Merge pull request #74 from hecrj/fix/font-load-panic

Fallback to embedded font when system font is unsupported

4 files changed, 119 insertions, 24 deletions

diff --git a/wgpu/Cargo.toml b/wgpu/Cargo.toml
index f008a99c..47ec0537 100644
--- a/wgpu/Cargo.toml
+++ b/wgpu/Cargo.toml
@@ -4,14 +4,14 @@ version = "0.1.0"
 authors = ["Héctor Ramón Jiménez <hector0193@gmail.com>"]
 edition = "2018"
 description = "A wgpu renderer for Iced"
-license = "MIT"
+license = "MIT AND OFL-1.1"
 repository = "https://github.com/hecrj/iced"
 
 [dependencies]
 iced_native = { version = "0.1.0", path = "../native" }
 wgpu = "0.4"
 glyph_brush = "0.6"
-wgpu_glyph = "0.6"
+wgpu_glyph = { version = "0.7", git = "https://github.com/hecrj/wgpu_glyph", branch = "fix/font-load-panic" }
 raw-window-handle = "0.3"
 image = "0.22"
 glam = "0.8"
diff --git a/wgpu/fonts/Lato-Regular.ttf b/wgpu/fonts/Lato-Regular.ttf
new file mode 100644
index 00000000..33eba8b1
--- /dev/null
+++ b/wgpu/fonts/Lato-Regular.ttf
diff --git a/wgpu/fonts/OFL.txt b/wgpu/fonts/OFL.txt
new file mode 100644
index 00000000..dfca0da4
--- /dev/null
+++ b/wgpu/fonts/OFL.txt
@@ -0,0 +1,93 @@
+Copyright (c) 2010-2014 by tyPoland Lukasz Dziedzic (team@latofonts.com) with Reserved Font Name "Lato"

+

+This Font Software is licensed under the SIL Open Font License, Version 1.1.

+This license is copied below, and is also available with a FAQ at:

+http://scripts.sil.org/OFL

+

+

+-----------------------------------------------------------

+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007

+-----------------------------------------------------------

+

+PREAMBLE

+The goals of the Open Font License (OFL) are to stimulate worldwide

+development of collaborative font projects, to support the font creation

+efforts of academic and linguistic communities, and to provide a free and

+open framework in which fonts may be shared and improved in partnership

+with others.

+

+The OFL allows the licensed fonts to be used, studied, modified and

+redistributed freely as long as they are not sold by themselves. The

+fonts, including any derivative works, can be bundled, embedded, 

+redistributed and/or sold with any software provided that any reserved

+names are not used by derivative works. The fonts and derivatives,

+however, cannot be released under any other type of license. The

+requirement for fonts to remain under this license does not apply

+to any document created using the fonts or their derivatives.

+

+DEFINITIONS

+"Font Software" refers to the set of files released by the Copyright

+Holder(s) under this license and clearly marked as such. This may

+include source files, build scripts and documentation.

+

+"Reserved Font Name" refers to any names specified as such after the

+copyright statement(s).

+

+"Original Version" refers to the collection of Font Software components as

+distributed by the Copyright Holder(s).

+

+"Modified Version" refers to any derivative made by adding to, deleting,

+or substituting -- in part or in whole -- any of the components of the

+Original Version, by changing formats or by porting the Font Software to a

+new environment.

+

+"Author" refers to any designer, engineer, programmer, technical

+writer or other person who contributed to the Font Software.

+

+PERMISSION & CONDITIONS

+Permission is hereby granted, free of charge, to any person obtaining

+a copy of the Font Software, to use, study, copy, merge, embed, modify,

+redistribute, and sell modified and unmodified copies of the Font

+Software, subject to the following conditions:

+

+1) Neither the Font Software nor any of its individual components,

+in Original or Modified Versions, may be sold by itself.

+

+2) Original or Modified Versions of the Font Software may be bundled,

+redistributed and/or sold with any software, provided that each copy

+contains the above copyright notice and this license. These can be

+included either as stand-alone text files, human-readable headers or

+in the appropriate machine-readable metadata fields within text or

+binary files as long as those fields can be easily viewed by the user.

+

+3) No Modified Version of the Font Software may use the Reserved Font

+Name(s) unless explicit written permission is granted by the corresponding

+Copyright Holder. This restriction only applies to the primary font name as

+presented to the users.

+

+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font

+Software shall not be used to promote, endorse or advertise any

+Modified Version, except to acknowledge the contribution(s) of the

+Copyright Holder(s) and the Author(s) or with their explicit written

+permission.

+

+5) The Font Software, modified or unmodified, in part or in whole,

+must be distributed entirely under this license, and must not be

+distributed under any other license. The requirement for fonts to

+remain under this license does not apply to any document created

+using the Font Software.

+

+TERMINATION

+This license becomes null and void if any of the above conditions are

+not met.

+

+DISCLAIMER

+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF

+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT

+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE

+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL

+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM

+OTHER DEALINGS IN THE FONT SOFTWARE.

diff --git a/wgpu/src/text.rs b/wgpu/src/text.rs
index bf37abe5..e9a1602f 100644
--- a/wgpu/src/text.rs
+++ b/wgpu/src/text.rs
@@ -11,6 +11,8 @@ pub const BUILTIN_ICONS: iced_native::Font = iced_native::Font::External {
 
 pub const CHECKMARK_ICON: char = '\u{F00C}';
 
+const FALLBACK_FONT: &[u8] = include_bytes!("../fonts/Lato-Regular.ttf");
+
 #[derive(Debug)]
 pub struct Pipeline {
     draw_brush: RefCell<wgpu_glyph::GlyphBrush<'static, ()>>,
@@ -26,24 +28,31 @@ impl Pipeline {
 
         let default_font = font_source
             .load(&[font::Family::SansSerif, font::Family::Serif])
-            .expect("Find sans-serif or serif font");
+            .unwrap_or_else(|_| FALLBACK_FONT.to_vec());
+
+        let load_glyph_brush = |font: Vec<u8>| {
+            let builder =
+                wgpu_glyph::GlyphBrushBuilder::using_fonts_bytes(vec![
+                    font.clone()
+                ])?;
+
+            Ok((
+                builder,
+                glyph_brush::GlyphBrushBuilder::using_font_bytes(font).build(),
+            ))
+        };
+
+        let (brush_builder, measure_brush) = load_glyph_brush(default_font)
+            .unwrap_or_else(|_: wgpu_glyph::rusttype::Error| {
+                log::warn!("System font failed to load. Falling back to embedded font...");
 
-        let mono_font = font_source
-            .load(&[font::Family::Monospace])
-            .expect("Find monospace font");
+                load_glyph_brush(FALLBACK_FONT.to_vec()).expect("Load fallback font")
+            });
 
-        let draw_brush =
-            wgpu_glyph::GlyphBrushBuilder::using_fonts_bytes(vec![
-                mono_font,
-                default_font.clone(),
-            ])
+        let draw_brush = brush_builder
             .initial_cache_size((2048, 2048))
             .build(device, wgpu::TextureFormat::Bgra8UnormSrgb);
 
-        let measure_brush =
-            glyph_brush::GlyphBrushBuilder::using_font_bytes(default_font)
-                .build();
-
         Pipeline {
             draw_brush: RefCell::new(draw_brush),
             draw_font_map: RefCell::new(HashMap::new()),
@@ -95,14 +104,7 @@ impl Pipeline {
             text: content,
             scale: wgpu_glyph::Scale { x: size, y: size },
             bounds: (bounds.width, bounds.height),
-
-            // TODO: This is a bit hacky. We are loading the debug font as the
-            // first font in the `draw_brush`. The `measure_brush` does not
-            // contain this, hence we subtract 1.
-            //
-            // This should go away once we unify `draw_brush` and
-            // `measure_brush`.
-            font_id: wgpu_glyph::FontId(font_id - 1),
+            font_id: wgpu_glyph::FontId(font_id),
             ..Default::default()
         };
 
@@ -143,7 +145,7 @@ impl Pipeline {
 
     pub fn find_font(&self, font: iced_native::Font) -> wgpu_glyph::FontId {
         match font {
-            iced_native::Font::Default => wgpu_glyph::FontId(1),
+            iced_native::Font::Default => wgpu_glyph::FontId(0),
             iced_native::Font::External { name, bytes } => {
                 if let Some(font_id) = self.draw_font_map.borrow().get(name) {
                     return *font_id;