From e3073212625aef2f5c61fd4761ca8fd482f71458 Mon Sep 17 00:00:00 2001
From: JupiterRider <60042618+JupiterRider@users.noreply.github.com>
Date: Wed, 29 May 2024 18:10:10 +0200
Subject: [PATCH] purego_unix.go created

---
 raylib/purego_unix.go | 71 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100644 raylib/purego_unix.go

diff --git a/raylib/purego_unix.go b/raylib/purego_unix.go
new file mode 100644
index 0000000..b039ad6
--- /dev/null
+++ b/raylib/purego_unix.go
@@ -0,0 +1,71 @@
+//go:build !cgo && (freebsd || linux)
+
+package rl
+
+import (
+	"fmt"
+	"runtime"
+	"unsafe"
+
+	"github.com/ebitengine/purego"
+	"golang.org/x/sys/unix"
+)
+
+const (
+	libname         = "libraylib.so"
+	requiredVersion = "5.0"
+)
+
+var vsprintf uintptr
+
+func init() {
+	var filename string
+	switch runtime.GOOS {
+	case "linux":
+		filename = "libc.so.6"
+	case "freebsd":
+		filename = "libc.so.7"
+	}
+
+	handle, err := purego.Dlopen(filename, purego.RTLD_LAZY)
+	if err == nil {
+		vsprintf, _ = purego.Dlsym(handle, "vsprintf")
+	}
+}
+
+// loadLibrary loads the raylib dll and panics on error
+func loadLibrary() uintptr {
+	handle, err := purego.Dlopen(libname, purego.RTLD_LAZY)
+	if err != nil {
+		panic(fmt.Errorf("cannot load library %s: %w", libname, err))
+	}
+
+	proc, err := purego.Dlsym(handle, "raylib_version")
+	if err != nil {
+		panic(err)
+	}
+
+	version := unix.BytePtrToString(**(***byte)(unsafe.Pointer(&proc)))
+	if version != requiredVersion {
+		panic(fmt.Errorf("version %s of %s doesn't match the required version %s", version, libname, requiredVersion))
+	}
+
+	//DEBUG
+	fmt.Println(version)
+
+	return uintptr(handle)
+}
+
+func traceLogCallbackWrapper(fn TraceLogCallbackFun) uintptr {
+	return purego.NewCallback(func(logLevel int32, text *byte, args unsafe.Pointer) uintptr {
+		if vsprintf != 0 {
+			var buffer [1024]byte // Max size is 1024 (see https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-wvsprintfa)
+			_, _, errno := purego.SyscallN(vsprintf, uintptr(unsafe.Pointer(&buffer[0])), uintptr(unsafe.Pointer(text)), uintptr(args))
+			if errno == 0 {
+				text = &buffer[0]
+			}
+		}
+		fn(int(logLevel), unix.BytePtrToString(text))
+		return 0
+	})
+}