// Initialize enough of the opengl context that some OpenGL information
// can be dumped to screen along with the bindings. This is a basic graphics
// package test that checks if the underlying OpenGL functions are available.
// Columns of function names marked as [+] (available) or [ ] (missing) will
// be written the the console if everything is ok.
func dg() {
gl.Dump() // doesn't need context.
// Also print the opengl version which does need a context.
app := device.New("Dump", 400, 100, 600, 600)
fmt.Printf("%s %s", gl.GetString(gl.RENDERER), gl.GetString(gl.VERSION))
fmt.Printf(" GLSL %s\n", gl.GetString(gl.SHADING_LANGUAGE_VERSION))
app.Dispose()
}
// ld loads a mesh model that has been exported from another tool -
// a .obj file from Blender in this case. It is really testing the
// "data" package with the key line being:
// loader.Load("monkey", &mesh)
//
// This also demonstrates basic rendering by using OpenGL calls from
// package "vu/render/gl" to render the imported mesh.
func ld() {
ld := &ldtag{}
dev := device.New("Load Model", 400, 100, 800, 600)
ld.initScene()
dev.Open()
for dev.IsAlive() {
ld.update(dev)
ld.render()
dev.SwapBuffers()
}
dev.Dispose()
}
// tb shows how a basic texture is used in OpenGL. One texture is loaded and
// rendered on a single mesh. This example is useful in understanding texture
// basics.
//
// This also demonstrates basic rendering by using OpenGL calls from
// package "vu/render/gl" for rendering.
func tb() {
tb := new(tbtag)
dev := device.New("Texture:Basic", 400, 100, 500, 500)
tb.initScene()
dev.Open()
for dev.IsAlive() {
tb.update(dev)
tb.drawScene()
dev.SwapBuffers()
}
dev.Dispose()
}
// sf demonstrates one example of shader only rendering. This shows the power of shaders using
// an example from shadertoy.com. Specifically:
// https://www.shadertoy.com/view/Xsl3zN
// For more shader examples also check out:
// http://glsl.heroku.com
// The real star of this demo though is found in ./shaders/fire.fsh. Kudos to @301z and
// the other contributors to shadertoy and heroku.
//
// This also demonstrates basic rendering by using OpenGL calls from
// package "vu/render/gl" for rendering.
func sf() {
sf := new(sftag)
dev := device.New("Shader Fire", 400, 100, 500, 500)
sf.initScene()
dev.Open()
for dev.IsAlive() {
sf.update(dev)
sf.drawScene()
dev.SwapBuffers()
}
dev.Dispose()
}
// tr demonstrates basic OpenGL by drawing a triangle. If anything this example
// shows that basic OpenGL is not all that basic. Check out the following methods:
// - initData() creates a triangle mesh that includes vertex points, faces, and colours.
// - initScene() makes the data available to the graphics card.
// - initShader() uses render.BindProgram to load and prepare the shader programs.
// - drawScene() is called to render and spin the triangle.
func tr() {
tag := &trtag{}
dev := device.New("Triangle", 400, 100, 600, 600)
tag.initScene()
dev.Open()
tag.resize(600, 600)
for dev.IsAlive() {
dev.Update()
tag.drawScene()
dev.SwapBuffers()
}
dev.Dispose()
}
// sh is used to test and showcase the vu/device package. Just getting a window
// to appear demonstrates that the majority of the functionality is working.
// The remainder of the example dumps keyboard and mouse events showing that
// user input is being processed.
func sh() {
sh := &shtag{}
dev := device.New("Shell", 400, 100, 800, 600)
gl.Init()
fmt.Printf("%s %s", gl.GetString(gl.RENDERER), gl.GetString(gl.VERSION))
fmt.Printf(" GLSL %s\n", gl.GetString(gl.SHADING_LANGUAGE_VERSION))
dev.Open()
gl.ClearColor(0.3, 0.6, 0.4, 1.0)
for dev.IsAlive() {
sh.update(dev)
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
dev.SwapBuffers()
}
dev.ShowCursor(true)
dev.Dispose()
}
// New creates a 3D engine. The expected usage is:
// if eng, err = vu.New("Title", 100, 100, 800, 600); err != nil {
// log.Printf("Failed to initialize engine %s", err)
// return
// }
// defer eng.Shutdown() // Close down nicely.
// eng.SetDirector(app) // Enable application callbacks.
// // Application 3D setup and initialization.
// eng.Action() // Run application loop (does not return).
func New(name string, x, y, width, height int) (e Engine, err error) {
if name == "" {
name = "Title"
}
if width < 100 {
width = 100
}
if height < 100 {
height = 100
}
eng := &engine{}
// initialize the os specific shell, graphics context, and
// user input monitor.
eng.dev = device.New(name, x, y, width, height)
// initialize the audio layer.
eng.aud = audio.NewSoundListener()
eng.ac = audio.New()
if err = eng.ac.Init(); err != nil {
eng.Shutdown()
return // failed to initialize audio layer
}
// initialize the graphics layer.
eng.gc = render.New()
if err = eng.gc.Init(); err != nil {
eng.Shutdown()
return // failed to initialize graphics layer.
}
eng.res = newRoadie(eng.ac, eng.gc)
eng.gc.Viewport(width, height)
eng.dev.Open()
e = eng
return
}
