Make winit truly optional

.travis.yml

@@ -57,6 +57,9 @@ before_install:
 
 script:
   - cargo test
+  - cd wgpu-native && cargo check --features local,window-winit; fi
+  # TODO: Temporarily only test building the gl backend, properly test when it is usable from C
+  - if [[ $TRAVIS_OS_NAME == "linux" ]]; then cd wgpu-native && cargo check --features local,window-winit,gfx-backend-gl; fi
   - if [[ $TRAVIS_OS_NAME == "linux" ]]; then cargo check --release; fi
   - if [[ $TRAVIS_RUST_VERSION == "nightly" ]]; then cargo +nightly install cbindgen; fi
   - if [[ $TRAVIS_RUST_VERSION == "nightly" ]] && [[ $TRAVIS_OS_NAME == "windows" ]]; then
@@ -72,5 +75,3 @@ script:
       make example-compute example-triangle VERBOSE=1;
     fi
   - if [[ $TRAVIS_RUST_VERSION == "nightly" ]] && [[ $TRAVIS_OS_NAME != "windows" ]]; then make VERBOSE=1; fi
-  # TODO: Temporarily only test building the gl backend, properly test when it is usable from C
-  - if [[ $TRAVIS_OS_NAME == "linux" ]]; then cd wgpu-native && cargo build --features local,gfx-backend-gl; fi

ffi/wgpu.h

@@ -845,6 +845,7 @@ void wgpu_render_pass_set_scissor_rect(WGPURenderPassId pass_id,
 void wgpu_render_pass_set_stencil_reference(WGPURenderPassId pass_id, uint32_t value);
 
 void wgpu_render_pass_set_vertex_buffers(WGPURenderPassId pass_id,
+                                         uint32_t start_slot,
                                          const WGPUBufferId *buffers,
                                          const WGPUBufferAddress *offsets,
                                          uintptr_t length);

wgpu-native/Cargo.toml

@@ -20,7 +20,7 @@ default = []
 local = []
 remote = ["serde"]
 metal-auto-capture = ["gfx-backend-metal/auto-capture"]
-window-winit = ["winit", "gfx-backend-empty/winit"]
+window-winit = ["winit", "gfx-backend-empty/winit", "gfx-backend-vulkan/winit", "gfx-backend-dx11/winit", "gfx-backend-dx12/winit", "gfx-backend-metal/winit", "gfx-backend-gl/glutin"]
 
 [dependencies]
 arrayvec = "0.4"
@@ -29,12 +29,12 @@ copyless = "0.1"
 lazy_static = "1.1.0"
 log = "0.4"
 hal = { package = "gfx-hal", version = "0.3.0" }
-gfx-backend-empty = { version = "0.3.0", features = ["winit"] }
-gfx-backend-vulkan = { version = "0.3.0", features = ["winit", "x11"], optional = true }
-gfx-backend-dx11 = { version = "0.3.0", features = ["winit"], optional = true }
-gfx-backend-dx12 = { version = "0.3.0", features = ["winit"], optional = true }
-gfx-backend-metal = { version = "0.3.0", features = ["winit"], optional = true }
-gfx-backend-gl = { version = "0.3.0", features = ["winit", "glutin"], optional = true }
+gfx-backend-empty = { version = "0.3.0" }
+gfx-backend-vulkan = { version = "0.3.0", features = ["x11"], optional = true }
+gfx-backend-dx11 = { version = "0.3.0", optional = true }
+gfx-backend-dx12 = { version = "0.3.0", optional = true }
+gfx-backend-metal = { version = "0.3.0", optional = true }
+gfx-backend-gl = { version = "0.3.0", optional = true }
 parking_lot = { version = "0.9" }
 rendy-memory = { git = "https://github.com/amethyst/rendy", rev = "db6adbe7454f52ebf559a38dd88580aa3ebbcaaf" }
 rendy-descriptor = { git = "https://github.com/amethyst/rendy", rev = "db6adbe7454f52ebf559a38dd88580aa3ebbcaaf" }

wgpu-native/src/instance.rs

@@ -75,7 +75,7 @@ pub extern "C" fn wgpu_create_instance() -> InstanceId {
     HUB.instances.register_local(inst, &mut Token::root())
 }
 
-#[cfg(all(feature = "local", feature = "gfx-backend-gl"))]
+#[cfg(all(feature = "local", feature = "window-winit", feature = "gfx-backend-gl"))]
 pub fn wgpu_create_gl_instance(windowed_context: back::glutin::RawContext<back::glutin::PossiblyCurrent>) -> InstanceId {
     let raw = back::Surface::from_context(windowed_context);
     let surface = SurfaceHandle::new(raw);
@@ -212,15 +212,17 @@ pub fn instance_get_adapter(
         let (instance_guard, _) = HUB.instances.read(token);
         instance_guard[instance_id].enumerate_adapters()
     };
-    #[cfg(feature = "gfx-backend-gl")]
+    #[cfg(all(feature = "window-winit", feature = "gfx-backend-gl"))]
     let adapters = {
         let (surface_guard, _) = HUB.surfaces.read(token);
         surface_guard[instance_id].raw.enumerate_adapters()
     };
+    #[cfg(all(not(feature = "windiw-winit"), feature = "gfx-backend-gl"))]
+    let adapters = Vec::<AdapterHandle>::new();
 
     let (mut integrated_first, mut discrete_first, mut discrete_last, mut alternative) =
         (None, None, None, None);
-        
+
     // On Windows > 1803, dx12 enumerate_adapters returns the adapters in order from highest to
     // lowest performance. Therefore, the first found adapter in each category is selected.
     //

wgpu-native/src/lib.rs

@@ -44,7 +44,7 @@ pub use hal::pso::read_spirv;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
-#[cfg(feature = "gfx-backend-gl")]
+#[cfg(all(feature = "window-winit", feature = "gfx-backend-gl"))]
 pub use back::glutin;
 
 use std::{