draw565: Add lighten/darken functions

Add functions to generate shades from a single (usually theme provided)
basic palette colour.

Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>

1 files changed, 41 insertions, 0 deletions

diff --git a/wasp/boards/simulator/test_unit.py b/wasp/boards/simulator/test_unit.py
new file mode 100644
index 0000000..8e62ea3
--- /dev/null
+++ b/wasp/boards/simulator/test_unit.py
@@ -0,0 +1,41 @@
+import draw565
+import pytest
+
+@pytest.fixture
+def draw():
+    """Provide a RGB565 drawing surface.
+
+    Currently most of the draw565 functions will not work since we haven't
+    mocked up the display. This limits the testing that we can perform.
+    """
+    d = draw565.Draw565(None)
+
+    return d
+
+def test_lighten(draw):
+    assert draw.lighten(0b00000_000000_00000         ) == 0b00001_000010_00001
+    assert draw.lighten(0b00000_000000_00000, 0b00001) == 0b00001_000010_00001
+    assert draw.lighten(0b00000_000000_00000, 0b00100) == 0b00100_001000_00100
+
+    assert draw.lighten(0b10000_100000_10000, 0b10000) == 0b11111_111111_11111
+    assert draw.lighten(0b11110_111100_11110, 0b00001) == 0b11111_111110_11111
+    assert draw.lighten(0b11110_111101_11110, 0b00001) == 0b11111_111111_11111
+
+    assert draw.lighten(0b11111_111111_11111, 0b00001) == 0b11111_111111_11111
+
+    assert draw.lighten(0b10000_010000_01000, 0b10000) == 0b11111_110000_11000
+    assert draw.lighten(0b01000_100000_01000, 0b10000) == 0b11000_111111_11000
+    assert draw.lighten(0b01000_010000_10000, 0b10000) == 0b11000_110000_11111
+
+def test_darken(draw):
+    assert draw.darken(0b00001_000010_00001, 0b00001) == 0b00000_000000_00000
+    assert draw.darken(0b00010_000100_00010         ) == 0b00001_000010_00001
+    assert draw.darken(0b00010_000100_00010, 0b00001) == 0b00001_000010_00001
+    assert draw.darken(0b10000_010000_00100, 0b00001) == 0b01111_001110_00011
+
+    assert draw.darken(0b00000_000000_00000, 0b00001) == 0b00000_000000_00000
+    assert draw.darken(0b00001_000001_00001, 0b00001) == 0b00000_000000_00000
+    assert draw.darken(0b10000_100000_10000, 0b10001) == 0b00000_000000_00000
+    assert draw.darken(0b10000_100010_10010, 0b10001) == 0b00000_000000_00001
+    assert draw.darken(0b10000_100100_10010, 0b10001) == 0b00000_000010_00001
+