From 62e8c800f4644557bcd3bbf4d46ce8b27a5de0b6 Mon Sep 17 00:00:00 2001
From: nyanpasu64 <nyanpasu64@tuta.io>
Date: Sat, 3 Nov 2018 22:36:37 -0700
Subject: [PATCH 1/5] Fix passing tuples/lists into RendererLayout

---
 ovgenpy/renderer.py    |  6 ++++--
 tests/test_renderer.py | 29 ++++++++++++++---------------
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/ovgenpy/renderer.py b/ovgenpy/renderer.py
index 439b86e..b6ee2c8 100644
--- a/ovgenpy/renderer.py
+++ b/ovgenpy/renderer.py
@@ -248,8 +248,10 @@ class RendererLayout:
         inds = np.arange(nspaces)
         rows, cols = np.unravel_index(inds, (self.nrows, self.ncols))
 
-        row_col = np.array([rows, cols]).T
-        regions = np.array([region_factory(*rc) for rc in row_col])  # type: np.ndarray[Region]
+        row_col = list(zip(rows, cols))
+        regions = np.empty(len(row_col), dtype=object)          # type: np.ndarray[Region]
+        regions[:] = [region_factory(*rc) for rc in row_col]
+
         regions2d = regions.reshape((self.nrows, self.ncols))   # type: np.ndarray[Region]
 
         # if column major:
diff --git a/tests/test_renderer.py b/tests/test_renderer.py
index ac10132..9d22f8d 100644
--- a/tests/test_renderer.py
+++ b/tests/test_renderer.py
@@ -31,44 +31,43 @@ def test_config():
     LayoutConfig(ncols=2),
     LayoutConfig(nrows=8),
 ])
-def test_hlayout(lcfg):
+@pytest.mark.parametrize('region_type', [str, tuple, list])
+def test_hlayout(lcfg, region_type):
     nplots = 15
     layout = RendererLayout(lcfg, nplots)
 
     assert layout.ncols == 2
     assert layout.nrows == 8
 
-    # holy shit, passing tuples into a numpy array breaks things spectacularly, and it's
-    # painfully difficult to stuff tuples into 1D array.
-    # http://wesmckinney.com/blog/performance-quirk-making-a-1d-object-ndarray-of-tuples/
-    regions = layout.arrange(lambda row, col: str((row, col)))
+    regions = layout.arrange(lambda row, col: region_type((row, col)))
     assert len(regions) == nplots
 
-    assert regions[0] == '(0, 0)'
-    assert regions[1] == '(0, 1)'
-    assert regions[2] == '(1, 0)'
+    assert regions[0] == region_type((0, 0))
+    assert regions[1] == region_type((0, 1))
+    assert regions[2] == region_type((1, 0))
     m = nplots - 1
-    assert regions[m] == str((m // 2, m % 2))
+    assert regions[m] == region_type((m // 2, m % 2))
 
 
 @pytest.mark.parametrize('lcfg', [
     LayoutConfig(ncols=3, orientation='v'),
     LayoutConfig(nrows=3, orientation='v'),
 ])
-def test_vlayout(lcfg):
+@pytest.mark.parametrize('region_type', [str, tuple, list])
+def test_vlayout(lcfg, region_type):
     nplots = 7
     layout = RendererLayout(lcfg, nplots)
 
     assert layout.ncols == 3
     assert layout.nrows == 3
 
-    regions = layout.arrange(lambda row, col: str((row, col)))
+    regions = layout.arrange(lambda row, col: region_type((row, col)))
     assert len(regions) == nplots
 
-    assert regions[0] == '(0, 0)'
-    assert regions[2] == '(2, 0)'
-    assert regions[3] == '(0, 1)'
-    assert regions[6] == '(0, 2)'
+    assert regions[0] == region_type((0, 0))
+    assert regions[2] == region_type((2, 0))
+    assert regions[3] == region_type((0, 1))
+    assert regions[6] == region_type((0, 2))
 
 
 def test_renderer():

From 342752febfb2d8afd138f88e862ffd52c9628289 Mon Sep 17 00:00:00 2001
From: nyanpasu64 <nyanpasu64@tuta.io>
Date: Sat, 3 Nov 2018 22:53:07 -0700
Subject: [PATCH 2/5] Move LayoutConfig and RendererLayout to new file

---
 ovgenpy/layout.py      | 87 ++++++++++++++++++++++++++++++++++++++++++
 ovgenpy/ovgenpy.py     |  3 +-
 ovgenpy/renderer.py    | 84 ++--------------------------------------
 tests/test_layout.py   | 77 +++++++++++++++++++++++++++++++++++++
 tests/test_renderer.py | 85 +----------------------------------------
 5 files changed, 171 insertions(+), 165 deletions(-)
 create mode 100644 ovgenpy/layout.py
 create mode 100644 tests/test_layout.py

diff --git a/ovgenpy/layout.py b/ovgenpy/layout.py
new file mode 100644
index 0000000..b487daf
--- /dev/null
+++ b/ovgenpy/layout.py
@@ -0,0 +1,87 @@
+from typing import Optional, TypeVar, Callable, List
+
+import numpy as np
+
+from ovgenpy.config import register_config
+from ovgenpy.util import ceildiv
+
+
+@register_config(always_dump='orientation')
+class LayoutConfig:
+    orientation: str = 'h'
+    nrows: Optional[int] = None
+    ncols: Optional[int] = None
+
+    def __post_init__(self):
+        if not self.nrows:
+            self.nrows = None
+        if not self.ncols:
+            self.ncols = None
+
+        if self.nrows and self.ncols:
+            raise ValueError('cannot manually assign both nrows and ncols')
+
+        if not self.nrows and not self.ncols:
+            self.ncols = 1
+
+
+Region = TypeVar('Region')
+RegionFactory = Callable[[int, int], Region]   # f(row, column) -> Region
+
+
+class RendererLayout:
+    VALID_ORIENTATIONS = ['h', 'v']
+
+    def __init__(self, cfg: LayoutConfig, nplots: int):
+        self.cfg = cfg
+        self.nplots = nplots
+
+        # Setup layout
+        self.nrows, self.ncols = self._calc_layout()
+
+        self.orientation = cfg.orientation
+        if self.orientation not in self.VALID_ORIENTATIONS:
+            raise ValueError(f'Invalid orientation {self.orientation} not in '
+                             f'{self.VALID_ORIENTATIONS}')
+
+    def _calc_layout(self):
+        """
+        Inputs: self.cfg, self.waves
+        :return: (nrows, ncols)
+        """
+        cfg = self.cfg
+
+        if cfg.nrows:
+            nrows = cfg.nrows
+            if nrows is None:
+                raise ValueError('invalid cfg: rows_first is True and nrows is None')
+            ncols = ceildiv(self.nplots, nrows)
+        else:
+            ncols = cfg.ncols
+            if ncols is None:
+                raise ValueError('invalid cfg: rows_first is False and ncols is None')
+            nrows = ceildiv(self.nplots, ncols)
+
+        return nrows, ncols
+
+    def arrange(self, region_factory: RegionFactory) -> List[Region]:
+        """ Generates an array of regions.
+
+        index, row, column are fed into region_factory in a row-major order [row][col].
+        The results are possibly reshaped into column-major order [col][row].
+        """
+        nspaces = self.nrows * self.ncols
+        inds = np.arange(nspaces)
+        rows, cols = np.unravel_index(inds, (self.nrows, self.ncols))
+
+        row_col = list(zip(rows, cols))
+        regions = np.empty(len(row_col), dtype=object)          # type: np.ndarray[Region]
+        regions[:] = [region_factory(*rc) for rc in row_col]
+
+        regions2d = regions.reshape((self.nrows, self.ncols))   # type: np.ndarray[Region]
+
+        # if column major:
+        if self.orientation == 'v':
+            regions2d = regions2d.T
+
+        return regions2d.flatten()[:self.nplots].tolist()
diff --git a/ovgenpy/ovgenpy.py b/ovgenpy/ovgenpy.py
index 3e1a746..d0ccb93 100644
--- a/ovgenpy/ovgenpy.py
+++ b/ovgenpy/ovgenpy.py
@@ -8,7 +8,8 @@ from typing import Optional, List, Union, TYPE_CHECKING
 from ovgenpy import outputs
 from ovgenpy.channel import Channel, ChannelConfig
 from ovgenpy.config import register_config, register_enum, Ignored
-from ovgenpy.renderer import MatplotlibRenderer, RendererConfig, LayoutConfig
+from ovgenpy.renderer import MatplotlibRenderer, RendererConfig
+from ovgenpy.layout import LayoutConfig
 from ovgenpy.triggers import ITriggerConfig, CorrelationTriggerConfig, PerFrameCache, \
     LocalPostTriggerConfig
 from ovgenpy.util import pushd, coalesce
diff --git a/ovgenpy/renderer.py b/ovgenpy/renderer.py
index b6ee2c8..7da88bb 100644
--- a/ovgenpy/renderer.py
+++ b/ovgenpy/renderer.py
@@ -1,11 +1,12 @@
-from typing import Optional, List, TYPE_CHECKING, TypeVar, Callable, Any
+from typing import Optional, List, TYPE_CHECKING, Any
 
 import matplotlib
 import numpy as np
 
 from ovgenpy.config import register_config
+from ovgenpy.layout import RendererLayout
 from ovgenpy.outputs import RGB_DEPTH
-from ovgenpy.util import ceildiv, coalesce
+from ovgenpy.util import coalesce
 
 matplotlib.use('agg')
 from matplotlib import pyplot as plt
@@ -180,82 +181,3 @@ class MatplotlibRenderer:
         return buffer_rgb
 
 
-@register_config(always_dump='orientation')
-class LayoutConfig:
-    orientation: str = 'h'
-    nrows: Optional[int] = None
-    ncols: Optional[int] = None
-
-    def __post_init__(self):
-        if not self.nrows:
-            self.nrows = None
-        if not self.ncols:
-            self.ncols = None
-
-        if self.nrows and self.ncols:
-            raise ValueError('cannot manually assign both nrows and ncols')
-
-        if not self.nrows and not self.ncols:
-            self.ncols = 1
-
-
-Region = TypeVar('Region')
-RegionFactory = Callable[[int, int], Region]   # f(row, column) -> Region
-
-
-class RendererLayout:
-    VALID_ORIENTATIONS = ['h', 'v']
-
-    def __init__(self, cfg: LayoutConfig, nplots: int):
-        self.cfg = cfg
-        self.nplots = nplots
-
-        # Setup layout
-        self.nrows, self.ncols = self._calc_layout()
-
-        self.orientation = cfg.orientation
-        if self.orientation not in self.VALID_ORIENTATIONS:
-            raise ValueError(f'Invalid orientation {self.orientation} not in '
-                             f'{self.VALID_ORIENTATIONS}')
-
-    def _calc_layout(self):
-        """
-        Inputs: self.cfg, self.waves
-        :return: (nrows, ncols)
-        """
-        cfg = self.cfg
-
-        if cfg.nrows:
-            nrows = cfg.nrows
-            if nrows is None:
-                raise ValueError('invalid cfg: rows_first is True and nrows is None')
-            ncols = ceildiv(self.nplots, nrows)
-        else:
-            ncols = cfg.ncols
-            if ncols is None:
-                raise ValueError('invalid cfg: rows_first is False and ncols is None')
-            nrows = ceildiv(self.nplots, ncols)
-
-        return nrows, ncols
-
-    def arrange(self, region_factory: RegionFactory) -> List[Region]:
-        """ Generates an array of regions.
-
-        index, row, column are fed into region_factory in a row-major order [row][col].
-        The results are possibly reshaped into column-major order [col][row].
-        """
-        nspaces = self.nrows * self.ncols
-        inds = np.arange(nspaces)
-        rows, cols = np.unravel_index(inds, (self.nrows, self.ncols))
-
-        row_col = list(zip(rows, cols))
-        regions = np.empty(len(row_col), dtype=object)          # type: np.ndarray[Region]
-        regions[:] = [region_factory(*rc) for rc in row_col]
-
-        regions2d = regions.reshape((self.nrows, self.ncols))   # type: np.ndarray[Region]
-
-        # if column major:
-        if self.orientation == 'v':
-            regions2d = regions2d.T
-
-        return regions2d.flatten()[:self.nplots].tolist()
diff --git a/tests/test_layout.py b/tests/test_layout.py
new file mode 100644
index 0000000..949a3c9
--- /dev/null
+++ b/tests/test_layout.py
@@ -0,0 +1,77 @@
+import pytest
+
+from ovgenpy.layout import LayoutConfig, RendererLayout
+from ovgenpy.renderer import RendererConfig, MatplotlibRenderer
+from tests.test_renderer import WIDTH, HEIGHT
+
+
+def test_layout_config():
+    with pytest.raises(ValueError):
+        LayoutConfig(nrows=1, ncols=1)
+
+    one_col = LayoutConfig(ncols=1)
+    assert one_col
+
+    one_row = LayoutConfig(nrows=1)
+    assert one_row
+
+    default = LayoutConfig()
+    assert default.ncols == 1  # Should default to single-column layout
+    assert default.nrows is None
+    assert default.orientation == 'h'
+
+
+@pytest.mark.parametrize('lcfg', [
+    LayoutConfig(ncols=2),
+    LayoutConfig(nrows=8),
+])
+@pytest.mark.parametrize('region_type', [str, tuple, list])
+def test_hlayout(lcfg, region_type):
+    nplots = 15
+    layout = RendererLayout(lcfg, nplots)
+
+    assert layout.ncols == 2
+    assert layout.nrows == 8
+
+    regions = layout.arrange(lambda row, col: region_type((row, col)))
+    assert len(regions) == nplots
+
+    assert regions[0] == region_type((0, 0))
+    assert regions[1] == region_type((0, 1))
+    assert regions[2] == region_type((1, 0))
+    m = nplots - 1
+    assert regions[m] == region_type((m // 2, m % 2))
+
+
+@pytest.mark.parametrize('lcfg', [
+    LayoutConfig(ncols=3, orientation='v'),
+    LayoutConfig(nrows=3, orientation='v'),
+])
+@pytest.mark.parametrize('region_type', [str, tuple, list])
+def test_vlayout(lcfg, region_type):
+    nplots = 7
+    layout = RendererLayout(lcfg, nplots)
+
+    assert layout.ncols == 3
+    assert layout.nrows == 3
+
+    regions = layout.arrange(lambda row, col: region_type((row, col)))
+    assert len(regions) == nplots
+
+    assert regions[0] == region_type((0, 0))
+    assert regions[2] == region_type((2, 0))
+    assert regions[3] == region_type((0, 1))
+    assert regions[6] == region_type((0, 2))
+
+
+def test_renderer_layout():
+    # 2 columns
+    cfg = RendererConfig(WIDTH, HEIGHT)
+    lcfg = LayoutConfig(ncols=2)
+    nplots = 15
+
+    r = MatplotlibRenderer(cfg, lcfg, nplots)
+
+    # 2 columns, 8 rows
+    assert r.layout.ncols == 2
+    assert r.layout.nrows == 8
diff --git a/tests/test_renderer.py b/tests/test_renderer.py
index 9d22f8d..f557c43 100644
--- a/tests/test_renderer.py
+++ b/tests/test_renderer.py
@@ -4,93 +4,12 @@ from matplotlib.colors import to_rgb
 
 from ovgenpy.channel import ChannelConfig
 from ovgenpy.outputs import RGB_DEPTH
-from ovgenpy.renderer import RendererConfig, MatplotlibRenderer, LayoutConfig, \
-    RendererLayout
+from ovgenpy.renderer import RendererConfig, MatplotlibRenderer
+from ovgenpy.layout import LayoutConfig
 
 WIDTH = 640
 HEIGHT = 360
 
-
-def test_config():
-    with pytest.raises(ValueError):
-        LayoutConfig(nrows=1, ncols=1)
-
-    one_col = LayoutConfig(ncols=1)
-    assert one_col
-
-    one_row = LayoutConfig(nrows=1)
-    assert one_row
-
-    default = LayoutConfig()
-    assert default.ncols == 1  # Should default to single-column layout
-    assert default.nrows is None
-    assert default.orientation == 'h'
-
-
-@pytest.mark.parametrize('lcfg', [
-    LayoutConfig(ncols=2),
-    LayoutConfig(nrows=8),
-])
-@pytest.mark.parametrize('region_type', [str, tuple, list])
-def test_hlayout(lcfg, region_type):
-    nplots = 15
-    layout = RendererLayout(lcfg, nplots)
-
-    assert layout.ncols == 2
-    assert layout.nrows == 8
-
-    regions = layout.arrange(lambda row, col: region_type((row, col)))
-    assert len(regions) == nplots
-
-    assert regions[0] == region_type((0, 0))
-    assert regions[1] == region_type((0, 1))
-    assert regions[2] == region_type((1, 0))
-    m = nplots - 1
-    assert regions[m] == region_type((m // 2, m % 2))
-
-
-@pytest.mark.parametrize('lcfg', [
-    LayoutConfig(ncols=3, orientation='v'),
-    LayoutConfig(nrows=3, orientation='v'),
-])
-@pytest.mark.parametrize('region_type', [str, tuple, list])
-def test_vlayout(lcfg, region_type):
-    nplots = 7
-    layout = RendererLayout(lcfg, nplots)
-
-    assert layout.ncols == 3
-    assert layout.nrows == 3
-
-    regions = layout.arrange(lambda row, col: region_type((row, col)))
-    assert len(regions) == nplots
-
-    assert regions[0] == region_type((0, 0))
-    assert regions[2] == region_type((2, 0))
-    assert regions[3] == region_type((0, 1))
-    assert regions[6] == region_type((0, 2))
-
-
-def test_renderer():
-    """
-    TODO check image output using:
-    https://matplotlib.org/devel/testing.html#writing-an-image-comparison-test
-
-    https://stackoverflow.com/a/27950953
-    "[I]mage comparison tests end up bring more trouble than they are worth"
-    """
-
-    # 2 columns
-    cfg = RendererConfig(WIDTH, HEIGHT)
-    lcfg = LayoutConfig(ncols=2)
-    nplots = 15
-
-    r = MatplotlibRenderer(cfg, lcfg, nplots)
-
-    # 2 columns, 8 rows
-    assert r.layout.ncols == 2
-    assert r.layout.nrows == 8
-
-
 ALL_ZEROS = np.array([0,0])
 
 all_colors = pytest.mark.parametrize('bg_str,fg_str', [

From 60e465841390fd9ff0743c245c75105964806e08 Mon Sep 17 00:00:00 2001
From: nyanpasu64 <nyanpasu64@tuta.io>
Date: Sat, 3 Nov 2018 23:20:55 -0700
Subject: [PATCH 3/5] Add Renderer abstract class

---
 ovgenpy/renderer.py | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/ovgenpy/renderer.py b/ovgenpy/renderer.py
index 7da88bb..5bf418c 100644
--- a/ovgenpy/renderer.py
+++ b/ovgenpy/renderer.py
@@ -1,10 +1,11 @@
+from abc import ABC, abstractmethod
 from typing import Optional, List, TYPE_CHECKING, Any
 
 import matplotlib
 import numpy as np
 
 from ovgenpy.config import register_config
-from ovgenpy.layout import RendererLayout
+from ovgenpy.layout import RendererLayout, LayoutConfig
 from ovgenpy.outputs import RGB_DEPTH
 from ovgenpy.util import coalesce
 
@@ -39,7 +40,23 @@ class RendererConfig:
     create_window: bool = False
 
 
-class MatplotlibRenderer:
+class Renderer(ABC):
+    def __init__(self, cfg: RendererConfig, lcfg: 'LayoutConfig', nplots: int):
+        self.cfg = cfg
+        self.nplots = nplots
+        self.layout = RendererLayout(lcfg, nplots)
+
+    @abstractmethod
+    def set_colors(self, channel_cfgs: List['ChannelConfig']) -> None: ...
+
+    @abstractmethod
+    def render_frame(self, datas: List[np.ndarray]) -> None: ...
+
+    @abstractmethod
+    def get_frame(self) -> bytes: ...
+
+
+class MatplotlibRenderer(Renderer):
     """
     Renderer backend which takes data and produces images.
     Does not touch Wave or Channel.
@@ -62,17 +79,15 @@ class MatplotlibRenderer:
 
     DPI = 96
 
-    def __init__(self, cfg: RendererConfig, lcfg: 'LayoutConfig', nplots: int):
-        self.cfg = cfg
-        self.nplots = nplots
-        self.layout = RendererLayout(lcfg, nplots)
+    def __init__(self, *args, **kwargs):
+        Renderer.__init__(self, *args, **kwargs)
 
         # Flat array of nrows*ncols elements, ordered by cfg.rows_first.
         self._fig: 'Figure' = None
         self._axes: List['Axes'] = None        # set by set_layout()
         self._lines: List['Line2D'] = None     # set by render_frame() first call
 
-        self._line_colors: List = [None] * nplots
+        self._line_colors: List = [None] * self.nplots
 
         self._set_layout()   # mutates self
 
@@ -180,4 +195,3 @@ class MatplotlibRenderer:
 
         return buffer_rgb
 
-

From 5c7db2786283ed426db7a77bc49f844010b9c484 Mon Sep 17 00:00:00 2001
From: nyanpasu64 <nyanpasu64@tuta.io>
Date: Mon, 5 Nov 2018 15:30:06 -0800
Subject: [PATCH 4/5] Improve error message of test_renderer

If the foreground color is 136 instead of the right color,
this corresponds to the global foreground color #888888,
which means the per-channel foreground color wasn't applied.
---
 tests/test_renderer.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/test_renderer.py b/tests/test_renderer.py
index f557c43..56ecab9 100644
--- a/tests/test_renderer.py
+++ b/tests/test_renderer.py
@@ -72,7 +72,8 @@ def verify(r: MatplotlibRenderer, bg_str, fg_str):
     assert (frame_colors[0] == bg_u8).all()
 
     # Ensure foreground is present
-    assert np.prod(frame_colors == fg_u8, axis=-1).any()
+    assert np.prod(frame_colors == fg_u8, axis=-1).any(), \
+        'incorrect foreground, it might be 136 = #888888'
 
     assert (np.amax(frame_colors, axis=0) == np.maximum(bg_u8, fg_u8)).all()
     assert (np.amin(frame_colors, axis=0) == np.minimum(bg_u8, fg_u8)).all()

From 88a79a97e817c68e524039fac673067e999a380f Mon Sep 17 00:00:00 2001
From: nyanpasu64 <nyanpasu64@tuta.io>
Date: Mon, 5 Nov 2018 15:45:38 -0800
Subject: [PATCH 5/5] Remove Renderer.set_colors(), move into constructor

Makes it simpler to create an impl which constructs all canvases
within __init__, not on first frame.
---
 ovgenpy/ovgenpy.py     |  4 ++--
 ovgenpy/renderer.py    | 28 +++++++++++-----------------
 tests/test_layout.py   |  2 +-
 tests/test_output.py   |  2 +-
 tests/test_renderer.py | 10 +++++-----
 5 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/ovgenpy/ovgenpy.py b/ovgenpy/ovgenpy.py
index d0ccb93..2ccc445 100644
--- a/ovgenpy/ovgenpy.py
+++ b/ovgenpy/ovgenpy.py
@@ -140,8 +140,8 @@ class Ovgen:
                 yield
 
     def _load_renderer(self):
-        renderer = MatplotlibRenderer(self.cfg.render, self.cfg.layout, self.nchan)
-        renderer.set_colors(self.cfg.channels)
+        renderer = MatplotlibRenderer(self.cfg.render, self.cfg.layout, self.nchan,
+                                      self.cfg.channels)
         return renderer
 
     def play(self):
diff --git a/ovgenpy/renderer.py b/ovgenpy/renderer.py
index 5bf418c..81bbb2d 100644
--- a/ovgenpy/renderer.py
+++ b/ovgenpy/renderer.py
@@ -41,13 +41,21 @@ class RendererConfig:
 
 
 class Renderer(ABC):
-    def __init__(self, cfg: RendererConfig, lcfg: 'LayoutConfig', nplots: int):
+    def __init__(self, cfg: RendererConfig, lcfg: 'LayoutConfig', nplots: int,
+                 channel_cfgs: Optional[List['ChannelConfig']]):
         self.cfg = cfg
         self.nplots = nplots
         self.layout = RendererLayout(lcfg, nplots)
 
-    @abstractmethod
-    def set_colors(self, channel_cfgs: List['ChannelConfig']) -> None: ...
+        # Load line colors.
+        if channel_cfgs is not None:
+            if len(channel_cfgs) != self.nplots:
+                raise ValueError(
+                    f"cannot assign {len(channel_cfgs)} colors to {self.nplots} plots"
+                )
+            self._line_colors = [cfg.line_color for cfg in channel_cfgs]
+        else:
+            self._line_colors = [None] * self.nplots
 
     @abstractmethod
     def render_frame(self, datas: List[np.ndarray]) -> None: ...
@@ -87,8 +95,6 @@ class MatplotlibRenderer(Renderer):
         self._axes: List['Axes'] = None        # set by set_layout()
         self._lines: List['Line2D'] = None     # set by render_frame() first call
 
-        self._line_colors: List = [None] * self.nplots
-
         self._set_layout()   # mutates self
 
     def _set_layout(self) -> None:
@@ -130,18 +136,6 @@ class MatplotlibRenderer(Renderer):
         if self.cfg.create_window:
             plt.show(block=False)
 
-    def set_colors(self, channel_cfgs: List['ChannelConfig']):
-        if len(channel_cfgs) != self.nplots:
-            raise ValueError(
-                f"cannot assign {len(channel_cfgs)} colors to {self.nplots} plots"
-            )
-
-        if self._lines is not None:
-            raise ValueError(
-                f'cannot set line colors after calling render_frame()'
-            )
-        self._line_colors = [cfg.line_color for cfg in channel_cfgs]
-
     def render_frame(self, datas: List[np.ndarray]) -> None:
         ndata = len(datas)
         if self.nplots != ndata:
diff --git a/tests/test_layout.py b/tests/test_layout.py
index 949a3c9..6490f02 100644
--- a/tests/test_layout.py
+++ b/tests/test_layout.py
@@ -70,7 +70,7 @@ def test_renderer_layout():
     lcfg = LayoutConfig(ncols=2)
     nplots = 15
 
-    r = MatplotlibRenderer(cfg, lcfg, nplots)
+    r = MatplotlibRenderer(cfg, lcfg, nplots, None)
 
     # 2 columns, 8 rows
     assert r.layout.ncols == 2
diff --git a/tests/test_output.py b/tests/test_output.py
index f0ad4e2..115c667 100644
--- a/tests/test_output.py
+++ b/tests/test_output.py
@@ -19,7 +19,7 @@ NULL_CFG = FFmpegOutputConfig(None, '-f null')
 
 def test_render_output():
     """ Ensure rendering to output does not raise exceptions. """
-    renderer = MatplotlibRenderer(CFG.render, CFG.layout, nplots=1)
+    renderer = MatplotlibRenderer(CFG.render, CFG.layout, nplots=1, channel_cfgs=None)
     out: FFmpegOutput = NULL_CFG(CFG)
 
     renderer.render_frame([ALL_ZEROS])
diff --git a/tests/test_renderer.py b/tests/test_renderer.py
index 56ecab9..51cfe5e 100644
--- a/tests/test_renderer.py
+++ b/tests/test_renderer.py
@@ -32,13 +32,13 @@ def test_default_colors(bg_str, fg_str):
     lcfg = LayoutConfig()
     nplots = 1
 
-    r = MatplotlibRenderer(cfg, lcfg, nplots)
+    r = MatplotlibRenderer(cfg, lcfg, nplots, None)
     verify(r, bg_str, fg_str)
 
     # Ensure default ChannelConfig(line_color=None) does not override line color
-    r = MatplotlibRenderer(cfg, lcfg, nplots)
     chan = ChannelConfig(wav_path='')
-    r.set_colors([chan] * nplots)
+    channels = [chan] * nplots
+    r = MatplotlibRenderer(cfg, lcfg, nplots, channels)
     verify(r, bg_str, fg_str)
 
 
@@ -54,9 +54,9 @@ def test_line_colors(bg_str, fg_str):
     lcfg = LayoutConfig()
     nplots = 1
 
-    r = MatplotlibRenderer(cfg, lcfg, nplots)
     chan = ChannelConfig(wav_path='', line_color=fg_str)
-    r.set_colors([chan] * nplots)
+    channels = [chan] * nplots
+    r = MatplotlibRenderer(cfg, lcfg, nplots, channels)
     verify(r, bg_str, fg_str)