80 lines
2.6 KiB
Rust
80 lines
2.6 KiB
Rust
// SPDX-License-Identifier: MIT OR Apache-2.0
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//! Run this example with `cargo run --package terminal`
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//! or `cargo run --package terminal -- "my own text"`
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use colored::Colorize;
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use cosmic_text::{Attrs, Buffer, Color, FontSystem, Metrics, Shaping, SwashCache};
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use std::fmt::Write;
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fn main() {
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// A FontSystem provides access to detected system fonts, create one per application
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let mut font_system = FontSystem::new();
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// A SwashCache stores rasterized glyphs, create one per application
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let mut swash_cache = SwashCache::new();
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// Text metrics indicate the font size and line height of a buffer
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const FONT_SIZE: f32 = 14.0;
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const LINE_HEIGHT: f32 = FONT_SIZE * 1.2;
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let metrics = Metrics::new(FONT_SIZE, LINE_HEIGHT);
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// A Buffer provides shaping and layout for a UTF-8 string, create one per text widget
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let mut buffer = Buffer::new(&mut font_system, metrics);
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let mut buffer = buffer.borrow_with(&mut font_system);
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// Set a size for the text buffer, in pixels
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let width = 80.0;
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// The height is unbounded
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buffer.set_size(Some(width), None);
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// Attributes indicate what font to choose
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let attrs = Attrs::new();
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// Add some text!
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let text = std::env::args()
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.nth(1)
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.unwrap_or(" Hi, Rust! 🦀 ".to_string());
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buffer.set_text(&text, &attrs, Shaping::Advanced, None);
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// Perform shaping as desired
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buffer.shape_until_scroll(true);
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// Default text color (0xFF, 0xFF, 0xFF is white)
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const TEXT_COLOR: Color = Color::rgb(0xFF, 0xFF, 0xFF);
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// Set up the canvas
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let height = LINE_HEIGHT * buffer.layout_runs().count() as f32;
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let mut canvas = vec![vec![None; width as usize]; height as usize];
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// Draw to the canvas
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buffer.draw(&mut swash_cache, TEXT_COLOR, |x, y, w, h, color| {
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let a = color.a();
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if a == 0 || x < 0 || x >= width as i32 || y < 0 || y >= height as i32 || w != 1 || h != 1 {
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// Ignore alphas of 0, or invalid x, y coordinates, or unimplemented sizes
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return;
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}
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// Scale by alpha (mimics blending with black)
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let scale = |c: u8| (c as i32 * a as i32 / 255).clamp(0, 255) as u8;
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let r = scale(color.r());
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let g = scale(color.g());
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let b = scale(color.b());
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canvas[y as usize][x as usize] = Some((r, g, b));
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});
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// Render the canvas
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let mut output = String::new();
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for row in canvas {
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for pixel in row {
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let (r, g, b) = pixel.unwrap_or((0, 0, 0));
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write!(&mut output, "{}", " ".on_truecolor(r, g, b)).ok();
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}
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writeln!(&mut output).ok();
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}
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print!("{}", output);
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}
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