Make text rendering optional in pathfinder_canvas

c/Cargo.toml

@@ -15,6 +15,7 @@ gl = "0.6"
 libc = "0.2"
 
 [dependencies.pathfinder_canvas]
+features = ["text"]
 path = "../canvas"
 
 [dependencies.pathfinder_content]

canvas/Cargo.toml

@@ -8,7 +8,7 @@ edition = "2018"
 crate-type = ["rlib", "staticlib"]
 
 [dependencies]
-font-kit = "0.2"
+font-kit = { version = "0.2", optional = true }
 
 [dependencies.pathfinder_content]
 path = "../content"
@@ -21,7 +21,12 @@ path = "../renderer"
 
 [dependencies.pathfinder_text]
 path = "../text"
+optional = true
 
 [dependencies.skribo]
 git = "https://github.com/linebender/skribo.git"
 rev = "a2d683856ba1f2d0095b12dd7823d1602a87614e"
+optional = true
+
+[features]
+text = ["pathfinder_text", "skribo", "font-kit"]

canvas/src/lib.rs

@@ -10,13 +10,6 @@
 
 //! A simple API for Pathfinder that mirrors a subset of HTML canvas.
 
-use font_kit::family_name::FamilyName;
-use font_kit::handle::Handle;
-use font_kit::hinting::HintingOptions;
-use font_kit::loaders::default::Font;
-use font_kit::properties::Properties;
-use font_kit::source::{Source, SystemSource};
-use font_kit::sources::mem::MemSource;
 use pathfinder_content::color::ColorU;
 use pathfinder_content::dash::OutlineDash;
 use pathfinder_content::outline::{ArcDirection, Contour, Outline};
@@ -28,17 +21,33 @@ use pathfinder_geometry::rect::RectF;
 use pathfinder_geometry::transform2d::Transform2F;
 use pathfinder_renderer::paint::{Paint, PaintId};
 use pathfinder_renderer::scene::{PathObject, Scene};
-use pathfinder_text::{SceneExt, TextRenderMode};
-use skribo::{FontCollection, FontFamily, Layout, TextStyle};
 use std::default::Default;
 use std::f32::consts::PI;
-use std::iter;
 use std::mem;
 use std::sync::Arc;
+#[cfg(feature = "text")]
+use text_imports::*;
 
 const HAIRLINE_STROKE_WIDTH: f32 = 0.0333;
 const DEFAULT_FONT_SIZE: f32 = 10.0;
 
+#[cfg(feature = "text")]
+mod text_imports {
+    pub use std::iter;
+    pub use font_kit::family_name::FamilyName;
+    pub use font_kit::handle::Handle;
+    pub use font_kit::hinting::HintingOptions;
+    pub use font_kit::loaders::default::Font;
+    pub use font_kit::properties::Properties;
+    pub use font_kit::source::{Source, SystemSource};
+    pub use font_kit::sources::mem::MemSource;
+    pub use skribo::{FontCollection, FontFamily, Layout, TextStyle};
+    pub use pathfinder_text::{SceneExt, TextRenderMode};
+}
+
+#[cfg(not(feature = "text"))]
+pub struct FontCollection;
+
 pub struct CanvasRenderingContext2D {
     scene: Scene,
     current_state: State,
@@ -56,9 +65,13 @@ impl CanvasRenderingContext2D {
     }
 
     pub fn from_scene(font_context: CanvasFontContext, scene: Scene) -> CanvasRenderingContext2D {
+        #[cfg(feature = "text")]
+        let default_font_collection = font_context.default_font_collection.clone();
+        #[cfg(not(feature = "text"))]
+        let default_font_collection = Arc::new(FontCollection);
         CanvasRenderingContext2D {
             scene,
-            current_state: State::default(font_context.default_font_collection.clone()),
+            current_state: State::default(default_font_collection),
             saved_states: vec![],
             font_context,
         }
@@ -85,63 +98,6 @@ impl CanvasRenderingContext2D {
         self.stroke_path(path);
     }
 
-    // Drawing text
-
-    pub fn fill_text(&mut self, string: &str, position: Vector2F) {
-        let paint_id = self.scene.push_paint(&self.current_state.fill_paint);
-        self.fill_or_stroke_text(string, position, paint_id, TextRenderMode::Fill);
-    }
-
-    pub fn stroke_text(&mut self, string: &str, position: Vector2F) {
-        let paint_id = self.scene.push_paint(&self.current_state.stroke_paint);
-        let render_mode = TextRenderMode::Stroke(self.current_state.resolve_stroke_style());
-        self.fill_or_stroke_text(string, position, paint_id, render_mode);
-    }
-
-    pub fn measure_text(&self, string: &str) -> TextMetrics {
-        TextMetrics { width: self.layout_text(string).width() }
-    }
-
-    pub fn fill_layout(&mut self, layout: &Layout, transform: Transform2F) {
-        let paint_id = self.scene.push_paint(&self.current_state.fill_paint);
-        drop(self.scene.push_layout(&layout,
-                                    &TextStyle { size: self.current_state.font_size },
-                                    &(transform * self.current_state.transform),
-                                    TextRenderMode::Fill,
-                                    HintingOptions::None,
-                                    paint_id));
-    }
-    
-    fn fill_or_stroke_text(&mut self,
-                           string: &str,
-                           mut position: Vector2F,
-                           paint_id: PaintId,
-                           render_mode: TextRenderMode) {
-        let layout = self.layout_text(string);
-
-        match self.current_state.text_align {
-            TextAlign::Left => {},
-            TextAlign::Right => position.set_x(position.x() - layout.width()),
-            TextAlign::Center => position.set_x(position.x() - layout.width() * 0.5),
-        }
-
-        let transform = self.current_state.transform * Transform2F::from_translation(position);
-
-        // TODO(pcwalton): Report errors.
-        drop(self.scene.push_layout(&layout,
-                                    &TextStyle { size: self.current_state.font_size },
-                                    &transform,
-                                    render_mode,
-                                    HintingOptions::None,
-                                    paint_id));
-    }
-
-    fn layout_text(&self, string: &str) -> Layout {
-        skribo::layout(&TextStyle { size: self.current_state.font_size },
-                       &self.current_state.font_collection,
-                       string)
-    }
-
     // Line styles
 
     #[inline]
@@ -181,52 +137,6 @@ impl CanvasRenderingContext2D {
         self.current_state.line_dash_offset = new_line_dash_offset
     }
 
-    // Text styles
-
-    #[inline]
-    pub fn set_font_collection(&mut self, font_collection: Arc<FontCollection>) {
-        self.current_state.font_collection = font_collection;
-    }
-
-    #[inline]
-    pub fn set_font_families<I>(&mut self, font_families: I) where I: Iterator<Item = FontFamily> {
-        let mut font_collection = FontCollection::new();
-        for font_family in font_families {
-            font_collection.add_family(font_family);
-        }
-        self.current_state.font_collection = Arc::new(font_collection);
-    }
-
-    /// A convenience method to set a single font family.
-    #[inline]
-    pub fn set_font_family(&mut self, font_family: FontFamily) {
-        self.set_font_families(iter::once(font_family))
-    }
-
-    /// A convenience method to set a single font family consisting of a single font.
-    #[inline]
-    pub fn set_font(&mut self, font: Font) {
-        self.set_font_family(FontFamily::new_from_font(font))
-    }
-
-    /// A convenience method to set a single font family consisting of a font
-    /// described by a PostScript name.
-    #[inline]
-    pub fn set_font_by_postscript_name(&mut self, postscript_name: &str) {
-        let font = self.font_context.font_source.select_by_postscript_name(postscript_name);
-        self.set_font(font.expect("Didn't find the font!").load().unwrap());
-    }
-
-    #[inline]
-    pub fn set_font_size(&mut self, new_font_size: f32) {
-        self.current_state.font_size = new_font_size;
-    }
-
-    #[inline]
-    pub fn set_text_align(&mut self, new_text_align: TextAlign) {
-        self.current_state.text_align = new_text_align;
-    }
-
     // Fill and stroke styles
 
     #[inline]
@@ -346,6 +256,111 @@ impl CanvasRenderingContext2D {
     }
 }
 
+// Drawing text
+#[cfg(feature = "text")]
+impl CanvasRenderingContext2D {
+    pub fn fill_text(&mut self, string: &str, position: Vector2F) {
+        let paint_id = self.scene.push_paint(&self.current_state.fill_paint);
+        self.fill_or_stroke_text(string, position, paint_id, TextRenderMode::Fill);
+    }
+
+    pub fn stroke_text(&mut self, string: &str, position: Vector2F) {
+        let paint_id = self.scene.push_paint(&self.current_state.stroke_paint);
+        let render_mode = TextRenderMode::Stroke(self.current_state.resolve_stroke_style());
+        self.fill_or_stroke_text(string, position, paint_id, render_mode);
+    }
+
+    pub fn measure_text(&self, string: &str) -> TextMetrics {
+        TextMetrics { width: self.layout_text(string).width() }
+    }
+
+    pub fn fill_layout(&mut self, layout: &Layout, transform: Transform2F) {
+        let paint_id = self.scene.push_paint(&self.current_state.fill_paint);
+        drop(self.scene.push_layout(&layout,
+                                    &TextStyle { size: self.current_state.font_size },
+                                    &(transform * self.current_state.transform),
+                                    TextRenderMode::Fill,
+                                    HintingOptions::None,
+                                    paint_id));
+    }
+
+    fn fill_or_stroke_text(&mut self,
+                           string: &str,
+                           mut position: Vector2F,
+                           paint_id: PaintId,
+                           render_mode: TextRenderMode) {
+        let layout = self.layout_text(string);
+
+        match self.current_state.text_align {
+            TextAlign::Left => {},
+            TextAlign::Right => position.set_x(position.x() - layout.width()),
+            TextAlign::Center => position.set_x(position.x() - layout.width() * 0.5),
+        }
+
+        let transform = self.current_state.transform * Transform2F::from_translation(position);
+
+        // TODO(pcwalton): Report errors.
+        drop(self.scene.push_layout(&layout,
+                                    &TextStyle { size: self.current_state.font_size },
+                                    &transform,
+                                    render_mode,
+                                    HintingOptions::None,
+                                    paint_id));
+    }
+
+    fn layout_text(&self, string: &str) -> Layout {
+        skribo::layout(&TextStyle { size: self.current_state.font_size },
+                       &self.current_state.font_collection,
+                       string)
+    }
+
+    // Text styles
+
+    #[inline]
+    pub fn set_font_collection(&mut self, font_collection: Arc<FontCollection>) {
+        self.current_state.font_collection = font_collection;
+    }
+
+    #[inline]
+    pub fn set_font_families<I>(&mut self, font_families: I) where I: Iterator<Item = FontFamily> {
+        let mut font_collection = FontCollection::new();
+        for font_family in font_families {
+            font_collection.add_family(font_family);
+        }
+        self.current_state.font_collection = Arc::new(font_collection);
+    }
+
+    /// A convenience method to set a single font family.
+    #[inline]
+    pub fn set_font_family(&mut self, font_family: FontFamily) {
+        self.set_font_families(iter::once(font_family))
+    }
+
+    /// A convenience method to set a single font family consisting of a single font.
+    #[inline]
+    pub fn set_font(&mut self, font: Font) {
+        self.set_font_family(FontFamily::new_from_font(font))
+    }
+
+    /// A convenience method to set a single font family consisting of a font
+    /// described by a PostScript name.
+    #[inline]
+    pub fn set_font_by_postscript_name(&mut self, postscript_name: &str) {
+        let font = self.font_context.font_source.select_by_postscript_name(postscript_name);
+        self.set_font(font.expect("Didn't find the font!").load().unwrap());
+    }
+
+    #[inline]
+    pub fn set_font_size(&mut self, new_font_size: f32) {
+        self.current_state.font_size = new_font_size;
+    }
+
+    #[inline]
+    pub fn set_text_align(&mut self, new_text_align: TextAlign) {
+        self.current_state.text_align = new_text_align;
+    }
+}
+
 #[derive(Clone)]
 struct State {
     transform: Transform2F,
@@ -544,12 +559,14 @@ pub enum LineJoin {
 }
 
 // TODO(pcwalton): Support other fields.
+#[cfg(feature = "text")]
 #[derive(Clone, Copy, Debug)]
 pub struct TextMetrics {
     pub width: f32,
 }
 
 #[derive(Clone)]
+#[cfg(feature = "text")]
 pub struct CanvasFontContext {
     #[allow(dead_code)]
     font_source: Arc<dyn Source>,
@@ -557,6 +574,7 @@ pub struct CanvasFontContext {
     default_font_collection: Arc<FontCollection>,
 }
 
+#[cfg(feature = "text")]
 impl CanvasFontContext {
     pub fn new(font_source: Arc<dyn Source>) -> CanvasFontContext {
         let mut default_font_collection = FontCollection::new();
@@ -585,12 +603,24 @@ impl CanvasFontContext {
     }
 }
 
+#[cfg(not(feature = "text"))]
+pub struct CanvasFontContext;
+
+#[cfg(not(feature = "text"))]
+impl CanvasFontContext {
+    pub fn from_system_source() -> Self {
+        CanvasFontContext
+    }
+}
+
 // Text layout utilities
 
+#[cfg(feature = "text")]
 trait LayoutExt {
     fn width(&self) -> f32;
 }
 
+#[cfg(feature = "text")]
 impl LayoutExt for Layout {
     fn width(&self) -> f32 {
         let last_glyph = match self.glyphs.last() {

examples/canvas_metal_minimal/Cargo.toml

@@ -13,6 +13,7 @@ sdl2 = "0.32"
 sdl2-sys = "0.32"
 
 [dependencies.pathfinder_canvas]
+features = ["text"]
 path = "../../canvas"
 
 [dependencies.pathfinder_content]

examples/canvas_moire/Cargo.toml

@@ -10,6 +10,7 @@ sdl2 = "0.32"
 sdl2-sys = "0.32"
 
 [dependencies.pathfinder_canvas]
+features = ["text"]
 path = "../../canvas"
 
 [dependencies.pathfinder_content]

examples/canvas_text/Cargo.toml

@@ -11,6 +11,7 @@ sdl2 = "0.32"
 sdl2-sys = "0.32"
 
 [dependencies.pathfinder_canvas]
+features = ["text"]
 path = "../../canvas"
 
 [dependencies.pathfinder_content]