Require use of the ChannelMixer / ChannelScaler types in mix()

.. and update the test accordingly, fixing a bug discovered in the
process.

Author: jepler

locale/circuitpython.pot

@@ -4324,16 +4324,16 @@ msgstr ""
 msgid "wbits"
 msgstr ""
 
-#: shared-bindings/bitmapfilter/__init__.c
-msgid "weights must be a sequence of length 3, 6, 9, or 12"
-msgstr ""
-
 #: shared-bindings/bitmapfilter/__init__.c
 msgid ""
 "weights must be a sequence with an odd square number of elements (usually 9 "
 "or 25)"
 msgstr ""
 
+#: shared-bindings/bitmapfilter/__init__.c
+msgid "weights must be an object of type %q, %q, %q, or %q, not %q "
+msgstr ""
+
 #: shared-bindings/is31fl3741/FrameBuffer.c
 msgid "width must be greater than zero"
 msgstr ""

shared-bindings/bitmapfilter/__init__.c

@@ -273,7 +273,7 @@ static const mp_obj_namedtuple_type_t bitmapfilter_channel_mixer_type = {
 //|
 static const mp_obj_namedtuple_type_t bitmapfilter_channel_mixer_offset_type = {
     NAMEDTUPLE_TYPE_BASE_AND_SLOTS(MP_QSTR_ChannelMixerOffset),
-    .n_fields = 9,
+    .n_fields = 12,
     .fields = {
         MP_QSTR_rr,
         MP_QSTR_rg,
@@ -359,33 +359,30 @@ STATIC mp_obj_t bitmapfilter_mix(size_t n_args, const mp_obj_t *pos_args, mp_map
     memset(weights, 0, sizeof(weights));
 
     mp_obj_t weights_obj = args[ARG_weights].u_obj;
-    mp_int_t len = mp_obj_get_int(mp_obj_len(weights_obj));
-
-    switch (len) {
-        case 3:
-            for (int i = 0; i < 3; i++) {
-                weights[5 * i] = float_subscr(weights_obj, i);
-            }
-            break;
-        case 6:
-            for (int i = 0; i < 3; i++) {
-                weights[5 * i] = float_subscr(weights_obj, i * 2);
-                weights[4 * i + 3] = float_subscr(weights_obj, i * 2 + 1);
-            }
-            break;
-        case 9:
-            for (int i = 0; i < 9; i++) {
-                weights[i + i / 3] = float_subscr(weights_obj, i);
-            }
-            break;
-        case 12:
-            for (int i = 0; i < 12; i++) {
-                weights[i] = float_subscr(weights_obj, i);
-            }
-            break;
-        default:
-            mp_raise_ValueError(
-                MP_ERROR_TEXT("weights must be a sequence of length 3, 6, 9, or 12"));
+    if (mp_obj_is_type(weights_obj, (const mp_obj_type_t *)&bitmapfilter_channel_scale_type)) {
+        for (int i = 0; i < 3; i++) {
+            weights[5 * i] = float_subscr(weights_obj, i);
+        }
+    } else if (mp_obj_is_type(weights_obj, (const mp_obj_type_t *)&bitmapfilter_channel_scale_offset_type)) {
+        for (int i = 0; i < 3; i++) {
+            weights[5 * i] = float_subscr(weights_obj, i * 2);
+            weights[4 * i + 3] = float_subscr(weights_obj, i * 2 + 1);
+        }
+    } else if (mp_obj_is_type(weights_obj, (const mp_obj_type_t *)&bitmapfilter_channel_mixer_type)) {
+        for (int i = 0; i < 9; i++) {
+            weights[i + i / 3] = float_subscr(weights_obj, i);
+        }
+    } else if (mp_obj_is_type(weights_obj, (const mp_obj_type_t *)&bitmapfilter_channel_mixer_offset_type)) {
+        for (int i = 0; i < 12; i++) {
+            weights[i] = float_subscr(weights_obj, i);
+        }
+    } else {
+        mp_raise_ValueError_varg(
+            MP_ERROR_TEXT("weights must be an object of type %q, %q, %q, or %q, not %q "),
+            MP_QSTR_ScaleMixer, MP_QSTR_ScaleMixerOffset,
+            MP_QSTR_ChannelMixer, MP_QSTR_ChannelMixerOffset,
+            mp_obj_get_type_qstr(weights_obj)
+            );
     }
 
 

tests/circuitpython/bitmapfilter_mix.py

@@ -21,7 +21,9 @@ def make_quadrant_bitmap():
 b = test_pattern()
 dump_bitmap_rgb_swapped(b)
 
-sepia_weights = [0.393, 0.769, 0.189, 0.349, 0.686, 0.168, 0.272, 0.534, 0.131]
+sepia_weights = bitmapfilter.ChannelMixer(
+    0.393, 0.769, 0.189, 0.349, 0.686, 0.168, 0.272, 0.534, 0.131
+)
 
 print("sepia")
 bitmapfilter.mix(b, sepia_weights)
@@ -30,23 +32,23 @@ def make_quadrant_bitmap():
 # Red channel only
 print("red channel only (note: masked)")
 b = test_pattern()
-bitmapfilter.mix(b, [1, 0, 0], mask=q)
+bitmapfilter.mix(b, bitmapfilter.ChannelScale(1, 0, 0), mask=q)
 dump_bitmap_rgb_swapped(b)
 
 # Scale green channel
 print("scale green channel (note: masked)")
 b = test_pattern()
-bitmapfilter.mix(b, [1, 2, 0], mask=q)
+bitmapfilter.mix(b, bitmapfilter.ChannelScale(1, 2, 0), mask=q)
 dump_bitmap_rgb_swapped(b)
 
 # Swap R & G channels
 print("swap R&G")
 b = test_pattern()
-bitmapfilter.mix(b, [0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0])
+bitmapfilter.mix(b, bitmapfilter.ChannelMixerOffset(0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0))
 dump_bitmap_rgb_swapped(b)
 
 # invert B
 print("invert B")
 b = test_pattern()
-bitmapfilter.mix(b, [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, -1, 1])
+bitmapfilter.mix(b, bitmapfilter.ChannelScaleOffset(1, 0, 1, 0, -1, 1))
 dump_bitmap_rgb_swapped(b)