core: cleanup sysgpu feature flag logic

* `@import("mach").core.gpu` has been renamed to `@import("mach").gpu`
* `pub const SYSGPUInterface` now has a default value (i.e. you do not need to write it in your main.zig, if you were.)
* You can now check `if (comptime mach.use_sysgpu)` for any conditional code you might have that should only run with sysgpu.

This (old):

```
pub const mach_core_options = core.ComptimeOptions{
    .use_wgpu = false,
    .use_sysgpu = true,
};
```

Has been replaced by this:

```
pub const use_sysgpu = true;
```

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

src/Core.zig

@@ -34,8 +34,8 @@ should_exit: bool = false,
 
 fn init(core: *Mod) !void {
     // Initialize GPU implementation
-    if (comptime mach.core.options.use_wgpu) try mach.core.wgpu.Impl.init(mach.core.allocator, .{});
+    if (comptime !mach.use_sysgpu) try mach.wgpu.Impl.init(mach.core.allocator, .{});
-    if (comptime mach.core.options.use_sysgpu) try mach.core.sysgpu.Impl.init(mach.core.allocator, .{});
+    if (comptime mach.use_sysgpu) try mach.sysgpu.Impl.init(mach.core.allocator, .{});
 
     mach.core.allocator = gpa.allocator(); // TODO: banish this global allocator
     try mach.core.init(.{});

src/core/examples/cubemap/main.zig

@@ -2,6 +2,7 @@ const std = @import("std");
 
 const mach = @import("mach");
 const core = mach.core;
+const gpu = mach.gpu;
 
 const zm = @import("zmath");
 const zigimg = @import("zigimg");

src/core/examples/sysgpu/boids/main.zig

@@ -4,7 +4,7 @@ const std = @import("std");
 
 const mach = @import("mach");
 const core = mach.core;
-const gpu = core.gpu;
+const gpu = mach.gpu;
 
 title_timer: core.Timer,
 timer: core.Timer,
@@ -18,10 +18,8 @@ frame_counter: usize,
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 

src/core/examples/sysgpu/clear-color/main.zig

@@ -2,16 +2,14 @@ const std = @import("std");
 
 const mach = @import("mach");
 const core = mach.core;
-const gpu = core.gpu;
+const gpu = mach.gpu;
 
 const renderer = @import("renderer.zig");
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 

src/core/examples/sysgpu/cubemap/main.zig

@@ -27,10 +27,8 @@ depth_texture_view: *gpu.TextureView,
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 pub fn init(app: *App) !void {
     try core.init(.{});

src/core/examples/sysgpu/deferred-rendering/main.zig

@@ -11,10 +11,8 @@ const VertexWriter = @import("vertex_writer.zig").VertexWriter;
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 const Vec2 = [2]f32;
 const Vec3 = [3]f32;

src/core/examples/sysgpu/fractal-cube/main.zig

@@ -20,10 +20,8 @@ const vertices = @import("cube_mesh.zig").vertices;
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 const UniformBufferObject = struct {
     mat: zm.Mat,

src/core/examples/sysgpu/gen-texture-light/main.zig

@@ -19,10 +19,8 @@ const Quat = zm.Quat;
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 

src/core/examples/sysgpu/image-blur/main.zig

@@ -22,10 +22,8 @@ img_size: gpu.Extent3D,
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 // Constants from the blur.wgsl shader
 const tile_dimension: u32 = 128;

src/core/examples/sysgpu/image/main.zig

@@ -7,10 +7,8 @@ const gpu = mach.gpu;
 const zigimg = @import("zigimg");
 const assets = @import("assets");
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 title_timer: core.Timer,
 pipeline: *gpu.RenderPipeline,

src/core/examples/sysgpu/instanced-cube/main.zig

@@ -24,10 +24,8 @@ bind_group: *gpu.BindGroup,
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 pub fn init(app: *App) !void {
     try core.init(.{});

src/core/examples/sysgpu/map-async/main.zig

@@ -6,10 +6,8 @@ const gpu = mach.gpu;
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 

src/core/examples/sysgpu/pbr-basic/main.zig

@@ -11,10 +11,8 @@ const VertexWriter = @import("vertex_writer.zig").VertexWriter;
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 const Vec4 = [4]f32;
 const Vec3 = [3]f32;

src/core/examples/sysgpu/pixel-post-process/main.zig

@@ -13,10 +13,8 @@ const quad = @import("quad_mesh.zig").quad;
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 const pixel_size = 8;
 

src/core/examples/sysgpu/procedural-primitives/main.zig

@@ -8,10 +8,9 @@ const renderer = @import("renderer.zig");
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
+
-};
 var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 
 title_timer: core.Timer,

src/core/examples/sysgpu/rgb-quad/main.zig

@@ -16,10 +16,8 @@ const vertices = [_]Vertex{
 };
 const index_data = [_]u32{ 0, 1, 2, 2, 3, 0 };
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 pub const App = @This();
 

src/core/examples/sysgpu/rotating-cube/main.zig

@@ -10,10 +10,8 @@ const vertices = @import("cube_mesh.zig").vertices;
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 const UniformBufferObject = struct {

src/core/examples/sysgpu/sprite2d/main.zig

@@ -11,10 +11,8 @@ const json = std.json;
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 const speed = 2.0 * 100.0; // pixels per second
 

src/core/examples/sysgpu/textured-cube/main.zig

@@ -12,10 +12,8 @@ const assets = @import("assets");
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 const UniformBufferObject = struct {
     mat: zm.Mat,

src/core/examples/sysgpu/textured-quad/main.zig

@@ -22,10 +22,8 @@ const vertices = [_]Vertex{
 };
 const index_data = [_]u32{ 0, 1, 2, 2, 3, 0 };
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 

src/core/examples/sysgpu/triangle-msaa/main.zig

@@ -6,10 +6,8 @@ const gpu = mach.gpu;
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 title_timer: core.Timer,
 pipeline: *gpu.RenderPipeline,

src/core/examples/sysgpu/triangle/main.zig

@@ -6,10 +6,8 @@ const gpu = mach.gpu;
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 title_timer: core.Timer,
 pipeline: *gpu.RenderPipeline,

src/core/examples/sysgpu/two-cubes/main.zig

@@ -2,7 +2,7 @@ const std = @import("std");
 
 const mach = @import("mach");
 const core = mach.core;
-const gpu = core.gpu;
+const gpu = mach.gpu;
 
 const zm = @import("zmath");
 const Vertex = @import("cube_mesh.zig").Vertex;
@@ -24,10 +24,8 @@ bind_group2: *gpu.BindGroup,
 
 pub const App = @This();
 
-pub const mach_core_options = core.ComptimeOptions{
+// Use experimental sysgpu graphics API
-    .use_wgpu = false,
+pub const use_sysgpu = true;
-    .use_sysgpu = true,
-};
 
 pub fn init(app: *App) !void {
     try core.init(.{});

src/core/main.zig

@@ -44,30 +44,7 @@ fn ErrorSet(comptime F: type) type {
     return @typeInfo(@typeInfo(F).Fn.return_type.?).ErrorUnion.error_set;
 }
 
-/// Comptime options that you can configure in your main file by writing e.g.:
+const gpu = if (mach.use_sysgpu) sysgpu.sysgpu else @import("../gpu/main.zig");
-///
-/// ```
-/// pub const mach_core_options = core.ComptimeOptions{
-///     .use_wgpu = true,
-///     .use_sysgpu = true,
-/// };
-/// ```
-pub const ComptimeOptions = struct {
-    /// Whether to use
-    use_wgpu: bool = true,
-
-    /// Whether or not to use the experimental sysgpu graphics API.
-    use_sysgpu: bool = false,
-};
-
-pub const options = if (@hasDecl(@import("root"), "mach_core_options"))
-    @import("root").mach_core_options
-else
-    ComptimeOptions{};
-
-pub const wgpu = @import("../gpu/main.zig");
-
-pub const gpu = if (options.use_sysgpu) sysgpu.sysgpu else wgpu;
 
 pub fn AppInterface(comptime app_entry: anytype) void {
     if (!@hasDecl(app_entry, "App")) {

src/core/platform/common.zig

@@ -3,7 +3,7 @@ const builtin = @import("builtin");
 const mach = @import("../../main.zig");
 const gamemode = mach.gamemode;
 const mach_core = mach.core;
-const gpu = mach_core.gpu;
+const gpu = mach.gpu;
 
 pub inline fn printUnhandledErrorCallback(_: void, ty: gpu.ErrorType, message: [*:0]const u8) void {
     switch (ty) {

src/core/platform/glfw/Core.zig

@@ -1,8 +1,9 @@
 const builtin = @import("builtin");
 const std = @import("std");
 const glfw = @import("mach-glfw");
+const mach = @import("../../../main.zig");
 const mach_core = @import("../../main.zig");
-const gpu = mach_core.gpu;
+const gpu = mach.gpu;
 const objc = @import("objc.zig");
 const Options = @import("../../main.zig").Options;
 const Event = @import("../../main.zig").Event;
@@ -136,11 +137,11 @@ pub fn init(
     input: *Frequency,
     options: Options,
 ) !void {
-    if (!@import("builtin").is_test and mach_core.options.use_wgpu) _ = mach_core.wgpu.Export(blk: {
+    if (!@import("builtin").is_test and !mach.use_sysgpu) _ = mach.wgpu.Export(blk: {
         if (@hasDecl(@import("root"), "GPUInterface")) break :blk @import("root").GPUInterface;
-        break :blk mach_core.wgpu.dawn.Interface;
+        break :blk mach.wgpu.dawn.Interface;
     });
-    if (!@import("builtin").is_test and mach_core.options.use_sysgpu) _ = mach_core.sysgpu.sysgpu.Export(@import("root").SYSGPUInterface);
+    if (!@import("builtin").is_test and mach.use_sysgpu) _ = mach.sysgpu.sysgpu.Export(@import("root").SYSGPUInterface);
 
     const backend_type = try detectBackendType(allocator);
 

src/core/platform/native_entrypoint.zig

@@ -8,14 +8,16 @@ pub usingnamespace @import("app");
 const App = @import("app").App;
 
 const std = @import("std");
-const core = @import("mach").core;
+
+const mach = @import("mach");
+const core = mach.core;
 
 pub usingnamespace if (!@hasDecl(App, "GPUInterface")) struct {
-    pub const GPUInterface = core.wgpu.dawn.Interface;
+    pub const GPUInterface = mach.wgpu.dawn.Interface;
 } else struct {};
 
 pub usingnamespace if (!@hasDecl(App, "SYSGPUInterface")) extern struct {
-    pub const SYSGPUInterface = core.sysgpu.Impl;
+    pub const SYSGPUInterface = mach.sysgpu.Impl;
 } else struct {};
 
 pub fn main() !void {
@@ -29,8 +31,8 @@ pub fn main() !void {
     core.allocator = gpa.allocator();
 
     // Initialize GPU implementation
-    if (comptime core.options.use_wgpu) try core.wgpu.Impl.init(core.allocator, .{});
+    if (comptime !mach.use_sysgpu) try mach.wgpu.Impl.init(core.allocator, .{});
-    if (comptime core.options.use_sysgpu) try core.sysgpu.Impl.init(core.allocator, .{});
+    if (comptime mach.use_sysgpu) try mach.sysgpu.Impl.init(core.allocator, .{});
 
     var app: App = undefined;
     try app.init();

src/core/platform/wasm/Core.zig

@@ -1,8 +1,9 @@
 const std = @import("std");
 const js = @import("js.zig");
 const Timer = @import("Timer.zig");
+const mach = @import("../../../main.zig");
 const mach_core = @import("../../main.zig");
-const gpu = mach_core.gpu;
+const gpu = mach.gpu;
 const Options = @import("../../main.zig").Options;
 const Event = @import("../../main.zig").Event;
 const KeyEvent = @import("../../main.zig").KeyEvent;

src/core/platform/wasm/entrypoint.zig

@@ -8,8 +8,10 @@ pub usingnamespace @import("app");
 const App = @import("app").App;
 
 const std = @import("std");
-const core = @import("mach").core;
+
-const gpu = core.gpu;
+const mach = @import("mach");
+const core = mach.core;
+const gpu = mach.gpu;
 
 pub const GPUInterface = gpu.StubInterface;
 

src/core/platform/wayland/Core.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
+const mach = @import("../../../main.zig");
 const mach_core = @import("../../main.zig");
-const gpu = mach_core.gpu;
+const gpu = mach.gpu;
 const Options = @import("../../main.zig").Options;
 const Event = @import("../../main.zig").Event;
 const KeyEvent = @import("../../main.zig").KeyEvent;

src/core/platform/x11/Core.zig

@@ -1,8 +1,9 @@
 const builtin = @import("builtin");
 const std = @import("std");
 const glfw = @import("mach-glfw");
+const mach = @import("../../../main.zig");
 const mach_core = @import("../../main.zig");
-const gpu = mach_core.gpu;
+const gpu = mach.gpu;
 const unicode = @import("unicode.zig");
 const Options = @import("../../main.zig").Options;
 const Event = @import("../../main.zig").Event;
@@ -299,11 +300,11 @@ pub fn init(
     input: *Frequency,
     options: Options,
 ) !void {
-    if (!@import("builtin").is_test and mach_core.options.use_wgpu) _ = mach_core.wgpu.Export(blk: {
+    if (!@import("builtin").is_test and !mach.use_sysgpu) _ = mach.wgpu.Export(blk: {
         if (@hasDecl(@import("root"), "GPUInterface")) break :blk @import("root").GPUInterface;
-        break :blk mach_core.wgpu.dawn.Interface;
+        break :blk mach.wgpu.dawn.Interface;
     });
-    if (!@import("builtin").is_test and mach_core.options.use_sysgpu) _ = mach_core.sysgpu.sysgpu.Export(@import("root").SYSGPUInterface);
+    if (!@import("builtin").is_test and mach.use_sysgpu) _ = mach.sysgpu.sysgpu.Export(@import("root").SYSGPUInterface);
 
     const libx11 = try LibX11.load();
     const libxcursor: ?LibXCursor = LibXCursor.load() catch |err| switch (err) {

src/main.zig

@@ -4,7 +4,7 @@ const builtin = @import("builtin");
 // Core
 pub const core = if (build_options.want_core) @import("core/main.zig") else struct {};
 pub const Timer = if (build_options.want_core) core.Timer else struct {};
-pub const gpu = if (build_options.want_core) core.gpu else struct {};
+pub const wgpu = if (build_options.want_core) @import("gpu/main.zig") else struct {};
 pub const sysjs = if (build_options.want_core) @import("mach-sysjs") else struct {};
 pub const Core = if (build_options.want_core) @import("Core.zig") else struct {};
 
@@ -32,6 +32,14 @@ pub const Mod = ModSet(modules).Mod;
 pub const EntityID = @import("module/main.zig").EntityID; // TODO: rename to just Entity?
 pub const Archetype = @import("module/main.zig").Archetype;
 
+/// To use experimental sysgpu graphics API, you can write this in your main.zig:
+///
+/// ```
+/// pub const use_sysgpu = true;
+/// ```
+pub const use_sysgpu = if (@hasDecl(@import("root"), "use_sysgpu")) @import("root").use_sysgpu else false;
+pub const gpu = if (use_sysgpu) sysgpu.sysgpu else wgpu;
+
 test {
     const std = @import("std");
     // TODO: refactor code so we can use this here: