Merge pull request #308 from JupiterRider/master

First approach for purego

README.md

@@ -9,6 +9,8 @@ Golang bindings for [raylib](http://www.raylib.com/), a simple and easy-to-use l
 
 raylib C source code is included and compiled together with bindings. Note that the first build can take a few minutes.
 
+It is also possible to use raylib-go without cgo (Windows only; see requirements below).
+
 ### Requirements
 
 ##### Ubuntu
@@ -37,6 +39,17 @@ On macOS you need Xcode or Command Line Tools for Xcode.
 
 ##### Windows
 
+###### purego (without cgo)
+
+Download the raylib.dll from the assets on the [releases page](https://github.com/raysan5/raylib/releases). It is contained in the `raylib-*_win64_msvc*.zip`.
+Put the raylib.dll into the root folder of your project or copy it into `C:\Windows\System32` for a system-wide installation.
+
+As of November 15, 2023, raylib 5.0 is the required version.
+
+It is also possible build the dll yourself. You can find more infos at [raylib's wiki](https://github.com/raysan5/raylib/wiki/Working-on-Windows).
+
+###### cgo
+
 On Windows you need C compiler, like [Mingw-w64](https://mingw-w64.org) or [TDM-GCC](http://tdm-gcc.tdragon.net/).
 You can also build binary in [MSYS2](https://msys2.github.io/) shell.
 

raylib/go.mod

@@ -1,3 +1,8 @@
 module github.com/gen2brain/raylib-go/raylib
 
 go 1.21
+
+require (
+	github.com/ebitengine/purego v0.5.0
+	golang.org/x/sys v0.14.0
+)

raylib/go.sum

@@ -0,0 +1,4 @@
+github.com/ebitengine/purego v0.5.0 h1:JrMGKfRIAM4/QVKaesIIT7m/UVjTj5GYhRSQYwfVdpo=
+github.com/ebitengine/purego v0.5.0/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=

raylib/purego_windows.go

@@ -0,0 +1,44 @@
+//go:build !cgo && windows
+// +build !cgo,windows
+
+package rl
+
+import (
+	"fmt"
+	"unsafe"
+
+	"github.com/ebitengine/purego"
+	"golang.org/x/sys/windows"
+)
+
+const (
+	libname         = "raylib.dll"
+	requiredVersion = "5.0"
+)
+
+// loadLibrary loads the raylib dll and panics on error
+func loadLibrary() uintptr {
+	handle, err := windows.LoadLibrary(libname)
+	if err != nil {
+		panic(fmt.Errorf("cannot load library %s: %w", libname, err))
+	}
+
+	proc, err := windows.GetProcAddress(handle, "raylib_version")
+	if err != nil {
+		panic(err)
+	}
+
+	version := windows.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), windows.BytePtrToString(text))
+		return 0
+	})
+}