// NewDenseIIR wrapps a sound in an IIR filter, as specified by the coefficients.
// TODO(padster): Also implement the filter design algorithms, e.g:
// http://engineerjs.com/?sidebar=docs/iir.html
// http://www.mikroe.com/chapters/view/73/chapter-3-iir-filters/
// http://www-users.cs.york.ac.uk/~fisher/mkfilter/
//
// For example, to use a high-pass filter for 800hz+ with sample rate of 44.1k:
// sound := s.NewDenseIIR(...some sound...,
// []float64{0.8922, -2.677, 2.677, -0.8922},
// []float64{2.772, -2.57, 0.7961},
// )
func NewDenseIIR(wrapped Sound, inCoef []float64, outCoef []float64) Sound {
// TODO(padster): Verify this is doing what it should...hard to tell just by listening.
data := denseIIR{
wrapped,
inCoef,
outCoef,
types.NewBuffer(len(inCoef)),
types.NewBuffer(len(outCoef)),
}
return NewBaseSound(&data, wrapped.Length())
}
// RenderLinesWithEvents renders multiple channels of samples to screen, and draws events.
func (s *Screen) RenderLinesWithEvents(lines []Line, events <-chan interface{}, sampleRate int) {
s.lines = lines
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, "Muse", 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, -1.0] -> [width, 1.0], black.
gl.MatrixMode(gl.MODELVIEW)
gl.LoadIdentity()
gl.Translated(-1, 0, 0)
gl.Scaled(2/float64(s.width), 1.0, 1.0)
gl.ClearColor(0.0, 0.0, 0.0, 0.0)
// Actually start writing data to the buffer
for i, _ := range s.lines {
s.lines[i].valueBuffer = types.NewBuffer(int(float64(s.width) / s.pixelsPerSample))
s.lines[i].valueBuffer.GoPushChannel(s.lines[i].Values, sampleRate)
}
if events != nil {
s.eventBuffer.GoPushChannel(events, sampleRate)
}
// 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()
}
}
