workflow_dispatch

Add support for fs.FS file system support

.github/workflows/run-assimp-go.yml

@@ -0,0 +1,21 @@
+name: Build-AssImp
+on:
+  workflow_dispatch:
+  create:
+
+jobs:
+  Run-assimp-go-macos:
+    runs-on: macos-11
+    steps:
+      - name: Install golang 1.17
+        uses: actions/setup-go@v2
+        with:
+          go-version: '^1.17'
+      - name: Clone assimp-go
+        run: git clone https://github.com/bloeys/assimp-go
+      - name: Copy dylib
+        working-directory: assimp-go
+        run: sudo mkdir -p /usr/local/lib && sudo cp asig/libs/libassimp_darwin_amd64.dylib /usr/local/lib/libassimp.5.dylib
+      - name: Run assimp-go
+        working-directory: assimp-go
+        run: go run .

.gitignore

@@ -19,3 +19,4 @@ vendor/
 *.fbx
 *.glb
 !libassimp_darwin_arm64.dylib
+!libassimp_darwin_amd64.dylib

README.md

@@ -1,5 +1,7 @@
 # assimp-go
 
+[![Build](https://github.com/bloeys/assimp-go/actions/workflows/run-assimp-go.yml/badge.svg)](https://github.com/bloeys/assimp-go/actions/workflows/run-assimp-go.yml)
+
 A Handcrafted Open Asset Import Library (AssImp) wrapper for Go.
 
 ## Features
@@ -25,19 +27,53 @@ Unimplemented (yet) AssImp Scene objects:
 
 To run the project you need:
 
+* A 64-bit machine (32-bit machines should be supportable if we get help adding the needed libs)
 * A recent version of [Go](https://golang.org/) installed (1.17+)
 * A C/C++ compiler installed and in your path
-  * Windows: [MingW](https://www.mingw-w64.org/downloads/#mingw-builds) or similar
-  * Mac/Linux: Should be installed by default, but if not try [GCC](https://gcc.gnu.org/) or [Clang](https://releases.llvm.org/download.html)
-* Download the appropriate DLL for your version and put it in the root of your Go project
+  * **Windows**: [MingW](https://www.mingw-w64.org/downloads/#mingw-builds) or similar
+  * **Mac/Linux**: Should be installed by default, but if not try [GCC](https://gcc.gnu.org/) or [Clang](https://releases.llvm.org/download.html)
 
-Then simply clone and use `go run .`
+Now to be able to run assimp-go you will need the AssImp shared libraries (DLLs/DyLibs), which you can
+download from the GitHub releases page.
+
+### Installing on Windows
+
+Download the **.dll** of the [release you want](https://github.com/bloeys/assimp-go/releases), and place it in the **root** of your Go project.
+
+### Installing on MacOS
+
+First, download the appropriate **.dylib** for your device (`_amd64` for Intel CPUs and `_arm64` for Apple CPUs).
+Next you will need to rename the lib to `libassimp.5.dylib` and move it to `/usr/local/lib` or `/usr/lib`.
+
+You can use this command to do it: `sudo mkdir -p /usr/local/lib && sudo cp libassimp_darwin*.dylib /usr/local/lib/libassimp.5.dylib`
+
+### Installing on Linux
+
+Download the the AssImp package for your distro, or build from source and add it to your path.
+> NOTE: Insatall assimp >= 3.1 for bindings to work as expected. 
+>       Though getting the latest version is always recommended. 
+
+#### Installing on Ubuntu
+You can install the Asset-Importer-Lib via apt:
+```
+sudo apt-get update
+sudo apt-get install libassimp-dev
+```
+
+#### Installing on Arch 
+You can install the Asset-Importer-Lib via pacman
+```
+sudo pacman -S assimp
+```
+#### Building From Source 
+To build the Asset Importer Package from sorce read the [sorce build guide](https://github.com/assimp/assimp/blob/master/Build.md)
+
+### Running assimp-go
+
+Use `go run .` to run the simple example in `main.go` ;)
 
 > Note: that it might take a while to run the first time because of downloading/compiling dependencies.
 
-`assimp-go` dynamically links (e.g. through a DLL) AssImp using platform dependent libraries, which are made available with the GitHub releases.
-Currently only `Windows` libraries are available, but more should be easy to add by compiling AssImp on the wanted platform. (Make a PR if you can help us get those binaries!)
-
 ### Getting Started
 
 ```Go
@@ -85,14 +121,13 @@ While `asig` functions should NOT be called on a Scene (or its objects) after th
 
 ## Developing assimp-go
 
-We link against assimp libraries that are built for each platform and the `*.a` files are added to the `asig/libs` package.
-Depending on the platform we select one of them and link against it when doing `go build`.
+We link against assimp libraries that are built for each platform and the `.a`/`.dylib` files are added to the `asig/libs` package.
+At build time, the `#cgo` directive choose the appropriate libs and links against them.
 
 The general steps are:
 
 * Copy assimp includes into `asig/assimp`
-* Copy `zlib.h`, `zconf.h` and `irrXML.h` into `asig/zlib` and `asig/irrxml` respectively.
-* Copy static libraries and DLL import libraries into `asig/libs`
+* Copy libraries and DLL import libraries into `asig/libs`
 
 > Note: When dealing with libraries the compiler will probably (e.g. MinGW does this) ignore `lib` prefixes and `.a`/`.lib` suffixes.
 So if your lib name is `libassimp.a` you need to pass it to CGO as `-l assimp`, otherwise you will get an error about library not found.
@@ -111,3 +146,9 @@ Now assuming you are using MinGW on windows:
 * Run `cmake --build . --parallel 6`
 * Copy the generated `*.lib` (or `*.a`) files from the `lib` folder and into `asig/libs`, and copy the generated dll from AssImp `bin` folder into the root of `assimp-go`.
 * Copy the generated `libzlibstatic.a` file from `contrib/zlib` and into the `asig/libs` folder.
+
+**MacOS**:
+
+* Clone wanted release of assimp and run `cmake CMakeLists.txt -D ASSIMP_BUILD_ZLIB=ON -D ASSIMP_BUILD_ASSIMP_TOOLS=OFF` in the root folder
+* Run `cmake --build . --parallel 6`
+* Copy the generated `*.dylib` files from the `bin` folder and into both `asig/libs` and `/usr/local/lib`

asig/asig.go

@@ -1,17 +1,24 @@
 package asig
 
 /*
-#cgo CFLAGS: -I .
-#cgo LDFLAGS: -L libs
-#cgo windows,amd64 LDFLAGS: -l assimp_windows_amd64
-#cgo darwin,arm64 LDFLAGS: -l assimp_darwin_arm64
+#cgo linux CFLAGS:
+#cgo windows,amd64 CFLAGS: -I .
+#cgo darwin,amd64 CFLAGS: -I .
+#cgo darwin,arm64 CFLAGS: -I .
 
-#include "wrap.c"
-#include <stdlib.h>
+#cgo linux LDFLAGS: -lassimp
+#cgo windows,amd64 LDFLAGS: -L libs -l assimp_windows_amd64
+#cgo darwin,amd64 LDFLAGS: -L libs -l assimp_darwin_amd64
+#cgo darwin,arm64 LDFLAGS: -Wl,-rpath,/usr/local/lib
+
+#include "wrap.h"
 */
 import "C"
 import (
 	"errors"
+	"io"
+	"io/fs"
+	"runtime"
 	"unsafe"
 
 	"github.com/bloeys/gglm/gglm"
@@ -157,6 +164,121 @@ func ImportFile(file string, postProcessFlags PostProcess) (s *Scene, release fu
 	return s, func() { s.releaseCResources() }, nil
 }
 
+//export go_aiFileOpenProc
+func go_aiFileOpenProc(io *C.struct_aiFileIO, name *C.char, flags *C.char) *C.struct_aiFile {
+	fsWrapper := (*fsWrapper)(unsafe.Pointer(io.UserData))
+
+	file, err := fsWrapper.fsys.Open(C.GoString(name))
+	if err != nil {
+		return nil
+	}
+	fsWrapper.Pin(&file)
+
+	ret := &C.struct_aiFile{
+		ReadProc:     (C.aiFileReadProc)(C.cgo_aiFileReadProc),
+		WriteProc:    (C.aiFileWriteProc)(C.cgo_aiFileWriteProc),
+		TellProc:     (C.aiFileTellProc)(C.cgo_aiFileTellProc),
+		FileSizeProc: (C.aiFileTellProc)(C.cgo_aiFileFileSizeProc),
+		SeekProc:     (C.aiFileSeek)(C.cgo_aiFileSeekProc),
+		FlushProc:    (C.aiFileFlushProc)(C.cgo_aiFileFlushProc),
+		UserData:     (*C.char)(unsafe.Pointer(&file)),
+	}
+	fsWrapper.Pin(ret)
+
+	return ret
+}
+
+//export go_aiFileCloseProc
+func go_aiFileCloseProc(io *C.struct_aiFileIO, file *C.struct_aiFile) {
+	f := *(*fs.File)(unsafe.Pointer(file.UserData))
+	f.Close()
+}
+
+//export go_aiFileReadProc
+func go_aiFileReadProc(file *C.struct_aiFile, buffer *C.char, size C.size_t, count C.size_t) C.size_t {
+	f := *(*fs.File)(unsafe.Pointer(file.UserData))
+	slice := unsafe.Slice((*byte)(unsafe.Pointer(buffer)), size*count)
+
+	n, err := f.Read(slice)
+	if err != nil {
+		return (C.size_t)(0)
+	}
+	return (C.size_t)(n)
+}
+
+//export go_aiFileWriteProc
+func go_aiFileWriteProc(file *C.struct_aiFile, buffer *C.char, size C.size_t, count C.size_t) C.size_t {
+	panic("aiFileWrite not supported")
+}
+
+//export go_aiFileFileSizeProc
+func go_aiFileFileSizeProc(file *C.struct_aiFile) C.size_t {
+	f := *(*fs.File)(unsafe.Pointer(file.UserData))
+	info, err := f.Stat()
+	if err != nil {
+		return 0
+	}
+	return (C.size_t)(info.Size())
+}
+
+//export go_aiFileFlushProc
+func go_aiFileFlushProc(file *C.struct_aiFile) {
+	panic("aiFileFlush not supported")
+}
+
+//export go_aiFileTellProc
+func go_aiFileTellProc(file *C.struct_aiFile) C.size_t {
+	panic("aiFileTell not supported")
+}
+
+//export go_aiFileSeekProc
+func go_aiFileSeekProc(file *C.struct_aiFile, offset C.size_t, origin C.enum_aiOrigin) C.enum_aiReturn {
+	f := *(*fs.File)(unsafe.Pointer(file.UserData))
+	if s, ok := f.(io.Seeker); ok {
+		_, err := s.Seek(int64(offset), int(origin))
+		if err == nil {
+			return aiReturnSuccess
+		}
+	}
+	return aiReturnFailure
+}
+
+type fsWrapper struct {
+	pinnedMemory runtime.Pinner
+	fsys         fs.FS
+}
+
+func (fws *fsWrapper) Pin(pointer interface{}) {
+	fws.pinnedMemory.Pin(pointer)
+}
+
+func ImportFileEx(file string, postProcessFlags PostProcess, fsys fs.FS) (s *Scene, release func(), err error) {
+	cstr := C.CString(file)
+	defer C.free(unsafe.Pointer(cstr))
+
+	wrapper := &fsWrapper{
+		pinnedMemory: runtime.Pinner{},
+		fsys:         fsys,
+	}
+	wrapper.Pin(wrapper)
+	defer wrapper.pinnedMemory.Unpin()
+
+	cio := &C.struct_aiFileIO{
+		OpenProc:  (C.aiFileOpenProc)(C.cgo_aiFileOpenProc),
+		CloseProc: (C.aiFileCloseProc)(C.cgo_aiFileCloseProc),
+		UserData:  (*C.char)(unsafe.Pointer(wrapper)),
+	}
+	wrapper.Pin(cio)
+
+	cs := C.aiImportFileEx(cstr, C.uint(postProcessFlags), cio)
+	if cs == nil {
+		return nil, func() {}, getAiErr()
+	}
+
+	s = parseScene(cs)
+	return s, func() { s.releaseCResources() }, nil
+}
+
 func getAiErr() error {
 	return errors.New("asig error: " + C.GoString(C.aiGetErrorString()))
 }
@@ -214,7 +336,7 @@ func parseNodes(cNodesIn **C.struct_aiNode, parent *Node, parentChildrenCount ui
 		}
 
 		//Parse node's children
-		nodes[i].Children = parseNodes(n.mChildren, nodes[i], parentChildrenCount)
+		nodes[i].Children = parseNodes(n.mChildren, nodes[i], uint(n.mNumChildren))
 	}
 
 	return nodes
@@ -518,6 +640,10 @@ func parseVertexWeights(cWeights *C.struct_aiVertexWeight, count uint) []VertexW
 }
 
 func parseAiString(aiString C.struct_aiString) string {
+	if aiString.length == 0 {
+		return ""
+	}
+
 	return C.GoStringN(&aiString.data[0], C.int(aiString.length))
 }
 

asig/material.go

@@ -1,13 +1,17 @@
 package asig
 
 /*
-#cgo CFLAGS: -I .
-#cgo LDFLAGS: -L libs
-#cgo windows,amd64 LDFLAGS: -l assimp_windows_amd64
-#cgo darwin,arm64 LDFLAGS: -l assimp_darwin_arm64
+#cgo linux CFLAGS:
+#cgo windows,amd64 CFLAGS: -I .
+#cgo darwin,amd64 CFLAGS: -I .
+#cgo darwin,arm64 CFLAGS: -I .
 
-#include "wrap.c"
-#include <stdlib.h>
+#cgo linux LDFLAGS: -lassimp
+#cgo windows,amd64 LDFLAGS: -L libs -l assimp_windows_amd64
+#cgo darwin,amd64 LDFLAGS: -L libs -l assimp_darwin_amd64
+#cgo darwin,arm64 LDFLAGS: -L libs -l assimp_darwin_arm64
+
+#include "wrap.h"
 */
 import "C"
 import (

asig/wrap.c

@@ -1,3 +1,50 @@
-#include <assimp/cimport.h>        // Plain-C interface
-#include <assimp/scene.h>          // Output data structure
-#include <assimp/postprocess.h>
+#include "wrap.h"
+#include <stdio.h>
+
+extern C_STRUCT aiFile *go_aiFileOpenProc(C_STRUCT aiFileIO *io, char *name, char *flags);
+C_STRUCT aiFile *cgo_aiFileOpenProc(C_STRUCT aiFileIO *io, const char *name, const char *flags)
+{
+	return go_aiFileOpenProc(io, (char *)name, (char *)flags);
+}
+
+extern void go_aiFileCloseProc(C_STRUCT aiFileIO *io, C_STRUCT aiFile *file);
+void cgo_aiFileCloseProc(C_STRUCT aiFileIO *io, C_STRUCT aiFile *file)
+{
+	go_aiFileCloseProc(io, file);
+}
+
+extern size_t go_aiFileWriteProc(C_STRUCT aiFile *file, const char *buffer, size_t size, size_t count);
+size_t cgo_aiFileWriteProc(C_STRUCT aiFile *file, const char *buffer, size_t size, size_t count)
+{
+	return go_aiFileWriteProc(file, (char *)buffer, size, count);
+}
+
+extern size_t go_aiFileReadProc(C_STRUCT aiFile *, char *, size_t, size_t);
+size_t cgo_aiFileReadProc(C_STRUCT aiFile *file, char *buffer, size_t size, size_t count)
+{
+	return go_aiFileReadProc(file, buffer, size, count);
+}
+
+extern size_t go_aiFileTellProc(C_STRUCT aiFile *file);
+size_t cgo_aiFileTellProc(C_STRUCT aiFile *file)
+{
+	return go_aiFileTellProc(file);
+}
+
+extern size_t go_aiFileFileSizeProc(C_STRUCT aiFile *file);
+size_t cgo_aiFileFileSizeProc(C_STRUCT aiFile *file)
+{
+	return go_aiFileFileSizeProc(file);
+}
+
+extern void go_aiFileFlushProc(C_STRUCT aiFile *file);
+void cgo_aiFileFlushProc(C_STRUCT aiFile *file)
+{
+	go_aiFileFlushProc(file);
+}
+
+extern C_ENUM aiReturn go_aiFileSeekProc(C_STRUCT aiFile *file, size_t offset, C_ENUM aiOrigin origin);
+C_ENUM aiReturn cgo_aiFileSeekProc(C_STRUCT aiFile *file, size_t offset, C_ENUM aiOrigin origin)
+{
+	return go_aiFileSeekProc(file, offset, origin);
+}

asig/wrap.h

@@ -0,0 +1,20 @@
+#ifndef WRAP_H
+#define WRAP_H
+
+#include <assimp/cimport.h> // Plain-C interface
+#include <assimp/cfileio.h> // Plain-C interface
+#include <assimp/scene.h>	// Output data structure
+#include <assimp/postprocess.h>
+#include <stdlib.h>
+
+C_STRUCT aiFile *cgo_aiFileOpenProc(C_STRUCT aiFileIO *io, const char *name, const char *flags);
+void cgo_aiFileCloseProc(C_STRUCT aiFileIO *io, C_STRUCT aiFile *file);
+
+size_t cgo_aiFileWriteProc(C_STRUCT aiFile *, const char *, size_t, size_t);
+size_t cgo_aiFileReadProc(C_STRUCT aiFile *, char *, size_t, size_t);
+size_t cgo_aiFileTellProc(C_STRUCT aiFile *);
+size_t cgo_aiFileFileSizeProc(C_STRUCT aiFile *);
+void cgo_aiFileFlushProc(C_STRUCT aiFile *);
+C_ENUM aiReturn cgo_aiFileSeekProc(C_STRUCT aiFile *, size_t, C_ENUM aiOrigin);
+
+#endif

main.go

@@ -4,13 +4,16 @@ import (
 	"bytes"
 	"fmt"
 	"image/png"
+	"os"
 
 	"github.com/bloeys/assimp-go/asig"
 )
 
 func main() {
 
-	scene, release, err := asig.ImportFile("obj.obj", asig.PostProcessTriangulate|asig.PostProcessJoinIdenticalVertices)
+	//scene, release, err := asig.ImportFile("obj.obj", asig.PostProcessTriangulate|asig.PostProcessJoinIdenticalVertices)
+	fsys := os.DirFS(".")
+	scene, release, err := asig.ImportFileEx("obj.obj", asig.PostProcessTriangulate|asig.PostProcessJoinIdenticalVertices, fsys)
 	if err != nil {
 		panic(err)
 	}