basisu: add bindings for basis-universal (supercompressed textures) (#477)

basisu/build.zig

@@ -0,0 +1,124 @@
+const std = @import("std");
+const Builder = std.build.Builder;
+
+const basisu_root = thisDir() ++ "/upstream/basisu";
+
+pub const pkg = std.build.Pkg{
+    .name = "basisu",
+    .source = .{
+        .path = "src/main.zig",
+    },
+};
+
+pub fn build(b: *Builder) void {
+    const mode = b.standardReleaseOptions();
+    const target = b.standardTargetOptions(.{});
+
+    const test_step = b.step("test", "Run library tests");
+    test_step.dependOn(&testStep(b, mode, target).step);
+}
+
+pub fn testStep(b: *Builder, mode: std.builtin.Mode, target: std.zig.CrossTarget) *std.build.RunStep {
+    const main_tests = b.addTestExe("basisu-tests", comptime thisDir() ++ "/src/main.zig");
+    main_tests.setBuildMode(mode);
+    main_tests.setTarget(target);
+    main_tests.main_pkg_path = thisDir();
+    link(b, main_tests, .{
+        .encoder = true,
+        .transcoder = true,
+    });
+    main_tests.install();
+    return main_tests.run();
+}
+
+pub fn link(b: *Builder, step: *std.build.LibExeObjStep, options: Options) void {
+    if (options.encoder) {
+        step.linkLibrary(buildEncoder(b));
+        step.addCSourceFile(comptime thisDir() ++ "/src/encoder/wrapper.cpp", &.{});
+        step.addIncludeDir(basisu_root ++ "/encoder");
+    }
+    if (options.transcoder) {
+        step.linkLibrary(buildTranscoder(b));
+        step.addCSourceFile(comptime thisDir() ++ "/src/transcoder/wrapper.cpp", &.{});
+        step.addIncludeDir(basisu_root ++ "/transcoder");
+    }
+}
+
+pub fn buildEncoder(b: *Builder) *std.build.LibExeObjStep {
+    // TODO(build-system): https://github.com/hexops/mach/issues/229#issuecomment-1100958939
+    ensureDependencySubmodule(b.allocator, "upstream") catch unreachable;
+
+    const encoder = b.addStaticLibrary("basisu-encoder", null);
+    encoder.linkLibCpp();
+    encoder.addCSourceFiles(
+        encoder_sources,
+        &.{},
+    );
+
+    encoder.defineCMacro("BASISU_FORCE_DEVEL_MESSAGES", "0");
+    encoder.defineCMacro("BASISD_SUPPORT_KTX2_ZSTD", "0");
+    encoder.install();
+    return encoder;
+}
+
+pub fn buildTranscoder(b: *Builder) *std.build.LibExeObjStep {
+    // TODO(build-system): https://github.com/hexops/mach/issues/229#issuecomment-1100958939
+    ensureDependencySubmodule(b.allocator, "upstream") catch unreachable;
+
+    const transcoder = b.addStaticLibrary("basisu-transcoder", null);
+    transcoder.linkLibCpp();
+    transcoder.addCSourceFiles(
+        transcoder_sources,
+        &.{},
+    );
+
+    transcoder.defineCMacro("BASISU_FORCE_DEVEL_MESSAGES", "0");
+    transcoder.defineCMacro("BASISD_SUPPORT_KTX2_ZSTD", "0");
+    transcoder.install();
+    return transcoder;
+}
+
+pub const Options = struct {
+    encoder: bool,
+    transcoder: bool,
+};
+
+fn thisDir() []const u8 {
+    return std.fs.path.dirname(@src().file) orelse ".";
+}
+
+fn ensureDependencySubmodule(allocator: std.mem.Allocator, path: []const u8) !void {
+    if (std.process.getEnvVarOwned(allocator, "NO_ENSURE_SUBMODULES")) |no_ensure_submodules| {
+        if (std.mem.eql(u8, no_ensure_submodules, "true")) return;
+    } else |_| {}
+    var child = std.ChildProcess.init(&.{ "git", "submodule", "update", "--init", path }, allocator);
+    child.cwd = (comptime thisDir());
+    child.stderr = std.io.getStdErr();
+    child.stdout = std.io.getStdOut();
+
+    _ = try child.spawnAndWait();
+}
+
+const transcoder_sources = &[_][]const u8{
+    basisu_root ++ "/transcoder/basisu_transcoder.cpp",
+};
+
+const encoder_sources = &[_][]const u8{
+    basisu_root ++ "/encoder/basisu_backend.cpp",
+    basisu_root ++ "/encoder/basisu_basis_file.cpp",
+    basisu_root ++ "/encoder/basisu_bc7enc.cpp",
+    basisu_root ++ "/encoder/basisu_comp.cpp",
+    basisu_root ++ "/encoder/basisu_enc.cpp",
+    basisu_root ++ "/encoder/basisu_etc.cpp",
+    basisu_root ++ "/encoder/basisu_frontend.cpp",
+    basisu_root ++ "/encoder/basisu_gpu_texture.cpp",
+    basisu_root ++ "/encoder/basisu_kernels_sse.cpp",
+    basisu_root ++ "/encoder/basisu_opencl.cpp",
+    basisu_root ++ "/encoder/basisu_pvrtc1_4.cpp",
+    basisu_root ++ "/encoder/basisu_resample_filters.cpp",
+    basisu_root ++ "/encoder/basisu_resampler.cpp",
+    basisu_root ++ "/encoder/basisu_ssim.cpp",
+    basisu_root ++ "/encoder/basisu_uastc_enc.cpp",
+    basisu_root ++ "/encoder/jpgd.cpp",
+    basisu_root ++ "/encoder/pvpngreader.cpp",
+};