From b780db3e8aecd52bcfafa42c8a3c4bdcc13bf3ac Mon Sep 17 00:00:00 2001
From: Connor Rowland <connor.k.rowland@icloud.com>
Date: Sat, 14 Dec 2024 16:20:48 -0800
Subject: [PATCH] Emscripten uses its own glfw library (#8)

---
 README.md     |  5 ++++-
 build.zig     |  2 ++
 src/zglfw.zig | 23 +++++++++++++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index d48844e..d7ce27b 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,10 @@ pub fn build(b: *std.Build) void {
 
     const zglfw = b.dependency("zglfw", .{});
     exe.root_module.addImport("zglfw", zglfw.module("root"));
-    exe.linkLibrary(zglfw.artifact("glfw"));
+
+    if (target.result.os.tag != .emscrpten) {
+        exe.linkLibrary(zglfw.artifact("glfw"));
+    }
 }
 ```
 
diff --git a/build.zig b/build.zig
index 0d9d3d1..48feb34 100644
--- a/build.zig
+++ b/build.zig
@@ -36,6 +36,8 @@ pub fn build(b: *std.Build) void {
         },
     });
 
+    if (target.result.os.tag == .emscripten) return;
+
     const glfw = if (options.shared) blk: {
         const lib = b.addSharedLibrary(.{
             .name = "glfw",
diff --git a/src/zglfw.zig b/src/zglfw.zig
index 5bf589a..9f0a698 100644
--- a/src/zglfw.zig
+++ b/src/zglfw.zig
@@ -1107,3 +1107,26 @@ fn _isLinuxDesktopLike() bool {
         else => false,
     };
 }
+
+//--------------------------------------------------------------------------------------------------
+//
+// Emscripten
+//
+//--------------------------------------------------------------------------------------------------
+const os = builtin.target.os.tag;
+usingnamespace if (os == .emscripten or os == .freestanding) struct {
+    // GLFW - emscripten uses older version that doesn't have these functions - implement dummies
+    var glfwGetGamepadStateWarnPrinted: bool = false;
+    pub export fn glfwGetGamepadState(_: i32, _: ?*anyopaque) i32 {
+        if (!glfwGetGamepadStateWarnPrinted) {
+            std.log.err("glfwGetGamepadState(): not implemented! Use emscripten specific functions: https://emscripten.org/docs/api_reference/html5.h.html?highlight=gamepadstate#c.emscripten_get_gamepad_status", .{});
+            glfwGetGamepadStateWarnPrinted = true;
+        }
+        return 0; // false - failure
+    }
+
+    /// use glfwSetCallback instead
+    pub export fn glfwGetError() i32 {
+        return 0; // no error
+    }
+} else struct {};