mirror of
https://github.com/italicsjenga/vello.git
synced 2025-01-10 20:51:29 +11:00
87 lines
2.9 KiB
Rust
87 lines
2.9 KiB
Rust
// Copyright 2022 The vello authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// Also licensed under MIT license, at your choice.
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use vello::{
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glyph::{
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pinot,
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pinot::{FontRef, TableProvider},
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GlyphContext,
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},
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kurbo::Affine,
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peniko::Brush,
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SceneBuilder,
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};
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// This is very much a hack to get things working.
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// On Windows, can set this to "c:\\Windows\\Fonts\\seguiemj.ttf" to get color emoji
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const FONT_DATA: &[u8] = include_bytes!("../../assets/roboto/Roboto-Regular.ttf");
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pub struct SimpleText {
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gcx: GlyphContext,
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}
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impl SimpleText {
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pub fn new() -> Self {
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Self {
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gcx: GlyphContext::new(),
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}
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}
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pub fn add(
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&mut self,
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builder: &mut SceneBuilder,
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font: Option<&FontRef>,
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size: f32,
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brush: Option<&Brush>,
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transform: Affine,
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text: &str,
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) {
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let font = font.unwrap_or(&FontRef {
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data: FONT_DATA,
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offset: 0,
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});
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if let Some(cmap) = font.cmap() {
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if let Some(hmtx) = font.hmtx() {
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let upem = font.head().map(|head| head.units_per_em()).unwrap_or(1000) as f64;
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let scale = size as f64 / upem;
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let vars: [(pinot::types::Tag, f32); 0] = [];
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let mut provider = self.gcx.new_provider(font, None, size, false, vars);
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let hmetrics = hmtx.hmetrics();
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let default_advance = hmetrics
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.get(hmetrics.len().saturating_sub(1))
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.map(|h| h.advance_width)
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.unwrap_or(0);
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let mut pen_x = 0f64;
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for ch in text.chars() {
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let gid = cmap.map(ch as u32).unwrap_or(0);
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let advance = hmetrics
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.get(gid as usize)
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.map(|h| h.advance_width)
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.unwrap_or(default_advance) as f64
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* scale;
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if let Some(glyph) = provider.get(gid, brush) {
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let xform = transform
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* Affine::translate((pen_x, 0.0))
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* Affine::scale_non_uniform(1.0, -1.0);
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builder.append(&glyph, Some(xform));
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}
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pen_x += advance;
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}
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}
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}
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}
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}
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