def render(self, buf):
table_rate = self.incr
mask = wavetable.TABLE_SIZE - 1
playback_rate = pow(2, self.detune / 1200.0)
for i in range(buf.size):
playback_pointer = i * playback_rate
# Let x, y be indeces into what would be the intermediate buffer.
x = int(floor(playback_pointer))
y = x + 1
# Let omega, theta be the interpolation factors for the
# interpolation step on what would be read from the intermediate.
theta = playback_pointer - float(x)
omega = 1.0 - theta
# So, assuming an existing intermediate buffer, E, we could compute
# Si = buf[i] = (omega * E[x]) + (theta * E[y])
# We now derive E[x] and E[y] to avoid the intermediate buffer.
# Remember from the StandardOscillator,
# E[x] = (beta * table[a]) + (alpha * table[b])
a = int(floor(table_rate * x))
b = a + 1
alpha = (table_rate * x) - float(a)
beta = 1.0 - alpha
a_wrapped = a & mask
b_wrapped = b & mask
ex = (beta * wavetable.get(a_wrapped)) + \
(alpha * wavetable.get(b_wrapped))
# Now we need E[y], which we can derive the same way.
_a = int(floor(table_rate * y))
_b = (_a + 1)
_alpha = (table_rate * y) - float(_a)
_beta = 1.0 - _alpha
_a_wrapped = _a & mask
_b_wrapped = _b & mask
ey = (_beta * wavetable.get(_a_wrapped)) + \
(_alpha * wavetable.get(_b_wrapped))
# From above, we now compute Si
si = (omega * ex) + (theta * ey)
buf[i] += si * self.level
def render(self, buf):
table_rate = self.incr
mask = wavetable.TABLE_SIZE - 1
playback_rate = pow(2, self.detune / 1200.0)
for i in range(buf.size):
playback_pointer = i * playback_rate
# Let x, y be indeces into what would be the intermediate buffer.
x = int(floor(playback_pointer))
y = x + 1
# Let omega, theta be the interpolation factors for the
# interpolation step on what would be read from the intermediate.
theta = playback_pointer - float(x)
omega = 1.0 - theta
# So, assuming an existing intermediate buffer, E, we could compute
# Si = buf[i] = (omega * E[x]) + (theta * E[y])
# We now derive E[x] and E[y] to avoid the intermediate buffer.
# Remember from the StandardOscillator,
# E[x] = (beta * table[a]) + (alpha * table[b])
a = int(floor(table_rate * x))
b = a + 1
alpha = (table_rate * x) - float(a)
beta = 1.0 - alpha
a_wrapped = a & mask
b_wrapped = b & mask
ex = (beta * wavetable.get(a_wrapped)) + \
(alpha * wavetable.get(b_wrapped))
# Now we need E[y], which we can derive the same way.
_a = int(floor(table_rate * y))
_b = (_a + 1)
_alpha = (table_rate * y) - float(_a)
_beta = 1.0 - _alpha
_a_wrapped = _a & mask
_b_wrapped = _b & mask
ey = (_beta * wavetable.get(_a_wrapped)) + \
(_alpha * wavetable.get(_b_wrapped))
# From above, we now compute Si
si = (omega * ex) + (theta * ey)
buf[i] += si * self.level
def render(self, buf):
for i in range(buf.size):
index = i * self.incr
read_index = int(floor(index))
mask = wavetable.TABLE_SIZE - 1
read_index_wrapped_left = read_index & mask
read_index_wrapped_right = (read_index + 1) & mask
left = wavetable.get(read_index_wrapped_left)
right = wavetable.get(read_index_wrapped_right)
alpha = index - float(read_index)
inv_alpha = 1.0 - alpha
sample = (inv_alpha * left) + (alpha * right)
buf[i] += sample * self.level
def render(self, buf):
for i in range(buf.size):
index = i * self.incr
read_index = int(floor(index))
mask = wavetable.TABLE_SIZE - 1
read_index_wrapped_left = read_index & mask
read_index_wrapped_right = (read_index + 1) & mask
left = wavetable.get(read_index_wrapped_left)
right = wavetable.get(read_index_wrapped_right)
alpha = index - float(read_index)
inv_alpha = 1.0 - alpha
sample = (inv_alpha * left) + (alpha * right)
buf[i] += sample * self.level
