Import of the watch repository from Pebble

src/fw/applib/ui/rotbmp_pair_layer.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "applib/ui/layer.h"
+#include "applib/ui/rotate_bitmap_layer.h"
+#include "applib/graphics/gtypes.h"
+
+/**
+   A pair of images, one drawn white-transparent, the other black-transparent
+   used to draw a single image which has white, black, and transparent regions
+ **/
+typedef struct {
+  Layer layer;
+
+  RotBitmapLayer white_layer;
+  RotBitmapLayer black_layer;
+
+} RotBmpPairLayer;
+
+//! white and black *must* have the same dimensions, and *shouldn't* have any overlapp of eachother
+void rotbmp_pair_layer_init(RotBmpPairLayer *pair, GBitmap *white, GBitmap *black);
+
+void rotbmp_pair_layer_deinit(RotBmpPairLayer *pair);
+
+void rotbmp_pair_layer_set_angle(RotBmpPairLayer *pair, int32_t angle);
+void rotbmp_pair_layer_increment_angle(RotBmpPairLayer *pair, int32_t angle_change);
+
+void rotbmp_pair_layer_set_src_ic(RotBmpPairLayer *pair, GPoint ic);
+
+//! exchanges black with white
+void rotbmp_pair_layer_inver_colors(RotBmpPairLayer *pair);