Add LaTeX rendering to Markdown preview

Cargo.toml

@@ -104,6 +104,7 @@ members = [
     "crates/language_selector",
     "crates/language_tools",
     "crates/languages",
+    "crates/latex_render",
     "crates/line_ending_selector",
     "crates/livekit_api",
     "crates/livekit_client",
@@ -343,6 +344,7 @@ language_onboarding = { path = "crates/language_onboarding" }
 language_selector = { path = "crates/language_selector" }
 language_tools = { path = "crates/language_tools" }
 languages = { path = "crates/languages" }
+latex_render = { path = "crates/latex_render" }
 line_ending_selector = { path = "crates/line_ending_selector" }
 livekit_api = { path = "crates/livekit_api" }
 livekit_client = { path = "crates/livekit_client" }

crates/latex_render/Cargo.toml

@@ -0,0 +1,37 @@
+[package]
+name = "latex_render"
+version = "0.1.0"
+edition.workspace = true
+publish.workspace = true
+license = "GPL-3.0-or-later"
+
+[lints]
+workspace = true
+
+[lib]
+path = "src/latex_render.rs"
+doctest = false
+
+[[example]]
+name = "latex_demo"
+path = "examples/latex_demo.rs"
+
+[features]
+test-support = ["gpui/test-support"]
+
+[dependencies]
+anyhow.workspace = true
+collections.workspace = true
+gpui.workspace = true
+image = { workspace = true }
+parking_lot.workspace = true
+smallvec.workspace = true
+regex.workspace = true
+tiny-skia = "0.11"
+ttf-parser = "0.20"
+
+# ReX library from the fork (with Windows compatibility fixes)
+rex = { git = "https://github.com/MostlyKIGuess/ReX", features = ["tinyskia-renderer", "ttfparser-fontparser"] }
+
+[dev-dependencies]
+gpui = { workspace = true, features = ["test-support"] }

crates/latex_render/LICENSE-GPL

@@ -0,0 +1 @@
+../../LICENSE-GPL

crates/latex_render/examples/latex_demo.rs

@@ -0,0 +1,108 @@
+use gpui::{
+    App, AppContext, Application, Bounds, Context, InteractiveElement, ParentElement, Render,
+    StatefulInteractiveElement, Styled, Window, WindowOptions, div, img, point, px, size,
+};
+use latex_render::{LatexColor, LatexRenderer};
+use std::sync::Arc;
+
+struct LatexDemo {
+    renderer: Arc<LatexRenderer>,
+    formulas: Vec<&'static str>,
+}
+
+impl LatexDemo {
+    fn new(renderer: Arc<LatexRenderer>) -> Self {
+        Self {
+            renderer,
+            formulas: vec![
+                r"x",
+                r"X",
+                r"x_{1,2}",
+                r"x\_{1,2}", // Prettier way of writing underscore, added a special sanitization in renderer
+                r"\sum n \pi",
+                r"x_{1,2} = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}",
+                r"| \vec{A}|=\sqrt{A_x^2 + A_y^2 + A_z^2}",
+                r"| \vec{A}|=\sqrt{A_x^2 + A_y^2 + A_z^2} \tag{1}", // tags aren't supported, sanitization test
+                r"E = mc^2",
+                r"x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}",
+                r"\int_{-\infty}^{\infty} e^{-x^2} dx = \sqrt{\pi}",
+                r"\sum_{n=1}^{\infty} \frac{1}{n^2} = \frac{\pi^2}{6}",
+                r"\nabla \times \mathbf{E} = -\frac{\partial \mathbf{B}}{\partial t}",
+                r"\lim_{n \to \infty} \left(1 + \frac{1}{n}\right)^n = e",
+                r"\begin{pmatrix} a & b \\ c & d \end{pmatrix}",
+            ],
+        }
+    }
+}
+
+impl Render for LatexDemo {
+    fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl gpui::IntoElement {
+        let font_size = 16.0;
+        let color = LatexColor::BLACK;
+
+        div()
+            .id("latex-demo")
+            .flex()
+            .flex_col()
+            .gap_4()
+            .p_4()
+            .bg(gpui::white())
+            .size_full()
+            .overflow_y_scroll()
+            .children(self.formulas.iter().enumerate().map(|(_i, formula)| {
+                let result = self.renderer.render(formula, font_size, color, true);
+
+                div()
+                    .flex()
+                    .flex_row()
+                    .gap_2()
+                    .p_2()
+                    .border_1()
+                    .border_color(gpui::rgb(0xcccccc))
+                    .rounded_md()
+                    .child(
+                        div()
+                            .w(px(300.0))
+                            .overflow_hidden()
+                            .child(formula.to_string()),
+                    )
+                    .child(
+                        div().flex_1().child(match result {
+                            Some(Ok((image, (width, height)))) => div().child(
+                                img(gpui::ImageSource::Render(image))
+                                    .w(px(width as f32))
+                                    .h(px(height as f32)),
+                            ),
+                            Some(Err(e)) => {
+                                div().text_color(gpui::red()).child(format!("Error: {}", e))
+                            }
+                            None => div().text_color(gpui::rgb(0x888888)).child("Rendering..."),
+                        }),
+                    )
+            }))
+    }
+}
+
+fn main() {
+    Application::new().run(|cx: &mut App| {
+        let window_options = WindowOptions {
+            window_bounds: Some(gpui::WindowBounds::Windowed(Bounds {
+                origin: point(px(100.0), px(100.0)),
+                size: size(px(900.0), px(600.0)),
+            })),
+            titlebar: Some(gpui::TitlebarOptions {
+                title: Some("LaTeX Rendering Demo (ReX)".into()),
+                ..Default::default()
+            }),
+            focus: true,
+            show: true,
+            ..Default::default()
+        };
+
+        cx.open_window(window_options, |_, cx| {
+            let renderer = Arc::new(LatexRenderer::new(cx.background_executor().clone()));
+            cx.new(|_| LatexDemo::new(renderer))
+        })
+        .unwrap();
+    });
+}