Implement very basic glyph rasterization

There are several assumptions made at this point and very little (no)
error handling done.

5 files changed, 144 insertions, 19 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 5afbf7ed..6cb37f09 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,12 +2,17 @@
 name = "alacritty"
 version = "0.1.0"
 dependencies = [
- "freetype 0.1.0 (git+https://github.com/servo/rust-freetype.git)",
+ "freetype-rs 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "servo-fontconfig 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo-fontconfig 0.2.0 (git+https://github.com/jwilm/rust-fontconfig)",
 ]
 
 [[package]]
+name = "bitflags"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "expat-sys"
 version = "2.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -17,19 +22,46 @@ dependencies = [
 ]
 
 [[package]]
-name = "freetype"
-version = "0.1.0"
-source = "git+https://github.com/servo/rust-freetype.git#d564ff90a3c69d987f5c015d7ec034cfaee21aff"
+name = "freetype-rs"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
+ "bitflags 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "freetype-sys 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
+name = "freetype-sys"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libz-sys 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "pkg-config 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "gcc"
+version = "0.3.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "libc"
 version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "libz-sys"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gcc 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "pkg-config 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "make-cmd"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -42,27 +74,19 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "servo-fontconfig"
 version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+source = "git+https://github.com/jwilm/rust-fontconfig#419135e5e1106ec0973dd4923bd9c70d8e438cc8"
 dependencies = [
  "libc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "servo-fontconfig-sys 2.11.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo-fontconfig-sys 2.11.3 (git+https://github.com/jwilm/libfontconfig)",
 ]
 
 [[package]]
 name = "servo-fontconfig-sys"
 version = "2.11.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+source = "git+https://github.com/jwilm/libfontconfig#1d7544dc1ff6a7d0f3a9e6a27b5373a89afa8c38"
 dependencies = [
  "expat-sys 2.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "pkg-config 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "servo-freetype-sys 2.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "servo-freetype-sys"
-version = "2.4.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
+ "freetype-sys 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "pkg-config 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index d2aa21e5..ff4a0a7a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,6 +4,6 @@ version = "0.1.0"
 authors = ["Joe Wilm <joe@jwilm.com>"]
 
 [dependencies]
-servo-fontconfig = "0.2"
-freetype = { git = "https://github.com/servo/rust-freetype.git" }
+servo-fontconfig = { git = "https://github.com/jwilm/rust-fontconfig" }
+freetype-rs = "0.5.0"
 libc = "*"
diff --git a/src/list_fonts.rs b/src/list_fonts.rs
index c418bc02..c7cd60ca 100644
--- a/src/list_fonts.rs
+++ b/src/list_fonts.rs
@@ -69,12 +69,31 @@ pub struct Variant {
     index: usize,
 }
 
+impl Variant {
+    #[inline]
+    pub fn filepath(&self) -> &::std::path::Path {
+        self.file.as_path()
+    }
+}
+
 #[derive(Debug)]
 pub struct Family {
     name: String,
     variants: Vec<Variant>,
 }
 
+impl Family {
+    #[inline]
+    pub fn name(&self) -> &str {
+        &self.name[..]
+    }
+
+    #[inline]
+    pub fn variants(&self) -> &[Variant] {
+        &self.variants[..]
+    }
+}
+
 static FILE: &'static [u8] = b"file\0";
 static FAMILY: &'static [u8] = b"family\0";
 static INDEX: &'static [u8] = b"index\0";
diff --git a/src/main.rs b/src/main.rs
index 66be9b34..7356bd36 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@ extern crate freetype;
 extern crate libc;
 
 mod list_fonts;
+mod text;
 
 fn main() {
     println!("Hello, world!");
diff --git a/src/text.rs b/src/text.rs
new file mode 100644
index 00000000..5694e2ce
--- /dev/null
+++ b/src/text.rs
@@ -0,0 +1,81 @@
+use list_fonts::get_font_families;
+
+use freetype::Library;
+use freetype::Face;
+use freetype;
+
+/// Rasterizes glyphs for a single font face.
+pub struct Rasterizer {
+    face: Face<'static>,
+    library: Library,
+}
+
+#[inline]
+fn to_freetype_26_6(f: f32) -> isize {
+    ((1i32 << 6) as f32 * f) as isize
+}
+
+impl Rasterizer {
+    pub fn new() -> Rasterizer {
+        let library = Library::init().unwrap();
+
+        let family = get_font_families().into_iter()
+                                        .filter(|f| f.name() == "Inconsolata-dz")
+                                        .nth(0).unwrap(); // TODO
+
+        let variant = family.variants().first().unwrap();
+        let path = variant.filepath();
+
+        Rasterizer {
+            face: library.new_face(path, 0).expect("Create font face"),
+            library: library,
+        }
+    }
+
+    pub fn get_glyph(&self, size: f32, c: char) -> RasterizedGlyph {
+        // TODO DPI
+        self.face.set_char_size(to_freetype_26_6(size), 0, 96, 0).unwrap();
+        self.face.load_char(c as usize, freetype::face::RENDER).unwrap();
+        let glyph = self.face.glyph();
+
+        RasterizedGlyph {
+            top: glyph.bitmap_top() as usize,
+            left: glyph.bitmap_left() as usize,
+            width: glyph.bitmap().width() as usize,
+            height: glyph.bitmap().rows() as usize,
+            buf: glyph.bitmap().buffer().to_vec(),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct RasterizedGlyph {
+    width: usize,
+    height: usize,
+    top: usize,
+    left: usize,
+    buf: Vec<u8>,
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::Rasterizer;
+
+    #[test]
+    fn create_rasterizer_and_render_glyph() {
+        let rasterizer = Rasterizer::new();
+        let glyph = rasterizer.get_glyph(24., 'U');
+
+        println!("glyph: {:?}", glyph);
+
+        for j in 0..glyph.height {
+            for i in 0..glyph.width {
+                let val = glyph.buf[j * glyph.width + i];
+                print!("{}", if val < 122 { " " } else { "%"});
+            }
+
+            print!("\n");
+        }
+    }
+}