updated README.md

README.md

@@ -1,213 +1,152 @@
 
-<p align="center"><img width="150" src="https://github.com/g3n/g3nd/blob/master/data/images/g3n_logo.png" alt="G3N Banner"/></p>
-<p align="center">
-  <a href="https://godoc.org/github.com/g3n/engine"><img src="https://godoc.org/github.com/g3n/engine?status.svg" alt="Godoc"></img></a>
-  <a href="https://goreportcard.com/report/github.com/g3n/engine"><img src="https://goreportcard.com/badge/github.com/g3n/engine"  alt="Go Report Card"/></a>
-</p>
-<p><h1 align="center">G3N - Go 3D Game Engine</h1></p>
-
-G3N (pronounced "gen") is an OpenGL 3D game engine written in Go.
-G3N was heavily inspired by [three.js](https://threejs.org/).
-
-### **To see G3N in action try the [G3N demo](https://github.com/g3n/g3nd) or the [Gokoban](https://github.com/danaugrs/gokoban) award winning game.**
-
-<p align="center">
-  <img style="float: right;" src="https://raw.githubusercontent.com/g3n/g3nd/master/data/images/g3nd_screenshots.png" alt="G3ND In Action"/>
-</p>
-
-## Highlighted Projects
-
-[Gokoban - 3D Puzzle Game (_1st place in the 2017 Gopher Game Jam_)](https://github.com/danaugrs/gokoban)
-
-## Dependencies
-
-**G3N requires Go 1.8+**
-
-The engine needs an OpenGL driver installed in the system and on Unix like systems
-depends on some C libraries that can be installed using the distribution package manager.
-In all cases it is necessary to have a gcc compatible C compiler installed.
-
-* For Ubuntu/Debian-like Linux distributions, install the following packages:
-  * `xorg-dev`
-  * `libgl1-mesa-dev`
-  * `libopenal1`
-  * `libopenal-dev`
-  * `libvorbis0a`
-  * `libvorbis-dev`
-  * `libvorbisfile3`
-* For CentOS/Fedora-like Linux distributions, install the following packages:
-  * `xorg-x11-devel.x86_64`
-  * `mesa-libGL.x86_64`
-  * `mesa-libGL-devel.x86_64`
-  * `openal-soft.x86_64`
-  * `openal-soft-devel.x86_64`
-  * `libvorbis.x86_64`
-  * `libvorbis-devel.x86_64`
-* For Windows the necessary audio libraries sources and `dlls` are supplied but they need to be installed
-  manually. Please see [Audio libraries for Windows](audio/windows) for details.
-  We tested the Windows build using the [mingw-w64](https://mingw-w64.org) toolchain.
-* (Not fully-tested on OSX) On OSX, you should install the development files of OpenAL and Vorbis. If
-  your are using [Homebrew](https://brew.sh/) as your package manager, run:
-  `brew install libvorbis openal-soft`
-
-## Installation
-
-The following command will download the engine and all its dependencies, compile and
-install the packages. Make sure your GOPATH is set correctly. 
-
-`go get -u github.com/g3n/engine/...`
-
-## Features
-
-* Hierarchical scene graph. Any node can contain other nodes.
-* Supports perspective and orthographic cameras. The camera can be controlled
-  by the orbit control which allow zooming, rotation and panning using the mouse or keyboard.
-* Suports ambient, directional, point and spot lights. Many lights can be added to the scene.
-* Generators for primitive geometries such as: lines, box, sphere, cylinder and torus.
-* Geometries can support multimaterials.
-* Image textures can loaded from GIF, PNG or JPEG files and applied to materials.
-* Loaders for the following 3D formats: Obj and Collada
-* Text support allowing loading freetype fonts.
-* Basic GUI supporting the widgets: label, image, button, checkbox, radiobutton,
-  edit, scrollbar, slider, splitter, list, dropdown, tree, folder, window and layout managers
-  (horizontal box, vertical box, grid, dock)
-* Spatial audio support allowing playing sound from wave or Ogg Vorbis files.
-* Users' applications can use their own vertex and fragment shaders.
-
-<p align="center">
-  <img style="float: right;" src="https://github.com/g3n/g3n.github.io/raw/master/img/g3n_banner_small.png" alt="G3N Banner"/>
-</p>
-
-## Basic application
-
-The following code shows a basic G3N application 
-([hellog3n](https://github.com/g3n/demos/tree/master/hellog3n))
-which shows a wireframed sphere rotating.
-You can install hellog3n using: `go get -u github.com/g3n/demos/hellog3n`
-
-For more complex demos please see the [G3N demo program](https://github.com/g3n/g3nd).
-
-```Go
-package main
-
-import (
-	"github.com/g3n/engine/camera"
-	"github.com/g3n/engine/core"
-	"github.com/g3n/engine/geometry"
-	"github.com/g3n/engine/gls"
-	"github.com/g3n/engine/graphic"
-	"github.com/g3n/engine/light"
-	"github.com/g3n/engine/material"
-	"github.com/g3n/engine/math32"
-	"github.com/g3n/engine/renderer"
-	"github.com/g3n/engine/window"
-	"math"
-	"runtime"
-)
-
-func main() {
-
-	// Creates window and OpenGL context
-	wmgr, err := window.Manager("glfw")
-	if err != nil {
-		panic(err)
-	}
-	win, err := wmgr.CreateWindow(800, 600, "Hello G3N", false)
-	if err != nil {
-		panic(err)
-	}
-
-	// OpenGL functions must be executed in the same thread where
-	// the context was created (by CreateWindow())
-	runtime.LockOSThread()
-
-	// Create OpenGL state
-	gs, err := gls.New()
-	if err != nil {
-		panic(err)
-	}
-
-	// Sets the OpenGL viewport size the same as the window size
-	// This normally should be updated if the window is resized.
-	width, height := win.Size()
-	gs.Viewport(0, 0, int32(width), int32(height))
-
-	// Creates scene for 3D objects
-	scene := core.NewNode()
-
-	// Adds white ambient light to the scene
-	ambLight := light.NewAmbient(&math32.Color{1.0, 1.0, 1.0}, 0.5)
-	scene.Add(ambLight)
-
-	// Adds a perspective camera to the scene
-	// The camera aspect ratio should be updated if the window is resized.
-	aspect := float32(width) / float32(height)
-	camera := camera.NewPerspective(65, aspect, 0.01, 1000)
-	camera.SetPosition(0, 0, 5)
-
-	// Add an axis helper to the scene
-	axis := graphic.NewAxisHelper(2)
-	scene.Add(axis)
-
-	// Creates a wireframe sphere positioned at the center of the scene
-	geom := geometry.NewSphere(2, 16, 16, 0, math.Pi*2, 0, math.Pi)
-	mat := material.NewStandard(math32.NewColor("White"))
-	mat.SetSide(material.SideDouble)
-	mat.SetWireframe(true)
-	sphere := graphic.NewMesh(geom, mat)
-	scene.Add(sphere)
-
-	// Creates a renderer and adds default shaders
-	rend := renderer.NewRenderer(gs)
-	err = rend.AddDefaultShaders()
-	if err != nil {
-		panic(err)
-	}
-	rend.SetScene(scene)
-
-	// Sets window background color
-	gs.ClearColor(0, 0, 0, 1.0)
-
-	// Render loop
-	for !win.ShouldClose() {
-
-		// Rotates the sphere a bit around the Z axis (up)
-		sphere.AddRotationY(0.005)
-
-		// Render the scene using the specified camera
-		rend.Render(camera)
-
-		// Update window and checks for I/O events
-		win.SwapBuffers()
-		wmgr.PollEvents()
-	}
-}
-
-```
-
-<p align="center">
-  <img style="float: right;" src="https://github.com/g3n/demos/blob/master/hellog3n/screenshot.png" alt="hellog3n Screenshot"/>
-</p>
-
-## To Do
-
-G3N is a basic game engine. There is a lot of things to do.
-We will soon insert here a list of the most important missing features.
-
-## Documentation
-
-For the engine API reference, please use
-[![GoDoc](https://godoc.org/github.com/g3n/engine?status.svg)](https://godoc.org/github.com/g3n/engine).
-Currently the best way to learn how to use the engine is to see the source code
-of the demos from [G3ND](https://github.com/g3n/g3nd).
-We intend to write in the future documentation topics
-to build a user guide in the [wiki](https://github.com/g3n/engine/wiki).
-
-## Contributing
-
-If you spot a bug or create a new feature you are encouraged to
-send pull requests.
-
-## Community
-
-Join our [channel](https://gophers.slack.com/messages/g3n) on Gophers Slack ([Click here to register for Gophers Slack](https://invite.slack.golangbridge.org/)).
+  <p align="center"><img width="150" src="https://github.com/g3n/g3nd/blob/master/data/images/g3n_logo.png" alt="G3N Banner"/></p>
+  <p align="center">
+    <a href="https://godoc.org/github.com/g3n/engine"><img src="https://godoc.org/github.com/g3n/engine?status.svg" alt="Godoc"></img></a>
+    <a href="https://goreportcard.com/report/github.com/g3n/engine"><img src="https://goreportcard.com/badge/github.com/g3n/engine"  alt="Go Report Card"/></a>
+  </p>
+  <p><h1 align="center">G3N - Go 3D Game Engine</h1></p>
+
+  G3N (pronounced "gen") is a cross-platform OpenGL 3D game engine written in Go.
+
+  ### **To see G3N in action try the [G3N demo](https://github.com/g3n/g3nd) or the [Gokoban](https://github.com/danaugrs/gokoban) award winning game.**
+
+  <p align="center">
+    <img style="float: right;" src="https://raw.githubusercontent.com/g3n/g3nd/master/data/images/g3nd_screenshots.png" alt="G3ND In Action"/>
+  </p>
+
+  ## Highlighted Projects
+
+  [Gokoban - 3D Puzzle Game (_1st place in the 2017 Gopher Game Jam_)](https://github.com/danaugrs/gokoban)
+
+  ## Dependencies
+
+  **G3N requires Go 1.8+**
+
+  The engine requires an OpenGL driver and a GCC-compatible C compiler to be installed.
+
+  On Unix-based systems the engine depends on some C libraries that can be installed using the appropriate distribution package manager.
+
+  * For Ubuntu/Debian-like Linux distributions, install the following packages:
+    * `xorg-dev`
+    * `libgl1-mesa-dev`
+    * `libopenal1`
+    * `libopenal-dev`
+    * `libvorbis0a`
+    * `libvorbis-dev`
+    * `libvorbisfile3`
+  * For CentOS/Fedora-like Linux distributions, install the following packages:
+    * `xorg-x11-devel.x86_64`
+    * `mesa-libGL.x86_64`
+    * `mesa-libGL-devel.x86_64`
+    * `openal-soft.x86_64`
+    * `openal-soft-devel.x86_64`
+    * `libvorbis.x86_64`
+    * `libvorbis-devel.x86_64`
+  * For Windows, the necessary audio libraries sources and DLLs are supplied but they need to be installed
+    manually. Please see [Audio libraries for Windows](audio/windows) for details.
+    We tested the Windows build using the [mingw-w64](https://mingw-w64.org) toolchain.
+  * For macOS, you should install the development files of OpenAL and Vorbis. If
+    you are using [Homebrew](https://brew.sh/) as your package manager, run:
+    `brew install libvorbis openal-soft`
+
+  ## Installation
+
+  The following command will download the engine along with all its Go dependencies:
+
+  `go get -u github.com/g3n/engine/...`
+
+  ## Features
+
+  * Cross-platform: Windows, Linux, and macOS
+  * Integrated GUI (graphical user interface) with many widgets
+  * Hierarchical scene graph - nodes can contain other nodes
+  * 3D spatial audio via OpenAL (.wav, .ogg)
+  * Real-time lighting: ambient, directional, point, and spot lights
+  * Physically-based rendering: fresnel reflectance, geometric occlusion, microfacet distribution
+  * Model loaders: glTF (.gltf, .glb), Wavefront OBJ (.obj), and COLLADA (.dae)
+  * Geometry generators: box, sphere, cylinder, torus, etc...
+  * Geometries support morph targets and multimaterials
+  * Support for animated sprites based on sprite sheets
+  * Perspective and ortographic cameras
+  * Text image generation and support for TrueType fonts
+  * Image textures can be loaded from GIF, PNG or JPEG files
+  * Animation framework for position, rotation, and scale of objects
+  * Support for user-created GLSL shaders: vertex, fragment, and geometry shaders
+  * Integrated basic physics engine (experimental/incomplete)
+  * Support for HiDPI displays
+
+  <p align="center">
+    <img style="float: right;" src="https://github.com/g3n/g3n.github.io/raw/master/img/g3n_banner_small.png" alt="G3N Banner"/>
+  </p>
+
+  ## Hello G3N
+
+  The code below is a basic "hello world" application 
+  ([hellog3n](https://github.com/g3n/demos/tree/master/hellog3n))
+  that shows a blue torus.
+  You can download and install `hellog3n` via: `go get -u github.com/g3n/demos/hellog3n`
+
+  For more complex demos please see the [G3N demo program](https://github.com/g3n/g3nd).
+
+  ```Go
+  package main
+
+  import (
+      "github.com/g3n/engine/util/application"
+      "github.com/g3n/engine/geometry"
+      "github.com/g3n/engine/material"
+      "github.com/g3n/engine/math32"
+      "github.com/g3n/engine/graphic"
+      "github.com/g3n/engine/light"
+  )
+
+  func main() {
+
+      app, _ := application.Create(application.Options{
+          Title:  "Hello G3N",
+          Width:  800,
+          Height: 600,
+      })
+
+      // Create a blue torus and add it to the scene
+      geom := geometry.NewTorus(1, .4, 12, 32, math32.Pi*2)
+      mat := material.NewPhong(math32.NewColor("DarkBlue"))
+      torusMesh := graphic.NewMesh(geom, mat)
+      app.Scene().Add(torusMesh)
+
+      // Add lights to the scene
+      ambientLight := light.NewAmbient(&math32.Color{1.0, 1.0, 1.0}, 0.8)
+      app.Scene().Add(ambientLight)
+      pointLight := light.NewPoint(&math32.Color{1, 1, 1}, 5.0)
+      pointLight.SetPosition(1, 0, 2)
+      app.Scene().Add(pointLight)
+
+      // Add an axis helper to the scene
+      axis := graphic.NewAxisHelper(0.5)
+      app.Scene().Add(axis)
+
+      app.CameraPersp().SetPosition(0, 0, 3)
+      app.Run()
+  }
+  ```
+
+  <p align="center">
+    <img style="float: right;" src="https://github.com/g3n/demos/blob/master/hellog3n/screenshot.png" alt="hellog3n Screenshot"/>
+  </p>
+
+  ## Documentation
+
+  For the engine API reference, please see
+  [![GoDoc](https://godoc.org/github.com/g3n/engine?status.svg)](https://godoc.org/github.com/g3n/engine).
+  
+  Currently, the best way to learn how to use G3N is to look at the source code
+  of the demos from [G3ND](https://github.com/g3n/g3nd).
+  In the future we would like to have a "Getting Started" guide along with tutorials in the [wiki](https://github.com/g3n/engine/wiki).
+
+  ## Contributing
+
+  If you find a bug or create a new feature you are encouraged to send pull requests!
+
+  ## Community
+
+  Join our [channel](https://gophers.slack.com/messages/g3n) on Gophers Slack ([Click here to register for Gophers Slack](https://invite.slack.golangbridge.org/)). It's a great way to have your questions answered quickly by the G3N community.