pkg/dcimgui: add freetype

pkg/dcimgui/build.zig

@@ -4,12 +4,14 @@ const NativeTargetInfo = std.zig.system.NativeTargetInfo;
 pub fn build(b: *std.Build) !void {
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
+    const freetype = b.option(bool, "freetype", "Use Freetype") orelse false;
     const backend_opengl3 = b.option(bool, "backend-opengl3", "OpenGL3 backend") orelse false;
     const backend_metal = b.option(bool, "backend-metal", "Metal backend") orelse false;
     const backend_osx = b.option(bool, "backend-osx", "OSX backend") orelse false;
 
     // Build options
     const options = b.addOptions();
+    options.addOption(bool, "freetype", freetype);
     options.addOption(bool, "backend_opengl3", backend_opengl3);
     options.addOption(bool, "backend_metal", backend_metal);
     options.addOption(bool, "backend_osx", backend_osx);
@@ -50,6 +52,9 @@ pub fn build(b: *std.Build) !void {
         "-DIMGUI_USE_WCHAR32=1",
         "-DIMGUI_DISABLE_OBSOLETE_FUNCTIONS=1",
     });
+    if (freetype) try flags.appendSlice(b.allocator, &.{
+        "-DIMGUI_ENABLE_FREETYPE=1",
+    });
     if (target.result.os.tag == .windows) {
         try flags.appendSlice(b.allocator, &.{
             "-DIMGUI_IMPL_API=extern\t\"C\"\t__declspec(dllexport)",
@@ -84,6 +89,30 @@ pub fn build(b: *std.Build) !void {
             .{ .include_extensions = &.{".h"} },
         );
 
+        if (freetype) {
+            lib.addCSourceFile(.{
+                .file = upstream.path("misc/freetype/imgui_freetype.cpp"),
+                .flags = flags.items,
+            });
+
+            if (b.systemIntegrationOption("freetype", .{})) {
+                lib.linkSystemLibrary2("freetype2", dynamic_link_opts);
+            } else {
+                const freetype_dep = b.dependency("freetype", .{
+                    .target = target,
+                    .optimize = optimize,
+                    .@"enable-libpng" = true,
+                });
+                lib.linkLibrary(freetype_dep.artifact("freetype"));
+                if (freetype_dep.builder.lazyDependency(
+                    "freetype",
+                    .{},
+                )) |freetype_upstream| {
+                    mod.addIncludePath(freetype_upstream.path("include"));
+                }
+            }
+        }
+
         if (backend_metal) {
             lib.addCSourceFiles(.{
                 .root = upstream.path("backends"),
@@ -160,3 +189,11 @@ pub fn build(b: *std.Build) !void {
     const test_step = b.step("test", "Run tests");
     test_step.dependOn(&tests_run.step);
 }
+
+// For dynamic linking, we prefer dynamic linking and to search by
+// mode first. Mode first will search all paths for a dynamic library
+// before falling back to static.
+const dynamic_link_opts: std.Build.Module.LinkSystemLibraryOptions = .{
+    .preferred_link_mode = .dynamic,
+    .search_strategy = .mode_first,
+};

src/build/SharedDeps.zig

@@ -135,29 +135,28 @@ pub fn add(
     // Every exe needs the terminal options
     self.config.terminalOptions().add(b, step.root_module);
 
-    // Freetype
+    // Freetype. We always include this even if our font backend doesn't
+    // use it because Dear Imgui uses Freetype.
     _ = b.systemIntegrationOption("freetype", .{}); // Shows it in help
-    if (self.config.font_backend.hasFreetype()) {
+    if (b.lazyDependency("freetype", .{
-        if (b.lazyDependency("freetype", .{
+        .target = target,
-            .target = target,
+        .optimize = optimize,
-            .optimize = optimize,
+        .@"enable-libpng" = true,
-            .@"enable-libpng" = true,
+    })) |freetype_dep| {
-        })) |freetype_dep| {
+        step.root_module.addImport(
-            step.root_module.addImport(
+            "freetype",
-                "freetype",
+            freetype_dep.module("freetype"),
-                freetype_dep.module("freetype"),
+        );
-            );
 
-            if (b.systemIntegrationOption("freetype", .{})) {
+        if (b.systemIntegrationOption("freetype", .{})) {
-                step.linkSystemLibrary2("bzip2", dynamic_link_opts);
+            step.linkSystemLibrary2("bzip2", dynamic_link_opts);
-                step.linkSystemLibrary2("freetype2", dynamic_link_opts);
+            step.linkSystemLibrary2("freetype2", dynamic_link_opts);
-            } else {
+        } else {
-                step.linkLibrary(freetype_dep.artifact("freetype"));
+            step.linkLibrary(freetype_dep.artifact("freetype"));
-                try static_libs.append(
+            try static_libs.append(
-                    b.allocator,
+                b.allocator,
-                    freetype_dep.artifact("freetype").getEmittedBin(),
+                freetype_dep.artifact("freetype").getEmittedBin(),
-                );
+            );
-            }
         }
     }
 
@@ -482,6 +481,7 @@ pub fn add(
     if (b.lazyDependency("dcimgui", .{
         .target = target,
         .optimize = optimize,
+        .freetype = true,
         .@"backend-metal" = target.result.os.tag.isDarwin(),
         .@"backend-osx" = target.result.os.tag == .macos,
         .@"backend-opengl3" = target.result.os.tag != .macos,