Add purego support for unix

Author: Allen Ray

raylib/go.mod

@@ -3,6 +3,6 @@ module github.com/gen2brain/raylib-go/raylib
 go 1.21
 
 require (
-	github.com/ebitengine/purego v0.6.0-alpha.1.0.20231122024802-192c5e846faa
-	golang.org/x/sys v0.14.0
+	github.com/ebitengine/purego v0.6.1
+	golang.org/x/sys v0.18.0
 )

raylib/go.sum

@@ -1,4 +1,4 @@
-github.com/ebitengine/purego v0.6.0-alpha.1.0.20231122024802-192c5e846faa h1:Ik7QikRgeH+bFOfAcMpttCbs6XxWXxCLXMm4awxtOXk=
-github.com/ebitengine/purego v0.6.0-alpha.1.0.20231122024802-192c5e846faa/go.mod h1:ah1In8AOtksoNK6yk5z1HTJeUkC1Ez4Wk2idgGslMwQ=
-golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
-golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+github.com/ebitengine/purego v0.6.1 h1:sjN8rfzbhXQ59/pE+wInswbU9aMDHiwlup4p/a07Mkg=
+github.com/ebitengine/purego v0.6.1/go.mod h1:ah1In8AOtksoNK6yk5z1HTJeUkC1Ez4Wk2idgGslMwQ=
+golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
+golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

raylib/purego.go

@@ -0,0 +1,8 @@
+//go:build !cgo
+// +build !cgo
+
+package rl
+
+const (
+	requiredVersion = "5.0"
+)

raylib/purego_unix.go

@@ -0,0 +1,45 @@
+//go:build !cgo && (darwin || openbsd || freebsd || linux)
+
+package rl
+
+import (
+	"fmt"
+	"runtime"
+	"unsafe"
+
+	"github.com/ebitengine/purego"
+	"golang.org/x/sys/unix"
+)
+
+// loadLibrary loads the raylib dll and panics on error
+func loadLibrary() uintptr {
+	libname := "./raylib.so"
+	switch runtime.GOOS {
+	case "darwin":
+		libname = "./raylib.dylib"
+	}
+
+	handle, err := purego.Dlopen(libname, purego.RTLD_NOW|purego.RTLD_GLOBAL)
+	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))
+	}
+
+	return uintptr(handle)
+}
+
+func traceLogCallbackWrapper(fn TraceLogCallbackFun) uintptr {
+	return purego.NewCallback(func(logLevel int32, text *byte) uintptr {
+		fn(int(logLevel), unix.BytePtrToString(text))
+		return 0
+	})
+}

raylib/purego_windows.go

@@ -12,8 +12,7 @@ import (
 )
 
 const (
-	libname         = "raylib.dll"
-	requiredVersion = "5.0"
+	libname = "raylib.dll"
 )
 
 // loadLibrary loads the raylib dll and panics on error

raylib/raylib_purego.go

@@ -1,5 +1,5 @@
-//go:build !cgo && windows
-// +build !cgo,windows
+//go:build !cgo
+// +build !cgo
 
 package rl
 

raylib/rlgl_purego.go

@@ -1,5 +1,5 @@
-//go:build !cgo && windows
-// +build !cgo,windows
+//go:build !cgo
+// +build !cgo
 
 package rl