[build] remove examples/build.zig, incorporate into main build.zig

Removes the second build.zig in the examples directory and incorporates it
into the main build.zig. This gives the zig build system the data needed to
know if the raylib library needs to be rebuilt when running any example.

build.zig

@@ -406,6 +406,16 @@ pub fn build(b: *std.Build) !void {
     lib.installHeader(b.path("src/rlgl.h"), "rlgl.h");
 
     b.installArtifact(lib);
+
+    const examples = b.step("examples", "Build/Install all examples");
+    examples.dependOn(try addExamples("audio", b, target, optimize, lib));
+    examples.dependOn(try addExamples("core", b, target, optimize, lib));
+    examples.dependOn(try addExamples("models", b, target, optimize, lib));
+    examples.dependOn(try addExamples("others", b, target, optimize, lib));
+    examples.dependOn(try addExamples("shaders", b, target, optimize, lib));
+    examples.dependOn(try addExamples("shapes", b, target, optimize, lib));
+    examples.dependOn(try addExamples("text", b, target, optimize, lib));
+    examples.dependOn(try addExamples("textures", b, target, optimize, lib));
 }
 
 fn waylandGenerate(
@@ -430,3 +440,95 @@ fn waylandGenerate(
     raylib.step.dependOn(&client_step.step);
     raylib.step.dependOn(&private_step.step);
 }
+
+fn addExamples(
+    comptime module: []const u8,
+    b: *std.Build,
+    target: std.Build.ResolvedTarget,
+    optimize: std.builtin.OptimizeMode,
+    raylib: *std.Build.Step.Compile,
+) !*std.Build.Step {
+    if (target.result.os.tag == .emscripten) {
+        @panic("Emscripten building via Zig unsupported");
+    }
+
+    const all = b.step(module, "All " ++ module ++ " examples");
+    const module_subpath = b.pathJoin(&.{ "examples", module });
+    var dir = try std.fs.cwd().openDir(b.pathFromRoot(module_subpath), .{ .iterate = true });
+    defer if (comptime builtin.zig_version.minor >= 12) dir.close();
+
+    var iter = dir.iterate();
+    while (try iter.next()) |entry| {
+        if (entry.kind != .file) continue;
+        const extension_idx = std.mem.lastIndexOf(u8, entry.name, ".c") orelse continue;
+        const name = entry.name[0..extension_idx];
+        const path = b.pathJoin(&.{ module_subpath, entry.name });
+
+        // zig's mingw headers do not include pthread.h
+        if (std.mem.eql(u8, "core_loading_thread", name) and target.result.os.tag == .windows) continue;
+
+        const exe = b.addExecutable(.{
+            .name = name,
+            .target = target,
+            .optimize = optimize,
+        });
+        exe.addCSourceFile(.{ .file = b.path(path), .flags = &.{} });
+        exe.linkLibC();
+
+        // special examples that test using these external dependencies directly
+        // alongside raylib
+        if (std.mem.eql(u8, name, "rlgl_standalone")) {
+            exe.addIncludePath(b.path("src"));
+            exe.addIncludePath(b.path("src/external/glfw/include"));
+        }
+        if (std.mem.eql(u8, name, "raylib_opengl_interop")) {
+            exe.addIncludePath(b.path("src/external"));
+        }
+
+        exe.linkLibrary(raylib);
+
+        switch (target.result.os.tag) {
+            .windows => {
+                exe.linkSystemLibrary("winmm");
+                exe.linkSystemLibrary("gdi32");
+                exe.linkSystemLibrary("opengl32");
+
+                exe.root_module.addCMacro("PLATFORM_DESKTOP", "");
+            },
+            .linux => {
+                exe.linkSystemLibrary("GL");
+                exe.linkSystemLibrary("rt");
+                exe.linkSystemLibrary("dl");
+                exe.linkSystemLibrary("m");
+                exe.linkSystemLibrary("X11");
+
+                exe.root_module.addCMacro("PLATFORM_DESKTOP", "");
+            },
+            .macos => {
+                exe.linkFramework("Foundation");
+                exe.linkFramework("Cocoa");
+                exe.linkFramework("OpenGL");
+                exe.linkFramework("CoreAudio");
+                exe.linkFramework("CoreVideo");
+                exe.linkFramework("IOKit");
+
+                exe.root_module.addCMacro("PLATFORM_DESKTOP", "");
+            },
+            else => {
+                @panic("Unsupported OS");
+            },
+        }
+
+        const install_cmd = b.addInstallArtifact(exe, .{});
+
+        const run_cmd = b.addRunArtifact(exe);
+        run_cmd.cwd = b.path(module_subpath);
+        run_cmd.step.dependOn(&install_cmd.step);
+
+        const run_step = b.step(name, name);
+        run_step.dependOn(&run_cmd.step);
+
+        all.dependOn(&install_cmd.step);
+    }
+    return all;
+}

build.zig.zon

@@ -22,5 +22,6 @@
         "build.zig",
         "build.zig.zon",
         "src",
+        "examples",
     },
 }

examples/build.zig

@@ -1,110 +0,0 @@
-const std = @import("std");
-const builtin = @import("builtin");
-
-// This has been tested to work with zig 0.12.0
-fn add_module(comptime module: []const u8, b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) !*std.Build.Step {
-    if (target.result.os.tag == .emscripten) {
-        @panic("Emscripten building via Zig unsupported");
-    }
-
-    const all = b.step(module, "All " ++ module ++ " examples");
-    var dir = try std.fs.cwd().openDir(module, .{ .iterate = true });
-    defer if (comptime builtin.zig_version.minor >= 12) dir.close();
-
-    var iter = dir.iterate();
-    while (try iter.next()) |entry| {
-        if (entry.kind != .file) continue;
-        const extension_idx = std.mem.lastIndexOf(u8, entry.name, ".c") orelse continue;
-        const name = entry.name[0..extension_idx];
-        const path = try std.fs.path.join(b.allocator, &.{ module, entry.name });
-
-        // zig's mingw headers do not include pthread.h
-        if (std.mem.eql(u8, "core_loading_thread", name) and target.result.os.tag == .windows) continue;
-
-        const exe = b.addExecutable(.{
-            .name = name,
-            .target = target,
-            .optimize = optimize,
-        });
-        exe.addCSourceFile(.{ .file = b.path(path), .flags = &.{} });
-        exe.linkLibC();
-        exe.addObjectFile(switch (target.result.os.tag) {
-            .windows => b.path("../zig-out/lib/raylib.lib"),
-            .linux => b.path("../zig-out/lib/libraylib.a"),
-            .macos => b.path("../zig-out/lib/libraylib.a"),
-            .emscripten => b.path("../zig-out/lib/libraylib.a"),
-            else => @panic("Unsupported OS"),
-        });
-
-        exe.addIncludePath(b.path("../src"));
-        exe.addIncludePath(b.path("../src/external"));
-        exe.addIncludePath(b.path("../src/external/glfw/include"));
-
-        switch (target.result.os.tag) {
-            .windows => {
-                exe.linkSystemLibrary("winmm");
-                exe.linkSystemLibrary("gdi32");
-                exe.linkSystemLibrary("opengl32");
-
-                exe.root_module.addCMacro("PLATFORM_DESKTOP", "");
-            },
-            .linux => {
-                exe.linkSystemLibrary("GL");
-                exe.linkSystemLibrary("rt");
-                exe.linkSystemLibrary("dl");
-                exe.linkSystemLibrary("m");
-                exe.linkSystemLibrary("X11");
-
-                exe.root_module.addCMacro("PLATFORM_DESKTOP", "");
-            },
-            .macos => {
-                exe.linkFramework("Foundation");
-                exe.linkFramework("Cocoa");
-                exe.linkFramework("OpenGL");
-                exe.linkFramework("CoreAudio");
-                exe.linkFramework("CoreVideo");
-                exe.linkFramework("IOKit");
-
-                exe.root_module.addCMacro("PLATFORM_DESKTOP", "");
-            },
-            else => {
-                @panic("Unsupported OS");
-            },
-        }
-
-        const install_cmd = b.addInstallArtifact(exe, .{});
-
-        const run_cmd = b.addRunArtifact(exe);
-        run_cmd.cwd = b.path(module);
-        run_cmd.step.dependOn(&install_cmd.step);
-
-        const run_step = b.step(name, name);
-        run_step.dependOn(&run_cmd.step);
-
-        all.dependOn(&install_cmd.step);
-    }
-    return all;
-}
-
-pub fn build(b: *std.Build) !void {
-    // Standard target options allows the person running `zig build` to choose
-    // what target to build for. Here we do not override the defaults, which
-    // means any target is allowed, and the default is native. Other options
-    // for restricting supported target set are available.
-    const target = b.standardTargetOptions(.{});
-    // Standard optimization options allow the person running `zig build` to select
-    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
-    // set a preferred release mode, allowing the user to decide how to optimize.
-    const optimize = b.standardOptimizeOption(.{});
-
-    const all = b.getInstallStep();
-
-    all.dependOn(try add_module("audio", b, target, optimize));
-    all.dependOn(try add_module("core", b, target, optimize));
-    all.dependOn(try add_module("models", b, target, optimize));
-    all.dependOn(try add_module("others", b, target, optimize));
-    all.dependOn(try add_module("shaders", b, target, optimize));
-    all.dependOn(try add_module("shapes", b, target, optimize));
-    all.dependOn(try add_module("text", b, target, optimize));
-    all.dependOn(try add_module("textures", b, target, optimize));
-}