From 44fea82aaad92856917b6475b0ce9a3777f2e465 Mon Sep 17 00:00:00 2001
From: Simon Gardling <titaniumtown@proton.me>
Date: Fri, 5 Dec 2025 14:02:13 -0500
Subject: [PATCH] font subsetting: pyftsubset -> allsorts

---
 Cargo.lock | 337 +++++++++++++++++++++++++++++++++++++++--------------
 Cargo.toml |   2 +-
 build.rs   |  92 +++++++--------
 flake.nix  |   1 -
 4 files changed, 297 insertions(+), 135 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 6656d77..e43020d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -66,6 +66,56 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "aliasable"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "250f629c0161ad8107cf89319e990051fae62832fd343083bea452d93e2205fd"
+
+[[package]]
+name = "alloc-no-stdlib"
+version = "2.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc7bb162ec39d46ab1ca8c77bf72e890535becd1751bb45f64c597edb4c8c6b3"
+
+[[package]]
+name = "alloc-stdlib"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94fb8275041c72129eb51b7d0322c29b8387a0386127718b096429201a5d6ece"
+dependencies = [
+ "alloc-no-stdlib",
+]
+
+[[package]]
+name = "allsorts"
+version = "0.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ec6442ceba5ea9d0201cd0afe96ecac4e8253e5f5be725e074747e6f4238735"
+dependencies = [
+ "bitflags 1.3.2",
+ "bitreader",
+ "brotli-decompressor",
+ "byteorder",
+ "crc32fast",
+ "encoding_rs",
+ "flate2",
+ "glyph-names",
+ "itertools 0.10.5",
+ "lazy_static",
+ "libc",
+ "log",
+ "num-traits",
+ "ouroboros",
+ "pathfinder_geometry",
+ "rustc-hash 1.1.0",
+ "tinyvec",
+ "ucd-trie",
+ "unicode-canonical-combining-class",
+ "unicode-general-category",
+ "unicode-joining-type",
+]
+
 [[package]]
 name = "android-activity"
 version = "0.6.0"
@@ -217,6 +267,15 @@ version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
 
+[[package]]
+name = "bitreader"
+version = "0.3.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "886559b1e163d56c765bc3a985febb4eee8009f625244511d8ee3c432e08c066"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "block2"
 version = "0.5.1"
@@ -226,6 +285,16 @@ dependencies = [
  "objc2 0.5.2",
 ]
 
+[[package]]
+name = "brotli-decompressor"
+version = "4.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a334ef7c9e23abf0ce748e8cd309037da93e606ad52eb372e4ce327a0dcfbdfd"
+dependencies = [
+ "alloc-no-stdlib",
+ "alloc-stdlib",
+]
+
 [[package]]
 name = "bumpalo"
 version = "3.19.0"
@@ -249,9 +318,15 @@ checksum = "f9abbd1bc6865053c427f7198e6af43bfdedc55ab791faed4fbd361d789575ff"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
+[[package]]
+name = "byteorder"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
+
 [[package]]
 name = "byteorder-lite"
 version = "0.1.0"
@@ -632,7 +707,7 @@ checksum = "97369cbbc041bc366949bc74d34658d6cda5621039731c6310521892a3a20ae0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -665,12 +740,6 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d8b14ccef22fc6f5a8f4d7d768562a182c04ce9a3b3157b91390b52ddfdf1a76"
 
-[[package]]
-name = "dunce"
-version = "1.0.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "92773504d58c093f6de2459af4af33faa518c13451eb8f2b5698ed3d36e7c813"
-
 [[package]]
 name = "ecolor"
 version = "0.33.2"
@@ -814,6 +883,15 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "encoding_rs"
+version = "0.8.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75030f3c4f45dafd7586dd6780965a8c7e8e285a5ecb86713e63a79c5b2766f3"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "enumn"
 version = "0.1.14"
@@ -822,7 +900,7 @@ checksum = "2f9ed6b3789237c8a0c1c505af1c7eb2c560df6186f01b098c3a1064ea532f38"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -899,7 +977,7 @@ checksum = "a0aca10fb742cb43f9e7bb8467c91aa9bcb8e3ffbc6a6f7389bb93ffc920577d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -931,11 +1009,12 @@ dependencies = [
 
 [[package]]
 name = "flate2"
-version = "1.1.5"
+version = "1.0.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfe33edd8e85a12a67454e37f8c75e730830d83e313556ab9ebf9ee7fbeb3bfb"
+checksum = "c936bfdafb507ebbf50b8074c54fa31c5be9a1e7e5f467dd659697041407d07c"
 dependencies = [
  "crc32fast",
+ "libz-sys",
  "miniz_oxide",
 ]
 
@@ -963,7 +1042,7 @@ checksum = "1a5c6c585bc94aaf2c7b51dd4c2ba22680844aba4c687be581871a6f518c5742"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -981,16 +1060,6 @@ dependencies = [
  "percent-encoding",
 ]
 
-[[package]]
-name = "fsio"
-version = "0.4.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f4944f16eb6a05b4b2b79986b4786867bb275f52882adea798f17cc2588f25b2"
-dependencies = [
- "dunce",
- "rand",
-]
-
 [[package]]
 name = "gethostname"
 version = "1.1.0"
@@ -1109,6 +1178,12 @@ dependencies = [
  "gl_generator",
 ]
 
+[[package]]
+name = "glyph-names"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3531d702d6c1a3ba92a5fb55a404c7b8c476c8e7ca249951077afcbe4bc807f"
+
 [[package]]
 name = "half"
 version = "1.8.3"
@@ -1136,6 +1211,12 @@ dependencies = [
  "foldhash",
 ]
 
+[[package]]
+name = "heck"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
+
 [[package]]
 name = "hermit-abi"
 version = "0.1.19"
@@ -1704,7 +1785,7 @@ dependencies = [
  "proc-macro-crate",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -2017,6 +2098,30 @@ dependencies = [
  "libredox",
 ]
 
+[[package]]
+name = "ouroboros"
+version = "0.17.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2ba07320d39dfea882faa70554b4bd342a5f273ed59ba7c1c6b4c840492c954"
+dependencies = [
+ "aliasable",
+ "ouroboros_macro",
+ "static_assertions",
+]
+
+[[package]]
+name = "ouroboros_macro"
+version = "0.17.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec4c6225c69b4ca778c0aea097321a64c421cf4577b331c61b229267edabb6f8"
+dependencies = [
+ "heck",
+ "proc-macro-error",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.111",
+]
+
 [[package]]
 name = "owned_ttf_parser"
 version = "0.25.1"
@@ -2058,6 +2163,25 @@ dependencies = [
  "phf_codegen",
 ]
 
+[[package]]
+name = "pathfinder_geometry"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b7b7e7b4ea703700ce73ebf128e1450eb69c3a8329199ffbfb9b2a0418e5ad3"
+dependencies = [
+ "log",
+ "pathfinder_simd",
+]
+
+[[package]]
+name = "pathfinder_simd"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bf9027960355bf3afff9841918474a81a5f972ac6d226d518060bba758b5ad57"
+dependencies = [
+ "rustc_version",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.2"
@@ -2120,7 +2244,7 @@ checksum = "6e918e4ff8c4549eb882f14b3a4bc8c8bc93de829416eacf579f1207a8fbf861"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -2241,15 +2365,6 @@ dependencies = [
  "thiserror 1.0.69",
 ]
 
-[[package]]
-name = "ppv-lite86"
-version = "0.2.21"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85eae3c4ed2f50dcfe72643da4befc30deadb458a9b590d720cde2f2b1e97da9"
-dependencies = [
- "zerocopy",
-]
-
 [[package]]
 name = "proc-macro-crate"
 version = "3.4.0"
@@ -2259,6 +2374,30 @@ dependencies = [
  "toml_edit",
 ]
 
+[[package]]
+name = "proc-macro-error"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c"
+dependencies = [
+ "proc-macro-error-attr",
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+ "version_check",
+]
+
+[[package]]
+name = "proc-macro-error-attr"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1be40180e52ecc98ad80b184934baf3d0d29f979574e439af5a55274b35f869"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "version_check",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.103"
@@ -2322,35 +2461,6 @@ version = "5.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
 
-[[package]]
-name = "rand"
-version = "0.9.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6db2770f06117d490610c7488547d543617b21bfa07796d7a12f6f1bd53850d1"
-dependencies = [
- "rand_chacha",
- "rand_core",
-]
-
-[[package]]
-name = "rand_chacha"
-version = "0.9.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d3022b5f1df60f26e1ffddd6c66e8aa15de382ae63b3a0c1bfc0e4d3e3f325cb"
-dependencies = [
- "ppv-lite86",
- "rand_core",
-]
-
-[[package]]
-name = "rand_core"
-version = "0.9.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99d9a13982dcf210057a8a78572b2217b667c3beacbf3a0d8b454f6f82837d38"
-dependencies = [
- "getrandom",
-]
-
 [[package]]
 name = "raw-window-handle"
 version = "0.6.2"
@@ -2439,15 +2549,6 @@ dependencies = [
  "bytemuck",
 ]
 
-[[package]]
-name = "run_script"
-version = "0.11.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e8f982753d06bafa2d1e5c1bd5be496bcb3cd02919a89f07e7f21c7a6ecb4e1a"
-dependencies = [
- "fsio",
-]
-
 [[package]]
 name = "rustc-demangle"
 version = "0.1.26"
@@ -2466,6 +2567,15 @@ version = "2.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "357703d41365b4b27c590e3ed91eabb1b663f07c4c084095e60cbed4362dff0d"
 
+[[package]]
+name = "rustc_version"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cfcb3a22ef46e85b45de6ee7e79d063319ebb6594faafcf1c225ea92ab6e9b92"
+dependencies = [
+ "semver",
+]
+
 [[package]]
 name = "rustix"
 version = "0.38.44"
@@ -2534,6 +2644,12 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
+[[package]]
+name = "semver"
+version = "1.0.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d767eb0aabc880b29956c35734170f26ed551a859dbd361d140cdbeca61ab1e2"
+
 [[package]]
 name = "serde"
 version = "1.0.228"
@@ -2571,7 +2687,7 @@ checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -2770,6 +2886,16 @@ dependencies = [
  "symbolic-common",
 ]
 
+[[package]]
+name = "syn"
+version = "1.0.109"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
+dependencies = [
+ "proc-macro2",
+ "unicode-ident",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.111"
@@ -2789,7 +2915,7 @@ checksum = "728a70f3dbaf5bab7f0c4b1ac8d7ae5ea60a4b5549c8a5914361c99147a709d2"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -2840,7 +2966,7 @@ checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -2851,7 +2977,7 @@ checksum = "3ff15c8ecd7de3849db632e14d18d2571fa09dfc5ed93479bc4485c7a517c913"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -2930,6 +3056,21 @@ dependencies = [
  "serde_json",
 ]
 
+[[package]]
+name = "tinyvec"
+version = "1.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bfa5fdc3bce6191a1dbc8c02d5c8bffcf557bafa17c124c5264a458f1b0613fa"
+dependencies = [
+ "tinyvec_macros",
+]
+
+[[package]]
+name = "tinyvec_macros"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
+
 [[package]]
 name = "toml_datetime"
 version = "0.7.3"
@@ -2980,7 +3121,7 @@ checksum = "7490cfa5ec963746568740651ac6781f701c9c5ea257c58e057f3ba8cf69e8da"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -3076,12 +3217,36 @@ dependencies = [
  "tz-rs",
 ]
 
+[[package]]
+name = "ucd-trie"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2896d95c02a80c6d6a5d6e953d479f5ddf2dfdb6a244441010e373ac0fb88971"
+
+[[package]]
+name = "unicode-canonical-combining-class"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6925586af9268182c711e47c0853ed84131049efaca41776d0ca97f983865c32"
+
+[[package]]
+name = "unicode-general-category"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2281c8c1d221438e373249e065ca4989c4c36952c211ff21a0ee91c44a3869e7"
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
+[[package]]
+name = "unicode-joining-type"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22f8cb47ccb8bc750808755af3071da4a10dcd147b68fc874b7ae4b12543f6f5"
+
 [[package]]
 name = "unicode-segmentation"
 version = "1.12.0"
@@ -3190,7 +3355,7 @@ dependencies = [
  "log",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
  "wasm-bindgen-shared",
 ]
 
@@ -3225,7 +3390,7 @@ checksum = "9f07d2f20d4da7b26400c9f4a0511e6e0345b040694e8a75bd41d578fa4421d7"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
@@ -3564,7 +3729,7 @@ checksum = "053e2e040ab57b9dc951b72c264860db7eb3b0200ba345b4e4c3b14f67855ddf"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -3575,7 +3740,7 @@ checksum = "3f316c4a2570ba26bbec722032c4099d8c8bc095efccdc15688708623367e358"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -3968,7 +4133,7 @@ checksum = "b659052874eb698efe5b9e8cf382204678a0086ebf46982b79d6ca3182927e5d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
  "synstructure",
 ]
 
@@ -3976,6 +4141,7 @@ dependencies = [
 name = "ytbn_graphing_software"
 version = "0.1.0"
 dependencies = [
+ "allsorts",
  "base64",
  "benchmarks",
  "bincode",
@@ -3988,7 +4154,6 @@ dependencies = [
  "itertools 0.14.0",
  "lol_alloc",
  "parsing",
- "run_script",
  "ruzstd",
  "serde",
  "serde_json",
@@ -4020,7 +4185,7 @@ checksum = "d8a8d209fdf45cf5138cbb5a506f6b52522a25afccc534d1475dad8e31105c6a"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
@@ -4040,7 +4205,7 @@ checksum = "d71e5d6e06ab090c67b5e44993ec16b72dcbaabc526db883a360057678b48502"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
  "synstructure",
 ]
 
@@ -4074,7 +4239,7 @@ checksum = "eadce39539ca5cb3985590102671f2567e659fca9666581ad3411d59207951f3"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.111",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index 54675ba..f67c3af 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -72,8 +72,8 @@ bincode = "1.3"
 serde = "1"
 serde_json = "1"
 zstd = { version = "0.13", default-features = false, features = ["pkg-config"] }
-run_script = "0.11"
 itertools = "0.14"
+allsorts = "0.15"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 tracing-subscriber = "0.3"
diff --git a/build.rs b/build.rs
index dfd5aac..58c5e7b 100644
--- a/build.rs
+++ b/build.rs
@@ -1,8 +1,14 @@
-use epaint::{
-    FontFamily,
-    text::{FontData, FontDefinitions, FontTweak},
+use allsorts::{
+    binary::read::ReadScope,
+    font::{Font, MatchingPresentation},
+    font_data::FontData as AllsortsFontData,
+    subset::subset,
+    tag,
+};
+use epaint::{
+    text::{FontData, FontDefinitions, FontTweak},
+    FontFamily,
 };
-use run_script::ScriptOptions;
 use std::{
     collections::BTreeMap,
     env,
@@ -18,52 +24,44 @@ include!(concat!(
 ));
 
 fn font_stripper(from: &str, out: &str, unicodes: Vec<char>) -> Result<Vec<u8>, String> {
-    let unicodes: Vec<String> = unicodes.iter().map(|c| to_unicode_hash(*c)).collect();
+    let font_path = format!("{}/assets/{}", env!("CARGO_MANIFEST_DIR"), from);
+    let font_data = std::fs::read(&font_path).map_err(|e| e.to_string())?;
+    let scope = ReadScope::new(&font_data);
+    let font_file = scope
+        .read::<AllsortsFontData>()
+        .map_err(|e| format!("Failed to read font data: {}", e))?;
+    let provider = font_file
+        .table_provider(0)
+        .map_err(|e| format!("Failed to get table provider: {}", e))?;
+    let mut font = Font::new(provider).map_err(|e| format!("Failed to create font: {:?}", e))?;
+
+    let mut glyph_ids = Vec::new();
+    for &ch in &unicodes {
+        let mut glyph_ids_curr = font
+            .map_glyphs(
+                &ch.to_string(),
+                tag::LATN,
+                MatchingPresentation::NotRequired,
+            )
+            .into_iter()
+            .map(|glyph| glyph.glyph_index)
+            .collect();
+
+        glyph_ids.append(&mut glyph_ids_curr);
+    }
+    // Include .notdef glyph
+    glyph_ids.push(0);
+    glyph_ids.sort();
+    glyph_ids.dedup();
+
+    let subset_data = subset(&font.font_table_provider, &glyph_ids)
+        .map_err(|e| format!("Failed to subset font: {}", e))?;
 
     let new_path = [&env::var("OUT_DIR").unwrap(), out].concat();
-    let unicodes_formatted = unicodes
-        .iter()
-        .map(|u| format!("U+{}", u))
-        .collect::<Vec<String>>()
-        .join(",");
+    std::fs::write(&new_path, &subset_data)
+        .map_err(|e| format!("Failed to write subset font: {}", e))?;
 
-    // Test to see if pyftsubset is found
-    let pyftsubset_detect = run_script::run("whereis pyftsubset", &(vec![]), &ScriptOptions::new());
-    match pyftsubset_detect {
-        Ok((_i, s1, _s2)) => {
-            if s1 == "pyftsubset: " {
-                return Err(String::from("pyftsubset not found"));
-            }
-        }
-        // It was not, return an error and abort
-        Err(x) => return Err(x.to_string()),
-    }
-
-    let script_result = run_script::run(
-        &format!(
-            "pyftsubset {}/assets/{} --unicodes={}
-			mv {}/assets/{} {}",
-            env!("CARGO_MANIFEST_DIR"),
-            from,
-            unicodes_formatted,
-            env!("CARGO_MANIFEST_DIR"),
-            from.replace(".ttf", ".subset.ttf"),
-            new_path
-        ),
-        &(vec![]),
-        &ScriptOptions::new(),
-    );
-
-    if let Ok((_, _, error)) = script_result {
-        if error.is_empty() {
-            return Ok(std::fs::read(new_path).unwrap());
-        } else {
-            return Err(error);
-        }
-    } else if let Err(error) = script_result {
-        return Err(error.to_string());
-    }
-    unreachable!()
+    Ok(subset_data)
 }
 
 fn main() {
diff --git a/flake.nix b/flake.nix
index 33b8be4..d67a76e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -169,7 +169,6 @@
             rustToolchain
             wasm-bindgen-cli
             binaryen
-            python3Packages.fonttools
             rust-analyzer
             pkg-config
             clang