
f64::from(pixelsize) / f64::from(metrics.y_ppem)
};
@@ -465,7 +465,7 @@ impl FreeTypeRasterizer {
(false, fc::HintStyle::None, _) => LoadFlag::NO_HINTING | LoadFlag::MONOCHROME,
(false, ..) => LoadFlag::TARGET_MONO | LoadFlag::MONOCHROME,
(true, fc::HintStyle::None, _) => LoadFlag::NO_HINTING | LoadFlag::TARGET_NORMAL,
- // hintslight does *not* use LCD hinting even when a subpixel mode
+ // `hintslight` does *not* use LCD hinting even when a subpixel mode
// is selected.
//
// According to the FreeType docs,
@@ -478,7 +478,7 @@ impl FreeTypeRasterizer {
// In practice, this means we can have `FT_LOAD_TARGET_LIGHT` with
// subpixel render modes like `FT_RENDER_MODE_LCD`. Libraries like
// cairo take the same approach and consider `hintslight` to always
- // prefer `FT_LOAD_TARGET_LIGHT`
+ // prefer `FT_LOAD_TARGET_LIGHT`.
(true, fc::HintStyle::Slight, _) => LoadFlag::TARGET_LIGHT,
// If LCD hinting is to be used, must select hintmedium or hintfull,
// have AA enabled, and select a subpixel mode.
@@ -565,7 +565,7 @@ impl FreeTypeRasterizer {
while count != 0 {
let value = ((byte >> bit) & 1) * 255;
// Push value 3x since result buffer should be 1 byte
- // per channel
+ // per channel.
res.push(value);
res.push(value);
res.push(value);
@@ -623,7 +623,7 @@ impl FreeTypeRasterizer {
/// This will take the `bitmap_glyph` as input and return the glyph's content downscaled by
/// `fixup_factor`.
fn downsample_bitmap(mut bitmap_glyph: RasterizedGlyph, fixup_factor: f64) -> RasterizedGlyph {
- // Only scale colored buffers which are bigger than required
+ // Only scale colored buffers which are bigger than required.
let bitmap_buffer = match (&bitmap_glyph.buf, fixup_factor.partial_cmp(&1.0)) {
(BitmapBuffer::RGBA(buffer), Some(Ordering::Less)) => buffer,
_ => return bitmap_glyph,
@@ -635,19 +635,20 @@ fn downsample_bitmap(mut bitmap_glyph: RasterizedGlyph, fixup_factor: f64) -> Ra
let target_width = (bitmap_width as f64 * fixup_factor) as usize;
let target_height = (bitmap_height as f64 * fixup_factor) as usize;
- // Number of pixels in the input buffer, per pixel in the output buffer
+ // Number of pixels in the input buffer, per pixel in the output buffer.
let downsampling_step = 1.0 / fixup_factor;
let mut downsampled_buffer = Vec::<u8>::with_capacity(target_width * target_height * 4);
for line_index in 0..target_height {
- // Get the first and last line which will be consolidated in the current output pixel
+ // Get the first and last line which will be consolidated in the current output pixel.
let line_index = line_index as f64;
let source_line_start = (line_index * downsampling_step).round() as usize;
let source_line_end = ((line_index + 1.) * downsampling_step).round() as usize;
for column_index in 0..target_width {
- // Get the first and last column which will be consolidated in the current output pixel
+ // Get the first and last column which will be consolidated in the current output
+ // pixel.
let column_index = column_index as f64;
let source_column_start = (column_index * downsampling_step).round() as usize;
let source_column_end = ((column_index + 1.) * downsampling_step).round() as usize;
@@ -655,7 +656,7 @@ fn downsample_bitmap(mut bitmap_glyph: RasterizedGlyph, fixup_factor: f64) -> Ra
let (mut r, mut g, mut b, mut a) = (0u32, 0u32, 0u32, 0u32);
let mut pixels_picked: u32 = 0;
- // Consolidate all pixels within the source rectangle into a single averaged pixel
+ // Consolidate all pixels within the source rectangle into a single averaged pixel.
for source_line in source_line_start..source_line_end {
let source_pixel_index = source_line * bitmap_width;
@@ -669,7 +670,7 @@ fn downsample_bitmap(mut bitmap_glyph: RasterizedGlyph, fixup_factor: f64) -> Ra
}
}
- // Add a single pixel to the output buffer for the downscaled source rectangle
+ // Add a single pixel to the output buffer for the downscaled source rectangle.
downsampled_buffer.push((r / pixels_picked) as u8);
downsampled_buffer.push((g / pixels_picked) as u8);
downsampled_buffer.push((b / pixels_picked) as u8);
@@ -679,7 +680,7 @@ fn downsample_bitmap(mut bitmap_glyph: RasterizedGlyph, fixup_factor: f64) -> Ra
bitmap_glyph.buf = BitmapBuffer::RGBA(downsampled_buffer);
- // Downscale the metrics
+ // Downscale the metrics.
bitmap_glyph.top = (f64::from(bitmap_glyph.top) * fixup_factor) as i32;
bitmap_glyph.left = (f64::from(bitmap_glyph.left) * fixup_factor) as i32;
bitmap_glyph.width = target_width as i32;
@@ -688,19 +689,19 @@ fn downsample_bitmap(mut bitmap_glyph: RasterizedGlyph, fixup_factor: f64) -> Ra
bitmap_glyph
}
-/// Errors occurring when using the freetype rasterizer
+/// Errors occurring when using the freetype rasterizer.
#[derive(Debug)]
pub enum Error {
- /// Error occurred within the FreeType library
+ /// Error occurred within the FreeType library.
FreeType(freetype::Error),
- /// Couldn't find font matching description
+ /// Couldn't find font matching description.
MissingFont(FontDesc),
- /// Tried to get size metrics from a Face that didn't have a size
+ /// Tried to get size metrics from a Face that didn't have a size.
MissingSizeMetrics,
- /// Requested an operation with a FontKey that isn't known to the rasterizer
+ /// Requested an operation with a FontKey that isn't known to the rasterizer.
FontNotLoaded,
}
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