зеркало из https://github.com/mozilla/gecko-dev.git
servo: Merge #11347 - Don't create HarfBuzz shaper if it isn't used (from mbrubeck:fast-shape); r=pcwalton
Move the fast shaping code out of `text::shaping::harfbuzz`, and initialize the HarfBuzz shaper lazily to avoid allocating unnecessary HarfBuzz objects. Note: As the fast shaping code grows and gains OpenType support, I'll probably factor it out into a whole new `text::shaping::fast` module. r? @pcwalton Source-Repo: https://github.com/servo/servo Source-Revision: 8b633c979eb57c94e59d93888df9971193a3d533
This commit is contained in:
Родитель
5213796900
Коммит
033133b73c
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@ -9,6 +9,7 @@ use platform::font::{FontHandle, FontTable};
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use platform::font_context::FontContextHandle;
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use platform::font_template::FontTemplateData;
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use smallvec::SmallVec;
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use std::ascii::AsciiExt;
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use std::borrow::ToOwned;
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use std::cell::RefCell;
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use std::rc::Rc;
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@ -17,7 +18,7 @@ use std::sync::Arc;
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use std::sync::atomic::{ATOMIC_USIZE_INIT, AtomicUsize, Ordering};
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use style::computed_values::{font_stretch, font_variant, font_weight};
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use text::Shaper;
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use text::glyph::{GlyphId, GlyphStore};
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use text::glyph::{ByteIndex, GlyphData, GlyphId, GlyphStore};
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use text::shaping::ShaperMethods;
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use time;
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use unicode_script::Script;
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@ -108,8 +109,8 @@ pub struct Font {
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pub requested_pt_size: Au,
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pub actual_pt_size: Au,
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shaper: Option<Shaper>,
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shape_cache: HashCache<ShapeCacheEntry, Arc<GlyphStore>>,
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glyph_advance_cache: HashCache<u32, FractionalPixel>,
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shape_cache: RefCell<HashCache<ShapeCacheEntry, Arc<GlyphStore>>>,
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glyph_advance_cache: RefCell<HashCache<u32, FractionalPixel>>,
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pub font_key: Option<webrender_traits::FontKey>,
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}
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@ -129,8 +130,8 @@ impl Font {
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requested_pt_size: requested_pt_size,
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actual_pt_size: actual_pt_size,
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metrics: metrics,
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shape_cache: HashCache::new(),
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glyph_advance_cache: HashCache::new(),
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shape_cache: RefCell::new(HashCache::new()),
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glyph_advance_cache: RefCell::new(HashCache::new()),
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font_key: font_key,
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}
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}
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@ -172,42 +173,74 @@ struct ShapeCacheEntry {
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impl Font {
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pub fn shape_text(&mut self, text: &str, options: &ShapingOptions) -> Arc<GlyphStore> {
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self.make_shaper(options);
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let this = self as *const Font;
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let mut shaper = self.shaper.take();
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//FIXME: find the equivalent of Equiv and the old ShapeCacheEntryRef
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let shaper = &self.shaper;
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let lookup_key = ShapeCacheEntry {
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text: text.to_owned(),
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options: *options,
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};
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self.shape_cache.find_or_create(lookup_key, || {
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let result = self.shape_cache.borrow_mut().find_or_create(lookup_key, || {
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let start_time = time::precise_time_ns();
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let mut glyphs = GlyphStore::new(text.len(),
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options.flags.contains(IS_WHITESPACE_SHAPING_FLAG),
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options.flags.contains(RTL_FLAG));
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shaper.as_ref().unwrap().shape_text(text, options, &mut glyphs);
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let glyphs = Arc::new(glyphs);
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if self.can_do_fast_shaping(text, options) {
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debug!("shape_text: Using ASCII fast path.");
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self.shape_text_fast(text, options, &mut glyphs);
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} else {
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debug!("shape_text: Using Harfbuzz.");
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if shaper.is_none() {
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shaper = Some(Shaper::new(this));
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}
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shaper.as_ref().unwrap().shape_text(text, options, &mut glyphs);
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}
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let end_time = time::precise_time_ns();
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TEXT_SHAPING_PERFORMANCE_COUNTER.fetch_add((end_time - start_time) as usize,
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Ordering::Relaxed);
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glyphs
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})
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Arc::new(glyphs)
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});
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self.shaper = shaper;
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result
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}
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fn make_shaper<'a>(&'a mut self, options: &ShapingOptions) -> &'a Shaper {
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// fast path: already created a shaper
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if let Some(ref mut shaper) = self.shaper {
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shaper.set_options(options);
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return shaper
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fn can_do_fast_shaping(&self, text: &str, options: &ShapingOptions) -> bool {
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options.script == Script::Latin &&
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!options.flags.contains(RTL_FLAG) &&
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self.handle.can_do_fast_shaping() &&
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text.is_ascii()
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}
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let shaper = Shaper::new(self, options);
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self.shaper = Some(shaper);
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self.shaper.as_ref().unwrap()
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/// Fast path for ASCII text that only needs simple horizontal LTR kerning.
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fn shape_text_fast(&self, text: &str, options: &ShapingOptions, glyphs: &mut GlyphStore) {
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let mut prev_glyph_id = None;
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for (i, byte) in text.bytes().enumerate() {
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let character = byte as char;
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let glyph_id = match self.glyph_index(character) {
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Some(id) => id,
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None => continue,
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};
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let mut advance = Au::from_f64_px(self.glyph_h_advance(glyph_id));
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if character == ' ' {
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advance += options.word_spacing;
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}
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if let Some(letter_spacing) = options.letter_spacing {
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advance += letter_spacing;
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}
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let offset = prev_glyph_id.map(|prev| {
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let h_kerning = Au::from_f64_px(self.glyph_h_kerning(prev, glyph_id));
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advance += h_kerning;
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Point2D::new(h_kerning, Au(0))
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});
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let glyph = GlyphData::new(glyph_id, advance, offset, true, true);
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glyphs.add_glyph_for_byte_index(ByteIndex(i as isize), character, &glyph);
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prev_glyph_id = Some(glyph_id);
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}
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glyphs.finalize_changes();
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}
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pub fn table_for_tag(&self, tag: FontTableTag) -> Option<FontTable> {
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@ -230,15 +263,14 @@ impl Font {
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self.handle.glyph_index(codepoint)
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}
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pub fn glyph_h_kerning(&mut self, first_glyph: GlyphId, second_glyph: GlyphId)
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pub fn glyph_h_kerning(&self, first_glyph: GlyphId, second_glyph: GlyphId)
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-> FractionalPixel {
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self.handle.glyph_h_kerning(first_glyph, second_glyph)
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}
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pub fn glyph_h_advance(&mut self, glyph: GlyphId) -> FractionalPixel {
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let handle = &self.handle;
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self.glyph_advance_cache.find_or_create(glyph, || {
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match handle.glyph_h_advance(glyph) {
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pub fn glyph_h_advance(&self, glyph: GlyphId) -> FractionalPixel {
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self.glyph_advance_cache.borrow_mut().find_or_create(glyph, || {
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match self.handle.glyph_h_advance(glyph) {
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Some(adv) => adv,
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None => 10f64 as FractionalPixel // FIXME: Need fallback strategy
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}
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@ -4,7 +4,7 @@
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use app_units::Au;
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use euclid::Point2D;
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use font::{DISABLE_KERNING_SHAPING_FLAG, Font, FontHandleMethods, FontTableMethods, FontTableTag};
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use font::{DISABLE_KERNING_SHAPING_FLAG, Font, FontTableMethods, FontTableTag};
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use font::{IGNORE_LIGATURES_SHAPING_FLAG, KERN, RTL_FLAG, ShapingOptions};
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use harfbuzz::{HB_DIRECTION_LTR, HB_DIRECTION_RTL, HB_MEMORY_MODE_READONLY};
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use harfbuzz::{hb_blob_create, hb_face_create_for_tables};
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@ -34,12 +34,10 @@ use harfbuzz::{hb_glyph_position_t};
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use harfbuzz::{hb_position_t, hb_tag_t};
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use libc::{c_char, c_int, c_uint, c_void};
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use platform::font::FontTable;
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use std::ascii::AsciiExt;
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use std::{char, cmp, ptr};
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use text::glyph::{ByteIndex, GlyphData, GlyphId, GlyphStore};
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use text::shaping::ShaperMethods;
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use text::util::{fixed_to_float, float_to_fixed, is_bidi_control};
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use unicode_script::Script;
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const NO_GLYPH: i32 = -1;
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const LIGA: u32 = ot_tag!('l', 'i', 'g', 'a');
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@ -126,17 +124,11 @@ impl ShapedGlyphData {
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}
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}
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#[derive(Debug)]
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struct FontAndShapingOptions {
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font: *mut Font,
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options: ShapingOptions,
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}
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#[derive(Debug)]
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pub struct Shaper {
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hb_face: *mut hb_face_t,
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hb_font: *mut hb_font_t,
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font_and_shaping_options: Box<FontAndShapingOptions>,
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font: *const Font,
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}
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impl Drop for Shaper {
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@ -152,20 +144,16 @@ impl Drop for Shaper {
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}
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impl Shaper {
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pub fn new(font: &mut Font, options: &ShapingOptions) -> Shaper {
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pub fn new(font: *const Font) -> Shaper {
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unsafe {
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let mut font_and_shaping_options = box FontAndShapingOptions {
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font: font,
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options: *options,
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};
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let hb_face: *mut hb_face_t =
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hb_face_create_for_tables(Some(font_table_func),
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&mut *font_and_shaping_options as *mut _ as *mut c_void,
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font as *const c_void as *mut c_void,
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None);
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let hb_font: *mut hb_font_t = hb_font_create(hb_face);
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// Set points-per-em. if zero, performs no hinting in that direction.
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let pt_size = font.actual_pt_size.to_f64_px();
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let pt_size = (*font).actual_pt_size.to_f64_px();
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hb_font_set_ppem(hb_font, pt_size as c_uint, pt_size as c_uint);
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// Set scaling. Note that this takes 16.16 fixed point.
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@ -179,15 +167,11 @@ impl Shaper {
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Shaper {
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hb_face: hb_face,
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hb_font: hb_font,
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font_and_shaping_options: font_and_shaping_options,
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font: font,
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}
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}
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}
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pub fn set_options(&mut self, options: &ShapingOptions) {
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self.font_and_shaping_options.options = *options
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}
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fn float_to_fixed(f: f64) -> i32 {
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float_to_fixed(16, f)
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}
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@ -201,14 +185,7 @@ impl ShaperMethods for Shaper {
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/// Calculate the layout metrics associated with the given text when painted in a specific
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/// font.
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fn shape_text(&self, text: &str, options: &ShapingOptions, glyphs: &mut GlyphStore) {
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if self.can_use_fast_path(text, options) {
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debug!("shape_text: Using ASCII fast path.");
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self.shape_text_fast(text, options, glyphs);
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return;
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}
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unsafe {
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debug!("shape_text: Using Harfbuzz.");
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let hb_buffer: *mut hb_buffer_t = hb_buffer_create();
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hb_buffer_set_direction(hb_buffer, if options.flags.contains(RTL_FLAG) {
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HB_DIRECTION_RTL
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@ -250,47 +227,6 @@ impl ShaperMethods for Shaper {
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}
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impl Shaper {
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fn can_use_fast_path(&self, text: &str, options: &ShapingOptions) -> bool {
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let font = self.font_and_shaping_options.font;
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options.script == Script::Latin &&
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!options.flags.contains(RTL_FLAG) &&
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unsafe { (*font).handle.can_do_fast_shaping() } &&
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text.is_ascii()
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}
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/// Fast path for ASCII text that only needs simple horizontal LTR kerning.
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fn shape_text_fast(&self, text: &str, options: &ShapingOptions, glyphs: &mut GlyphStore) {
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let font = unsafe { &mut *self.font_and_shaping_options.font };
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let mut prev_glyph_id = None;
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for (i, byte) in text.bytes().enumerate() {
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let character = byte as char;
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let glyph_id = match font.glyph_index(character) {
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Some(id) => id,
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None => continue,
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};
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let mut advance = Au::from_f64_px(font.glyph_h_advance(glyph_id));
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if character == ' ' {
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advance += options.word_spacing;
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}
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if let Some(letter_spacing) = options.letter_spacing {
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advance += letter_spacing;
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}
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let offset = prev_glyph_id.map(|prev| {
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let h_kerning = Au::from_f64_px(font.glyph_h_kerning(prev, glyph_id));
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advance += h_kerning;
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Point2D::new(h_kerning, Au(0))
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});
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let glyph = GlyphData::new(glyph_id, advance, offset, true, true);
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glyphs.add_glyph_for_byte_index(ByteIndex(i as isize), character, &glyph);
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prev_glyph_id = Some(glyph_id);
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}
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glyphs.finalize_changes();
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}
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fn save_glyph_results(&self,
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text: &str,
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options: &ShapingOptions,
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@ -409,8 +345,7 @@ impl Shaper {
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//
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// TODO: Proper tab stops.
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const TAB_COLS: i32 = 8;
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let font = self.font_and_shaping_options.font;
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let (space_glyph_id, space_advance) = glyph_space_advance(font);
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let (space_glyph_id, space_advance) = glyph_space_advance(self.font);
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let advance = Au::from_f64_px(space_advance) * TAB_COLS;
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let data = GlyphData::new(space_glyph_id,
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advance,
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@ -522,7 +457,7 @@ extern fn glyph_h_advance_func(_: *mut hb_font_t,
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}
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}
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fn glyph_space_advance(font: *mut Font) -> (hb_codepoint_t, f64) {
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fn glyph_space_advance(font: *const Font) -> (hb_codepoint_t, f64) {
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let space_unicode = ' ';
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let space_glyph: hb_codepoint_t;
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match unsafe { (*font).glyph_index(space_unicode) } {
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@ -557,13 +492,11 @@ extern fn font_table_func(_: *mut hb_face_t,
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-> *mut hb_blob_t {
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unsafe {
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// NB: These asserts have security implications.
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let font_and_shaping_options: *const FontAndShapingOptions =
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user_data as *const FontAndShapingOptions;
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assert!(!font_and_shaping_options.is_null());
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assert!(!(*font_and_shaping_options).font.is_null());
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let font = user_data as *const Font;
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assert!(!font.is_null());
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// TODO(Issue #197): reuse font table data, which will change the unsound trickery here.
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match (*(*font_and_shaping_options).font).table_for_tag(tag as FontTableTag) {
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match (*font).table_for_tag(tag as FontTableTag) {
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None => ptr::null_mut(),
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Some(font_table) => {
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// `Box::into_raw` intentionally leaks the FontTable so we don't destroy the buffer
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