Fix bug in parseNodes

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

@@ -0,0 +1,20 @@
+name: Build-AssImp
+on:
+  create:
+
+jobs:
+  Run-assimp-go-macos:
+    runs-on: macos-10.15
+    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

@@ -11,8 +11,12 @@
 # Output of the go coverage tool, specifically when used with LiteIDE
 *.out
 
-# Dependency directories (remove the comment below to include it)
+# Custom
 vendor/
+.DS_Store
 *.obj
+!obj.obj
 *.fbx
-*.glb
+*.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 +27,32 @@ 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, 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`
+
+### 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 +100,13 @@ 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 +125,9 @@ 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

@@ -1,12 +1,14 @@
 package asig
 
 /*
-//Note: We don't link directly to libIrrXML and libzlib libraries in `./libs`, but they are required by assimp. Removing them will error on compilation.
 #cgo CFLAGS: -I .
-#cgo LDFLAGS: -L ./libs -l assimp_windows_amd64
+#cgo LDFLAGS: -L libs
+#cgo windows,amd64 LDFLAGS: -l assimp_windows_amd64
+#cgo darwin,amd64 LDFLAGS: -l assimp_darwin_amd64
+#cgo darwin,arm64 LDFLAGS: -l assimp_darwin_arm64
 
-#include <wrap.cxx>
-#include <stdlib.h> //Needed for C.free
+#include "wrap.c"
+#include <stdlib.h>
 */
 import "C"
 import (
@@ -213,7 +215,7 @@ 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
@@ -517,6 +519,10 @@ 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

@@ -2,26 +2,12 @@ package asig
 
 /*
 #cgo CFLAGS: -I .
-#cgo LDFLAGS: -L ./libs -l assimp_windows_amd64 -l IrrXML_windows_amd64 -l zlib_windows_amd64
+#cgo LDFLAGS: -L libs
+#cgo windows,amd64 LDFLAGS: -l assimp_windows_amd64
+#cgo darwin,arm64 LDFLAGS: -l assimp_darwin_arm64
 
-#include <stdlib.h> //Needed for C.free
-
-#include <assimp/scene.h>
-
-//Functions
-unsigned int aiGetMaterialTextureCount(const struct aiMaterial* pMat, enum aiTextureType type);
-
-enum aiReturn aiGetMaterialTexture(
-	const struct aiMaterial* mat,
-    enum aiTextureType type,
-    unsigned int  index,
-    struct aiString* path,
-    enum aiTextureMapping* mapping,
-    unsigned int* uvindex,
-    ai_real* blend,
-    enum aiTextureOp* op,
-    enum aiTextureMapMode* mapmode,
-    unsigned int* flags);
+#include "wrap.c"
+#include <stdlib.h>
 */
 import "C"
 import (

main.go

@@ -10,7 +10,7 @@ import (
 
 func main() {
 
-	scene, release, err := asig.ImportFile("obj.fbx", asig.PostProcessTriangulate|asig.PostProcessJoinIdenticalVertices)
+	scene, release, err := asig.ImportFile("obj.obj", asig.PostProcessTriangulate|asig.PostProcessJoinIdenticalVertices)
 	if err != nil {
 		panic(err)
 	}

obj.obj

@@ -0,0 +1,46 @@
+# Blender v2.92.0 OBJ File: ''
+# www.blender.org
+mtllib obj.mtl
+o Cube
+v 2.275618 1.000000 0.349413
+v 3.520138 -1.000000 0.102233
+v 2.275618 1.000000 0.752820
+v 3.520138 -1.000000 1.000000
+v 0.244520 1.000000 0.349413
+v -1.000000 -1.000000 0.102233
+v 0.244520 1.000000 0.752820
+v -1.000000 -1.000000 1.000000
+vt 0.806168 0.568832
+vt 0.693832 0.681168
+vt 0.693832 0.568832
+vt 0.375000 1.000000
+vt 0.375000 0.750000
+vt 0.375000 0.000000
+vt 0.625000 0.250000
+vt 0.375000 0.250000
+vt 0.375000 0.500000
+vt 0.125000 0.750000
+vt 0.125000 0.500000
+vt 0.806168 0.681168
+vt 0.625000 0.931168
+vt 0.625000 0.068832
+vn 0.0000 1.0000 0.0000
+vn 0.0000 0.1227 0.9924
+vn -0.8490 0.5283 0.0000
+vn 0.0000 -1.0000 0.0000
+vn 0.8490 0.5283 0.0000
+vn 0.0000 0.1227 -0.9924
+usemtl Material
+s off
+f 5/1/1 3/2/1 1/3/1
+f 3/2/2 8/4/2 4/5/2
+f 8/6/3 5/7/3 6/8/3
+f 2/9/4 8/10/4 6/11/4
+f 1/3/5 4/5/5 2/9/5
+f 5/7/6 2/9/6 6/8/6
+f 5/1/1 7/12/1 3/2/1
+f 3/2/2 7/13/2 8/4/2
+f 8/6/3 7/14/3 5/7/3
+f 2/9/4 4/5/4 8/10/4
+f 1/3/5 3/2/5 4/5/5
+f 5/7/6 1/3/6 2/9/6