Migrate GLSL to Slang, text shader

build.zig

@@ -73,30 +73,36 @@ pub fn build(b: *std.Build) !void {
     run_step.dependOn(&run_cmd.step);
 }
 
-fn isShaderExtension(extension: []const u8) bool {
-    return std.mem.eql(u8, extension, ".vert") or
-        std.mem.eql(u8, extension, ".frag") or
-        std.mem.eql(u8, extension, ".comp");
-}
-
 fn addShaders(b: *std.Build, exe_mod: *std.Build.Module) !void {
     var dir = try b.build_root.handle.openDir(b.graph.io, "assets/shaders", .{ .iterate = true });
     defer dir.close(b.graph.io);
 
-    var walker = try dir.walk(b.allocator);
-    defer walker.deinit();
+    var it = dir.iterateAssumeFirstIteration();
 
-    while (try walker.next(b.graph.io)) |entry| {
+    while (try it.next(b.graph.io)) |entry| {
         if (entry.kind != .file) continue;
-        if (!isShaderExtension(std.fs.path.extension(entry.path))) continue;
 
-        const glslc = b.addSystemCommand(&.{ "glslc", "-g", "--target-env=vulkan1.2" });
-        glslc.addFileArg(b.path(b.pathJoin(&.{ "assets/shaders", entry.path })));
-        glslc.addArg("-o");
-        const spv = glslc.addOutputFileArg(b.fmt("{s}.spv", .{entry.basename}));
-        glslc.addArgs(&.{ "-MD", "-MF" });
-        _ = glslc.addDepFileOutputArg(b.fmt("{s}.d", .{entry.basename}));
+        const stem = std.fs.path.stem(entry.name);
+        const extension = std.fs.path.extension(entry.name);
+        if (!std.mem.eql(u8, extension, ".slang")) continue;
 
-        exe_mod.addAnonymousImport(b.fmt("shaders/{s}", .{entry.path}), .{ .root_source_file = spv });
+        const slangc = b.addSystemCommand(&.{
+            "slangc",
+            "-g",
+            "-target",
+            "spirv",
+            "-fvk-use-scalar-layout",
+            "-matrix-layout-column-major",
+        });
+
+        slangc.addArg("-o");
+        const spv = slangc.addOutputFileArg(b.fmt("{s}.spv", .{stem}));
+
+        slangc.addArg("-depfile");
+        _ = slangc.addDepFileOutputArg(b.fmt("{s}.d", .{stem}));
+
+        slangc.addFileArg(b.path(b.pathJoin(&.{ "assets/shaders", entry.name })));
+
+        exe_mod.addAnonymousImport(b.fmt("shaders/{s}", .{stem}), .{ .root_source_file = spv });
     }
 }