// NewScreen creates a new output screen of a given size and sample density.
func NewScreen(width int, height int, samplesPerPixel int) *Screen {
s := Screen{
width,
height,
1.0 / float64(samplesPerPixel),
types.NewTypedBuffer(width * samplesPerPixel),
nil, // lines
}
return &s
}
// NewScreen creates a new output screen of a given size and sample density.
func NewSpectrogramScreen(width int, height int, bpo int) *SpectrogramScreen {
samplesPerPixel := 1 // HACK - parameterize?
s := SpectrogramScreen{
width,
height,
bpo,
1.0 / float64(samplesPerPixel),
types.NewTypedBuffer(width * samplesPerPixel),
nil, // lines
}
return &s
}
// RenderLinesWithEvents renders multiple channels of samples to screen, and draws events.
func (s *SpectrogramScreen) RenderLineWithEvents(line *ComplexLine, events <-chan interface{}, sampleRate int) {
s.line = line
runtime.LockOSThread()
// NOTE: It appears that glfw 3.1 uses its own internal error callback.
// glfw.SetErrorCallback(func(err glfw.ErrorCode, desc string) {
// log.Fatalf("%v: %s\n", err, desc)
// })
if err := glfw.Init(); err != nil {
log.Fatalf("Can't init glfw: %v!", err)
}
defer glfw.Terminate()
window, err := glfw.CreateWindow(s.width, s.height, "Spectrogram", nil, nil)
if err != nil {
log.Fatalf("CreateWindow failed: %s", err)
}
if aw, ah := window.GetSize(); aw != s.width || ah != s.height {
log.Fatalf("Window doesn't have the requested size: want %d,%d got %d,%d", s.width, s.height, aw, ah)
}
window.MakeContextCurrent()
// Must gl.Init() *after* MakeContextCurrent
if err := gl.Init(); err != nil {
log.Fatalf("Can't init gl: %v!", err)
}
// Set window up to be [0, 0] -> [width, height], black.
gl.MatrixMode(gl.MODELVIEW)
gl.LoadIdentity()
gl.Translated(-1, -1, 0)
gl.Scaled(2/float64(s.width), 2/float64(s.height), 1.0)
gl.ClearColor(0.0, 0.0, 0.0, 0.0)
gl.ShadeModel(gl.FLAT)
// Actually start writing data to the buffer
s.line.valueBuffer = types.NewTypedBuffer(int(float64(s.width) / s.pixelsPerSample))
s.line.valueBuffer.GoPushChannel(hackWrapChannel(s.line.Values), sampleRate)
if events != nil {
s.eventBuffer.GoPushChannel(events, sampleRate)
}
gl.Hint(gl.POINT_SMOOTH_HINT, gl.FASTEST)
// Keep drawing while we still can (and should).
for !window.ShouldClose() && !s.bufferFinished() {
if window.GetKey(glfw.KeyEscape) == glfw.Press {
break
}
gl.Clear(gl.COLOR_BUFFER_BIT)
s.drawSignal()
window.SwapBuffers()
glfw.PollEvents()
}
// Keep window around, only close on esc.
for !window.ShouldClose() && window.GetKey(glfw.KeyEscape) != glfw.Press {
glfw.PollEvents()
}
}
