Improve ShaderCreateStep to work around cache issues

build.zig

@@ -2,117 +2,6 @@ const std = @import("std");
 const vkgen = @import("generator/index.zig");
 const Step = std.build.Step;
 const Builder = std.build.Builder;
-const Encoder = std.base64.standard_no_pad.Encoder;
-
-pub const ResourceGenStep = struct {
-    step: Step,
-    shader_step: *vkgen.ShaderCompileStep,
-    builder: *Builder,
-    package: std.build.Pkg,
-    output_file: std.build.GeneratedFile,
-    resources: std.ArrayList(u8),
-    base64_sources: std.ArrayList(Base64Source),
-    const Base64Source = struct {
-        file_name: []u8,
-        str_name: []const u8,
-    };
-
-    pub fn init(builder: *Builder, out: []const u8) *ResourceGenStep {
-        const self = builder.allocator.create(ResourceGenStep) catch unreachable;
-        const full_out_path = std.fs.path.join(builder.allocator, &[_][]const u8{
-            builder.build_root,
-            builder.cache_root,
-            out,
-        }) catch unreachable;
-
-        self.* = .{
-            .step = Step.init(.custom, "resources", builder.allocator, make),
-            .shader_step = vkgen.ShaderCompileStep.init(builder, &[_][]const u8{ "glslc", "--target-env=vulkan1.2" }, "shaders"),
-            .builder = builder,
-            .package = .{
-                .name = "resources",
-                .source = .{ .generated = &self.output_file },
-                .dependencies = null,
-            },
-            .output_file = .{
-                .step = &self.step,
-                .path = full_out_path,
-            },
-            .resources = std.ArrayList(u8).init(builder.allocator),
-            .base64_sources = std.ArrayList(Base64Source).init(builder.allocator),
-        };
-
-        self.step.dependOn(&self.shader_step.step);
-        return self;
-    }
-
-    fn renderPath(path: []const u8, writer: anytype) void {
-        const separators = &[_]u8{ std.fs.path.sep_windows, std.fs.path.sep_posix };
-        var i: usize = 0;
-        while (std.mem.indexOfAnyPos(u8, path, i, separators)) |j| {
-            writer.writeAll(path[i..j]) catch unreachable;
-            switch (std.fs.path.sep) {
-                std.fs.path.sep_windows => writer.writeAll("\\\\") catch unreachable,
-                std.fs.path.sep_posix => writer.writeByte(std.fs.path.sep_posix) catch unreachable,
-                else => unreachable,
-            }
-
-            i = j + 1;
-        }
-        writer.writeAll(path[i..]) catch unreachable;
-    }
-
-    pub fn addShader(self: *ResourceGenStep, name: []const u8, source: []const u8) void {
-        const shader_out_path = self.shader_step.add(source, .{});
-        var writer = self.resources.writer();
-
-        writer.print("pub const {s} align(@alignOf(u32)) = @embedFile(\"", .{name}) catch unreachable;
-        renderPath(shader_out_path, writer);
-        writer.writeAll("\").*;\n") catch unreachable;
-    }
-
-    /// Instead of using @embedFile as addShader does, write SPIR-V binaries to resources as base64-encoded strings
-    pub fn addShaderBase64(self: *ResourceGenStep, name: []const u8, source: []const u8) void {
-        const shader_out_path = self.shader_step.add(source, .{});
-        var fixed_shader_out_path = std.ArrayList(u8).init(self.builder.allocator);
-        defer fixed_shader_out_path.deinit();
-        var path_writer = fixed_shader_out_path.writer();
-        renderPath(shader_out_path, path_writer);
-
-        var base64_source = self.base64_sources.addOne() catch unreachable;
-        base64_source.str_name = name;
-        base64_source.file_name = fixed_shader_out_path.toOwnedSlice() catch unreachable;
-    }
-
-    fn make(step: *Step) !void {
-        const self = @fieldParentPtr(ResourceGenStep, "step", step);
-        const cwd = std.fs.cwd();
-
-        // Read SPIR-V binaries, encode as base64 string, and write the base64 string to resources
-        for (self.base64_sources.items) |base64_source| {
-            const spv_file = std.fs.cwd().readFileAllocOptions(
-                self.builder.allocator,
-                base64_source.file_name,
-                std.math.pow(u32, 2, 21), // max spv file size 2^21 bytes ~= 2 MB
-                std.math.pow(u32, 2, 13), // size hint 2^13 ~= 8 KB
-                @alignOf(u32),
-                null,
-            ) catch unreachable;
-            defer self.builder.allocator.free(spv_file);
-
-            const base64_len = Encoder.calcSize(spv_file.len);
-            var base64_str_mem = self.builder.allocator.alloc(u8, base64_len) catch unreachable;
-            const base64_str = Encoder.encode(base64_str_mem, spv_file);
-
-            var writer = self.resources.writer();
-            writer.print("pub const {s} = \"{s}\";\n", .{base64_source.str_name, base64_str}) catch unreachable;
-        }
-
-        const dir = std.fs.path.dirname(self.output_file.path.?).?;
-        try cwd.makePath(dir);
-        try cwd.writeFile(self.output_file.path.?, self.resources.items);
-    }
-};
 
 pub fn build(b: *Builder) void {
     const target = b.standardTargetOptions(.{});
@@ -135,10 +24,13 @@ pub fn build(b: *Builder) void {
     const gen = vkgen.VkGenerateStep.init(b, vk_xml_path, "vk.zig");
     triangle_exe.addPackage(gen.package);
 
-    const res = ResourceGenStep.init(b, "resources.zig");
-    res.addShaderBase64("triangle_vert", "examples/shaders/triangle.vert");
-    res.addShaderBase64("triangle_frag", "examples/shaders/triangle.frag");
-    triangle_exe.addPackage(res.package);
+    const shaders = vkgen.ShaderCompileStep.create(
+        b,
+        &[_][]const u8{ "glslc", "--target-env=vulkan1.2" },
+    );
+    shaders.add("triangle_vert", "examples/shaders/triangle.vert", .{});
+    shaders.add("triangle_frag", "examples/shaders/triangle.frag", .{});
+    triangle_exe.addPackage(shaders.getPackage("shaders"));
 
     const triangle_run_cmd = triangle_exe.run();
     triangle_run_cmd.step.dependOn(b.getInstallStep());