From f7f1ff699aeb035773ad47d3d5355f6409f9e332 Mon Sep 17 00:00:00 2001
From: Zicklag <zicklag@katharostech.com>
Date: Sat, 29 Aug 2020 14:58:28 -0500
Subject: [PATCH] Implement OpenGL Backend For Unix Platforms

---
 Cargo.lock                  | 678 +++++++++++++++++++++++++++++++-----
 wgpu-core/Cargo.toml        |  11 +-
 wgpu-core/build.rs          |   6 +-
 wgpu-core/src/device/mod.rs |  10 +-
 wgpu-core/src/hub.rs        |  19 +
 wgpu-core/src/instance.rs   |  25 +-
 wgpu-core/src/lib.rs        |   6 +
 7 files changed, 665 insertions(+), 90 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 04fc13f09..350062365 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,5 +1,20 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "addr2line"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c0929d69e78dd9bf5408269919fcbcaeb2e35e5d43e5815517cdc6a8e11a423"
+dependencies = [
+ "gimli",
+]
+
+[[package]]
+name = "adler"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee2a4ec343196209d6594e19543ae87a39f96d5534d7174822a3ad825dd6ed7e"
+
 [[package]]
 name = "aho-corasick"
 version = "0.7.10"
@@ -23,6 +38,12 @@ dependencies = [
  "xml-rs",
 ]
 
+[[package]]
+name = "android_glue"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "000444226fcff248f2bc4c7625be32c63caccfecc2723a2b9f78a7487a49c407"
+
 [[package]]
 name = "android_log-sys"
 version = "0.1.2"
@@ -65,12 +86,6 @@ dependencies = [
  "libloading 0.6.2",
 ]
 
-[[package]]
-name = "atom"
-version = "0.3.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3c86699c3f02778ec07158376991c8f783dd1f2f95c579ffaf0738dc984b2fe2"
-
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -88,12 +103,41 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"
 
+[[package]]
+name = "backtrace"
+version = "0.3.54"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2baad346b2d4e94a24347adeee9c7a93f412ee94b9cc26e5b59dea23848e9f28"
+dependencies = [
+ "addr2line",
+ "cfg-if 1.0.0",
+ "libc",
+ "miniz_oxide",
+ "object",
+ "rustc-demangle",
+]
+
 [[package]]
 name = "base64"
 version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3441f0f7b02788e948e47f457ca01f1d7e6d92c693bc132c22b087d3141c03ff"
 
+[[package]]
+name = "bit-set"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e11e16035ea35e4e5997b393eacbf6f63983188f7a2ad25bfb13465f5ad59de"
+dependencies = [
+ "bit-vec",
+]
+
+[[package]]
+name = "bit-vec"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f0dc55f2d8a1a85650ac47858bb001b4c0dd73d79e3c455a842925e68d29cd3"
+
 [[package]]
 name = "bitflags"
 version = "1.2.1"
@@ -134,6 +178,9 @@ name = "cc"
 version = "1.0.54"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7bbb73db36c1246e9034e307d0fba23f9a2e251faa47ade70c1bd252220c8311"
+dependencies = [
+ "jobserver",
+]
 
 [[package]]
 name = "cfg-if"
@@ -141,12 +188,27 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "cfg_aliases"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f6da2b592f5a2e590c3d94c44313bab369f2286cfe1e4134c830bf3317814866"
 
+[[package]]
+name = "cgl"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ced0551234e87afee12411d535648dd89d2e7f34c78b753395567aff3d447ff"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "chrono"
 version = "0.4.11"
@@ -176,6 +238,36 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "cocoa"
+version = "0.18.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1706996401131526e36b3b49f0c4d912639ce110996f3ca144d78946727bce54"
+dependencies = [
+ "bitflags",
+ "block",
+ "core-foundation 0.6.4",
+ "core-graphics 0.17.3",
+ "foreign-types",
+ "libc",
+ "objc",
+]
+
+[[package]]
+name = "cocoa"
+version = "0.19.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f29f7768b2d1be17b96158e3285951d366b40211320fb30826a76cb7a0da6400"
+dependencies = [
+ "bitflags",
+ "block",
+ "core-foundation 0.6.4",
+ "core-graphics 0.17.3",
+ "foreign-types",
+ "libc",
+ "objc",
+]
+
 [[package]]
 name = "cocoa"
 version = "0.20.1"
@@ -185,7 +277,7 @@ dependencies = [
  "bitflags",
  "block",
  "core-foundation 0.7.0",
- "core-graphics",
+ "core-graphics 0.19.0",
  "foreign-types",
  "libc",
  "objc",
@@ -212,6 +304,16 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2df960f5d869b2dd8532793fde43eb5427cceb126c929747a26823ab0eeb536"
 
+[[package]]
+name = "core-foundation"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "25b9e03f145fd4f2bf705e07b900cd41fc636598fe5dc452fd0db1441c3f496d"
+dependencies = [
+ "core-foundation-sys 0.6.2",
+ "libc",
+]
+
 [[package]]
 name = "core-foundation"
 version = "0.7.0"
@@ -232,6 +334,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "core-foundation-sys"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7ca8a5221364ef15ce201e8ed2f609fc312682a8f4e0e3d4aa5879764e0fa3b"
+
 [[package]]
 name = "core-foundation-sys"
 version = "0.7.0"
@@ -244,6 +352,18 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a21fa21941700a3cd8fcb4091f361a6a712fac632f85d9f487cc892045d55c6"
 
+[[package]]
+name = "core-graphics"
+version = "0.17.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56790968ab1c8a1202a102e6de05fc6e1ec87da99e4e93e9a7d13efbfc1e95a9"
+dependencies = [
+ "bitflags",
+ "core-foundation 0.6.4",
+ "foreign-types",
+ "libc",
+]
+
 [[package]]
 name = "core-graphics"
 version = "0.19.0"
@@ -274,9 +394,9 @@ version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34ecad23610ad9757664d644e369246edde1803fcb43ed72876565098a5d3828"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "core-foundation-sys 0.7.0",
- "core-graphics",
+ "core-graphics 0.19.0",
  "libc",
  "objc",
 ]
@@ -309,6 +429,18 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bd0c93bb4b0c6d9b77f4435b0ae98c24d17f1c45b2ff844c6151a07256ca923b"
 
+[[package]]
+name = "display-link"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "303de632386f9c82eb7823456f5932bd40b4de9521078901767bf16a9f331491"
+dependencies = [
+ "foreign-types",
+ "objc",
+ "objc-foundation",
+ "time-point",
+]
+
 [[package]]
 name = "dlib"
 version = "0.4.2"
@@ -344,6 +476,15 @@ dependencies = [
  "termcolor",
 ]
 
+[[package]]
+name = "euclid"
+version = "0.20.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2bb7ef65b3777a325d1eeefefab5b6d4959da54747e33bd6258e789640f307ad"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "fixedbitset"
 version = "0.2.0"
@@ -414,9 +555,9 @@ dependencies = [
 
 [[package]]
 name = "gfx-auxil"
-version = "0.5.0"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6311ee3cc7a3b4c8ae94c4513cd2cbe888ec37990cf0ffa672bd275391b12eb1"
+checksum = "07cd956b592970f08545b9325b87580eb95a51843b6f39da27b8667fec1a1216"
 dependencies = [
  "fxhash",
  "gfx-hal",
@@ -425,10 +566,11 @@ dependencies = [
 
 [[package]]
 name = "gfx-backend-dx11"
-version = "0.6.0"
+version = "0.6.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "de0a460b6458f3857af43064c687b1a010fe1f1b2e8c68fcd1d5db7206fa0809"
+checksum = "4ff6f4862cf86d969218e2ddd151816022aff86a1d99a09ffd114da8457c6013"
 dependencies = [
+ "arrayvec",
  "bitflags",
  "gfx-auxil",
  "gfx-hal",
@@ -437,18 +579,21 @@ dependencies = [
  "parking_lot 0.11.0",
  "range-alloc",
  "raw-window-handle",
- "smallvec",
+ "smallvec 1.4.2",
  "spirv_cross",
+ "thunderdome",
  "winapi 0.3.8",
  "wio",
 ]
 
 [[package]]
 name = "gfx-backend-dx12"
-version = "0.6.0"
+version = "0.6.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "815ea94b924aa3a98e52ba3f090564c2186c7ef33fc0afa2f6b72314935c8798"
+checksum = "018a08a0703ef8765ed25ecd48ec77b4d728233364d85b22b8ce24bcd5f71dda"
 dependencies = [
+ "arrayvec",
+ "bit-set",
  "bitflags",
  "d3d12",
  "gfx-auxil",
@@ -456,7 +601,7 @@ dependencies = [
  "log",
  "range-alloc",
  "raw-window-handle",
- "smallvec",
+ "smallvec 1.4.2",
  "spirv_cross",
  "winapi 0.3.8",
 ]
@@ -473,10 +618,34 @@ dependencies = [
 ]
 
 [[package]]
-name = "gfx-backend-metal"
+name = "gfx-backend-gl"
 version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42518c5b571be5ba337a89cfba5abfaf2d90b83fc4db96357f64f2ea05f20f81"
+checksum = "cb13142f794e5268b14a6dcd350cf60644e4c80e5221900b83dbbfa719aad392"
+dependencies = [
+ "arrayvec",
+ "bitflags",
+ "cfg_aliases",
+ "gfx-auxil",
+ "gfx-hal",
+ "glow",
+ "js-sys",
+ "lazy_static",
+ "log",
+ "parking_lot 0.11.0",
+ "raw-window-handle",
+ "smallvec 1.4.2",
+ "spirv_cross",
+ "surfman",
+ "wasm-bindgen",
+ "web-sys",
+]
+
+[[package]]
+name = "gfx-backend-metal"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60ba1c77c112e7d35786dbd49ed26f2a76ce53a44bc09fe964935e4e35ed7f2b"
 dependencies = [
  "arrayvec",
  "bitflags",
@@ -488,12 +657,12 @@ dependencies = [
  "gfx-hal",
  "lazy_static",
  "log",
- "metal",
+ "metal 0.20.0",
  "objc",
  "parking_lot 0.11.0",
  "range-alloc",
  "raw-window-handle",
- "smallvec",
+ "smallvec 1.4.2",
  "spirv_cross",
  "storage-map",
 ]
@@ -514,7 +683,7 @@ dependencies = [
  "log",
  "objc",
  "raw-window-handle",
- "smallvec",
+ "smallvec 1.4.2",
  "winapi 0.3.8",
  "x11",
 ]
@@ -543,17 +712,66 @@ dependencies = [
 
 [[package]]
 name = "gfx-memory"
-version = "0.2.0"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fe8d8855df07f438eb8a765e90356d5b821d644ea3b59b870091450b89576a9f"
+checksum = "dccdda5d2b39412f4ca2cb15c70b5a82783a86b0606f5e985342754c8ed88f05"
 dependencies = [
+ "bit-set",
  "fxhash",
  "gfx-hal",
- "hibitset",
  "log",
  "slab",
 ]
 
+[[package]]
+name = "gimli"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f6503fe142514ca4799d4c26297c4248239fe8838d827db6bd6065c6ed29a6ce"
+
+[[package]]
+name = "gl_generator"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca98bbde17256e02d17336a6bdb5a50f7d0ccacee502e191d3e3d0ec2f96f84a"
+dependencies = [
+ "khronos_api",
+ "log",
+ "xml-rs",
+]
+
+[[package]]
+name = "gl_generator"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a95dfc23a2b4a9a2f5ab41d194f8bfda3cabec42af4e39f08c339eb2a0c124d"
+dependencies = [
+ "khronos_api",
+ "log",
+ "xml-rs",
+]
+
+[[package]]
+name = "gleam"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ea4f9ba7411ae3f00516401fb811b4f4f37f5c926357f2a033d27f96b74c849"
+dependencies = [
+ "gl_generator 0.13.1",
+]
+
+[[package]]
+name = "glow"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1625b792e2f9267116dd41eb7d325e0ea2572ceba5069451906745e04f852f33"
+dependencies = [
+ "js-sys",
+ "slotmap",
+ "wasm-bindgen",
+ "web-sys",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.8.2"
@@ -572,15 +790,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "hibitset"
-version = "0.6.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93a1bb8316a44459a7d14253c4d28dd7395cbd23cc04a68c46e851b8e46d64b1"
-dependencies = [
- "atom",
-]
-
 [[package]]
 name = "humantime"
 version = "1.3.0"
@@ -612,6 +821,19 @@ version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7777a24a1ce5de49fcdde84ec46efa487c3af49d5b6e6e0a50367cc5c1096182"
 
+[[package]]
+name = "io-surface"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2279a6faecd06034f88218f77f7a767693e0957bce0323a96d92747e2760b445"
+dependencies = [
+ "cgl",
+ "core-foundation 0.6.4",
+ "gleam",
+ "leaky-cow",
+ "libc",
+]
+
 [[package]]
 name = "iovec"
 version = "0.1.4"
@@ -634,10 +856,19 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8eaf4bc02d17cbdd7ff4c7438cafcdf7fb9a4613313ad11b4f8fefe7d3fa0130"
 
 [[package]]
-name = "js-sys"
-version = "0.3.40"
+name = "jobserver"
+version = "0.1.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce10c23ad2ea25ceca0093bd3192229da4c5b3c0f2de499c1ecac0d98d452177"
+checksum = "5c71313ebb9439f74b00d9d2dcec36440beaf57a6aa0623068441dd7cd81a7f2"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "js-sys"
+version = "0.3.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca059e81d9486668f12d455a4ea6daa600bd408134cd17e3d3fb5a32d1f016f8"
 dependencies = [
  "wasm-bindgen",
 ]
@@ -652,6 +883,12 @@ dependencies = [
  "winapi-build",
 ]
 
+[[package]]
+name = "khronos_api"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2db585e1d738fc771bf08a151420d3ed193d9d895a36df7f6f8a9456b911ddc"
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -660,9 +897,24 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "lazycell"
-version = "1.2.1"
+version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
+checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
+
+[[package]]
+name = "leak"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bd100e01f1154f2908dfa7d02219aeab25d0b9c7fa955164192e3245255a0c73"
+
+[[package]]
+name = "leaky-cow"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40a8225d44241fd324a8af2806ba635fc7c8a7e9a7de4d5cf3ef54e71f5926fc"
+dependencies = [
+ "leak",
+]
 
 [[package]]
 name = "libc"
@@ -722,7 +974,7 @@ version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
 ]
 
 [[package]]
@@ -731,11 +983,20 @@ version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4ecc775857611e1df29abba5c41355cdf540e7e9d4acfdf0f355eefee82330b7"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "generator",
  "scoped-tls",
 ]
 
+[[package]]
+name = "mach"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b823e83b2affd8f40a9ee8c29dbc56404c1e34cd2710921f2801e2cf29527afa"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "malloc_buf"
 version = "0.0.6"
@@ -776,6 +1037,21 @@ dependencies = [
  "winapi 0.3.8",
 ]
 
+[[package]]
+name = "metal"
+version = "0.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e198a0ee42bdbe9ef2c09d0b9426f3b2b47d90d93a4a9b0395c4cea605e92dc0"
+dependencies = [
+ "bitflags",
+ "block",
+ "cocoa 0.20.1",
+ "core-graphics 0.19.0",
+ "foreign-types",
+ "log",
+ "objc",
+]
+
 [[package]]
 name = "metal"
 version = "0.20.0"
@@ -790,13 +1066,23 @@ dependencies = [
  "objc",
 ]
 
+[[package]]
+name = "miniz_oxide"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0f2d26ec3309788e423cfbf68ad1800f061638098d76a83681af979dc4eda19d"
+dependencies = [
+ "adler",
+ "autocfg",
+]
+
 [[package]]
 name = "mio"
 version = "0.6.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fce347092656428bc8eaf6201042cb551b8d67855af7374542a92a0fbfcac430"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "fuchsia-zircon",
  "fuchsia-zircon-sys",
  "iovec",
@@ -884,7 +1170,7 @@ version = "0.2.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2ba7c918ac76704fb42afcbbb43891e72731f3dcca3bef2a19786297baf14af7"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "winapi 0.3.8",
 ]
@@ -897,7 +1183,7 @@ checksum = "6c722bee1037d430d0f8e687bbdbf222f27cc6e4e68d5caf630857bb2b6dbdce"
 dependencies = [
  "bitflags",
  "cc",
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "void",
 ]
@@ -953,6 +1239,17 @@ dependencies = [
  "objc_exception",
 ]
 
+[[package]]
+name = "objc-foundation"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1add1b659e36c9607c7aab864a76c7a4c2760cd0cd2e120f3fb8b952c7e22bf9"
+dependencies = [
+ "block",
+ "objc",
+ "objc_id",
+]
+
 [[package]]
 name = "objc_exception"
 version = "0.1.2"
@@ -962,6 +1259,21 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "objc_id"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c92d4ddb4bd7b50d730c215ff871754d0da6b2178849f8a2a2ab69712d0c073b"
+dependencies = [
+ "objc",
+]
+
+[[package]]
+name = "object"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8d3b63360ec3cb337817c2dbd47ab4a0f170d285d8e5a2064600f3def1402397"
+
 [[package]]
 name = "once_cell"
 version = "1.4.0"
@@ -977,6 +1289,17 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "parking_lot"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f842b1982eb6c2fe34036a4fbfb06dd185a3f5c8edfaacdf7d1ea10b07de6252"
+dependencies = [
+ "lock_api 0.3.4",
+ "parking_lot_core 0.6.2",
+ "rustc_version",
+]
+
 [[package]]
 name = "parking_lot"
 version = "0.10.2"
@@ -998,17 +1321,32 @@ dependencies = [
  "parking_lot_core 0.8.0",
 ]
 
+[[package]]
+name = "parking_lot_core"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b876b1b9e7ac6e1a74a6da34d25c42e17e8862aa409cbbbdcfc8d86c6f3bc62b"
+dependencies = [
+ "cfg-if 0.1.10",
+ "cloudabi 0.0.3",
+ "libc",
+ "redox_syscall",
+ "rustc_version",
+ "smallvec 0.6.13",
+ "winapi 0.3.8",
+]
+
 [[package]]
 name = "parking_lot_core"
 version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d58c7c768d4ba344e3e8d72518ac13e259d7c7ade24167003b8488e10b6740a3"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "cloudabi 0.0.3",
  "libc",
  "redox_syscall",
- "smallvec",
+ "smallvec 1.4.2",
  "winapi 0.3.8",
 ]
 
@@ -1018,12 +1356,12 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c361aa727dd08437f2f1447be8b59a33b0edd15e0fcee698f935613d9efbca9b"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "cloudabi 0.1.0",
  "instant",
  "libc",
  "redox_syscall",
- "smallvec",
+ "smallvec 1.4.2",
  "winapi 0.3.8",
 ]
 
@@ -1063,7 +1401,7 @@ dependencies = [
  "wgpu-core",
  "wgpu-subscriber",
  "wgpu-types",
- "winit",
+ "winit 0.22.2",
 ]
 
 [[package]]
@@ -1198,6 +1536,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "rustc-demangle"
+version = "0.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e3bad0ee36814ca07d7968269dd4b7ec89ec2da10c4bb613928d3077083c232"
+
 [[package]]
 name = "rustc_version"
 version = "0.2.3"
@@ -1315,12 +1659,44 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 
+[[package]]
+name = "slotmap"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c46a3482db8f247956e464d783693ece164ca056e6e67563ee5505bdb86452cd"
+
+[[package]]
+name = "smallvec"
+version = "0.6.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7b0758c52e15a8b5e3691eae6cc559f08eee9406e548a4477ba4e67770a82b6"
+dependencies = [
+ "maybe-uninit",
+]
+
 [[package]]
 name = "smallvec"
 version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fbee7696b84bbf3d89a1c2eccff0850e3047ed46bfcd2e92c29a2d074d57e252"
 
+[[package]]
+name = "smithay-client-toolkit"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2ccb8c57049b2a34d2cc2b203fa785020ba0129d31920ef0d317430adaf748fa"
+dependencies = [
+ "andrew",
+ "bitflags",
+ "dlib",
+ "lazy_static",
+ "memmap",
+ "nix",
+ "wayland-client 0.21.13",
+ "wayland-commons 0.21.13",
+ "wayland-protocols 0.21.13",
+]
+
 [[package]]
 name = "smithay-client-toolkit"
 version = "0.6.6"
@@ -1333,15 +1709,15 @@ dependencies = [
  "lazy_static",
  "memmap",
  "nix",
- "wayland-client",
- "wayland-protocols",
+ "wayland-client 0.23.6",
+ "wayland-protocols 0.23.6",
 ]
 
 [[package]]
 name = "spirv_cross"
-version = "0.20.0"
+version = "0.22.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a33a9478e9c78782dd694d05dee074703a9c4c74b511de742b88a7e8149f1b37"
+checksum = "d8221f4aebf53a4447aebd4fe29ebff2c66dd2c2821e63675e09e85bd21c8633"
 dependencies = [
  "cc",
  "js-sys",
@@ -1376,6 +1752,36 @@ dependencies = [
  "lock_api 0.4.1",
 ]
 
+[[package]]
+name = "surfman"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3d85bf0eb91b66b93dda5c04627f00074ea1fa008c2980b132a065fafe7a1ab"
+dependencies = [
+ "bitflags",
+ "cfg_aliases",
+ "cgl",
+ "cocoa 0.19.1",
+ "core-foundation 0.6.4",
+ "core-graphics 0.17.3",
+ "display-link",
+ "euclid",
+ "gl_generator 0.14.0",
+ "io-surface",
+ "lazy_static",
+ "libc",
+ "log",
+ "mach",
+ "metal 0.18.0",
+ "objc",
+ "parking_lot 0.10.2",
+ "raw-window-handle",
+ "wayland-sys 0.24.1",
+ "winapi 0.3.8",
+ "winit 0.19.3",
+ "wio",
+]
+
 [[package]]
 name = "syn"
 version = "1.0.31"
@@ -1436,6 +1842,12 @@ dependencies = [
  "lazy_static",
 ]
 
+[[package]]
+name = "thunderdome"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7572415bd688d401c52f6e36f4c8e805b9ae1622619303b9fa835d531db0acae"
+
 [[package]]
 name = "time"
 version = "0.1.43"
@@ -1446,6 +1858,12 @@ dependencies = [
  "winapi 0.3.8",
 ]
 
+[[package]]
+name = "time-point"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06535c958d6abe68dc4b4ef9e6845f758fc42fe463d0093d0aca40254f03fb14"
+
 [[package]]
 name = "toml"
 version = "0.5.6"
@@ -1461,7 +1879,7 @@ version = "0.1.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a41f40ed0e162c911ac6fcb53ecdc8134c46905fdbbae8c50add462a538b495f"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "tracing-core",
 ]
 
@@ -1509,7 +1927,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sharded-slab",
- "smallvec",
+ "smallvec 1.4.2",
  "tracing-core",
  "tracing-log",
  "tracing-serde",
@@ -1546,19 +1964,19 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.63"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c2dc4aa152834bc334f506c1a06b866416a8b6697d5c9f75b9a689c8486def0"
+checksum = "1ac64ead5ea5f05873d7c12b545865ca2b8d28adfc50a49b84770a3a97265d42"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "wasm-bindgen-macro",
 ]
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.63"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ded84f06e0ed21499f6184df0e0cb3494727b0c5da89534e0fcc55c51d812101"
+checksum = "f22b422e2a757c35a73774860af8e112bff612ce6cb604224e8e47641a9e4f68"
 dependencies = [
  "bumpalo",
  "lazy_static",
@@ -1571,9 +1989,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.63"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "838e423688dac18d73e31edce74ddfac468e37b1506ad163ffaf0a46f703ffe3"
+checksum = "6b13312a745c08c469f0b292dd2fcd6411dba5f7160f593da6ef69b64e407038"
 dependencies = [
  "quote 1.0.7",
  "wasm-bindgen-macro-support",
@@ -1581,9 +1999,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.63"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3156052d8ec77142051a533cdd686cba889537b213f948cd1d20869926e68e92"
+checksum = "f249f06ef7ee334cc3b8ff031bfc11ec99d00f34d86da7498396dc1e3b1498fe"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
@@ -1594,9 +2012,24 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.63"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c9ba19973a58daf4db6f352eda73dc0e289493cd29fb2632eb172085b6521acd"
+checksum = "1d649a3145108d7d3fbcde896a468d1bd636791823c9921135218ad89be08307"
+
+[[package]]
+name = "wayland-client"
+version = "0.21.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49963e5f9eeaf637bfcd1b9f0701c99fd5cd05225eb51035550d4272806f2713"
+dependencies = [
+ "bitflags",
+ "downcast-rs",
+ "libc",
+ "nix",
+ "wayland-commons 0.21.13",
+ "wayland-scanner 0.21.13",
+ "wayland-sys 0.21.13",
+]
 
 [[package]]
 name = "wayland-client"
@@ -1610,9 +2043,19 @@ dependencies = [
  "libc",
  "mio",
  "nix",
- "wayland-commons",
- "wayland-scanner",
- "wayland-sys",
+ "wayland-commons 0.23.6",
+ "wayland-scanner 0.23.6",
+ "wayland-sys 0.23.6",
+]
+
+[[package]]
+name = "wayland-commons"
+version = "0.21.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40c08896768b667e1df195d88a62a53a2d1351a1ed96188be79c196b35bb32ec"
+dependencies = [
+ "nix",
+ "wayland-sys 0.21.13",
 ]
 
 [[package]]
@@ -1622,7 +2065,20 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bb66b0d1a27c39bbce712b6372131c6e25149f03ffb0cd017cf8f7de8d66dbdb"
 dependencies = [
  "nix",
- "wayland-sys",
+ "wayland-sys 0.23.6",
+]
+
+[[package]]
+name = "wayland-protocols"
+version = "0.21.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4afde2ea2a428eee6d7d2c8584fdbe8b82eee8b6c353e129a434cd6e07f42145"
+dependencies = [
+ "bitflags",
+ "wayland-client 0.21.13",
+ "wayland-commons 0.21.13",
+ "wayland-scanner 0.21.13",
+ "wayland-sys 0.21.13",
 ]
 
 [[package]]
@@ -1632,9 +2088,20 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6cc286643656742777d55dc8e70d144fa4699e426ca8e9d4ef454f4bf15ffcf9"
 dependencies = [
  "bitflags",
- "wayland-client",
- "wayland-commons",
- "wayland-scanner",
+ "wayland-client 0.23.6",
+ "wayland-commons 0.23.6",
+ "wayland-scanner 0.23.6",
+]
+
+[[package]]
+name = "wayland-scanner"
+version = "0.21.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bf3828c568714507315ee425a9529edc4a4aa9901409e373e9e0027e7622b79e"
+dependencies = [
+ "proc-macro2 0.4.30",
+ "quote 0.6.13",
+ "xml-rs",
 ]
 
 [[package]]
@@ -1648,6 +2115,16 @@ dependencies = [
  "xml-rs",
 ]
 
+[[package]]
+name = "wayland-sys"
+version = "0.21.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "520ab0fd578017a0ee2206623ba9ef4afe5e8f23ca7b42f6acfba2f4e66b1628"
+dependencies = [
+ "dlib",
+ "lazy_static",
+]
+
 [[package]]
 name = "wayland-sys"
 version = "0.23.6"
@@ -1658,6 +2135,26 @@ dependencies = [
  "lazy_static",
 ]
 
+[[package]]
+name = "wayland-sys"
+version = "0.24.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "537500923d50be11d95a63c4cb538145e4c82edf61296b7debc1f94a1a6514ed"
+dependencies = [
+ "dlib",
+ "lazy_static",
+]
+
+[[package]]
+name = "web-sys"
+version = "0.3.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4bf6ef87ad7ae8008e15a355ce696bed26012b7caa21605188cfd8214ab51e2d"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "wgpu-core"
 version = "0.6.0"
@@ -1670,6 +2167,7 @@ dependencies = [
  "gfx-backend-dx11",
  "gfx-backend-dx12",
  "gfx-backend-empty",
+ "gfx-backend-gl",
  "gfx-backend-metal",
  "gfx-backend-vulkan",
  "gfx-descriptor",
@@ -1681,7 +2179,7 @@ dependencies = [
  "raw-window-handle",
  "ron",
  "serde",
- "smallvec",
+ "smallvec 1.4.2",
  "thiserror",
  "tracing",
  "wgpu-types",
@@ -1750,6 +2248,30 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
+[[package]]
+name = "winit"
+version = "0.19.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d0da905e61ae52d55c5ca6f8bea1e09daf5e325b6c77b0947c65a5179b49f5f"
+dependencies = [
+ "android_glue",
+ "backtrace",
+ "bitflags",
+ "cocoa 0.18.5",
+ "core-foundation 0.6.4",
+ "core-graphics 0.17.3",
+ "lazy_static",
+ "libc",
+ "log",
+ "objc",
+ "parking_lot 0.9.0",
+ "percent-encoding",
+ "smithay-client-toolkit 0.4.6",
+ "wayland-client 0.21.13",
+ "winapi 0.3.8",
+ "x11-dl",
+]
+
 [[package]]
 name = "winit"
 version = "0.22.2"
@@ -1757,9 +2279,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e4ccbf7ddb6627828eace16cacde80fc6bf4dbb3469f88487262a02cf8e7862"
 dependencies = [
  "bitflags",
- "cocoa",
+ "cocoa 0.20.1",
  "core-foundation 0.7.0",
- "core-graphics",
+ "core-graphics 0.19.0",
  "core-video-sys",
  "dispatch",
  "instant",
@@ -1775,8 +2297,8 @@ dependencies = [
  "parking_lot 0.10.2",
  "percent-encoding",
  "raw-window-handle",
- "smithay-client-toolkit",
- "wayland-client",
+ "smithay-client-toolkit 0.6.6",
+ "wayland-client 0.23.6",
  "winapi 0.3.8",
  "x11-dl",
 ]
diff --git a/wgpu-core/Cargo.toml b/wgpu-core/Cargo.toml
index d27e99935..6c700a407 100644
--- a/wgpu-core/Cargo.toml
+++ b/wgpu-core/Cargo.toml
@@ -25,8 +25,8 @@ arrayvec = "0.5"
 bitflags = "1.0"
 copyless = "0.1"
 fxhash = "0.2"
-hal = { package = "gfx-hal", git = "https://github.com/gfx-rs/gfx.git", rev = "c9fcd08956eeddac8f6d85b02794fc5e3d1717f5" }
-gfx-backend-empty = { git = "https://github.com/gfx-rs/gfx.git", rev = "c9fcd08956eeddac8f6d85b02794fc5e3d1717f5" }
+hal = { package = "gfx-hal", version = "0.6" }
+gfx-backend-empty = "0.6"
 parking_lot = "0.11"
 raw-window-handle = { version = "0.3", optional = true }
 ron = { version = "0.6", optional = true }
@@ -34,8 +34,8 @@ serde = { version = "1.0", features = ["serde_derive"], optional = true }
 smallvec = "1"
 tracing = { version = "0.1", default-features = false, features = ["std"] }
 thiserror = "1"
-gfx-descriptor = { git = "https://github.com/katharostech/gfx-extras.git", branch = "gl-final-showdown" }
-gfx-memory = { git = "https://github.com/katharostech/gfx-extras.git", branch = "gl-final-showdown" }
+gfx-descriptor = "0.2"
+gfx-memory = "0.2"
 
 [dependencies.naga]
 version = "0.2"
@@ -48,6 +48,9 @@ path = "../wgpu-types"
 package = "wgpu-types"
 version = "0.6"
 
+[target.'cfg(all(unix, not(target_os = "ios")))'.dependencies]
+gfx-backend-gl = { version = "0.6" }
+
 [target.'cfg(any(target_os = "ios", target_os = "macos"))'.dependencies]
 gfx-backend-metal = { version = "0.6" }
 gfx-backend-vulkan = { version = "0.6.4", optional = true }
diff --git a/wgpu-core/build.rs b/wgpu-core/build.rs
index 5f7d660ab..ef07a993f 100644
--- a/wgpu-core/build.rs
+++ b/wgpu-core/build.rs
@@ -6,13 +6,15 @@ fn main() {
     // Setup cfg aliases
     cfg_aliases::cfg_aliases! {
         // Vendors/systems
-        apple: { any(target_os = "ios", target_os = "macos") },
+        ios: { target_os = "ios" },
+        macos: { target_os = "macos" },
+        apple: { any(ios, macos) },
 
         // Backends
         vulkan: { any(windows, all(unix, not(apple)), feature = "gfx-backend-vulkan") },
         metal: { apple },
         dx12: { windows },
         dx11: { windows },
-        gl: { unix },
+        gl: { all(unix, not(ios)) },
     }
 }
diff --git a/wgpu-core/src/device/mod.rs b/wgpu-core/src/device/mod.rs
index cf71ba88d..af8d4a12e 100644
--- a/wgpu-core/src/device/mod.rs
+++ b/wgpu-core/src/device/mod.rs
@@ -1736,16 +1736,16 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             None
         };
 
-        let actual_border = desc
+        let actual_border: hal::image::PackedColor = desc
             .border_color
             .map(|c| match c {
                 wgt::SamplerBorderColor::TransparentBlack => {
-                    hal::image::BorderColor::TransparentBlack
+                    [0., 0., 0., 0.].into()
                 }
-                wgt::SamplerBorderColor::OpaqueBlack => hal::image::BorderColor::OpaqueBlack,
-                wgt::SamplerBorderColor::OpaqueWhite => hal::image::BorderColor::OpaqueWhite,
+                wgt::SamplerBorderColor::OpaqueBlack => [0., 0., 0., 1.].into(),
+                wgt::SamplerBorderColor::OpaqueWhite => [1., 1., 1., 1.].into(),
             })
-            .unwrap_or(hal::image::BorderColor::OpaqueBlack);
+            .unwrap_or([0., 0., 0., 0.].into());
 
         let info = hal::image::SamplerDesc {
             min_filter: conv::map_filter(desc.min_filter),
diff --git a/wgpu-core/src/hub.rs b/wgpu-core/src/hub.rs
index 4252141e9..ca076c1d1 100644
--- a/wgpu-core/src/hub.rs
+++ b/wgpu-core/src/hub.rs
@@ -670,6 +670,8 @@ pub struct Hubs<F: GlobalIdentityHandlerFactory> {
     dx12: Hub<backend::Dx12, F>,
     #[cfg(dx11)]
     dx11: Hub<backend::Dx11, F>,
+    #[cfg(gl)]
+    gl: Hub<backend::Gl, F>,
 }
 
 impl<F: GlobalIdentityHandlerFactory> Hubs<F> {
@@ -683,6 +685,8 @@ impl<F: GlobalIdentityHandlerFactory> Hubs<F> {
             dx12: Hub::new(factory),
             #[cfg(dx11)]
             dx11: Hub::new(factory),
+            #[cfg(gl)]
+            gl: Hub::new(factory),
         }
     }
 }
@@ -734,6 +738,10 @@ impl<G: GlobalIdentityHandlerFactory> Drop for Global<G> {
             {
                 self.hubs.dx11.clear(&mut *surface_guard);
             }
+            #[cfg(gl)]
+            {
+                self.hubs.gl.clear(&mut *surface_guard);
+            }
 
             // destroy surfaces
             for element in surface_guard.map.drain(..) {
@@ -795,6 +803,17 @@ impl GfxBackend for backend::Dx11 {
     }
 }
 
+#[cfg(gl)]
+impl GfxBackend for backend::Gl {
+    const VARIANT: Backend = Backend::Gl;
+    fn hub<G: GlobalIdentityHandlerFactory>(global: &Global<G>) -> &Hub<Self, G> {
+        &global.hubs.gl
+    }
+    fn get_surface_mut(surface: &mut Surface) -> &mut Self::Surface {
+        surface.gl.as_mut().unwrap()
+    }
+}
+
 #[cfg(test)]
 fn _test_send_sync(global: &Global<IdentityManagerFactory>) {
     fn test_internal<T: Send + Sync>(_: T) {}
diff --git a/wgpu-core/src/instance.rs b/wgpu-core/src/instance.rs
index 2a76cb5cf..6e0f01e90 100644
--- a/wgpu-core/src/instance.rs
+++ b/wgpu-core/src/instance.rs
@@ -38,6 +38,8 @@ pub struct Instance {
     pub dx12: Option<gfx_backend_dx12::Instance>,
     #[cfg(dx11)]
     pub dx11: Option<gfx_backend_dx11::Instance>,
+    #[cfg(gl)]
+    pub gl: Option<gfx_backend_gl::Instance>,
 }
 
 impl Instance {
@@ -59,6 +61,8 @@ impl Instance {
                 dx12: map((Backend::Dx12, gfx_backend_dx12::Instance::create)),
                 #[cfg(dx11)]
                 dx11: map((Backend::Dx11, gfx_backend_dx11::Instance::create)),
+                #[cfg(gl)]
+                gl: map((Backend::Gl, gfx_backend_gl::Instance::create)),
             }
         }
     }
@@ -81,6 +85,8 @@ impl Instance {
             map((surface.dx12, &mut self.dx12)),
             #[cfg(dx11)]
             map((surface.dx11, &mut self.dx11)),
+            #[cfg(gl)]
+            map((surface.gl, &mut self.gl)),
         }
     }
 }
@@ -97,6 +103,8 @@ pub struct Surface {
     pub dx12: Option<GfxSurface<backend::Dx12>>,
     #[cfg(dx11)]
     pub dx11: Option<GfxSurface<backend::Dx11>>,
+    #[cfg(gl)]
+    pub gl: Option<GfxSurface<backend::Gl>>,
 }
 
 #[derive(Debug)]
@@ -341,7 +349,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
                     inst
                     .as_ref()
                     .and_then(|inst| inst.create_surface(handle).map_err(|e| {
-                        eprintln!("Error: {:?}", e);
+                        tracing::warn!("Error: {:?}", e);
                     }).ok())
                 };
 
@@ -354,6 +362,8 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
                     dx12: map(&self.instance.dx12),
                     #[cfg(dx11)]
                     dx11: map(&self.instance.dx11),
+                    #[cfg(gl)]
+                    gl: map(&self.instance.gl),
                 }
             }
         };
@@ -397,6 +407,8 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             map((&instance.dx12, Backend::Dx12, "Dx12", backend::Dx12::hub)),
             #[cfg(dx11)]
             map((&instance.dx11, Backend::Dx11, "Dx11", backend::Dx11::hub)),
+            #[cfg(gl)]
+            map((&instance.gl, Backend::Gl, "GL", backend::Gl::hub)),
         }
 
         adapters
@@ -426,6 +438,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         let mut id_metal = inputs.find(Backend::Metal);
         let mut id_dx12 = inputs.find(Backend::Dx12);
         let mut id_dx11 = inputs.find(Backend::Dx11);
+        let mut id_gl = inputs.find(Backend::Gl);
 
         backends_map! {
             let map = |(instance_backend, id_backend, surface_backend)| {
@@ -477,6 +490,13 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
                 }
                 surface_dx11
             }));
+            #[cfg(gl)]
+            let adapters_gl = map((&instance.gl, &id_gl, {
+                fn surface_gl(surf: &Surface) -> Option<&GfxSurface<backend::Gl>> {
+                    surf.gl.as_ref()
+                }
+                surface_gl
+            }));
         }
 
         if device_types.is_empty() {
@@ -532,6 +552,8 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             map(("Dx12", &mut id_dx12, adapters_dx12, backend::Dx12::hub)),
             #[cfg(dx11)]
             map(("Dx11", &mut id_dx11, adapters_dx11, backend::Dx11::hub)),
+            #[cfg(gl)]
+            map(("GL", &mut id_dx11, adapters_gl, backend::Gl::hub)),
         }
 
         let _ = (
@@ -540,6 +562,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             id_metal.take(),
             id_dx12.take(),
             id_dx11.take(),
+            id_gl.take(),
         );
         tracing::warn!("Some adapters are present, but enumerating them failed!");
         Err(RequestAdapterError::NotFound)
diff --git a/wgpu-core/src/lib.rs b/wgpu-core/src/lib.rs
index 0ec245a31..79f3143ad 100644
--- a/wgpu-core/src/lib.rs
+++ b/wgpu-core/src/lib.rs
@@ -19,6 +19,8 @@ pub mod backend {
     pub use gfx_backend_dx11::Backend as Dx11;
     #[cfg(dx12)]
     pub use gfx_backend_dx12::Backend as Dx12;
+    #[cfg(gl)]
+    pub use gfx_backend_gl::Backend as Gl;
     #[cfg(metal)]
     pub use gfx_backend_metal::Backend as Metal;
     #[cfg(vulkan)]
@@ -203,6 +205,8 @@ struct PrivateFeatures {
 #[macro_export]
 macro_rules! gfx_select {
     ($id:expr => $global:ident.$method:ident( $($param:expr),* )) => {
+        // Note: For some reason the cfg aliases defined in build.rs don't succesfully apply in this
+        // macro so we must specify their equivalents manually
         match $id.backend() {
             #[cfg(any(not(any(target_os = "ios", target_os = "macos")), feature = "gfx-backend-vulkan"))]
             wgt::Backend::Vulkan => $global.$method::<$crate::backend::Vulkan>( $($param),* ),
@@ -212,6 +216,8 @@ macro_rules! gfx_select {
             wgt::Backend::Dx12 => $global.$method::<$crate::backend::Dx12>( $($param),* ),
             #[cfg(windows)]
             wgt::Backend::Dx11 => $global.$method::<$crate::backend::Dx11>( $($param),* ),
+            #[cfg(all(unix, not(target_os = "ios")))]
+            wgt::Backend::Gl => $global.$method::<$crate::backend::Gl>( $($param),+ ),
             _ => unreachable!()
         }
     };