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ardour {
["type"] = "dsp",
name = "SinGen",
category = "Instrument",
license = "MIT",
author = "Ardour Team",
description = [[Sine Wave Generator (v1.2)]]
}
local lpf = 0
function dsp_params ()
return
{
{ ["type"] = "input", name = "Frequency", min = 20, max = 20000, default = 1000, unit="Hz", logarithmic = true },
{ ["type"] = "input", name = "Gain", min = -90, max = 0, default = -18, unit="dB" },
}
end
function dsp_ioconfig ()
return { [1] = { audio_in = -1, audio_out = -1}, }
end
function dsp_init (rate)
r = rate
lpf = 2048 / rate
end
function low_pass_filter_param(old, new, limit)
if math.abs (old - new) < limit then
return new
else
return old + lpf * (new - old)
end
end
local p = 0
local fo = 0
local ao = 0
function dsp_run (ins, outs, n_samples)
local ctrl = CtrlPorts:array() --call parameters
local a = {} --init array
local f = ctrl[1] or 1000
local amp = low_pass_filter_param(ao, ARDOUR.DSP.dB_to_coefficient(ctrl[2]), 0.02)
local inc = f / r
for s = 1, n_samples do --fill table with fragments of a sine wave
p = p + inc
a[s] = amp * math.sin(p * (2 * math.pi))
end
for c = 1,#outs do
outs[c]:set_table(a, n_samples) --passes array into buffer
end
if (f ~= fo) or (a ~= ao) then
self:queue_draw()
end
fo = f
ao = amp
end
function render_inline (ctx, w, max_h) --inline display
local ctrl = CtrlPorts:array()
h = 30
p = 0
inc = 1/w
f = ctrl[1] / 1000
if f < 0.5 then f = 0.5 end
if f > 8 then f = 8 end
--draw rectangle
ctx:rectangle(0, 0, w, h)
ctx:set_source_rgba(0, 0, 0, 1.0)
ctx:fill()
ctx:set_line_width(1.5)
ctx:set_source_rgba(0.8, 0.8, 0.8, 1.0)
l_x = 0
l_y = 0
for x = 0,w do
y = ARDOUR.DSP.dB_to_coefficient(ctrl[2]) * math.sin(f * (2 * math.pi * (p)))
yc = 0.5 * h + ((-0.5 * h) * y)
ctx:move_to (x, yc + 3)
ctx:line_to (l_x, l_y + 3)
l_x = x
l_y = yc
ctx:stroke()
p = p + inc
end
return {w, h + 6}
end
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