Merge 180882cb89 into eaeea4bdfa

app/CMakeLists.txt

@@ -80,6 +80,14 @@ target_sources_ifdef(CONFIG_ZMK_BACKLIGHT app PRIVATE src/behaviors/behavior_bac
 target_sources_ifdef(CONFIG_ZMK_BATTERY_REPORTING app PRIVATE src/events/battery_state_changed.c)
 target_sources_ifdef(CONFIG_ZMK_BATTERY_REPORTING app PRIVATE src/battery.c)
 
+target_sources_ifdef(CONFIG_ZMK_ANIMATION app PRIVATE src/animation/color.c)
+target_sources_ifdef(CONFIG_ZMK_ANIMATION app PRIVATE src/animation/animation_compose.c)
+target_sources_ifdef(CONFIG_ZMK_ANIMATION app PRIVATE src/animation/animation_control.c)
+target_sources_ifdef(CONFIG_ZMK_ANIMATION app PRIVATE src/animation/animation_ripple.c)
+target_sources_ifdef(CONFIG_ZMK_ANIMATION app PRIVATE src/animation/animation_solid.c)
+target_sources_ifdef(CONFIG_ZMK_ANIMATION app PRIVATE src/animation/animation.c)
+target_sources_ifdef(CONFIG_ZMK_ANIMATION app PRIVATE src/behaviors/behavior_animation.c)
+
 target_sources_ifdef(CONFIG_ZMK_SPLIT app PRIVATE src/events/split_peripheral_status_changed.c)
 add_subdirectory(src/split)
 

app/Kconfig

@@ -305,6 +305,24 @@ config ZMK_BACKLIGHT_AUTO_OFF_USB
 #ZMK_BACKLIGHT
 endif
 
+config ZMK_ANIMATION
+    bool "RGB Animations"
+    select LED_STRIP
+
+if ZMK_ANIMATION
+
+config ZMK_ANIMATION_FPS
+    int "Animation FPS"
+    range 1 60
+    default 30
+
+config ZMK_ANIMATION_PIXEL_DISTANCE
+    bool "Generate a lookup table for distances between pixels"
+    default y
+
+#ZMK_ANIMATION
+endif
+
 #Display/LED Options
 endmenu
 

app/drivers/CMakeLists.txt

@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: MIT
 
 add_subdirectory_ifdef(CONFIG_ZMK_DRIVERS_GPIO gpio)
+add_subdirectory_ifdef(CONFIG_ZMK_ANIUMATION animation)
 add_subdirectory(kscan)
 add_subdirectory(sensor)
 add_subdirectory(display)

app/dts/animation.dtsi

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2021 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/ {
+    /omit-if-no-ref/ pixel: animation_pixel {
+        compatible = "zmk,animation-pixel";
+        label = "PIXEL";
+        #pixel-cells = <2>;
+    };
+};

app/dts/behaviors.dtsi

@@ -18,4 +18,5 @@
 #include <behaviors/caps_word.dtsi>
 #include <behaviors/key_repeat.dtsi>
 #include <behaviors/backlight.dtsi>
-#include <behaviors/macros.dtsi>
+#include <behaviors/macros.dtsi>
+#include <behaviors/animation.dtsi>

app/dts/behaviors/animation.dtsi

@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/ {
+    behaviors {
+        /omit-if-no-ref/ animation: behavior_animation {
+            compatible = "zmk,behavior-animation";
+            label = "ANIMATION";
+            #binding-cells = <1>;
+        };
+    };
+};

app/dts/bindings/animations/animation_base.yaml

@@ -0,0 +1,22 @@
+# Copyright (c) 2020, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+properties:
+  pixels:
+    type: array
+    required: true
+    description: |
+      Pixel positions to which the animation should apply.
+
+  blending-mode:
+    type: string
+    enum:
+      - "normal"
+      - "multiply"
+      - "lighten"
+      - "darken"
+      - "screen"
+      - "subtract"
+    default: "normal"
+    description: |
+      Blending mode for the animation to use during render.

app/dts/bindings/animations/zmk,animation-compose.yaml

@@ -0,0 +1,15 @@
+# Copyright (c) 2020, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: |
+  Higher-order animation which allows for composing other animation
+  drivers and using different blending modes.
+
+compatible: "zmk,animation-compose"
+
+properties:
+  animations:
+    type: phandles
+    required: true
+    description: |
+      Animations to be combined.

app/dts/bindings/animations/zmk,animation-control.yaml

@@ -0,0 +1,26 @@
+# Copyright (c) 2020, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: |
+  Higher-order animation which allows for controlling animation drivers
+  placed underneath it by turning them on and off, cycling though them,
+  or changing the brightness.
+
+compatible: "zmk,animation-control"
+
+properties:
+  label:
+    type: string
+    required: true
+
+  animations:
+    type: phandles
+    required: true
+    description: |
+      Animations to be combined.
+
+  brightness-steps:
+    type: int
+    default: 5
+    description: |
+      How many brightness steps should be supported.

app/dts/bindings/animations/zmk,animation-ripple.yaml

@@ -0,0 +1,41 @@
+# Copyright (c) 2020, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: |
+  Animated 'ripples' trigered by key presses.
+
+compatible: "zmk,animation-ripple"
+
+include: animation_base.yaml
+
+properties:
+  duration:
+    type: int
+    default: 1000
+    description: |
+      Approximate ripple travel time in milliseconds.
+
+  color:
+    type: int
+    required: true
+    description: |
+      Ripple color in HSL format.
+
+  buffer-size:
+    type: int
+    default: 10
+    description: |
+      This will limit how many keystroke events the animation is able to track
+      at the same time. Depending on how fast you type and the animation duration
+      you might need to increase this number.
+
+  ripple-width:
+    type: int
+    default: 25
+    description: |
+      This setting determines the thickness of the ripple 'ring'.
+      Think of it as antialiasing. The further apart the pixels are, or if they're
+      spaced irregularly, the larger this number should be. Otherwise the animation
+      will look uneven or LEDs might not light up at all.
+      The effect is especially pronounced when lowering the effect duration or running
+      low FPS.

app/dts/bindings/animations/zmk,animation-solid.yaml

@@ -0,0 +1,24 @@
+# Copyright (c) 2020, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: |
+  Animation for displaying solid colors across the entire area
+
+compatible: "zmk,animation-solid"
+
+include: animation_base.yaml
+
+properties:
+  duration:
+    type: int
+    default: 5
+    description: |
+      Animation duration in seconds.
+      This is the time it takes for the animation to complete a full cycle and return to the original color.
+      Ignored if only a single color is given.
+
+  colors:
+    type: array
+    required: true
+    description: |
+      The colors to cycle through during the animation in HSL format.

app/dts/bindings/behaviors/zmk,behavior-animation.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2020 The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: Animation Action
+
+compatible: "zmk,behavior-animation"
+
+include: one_param.yaml

app/dts/bindings/zmk,animation-pixel.yaml

@@ -0,0 +1,10 @@
+# Copyright (c) 2020, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: Pixel configuration
+
+compatible: "zmk,animation-pixel"
+
+pixel-cells:
+  - position_x
+  - position_y

app/dts/bindings/zmk,animation.yaml

@@ -0,0 +1,36 @@
+# Copyright (c) 2020, The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: Global animation configuration
+
+compatible: "zmk,animation"
+
+properties:
+  drivers:
+    type: phandles
+    required: true
+    description: |
+      This array should contain all driver devices responsible for illuminating animated LEDs.
+      The devices must implement Zephyr's LED Strip Interface.
+
+  chain-lengths:
+    type: array
+    required: true
+    description: |
+      This field contains the number of LEDs controlled by each driver device.
+
+  pixels:
+    type: phandle-array
+    required: true
+    description: |
+      This field contains the pixel configuration for the entire board.
+      The order of this array determines in what order pixels are sent to the driver device API.
+      If multiple driving devices are used, their chain-length property determines the size of the buffer for each device.
+
+  key-pixels:
+    type: array
+    description: |
+      Use this field to specify the pixel index corresponding to each key
+      following the order used in your keymap.
+      When left unspecified, the driver assumes that for every key, the pixel has a matching id.
+      So for N keys, the first N pixels are exactly in the same order as keys in your keymap.

app/include/drivers/animation.h

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <zephyr/types.h>
+#include <zephyr/device.h>
+#include <zephyr/drivers/led_strip.h>
+
+#include <zmk/animation.h>
+
+/**
+ * @file
+ * #brief Public API for controlling animations.
+ *
+ * This library abstracts the implementation details
+ * for various types of 2D animations.
+ */
+
+struct animation_pixel {
+    const uint8_t position_x;
+    const uint8_t position_y;
+
+    struct zmk_color_rgb value;
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @typedef animation_start
+ * @brief Callback API for starting an animation.
+ *
+ * @see animation_start() for argument descriptions.
+ */
+typedef void (*animation_api_start)(const struct device *dev);
+
+/**
+ * @typedef animation_stop
+ * @brief Callback API for stopping an animation.
+ *
+ * @see animation_stop() for argument descriptions.
+ */
+typedef void (*animation_api_stop)(const struct device *dev);
+
+/**
+ * @typedef animation_render_frame
+ * @brief Callback API for generating the next animation frame.
+ *
+ * @see animation_render_frame() for argument descriptions.
+ */
+typedef void (*animation_api_render_frame)(const struct device *dev, struct animation_pixel *pixels,
+                                           size_t num_pixels);
+
+struct animation_api {
+    animation_api_start on_start;
+    animation_api_stop on_stop;
+    animation_api_render_frame render_frame;
+};
+
+static inline void animation_start(const struct device *dev) {
+    const struct animation_api *api = (const struct animation_api *)dev->api;
+
+    return api->on_start(dev);
+}
+
+static inline void animation_stop(const struct device *dev) {
+    const struct animation_api *api = (const struct animation_api *)dev->api;
+
+    return api->on_stop(dev);
+}
+
+static inline void animation_render_frame(const struct device *dev, struct animation_pixel *pixels,
+                                          size_t num_pixels) {
+    const struct animation_api *api = (const struct animation_api *)dev->api;
+
+    return api->render_frame(dev, pixels, num_pixels);
+}
+
+#ifdef __cplusplus
+}
+#endif

app/include/dt-bindings/zmk/animation.h

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/**
+ * Maps HSL color settings into a single uint32_t value
+ * that can be cast to zmk_color_hsl.
+ */
+#ifdef CONFIG_BIG_ENDIAN
+#define HSL(h, s, l) ((h << 16) + (s << 8) + l)
+#else
+#define HSL(h, s, l) (h + (s << 16) + (l << 24))
+#endif
+
+/**
+ * Animation blending modes
+ */
+#define BLENDING_MODE_NORMAL 0
+#define BLENDING_MODE_MULTIPLY 1
+#define BLENDING_MODE_LIGHTEN 2
+#define BLENDING_MODE_DARKEN 3
+#define BLENDING_MODE_SCREEN 4
+#define BLENDING_MODE_SUBTRACT 5
+
+/**
+ * Animation control commands
+ */
+#define ANIMATION_CMD_TOGGLE 0
+#define ANIMATION_CMD_NEXT 1
+#define ANIMATION_CMD_PREVIOUS 2
+#define ANIMATION_CMD_SELECT 3
+#define ANIMATION_CMD_BRIGHTEN 4
+#define ANIMATION_CMD_DIM 5
+#define ANIMATION_CMD_NEXT_CONTROL_ZONE 6
+#define ANIMATION_CMD_PREVIOUS_CONTROL_ZONE 7
+
+/**
+ * Generic animation command macro
+ */
+#define ANIMATION_CONTROL_CMD(command, zone, param) ((zone << 24) | (command << 16) | (param))
+
+/**
+ * Animation behavior helpers
+ */
+#define ANIMATION_TOGGLE(zone) ANIMATION_CONTROL_CMD(ANIMATION_CMD_TOGGLE, zone, 0)
+#define ANIMATION_NEXT(zone) ANIMATION_CONTROL_CMD(ANIMATION_CMD_NEXT, zone, 0)
+#define ANIMATION_PREVIOUS(zone) ANIMATION_CONTROL_CMD(ANIMATION_CMD_PREVIOUS, zone, 0)
+#define ANIMATION_SELECT(zone, target_animation)                                                   \
+    ANIMATION_CONTROL_CMD(ANIMATION_CMD_SELECT, zone, target_animation)
+#define ANIMATION_BRIGHTEN(zone) ANIMATION_CONTROL_CMD(ANIMATION_CMD_BRIGHTEN, zone, 0)
+#define ANIMATION_DIM(zone) ANIMATION_CONTROL_CMD(ANIMATION_CMD_DIM, zone, 0)
+#define ANIMATION_NEXT_CONTROL_ZONE ANIMATION_CONTROL_CMD(ANIMATION_CMD_NEXT_CONTROL_ZONE, 0, 0)
+#define ANIMATION_PREVIOUS_CONTROL_ZONE                                                            \
+    ANIMATION_CONTROL_CMD(ANIMATION_CMD_PREVIOUS_CONTROL_ZONE, 0, 0)

app/include/dt-bindings/zmk/animation_compose.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#define BLENDING_MODE_NORMAL 0
+#define BLENDING_MODE_MULTIPLY 1
+#define BLENDING_MODE_LIGHTEN 2
+#define BLENDING_MODE_DARKEN 3
+#define BLENDING_MODE_SCREEN 4
+#define BLENDING_MODE_SUBTRACT 5

app/include/zmk/animation.h

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2021 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/led_strip.h>
+
+#define ZMK_ANIMATION_BLENDING_MODE_NORMAL 0
+#define ZMK_ANIMATION_BLENDING_MODE_MULTIPLY 1
+#define ZMK_ANIMATION_BLENDING_MODE_LIGHTEN 2
+#define ZMK_ANIMATION_BLENDING_MODE_DARKEN 3
+#define ZMK_ANIMATION_BLENDING_MODE_SCREEN 4
+#define ZMK_ANIMATION_BLENDING_MODE_SUBTRACT 5
+
+struct zmk_color_rgb {
+    float r;
+    float g;
+    float b;
+};
+
+struct zmk_color_hsl {
+    uint16_t h;
+    uint8_t s;
+    uint8_t l;
+};
+
+#if DT_NODE_HAS_PROP(DT_INST(0, animation), key_position)
+size_t zmk_animation_get_pixel_by_key_position(size_t key_position);
+#else
+static inline size_t zmk_animation_get_pixel_by_key_position(size_t key_position) {
+    return key_position;
+}
+#endif
+
+#if defined(CONFIG_ZMK_ANIMATION_PIXEL_DISTANCE) && (CONFIG_ZMK_ANIMATION_PIXEL_DISTANCE == 1)
+uint8_t zmk_animation_get_pixel_distance(size_t pixel_idx, size_t other_pixel_idx);
+#endif
+
+/**
+ * Converts color from HSL to RGB.
+ *
+ * @param hsl Color to convert
+ * @param rgb Converted color
+ */
+void zmk_hsl_to_rgb(const struct zmk_color_hsl *hsl, struct zmk_color_rgb *rgb);
+
+/**
+ * Converts the internal RGB representation into a led_rgb struct
+ * for use with led_strip drivers.
+ *
+ * @param rgb Color to convert
+ * @param led Converted color
+ */
+void zmk_rgb_to_led_rgb(const struct zmk_color_rgb *rgb, struct led_rgb *led);
+
+/**
+ * Returns true if two HSL colors are the same.
+ *
+ * @param  a HSL color to compare
+ * @param  b HSL color to compare
+ * @return   True when colors share the same values
+ */
+bool zmk_cmp_hsl(const struct zmk_color_hsl *a, const struct zmk_color_hsl *b);
+
+/**
+ * Perform linear interpolation between HSL values of two colors
+ * at a given distance (step) and store the resulting value in the given pointer.
+ *
+ * @param from   HSL color to interpolate
+ * @param to     HSL color to interpolate
+ * @param result Resulting HSL color
+ * @param step   Interpolation step
+ */
+void zmk_interpolate_hsl(const struct zmk_color_hsl *from, const struct zmk_color_hsl *to,
+                         struct zmk_color_hsl *result, float step);
+
+void zmk_animation_request_frames(uint32_t frames);
+
+struct zmk_color_rgb __zmk_apply_blending_mode(struct zmk_color_rgb base_value,
+                                               struct zmk_color_rgb blend_value, uint8_t mode);
+
+static inline struct zmk_color_rgb zmk_apply_blending_mode(struct zmk_color_rgb base_value,
+                                                           struct zmk_color_rgb blend_value,
+                                                           uint8_t mode) {
+    if (mode == ZMK_ANIMATION_BLENDING_MODE_NORMAL) {
+        return blend_value;
+    }
+
+    return __zmk_apply_blending_mode(base_value, blend_value, mode);
+}

app/include/zmk/animation/animation_control.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <zephyr/device.h>
+#include <zephyr/kernel.h>
+
+/**
+ * Animation control commands
+ */
+#define ANIMATION_CMD_TOGGLE 0
+#define ANIMATION_CMD_NEXT 1
+#define ANIMATION_CMD_PREVIOUS 2
+#define ANIMATION_CMD_SELECT 3
+#define ANIMATION_CMD_BRIGHTEN 4
+#define ANIMATION_CMD_DIM 5
+#define ANIMATION_CMD_NEXT_CONTROL_ZONE 6
+#define ANIMATION_CMD_PREVIOUS_CONTROL_ZONE 7
+
+int animation_control_handle_command(const struct device *dev, uint8_t command, uint8_t param);

app/src/animation/animation.c

@@ -0,0 +1,200 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#define DT_DRV_COMPAT zmk_animation
+
+#include <stdlib.h>
+#include <math.h>
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/led_strip.h>
+#include <zephyr/init.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+
+#include <drivers/animation.h>
+
+#include <zmk/animation.h>
+#include <zmk/event_manager.h>
+#include <zmk/events/activity_state_changed.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#define PHANDLE_TO_DEVICE(node_id, prop, idx) DEVICE_DT_GET(DT_PHANDLE_BY_IDX(node_id, prop, idx)),
+
+#define PHANDLE_TO_PIXEL(node_id, prop, idx)                                                       \
+    {                                                                                              \
+        .position_x = DT_PHA_BY_IDX(node_id, prop, idx, position_x),                               \
+        .position_y = DT_PHA_BY_IDX(node_id, prop, idx, position_y),                               \
+    },
+
+/**
+ * LED Driver device pointers.
+ */
+static const struct device *drivers[] = {DT_INST_FOREACH_PROP_ELEM(0, drivers, PHANDLE_TO_DEVICE)};
+
+/**
+ * Size of the LED driver device pointers array.
+ */
+static const size_t drivers_size = DT_INST_PROP_LEN(0, drivers);
+
+/**
+ * Array containing the number of LEDs handled by each device.
+ */
+static const size_t pixels_per_driver[] = DT_INST_PROP(0, chain_lengths);
+
+/**
+ * Pointer to the root animation
+ */
+static const struct device *animation_root = DEVICE_DT_GET(DT_CHOSEN(zmk_animation));
+
+/**
+ * Pixel configuration.
+ */
+static struct animation_pixel pixels[] = {DT_INST_FOREACH_PROP_ELEM(0, pixels, PHANDLE_TO_PIXEL)};
+
+/**
+ * Size of the pixels array.
+ */
+static const size_t pixels_size = DT_INST_PROP_LEN(0, pixels);
+
+/**
+ * Buffer for RGB values ready to be sent to the drivers.
+ */
+static struct led_rgb px_buffer[DT_INST_PROP_LEN(0, pixels)];
+
+/**
+ * Counter for animation frames that have been requested but have yet to be executed.
+ */
+static uint32_t animation_timer_countdown = 0;
+
+/**
+ * Conditional implementation of zmk_animation_get_pixel_by_key_position
+ * if key-pixels is set.
+ */
+#if DT_INST_NODE_HAS_PROP(0, key_position)
+static const uint8_t pixels_by_key_position[] = DT_INST_PROP(0, key_pixels);
+
+size_t zmk_animation_get_pixel_by_key_position(size_t key_position) {
+    return pixels_by_key_position[key_position];
+}
+#endif
+
+#if defined(CONFIG_ZMK_ANIMATION_PIXEL_DISTANCE) && (CONFIG_ZMK_ANIMATION_PIXEL_DISTANCE == 1)
+
+/**
+ * Lookup table for distance between any two pixels.
+ *
+ * The values are stored as a triangular matrix which cuts the space requirement roughly in half.
+ */
+static uint8_t
+    pixel_distance[((DT_INST_PROP_LEN(0, pixels) + 1) * DT_INST_PROP_LEN(0, pixels)) / 2];
+
+uint8_t zmk_animation_get_pixel_distance(size_t pixel_idx, size_t other_pixel_idx) {
+    if (pixel_idx < other_pixel_idx) {
+        return zmk_animation_get_pixel_distance(other_pixel_idx, pixel_idx);
+    }
+
+    return pixel_distance[(((pixel_idx + 1) * pixel_idx) >> 1) + other_pixel_idx];
+}
+
+#endif
+
+static void zmk_animation_tick(struct k_work *work) {
+    LOG_DBG("Animation tick");
+    animation_render_frame(animation_root, &pixels[0], pixels_size);
+
+    for (size_t i = 0; i < pixels_size; ++i) {
+        zmk_rgb_to_led_rgb(&pixels[i].value, &px_buffer[i]);
+
+        // Reset values for the next cycle
+        pixels[i].value.r = 0;
+        pixels[i].value.g = 0;
+        pixels[i].value.b = 0;
+    }
+
+    size_t pixels_updated = 0;
+
+    for (size_t i = 0; i < drivers_size; ++i) {
+        led_strip_update_rgb(drivers[i], &px_buffer[pixels_updated], pixels_per_driver[i]);
+
+        pixels_updated += pixels_per_driver[i];
+    }
+}
+
+K_WORK_DEFINE(animation_work, zmk_animation_tick);
+
+static void zmk_animation_tick_handler(struct k_timer *timer) {
+    if (--animation_timer_countdown == 0) {
+        k_timer_stop(timer);
+    }
+
+    k_work_submit(&animation_work);
+}
+
+K_TIMER_DEFINE(animation_tick, zmk_animation_tick_handler, NULL);
+
+void zmk_animation_request_frames(uint32_t frames) {
+    if (frames <= animation_timer_countdown) {
+        return;
+    }
+
+    if (animation_timer_countdown == 0) {
+        k_timer_start(&animation_tick, K_MSEC(1000 / CONFIG_ZMK_ANIMATION_FPS),
+                      K_MSEC(1000 / CONFIG_ZMK_ANIMATION_FPS));
+    }
+
+    animation_timer_countdown = frames;
+}
+
+static int zmk_animation_on_activity_state_changed(const zmk_event_t *event) {
+    const struct zmk_activity_state_changed *activity_state_event;
+
+    if ((activity_state_event = as_zmk_activity_state_changed(event)) == NULL) {
+        // Event not supported.
+        return -ENOTSUP;
+    }
+
+    switch (activity_state_event->state) {
+    case ZMK_ACTIVITY_ACTIVE:
+        animation_start(animation_root);
+        return 0;
+    case ZMK_ACTIVITY_SLEEP:
+        animation_stop(animation_root);
+        k_timer_stop(&animation_tick);
+        animation_timer_countdown = 0;
+        return 0;
+    default:
+        return 0;
+    }
+}
+
+static int zmk_animation_init(const struct device *dev) {
+#if defined(CONFIG_ZMK_ANIMATION_PIXEL_DISTANCE) && (CONFIG_ZMK_ANIMATION_PIXEL_DISTANCE == 1)
+    // Prefill the pixel distance lookup table
+    int k = 0;
+    for (size_t i = 0; i < pixels_size; ++i) {
+        for (size_t j = 0; j <= i; ++j) {
+            // Distances are normalized to fit inside 0-255 range to fit inside uint8_t
+            // for better space efficiency
+            pixel_distance[k++] = sqrt(pow(pixels[i].position_x - pixels[j].position_x, 2) +
+                                       pow(pixels[i].position_y - pixels[j].position_y, 2)) *
+                                  255 / 360;
+        }
+    }
+#endif
+
+    LOG_INF("ZMK Animation Ready");
+
+    animation_start(animation_root);
+
+    return 0;
+}
+
+SYS_INIT(zmk_animation_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);
+
+ZMK_LISTENER(amk_animation, zmk_animation_on_activity_state_changed);
+ZMK_SUBSCRIPTION(amk_animation, zmk_activity_state_changed);

app/src/animation/animation_compose.c

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#define DT_DRV_COMPAT zmk_animation_compose
+
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/logging/log.h>
+
+#include <drivers/animation.h>
+
+#include <zmk/animation.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#define PHANDLE_TO_DEVICE(node_id, prop, idx) DEVICE_DT_GET(DT_PHANDLE_BY_IDX(node_id, prop, idx)),
+
+struct animation_compose_config {
+    const struct device **animations;
+    const size_t animations_size;
+};
+
+static void animation_compose_render_frame(const struct device *dev, struct animation_pixel *pixels,
+                                           size_t num_pixels) {
+    const struct animation_compose_config *config = dev->config;
+
+    for (size_t i = 0; i < config->animations_size; ++i) {
+        animation_render_frame(config->animations[i], pixels, num_pixels);
+    }
+}
+
+static void animation_compose_start(const struct device *dev) {
+    const struct animation_compose_config *config = dev->config;
+
+    for (size_t i = 0; i < config->animations_size; ++i) {
+        animation_start(config->animations[i]);
+    }
+}
+
+static void animation_compose_stop(const struct device *dev) {
+    const struct animation_compose_config *config = dev->config;
+
+    for (size_t i = 0; i < config->animations_size; ++i) {
+        animation_stop(config->animations[i]);
+    }
+}
+
+static int animation_compose_init(const struct device *dev) { return 0; }
+
+static const struct animation_api animation_compose_api = {
+    .on_start = animation_compose_start,
+    .on_stop = animation_compose_stop,
+    .render_frame = animation_compose_render_frame,
+};
+
+#define ANIMATION_COMPOSE_DEVICE(idx)                                                              \
+                                                                                                   \
+    static const struct device *animation_compose_##idx##_animations[] = {                         \
+        DT_INST_FOREACH_PROP_ELEM(idx, animations, PHANDLE_TO_DEVICE)};                            \
+                                                                                                   \
+    static struct animation_compose_config animation_compose_##idx##_config = {                    \
+        .animations = animation_compose_##idx##_animations,                                        \
+        .animations_size = DT_INST_PROP_LEN(idx, animations),                                      \
+    };                                                                                             \
+                                                                                                   \
+    DEVICE_DT_INST_DEFINE(idx, &animation_compose_init, NULL, NULL,                                \
+                          &animation_compose_##idx##_config, POST_KERNEL,                          \
+                          CONFIG_APPLICATION_INIT_PRIORITY, &animation_compose_api);
+
+DT_INST_FOREACH_STATUS_OKAY(ANIMATION_COMPOSE_DEVICE);

app/src/animation/animation_control.c

@@ -0,0 +1,264 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#define DT_DRV_COMPAT zmk_animation_control
+
+#include <stdio.h>
+
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/settings/settings.h>
+
+#include <drivers/animation.h>
+
+#include <zmk/animation.h>
+#include <zmk/animation/animation_control.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#define PHANDLE_TO_DEVICE(node_id, prop, idx) DEVICE_DT_GET(DT_PHANDLE_BY_IDX(node_id, prop, idx)),
+
+struct animation_control_work_context {
+    const struct device *animation;
+    struct k_work_delayable save_work;
+};
+
+struct animation_control_config {
+    const struct device **animations;
+    const size_t animations_size;
+    const uint8_t brightness_steps;
+    struct animation_control_work_context *work;
+    struct settings_handler *settings_handler;
+};
+
+struct animation_control_data {
+    bool active;
+    uint8_t brightness;
+    size_t current_animation;
+};
+
+static int animation_control_load_settings(const struct device *dev, const char *name, size_t len,
+                                           settings_read_cb read_cb, void *cb_arg) {
+#if IS_ENABLED(CONFIG_SETTINGS)
+    const char *next;
+    int rc;
+
+    if (settings_name_steq(name, "state", &next) && !next) {
+        if (len != sizeof(struct animation_control_data)) {
+            return -EINVAL;
+        }
+
+        rc = read_cb(cb_arg, dev->data, sizeof(struct animation_control_data));
+        if (rc >= 0) {
+            return 0;
+        }
+
+        return rc;
+    }
+
+    return -ENOENT;
+#else
+    return 0;
+#endif /* IS_ENABLED(CONFIG_SETTINGS) */
+}
+
+#if IS_ENABLED(CONFIG_SETTINGS)
+static void animation_control_save_work(struct k_work *work) {
+    struct animation_control_work_context *ctx =
+        CONTAINER_OF(work, struct animation_control_work_context, save_work);
+    const struct device *dev = ctx->animation;
+
+    char path[40];
+    snprintf(path, 40, "%s/state", dev->name);
+
+    settings_save_one(path, dev->data, sizeof(struct animation_control_data));
+};
+
+static int animation_control_save_settings(const struct device *dev) {
+    const struct animation_control_config *config = dev->config;
+    struct animation_control_work_context *ctx = config->work;
+
+    k_work_cancel_delayable(&ctx->save_work);
+
+    return k_work_reschedule(&ctx->save_work, K_MSEC(CONFIG_ZMK_SETTINGS_SAVE_DEBOUNCE));
+}
+#endif /* IS_ENABLED(CONFIG_SETTINGS) */
+
+int animation_control_handle_command(const struct device *dev, uint8_t command, uint8_t param) {
+    const struct animation_control_config *config = dev->config;
+    struct animation_control_data *data = dev->data;
+
+    switch (command) {
+    case ANIMATION_CMD_TOGGLE:
+        data->active = !data->active;
+
+        if (data->active) {
+            animation_start(config->animations[data->current_animation]);
+            break;
+        }
+
+        animation_stop(config->animations[data->current_animation]);
+        break;
+    case ANIMATION_CMD_NEXT:
+        data->current_animation++;
+
+        if (data->current_animation == config->animations_size) {
+            data->current_animation = 0;
+        }
+        break;
+    case ANIMATION_CMD_PREVIOUS:
+        if (data->current_animation == 0) {
+            data->current_animation = config->animations_size;
+        }
+
+        data->current_animation--;
+        break;
+    case ANIMATION_CMD_SELECT:
+        if (config->animations_size < param) {
+            return -ENOTSUP;
+        }
+
+        data->current_animation = param;
+        break;
+    case ANIMATION_CMD_DIM:
+        if (data->brightness == 0) {
+            return 0;
+        }
+
+        data->brightness--;
+
+        if (data->brightness == 0) {
+            animation_stop(config->animations[data->current_animation]);
+        }
+        break;
+    case ANIMATION_CMD_BRIGHTEN:
+        if (data->brightness == config->brightness_steps) {
+            return 0;
+        }
+
+        if (data->brightness == 0) {
+            animation_start(config->animations[data->current_animation]);
+        }
+
+        data->brightness++;
+        break;
+    }
+
+#if IS_ENABLED(CONFIG_SETTINGS)
+    animation_control_save_settings(dev);
+#endif /* IS_ENABLED(CONFIG_SETTINGS) */
+
+    // Force refresh
+    zmk_animation_request_frames(1);
+
+    return 0;
+}
+
+static void animation_control_render_frame(const struct device *dev, struct animation_pixel *pixels,
+                                           size_t num_pixels) {
+    const struct animation_control_config *config = dev->config;
+    const struct animation_control_data *data = dev->data;
+
+    if (!data->active) {
+        return;
+    }
+
+    animation_render_frame(config->animations[data->current_animation], pixels, num_pixels);
+
+    if (data->brightness == config->brightness_steps) {
+        return;
+    }
+
+    float brightness = (float)data->brightness / (float)config->brightness_steps;
+
+    for (size_t i = 0; i < num_pixels; ++i) {
+        pixels[i].value.r *= brightness;
+        pixels[i].value.g *= brightness;
+        pixels[i].value.b *= brightness;
+    }
+}
+
+static void animation_control_start(const struct device *dev) {
+    const struct animation_control_config *config = dev->config;
+    const struct animation_control_data *data = dev->data;
+
+    if (!data->active) {
+        return;
+    }
+
+    animation_start(config->animations[data->current_animation]);
+}
+
+static void animation_control_stop(const struct device *dev) {
+    const struct animation_control_config *config = dev->config;
+    const struct animation_control_data *data = dev->data;
+
+    animation_stop(config->animations[data->current_animation]);
+}
+
+static int animation_control_init(const struct device *dev) {
+#if IS_ENABLED(CONFIG_SETTINGS)
+    const struct animation_control_config *config = dev->config;
+
+    settings_subsys_init();
+
+    settings_register(config->settings_handler);
+
+    k_work_init_delayable(&config->work->save_work, animation_control_save_work);
+
+    settings_load_subtree(dev->name);
+#endif /* IS_ENABLED(CONFIG_SETTINGS) */
+
+    return 0;
+}
+
+static const struct animation_api animation_control_api = {
+    .on_start = animation_control_start,
+    .on_stop = animation_control_stop,
+    .render_frame = animation_control_render_frame,
+};
+
+#define ANIMATION_CONTROL_DEVICE(idx)                                                              \
+                                                                                                   \
+    static const struct device *animation_control_##idx##_animations[] = {                         \
+        DT_INST_FOREACH_PROP_ELEM(idx, animations, PHANDLE_TO_DEVICE)};                            \
+                                                                                                   \
+    static struct animation_control_work_context animation_control_##idx##_work = {                \
+        .animation = DEVICE_DT_GET(DT_DRV_INST(idx)),                                              \
+    };                                                                                             \
+                                                                                                   \
+    static int animation_control_##idx##_load_settings(const char *name, size_t len,               \
+                                                       settings_read_cb read_cb, void *cb_arg) {   \
+        const struct device *dev = DEVICE_DT_GET(DT_DRV_INST(idx));                                \
+                                                                                                   \
+        return animation_control_load_settings(dev, name, len, read_cb, cb_arg);                   \
+    }                                                                                              \
+                                                                                                   \
+    static struct settings_handler animation_control_##idx##_settings_handler = {                  \
+        .name = DT_INST_PROP(idx, label),                                                          \
+        .h_set = animation_control_##idx##_load_settings,                                          \
+    };                                                                                             \
+                                                                                                   \
+    static const struct animation_control_config animation_control_##idx##_config = {              \
+        .animations = animation_control_##idx##_animations,                                        \
+        .animations_size = DT_INST_PROP_LEN(idx, animations),                                      \
+        .brightness_steps = DT_INST_PROP(idx, brightness_steps) - 1,                               \
+        .work = &animation_control_##idx##_work,                                                   \
+        .settings_handler = &animation_control_##idx##_settings_handler,                           \
+    };                                                                                             \
+                                                                                                   \
+    static struct animation_control_data animation_control_##idx##_data = {                        \
+        .active = true,                                                                            \
+        .brightness = DT_INST_PROP(idx, brightness_steps) - 1,                                     \
+        .current_animation = 0,                                                                    \
+    };                                                                                             \
+                                                                                                   \
+    DEVICE_DT_INST_DEFINE(idx, &animation_control_init, NULL, &animation_control_##idx##_data,     \
+                          &animation_control_##idx##_config, POST_KERNEL,                          \
+                          CONFIG_APPLICATION_INIT_PRIORITY, &animation_control_api);
+
+DT_INST_FOREACH_STATUS_OKAY(ANIMATION_CONTROL_DEVICE);

app/src/animation/animation_ripple.c

@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#define DT_DRV_COMPAT zmk_animation_ripple
+
+#include <stdlib.h>
+#include <math.h>
+
+#include <zephyr/device.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+
+#include <drivers/animation.h>
+
+#include <zmk/animation.h>
+#include <zmk/event_manager.h>
+#include <zmk/events/position_state_changed.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+struct animation_ripple_event {
+    size_t pixel_id;
+    uint16_t distance;
+    uint8_t counter;
+};
+
+struct animation_ripple_config {
+    struct zmk_color_hsl *color_hsl;
+    size_t *pixel_map;
+    size_t pixel_map_size;
+    size_t event_buffer_size;
+    uint8_t blending_mode;
+    uint8_t distance_per_frame;
+    uint8_t ripple_width;
+    uint8_t event_frames;
+};
+
+struct animation_ripple_data {
+    struct zmk_color_rgb color_rgb;
+    struct animation_ripple_event *event_buffer;
+    size_t events_start;
+    size_t events_end;
+    size_t num_events;
+    bool is_active;
+};
+
+static int animation_ripple_on_key_press(const struct device *dev, const zmk_event_t *event) {
+    const struct animation_ripple_config *config = dev->config;
+    struct animation_ripple_data *data = dev->data;
+
+    const struct zmk_position_state_changed *pos_event;
+
+    if (!data->is_active) {
+        return 0;
+    }
+
+    if ((pos_event = as_zmk_position_state_changed(event)) == NULL) {
+        // Event not supported.
+        return -ENOTSUP;
+    }
+
+    if (!pos_event->state) {
+        // Don't track key releases.
+        return 0;
+    }
+
+    if (data->num_events == config->event_buffer_size) {
+        // Event buffer is full - new key press events are dropped.
+        return -ENOMEM;
+    }
+
+    data->event_buffer[data->events_end].pixel_id =
+        zmk_animation_get_pixel_by_key_position(pos_event->position);
+    data->event_buffer[data->events_end].distance = 0;
+    data->event_buffer[data->events_end].counter = 0;
+
+    data->events_end = (data->events_end + 1) % config->event_buffer_size;
+    data->num_events += 1;
+
+    zmk_animation_request_frames(config->event_frames);
+
+    return 0;
+}
+
+static void animation_ripple_render_frame(const struct device *dev, struct animation_pixel *pixels,
+                                          size_t num_pixels) {
+    const struct animation_ripple_config *config = dev->config;
+    struct animation_ripple_data *data = dev->data;
+
+    size_t *pixel_map = config->pixel_map;
+
+    size_t i = data->events_start;
+
+    while (i != data->events_end) {
+        struct animation_ripple_event *event = &data->event_buffer[i];
+
+        // Render all pixels for each event
+        for (int j = 0; j < config->pixel_map_size; ++j) {
+            uint8_t pixel_distance =
+                zmk_animation_get_pixel_distance(event->pixel_id, pixel_map[j]);
+
+            if (config->ripple_width > abs(pixel_distance - event->distance)) {
+                float intensity = 1.0f - (float)abs(pixel_distance - event->distance) /
+                                             (float)config->ripple_width;
+
+                struct zmk_color_rgb color = {
+                    .r = intensity * data->color_rgb.r,
+                    .g = intensity * data->color_rgb.g,
+                    .b = intensity * data->color_rgb.b,
+                };
+
+                pixels[pixel_map[j]].value = zmk_apply_blending_mode(pixels[pixel_map[j]].value,
+                                                                     color, config->blending_mode);
+            }
+        }
+
+        // Update event counter
+        if (event->counter < config->event_frames) {
+            event->distance += config->distance_per_frame;
+            event->counter += 1;
+        } else {
+            data->events_start = (data->events_start + 1) % config->event_buffer_size;
+            data->num_events -= 1;
+        }
+
+        if (++i == config->event_buffer_size) {
+            i = 0;
+        }
+    }
+}
+
+static void animation_ripple_start(const struct device *dev) {
+    struct animation_ripple_data *data = dev->data;
+
+    data->is_active = true;
+}
+
+static void animation_ripple_stop(const struct device *dev) {
+    struct animation_ripple_data *data = dev->data;
+
+    data->is_active = false;
+
+    // Cancel processing of any ongoing events.
+    data->num_events = 0;
+    data->events_start = 0;
+    data->events_end = 0;
+}
+
+static int animation_ripple_init(const struct device *dev) {
+    const struct animation_ripple_config *config = dev->config;
+    struct animation_ripple_data *data = dev->data;
+
+    zmk_hsl_to_rgb(config->color_hsl, &data->color_rgb);
+
+    return 0;
+}
+
+static const struct animation_api animation_ripple_api = {
+    .on_start = animation_ripple_start,
+    .on_stop = animation_ripple_stop,
+    .render_frame = animation_ripple_render_frame,
+};
+
+#define ANIMATION_RIPPLE_DEVICE(idx)                                                               \
+                                                                                                   \
+    static struct animation_ripple_event                                                           \
+        animation_ripple_##idx##_events[DT_INST_PROP(idx, buffer_size)];                           \
+                                                                                                   \
+    static struct animation_ripple_data animation_ripple_##idx##_data = {                          \
+        .event_buffer = animation_ripple_##idx##_events,                                           \
+        .events_start = 0,                                                                         \
+        .events_end = 0,                                                                           \
+        .num_events = 0,                                                                           \
+    };                                                                                             \
+                                                                                                   \
+    static size_t animation_ripple_##idx##_pixel_map[] = DT_INST_PROP(idx, pixels);                \
+                                                                                                   \
+    static uint32_t animation_ripple_##idx##_color = DT_INST_PROP(idx, color);                     \
+                                                                                                   \
+    static struct animation_ripple_config animation_ripple_##idx##_config = {                      \
+        .color_hsl = (struct zmk_color_hsl *)&animation_ripple_##idx##_color,                      \
+        .pixel_map = &animation_ripple_##idx##_pixel_map[0],                                       \
+        .pixel_map_size = DT_INST_PROP_LEN(idx, pixels),                                           \
+        .event_buffer_size = DT_INST_PROP(idx, buffer_size),                                       \
+        .blending_mode = DT_INST_ENUM_IDX(idx, blending_mode),                                     \
+        .distance_per_frame =                                                                      \
+            (255 * 1000 / DT_INST_PROP(idx, duration)) / CONFIG_ZMK_ANIMATION_FPS,                 \
+        .ripple_width = DT_INST_PROP(idx, ripple_width) / 2,                                       \
+        .event_frames =                                                                            \
+            255 / ((255 * 1000 / DT_INST_PROP(idx, duration)) / CONFIG_ZMK_ANIMATION_FPS),         \
+    };                                                                                             \
+                                                                                                   \
+    DEVICE_DT_INST_DEFINE(idx, &animation_ripple_init, NULL, &animation_ripple_##idx##_data,       \
+                          &animation_ripple_##idx##_config, POST_KERNEL,                           \
+                          CONFIG_APPLICATION_INIT_PRIORITY, &animation_ripple_api);                \
+                                                                                                   \
+    static int animation_ripple_##idx##_event_handler(const zmk_event_t *event) {                  \
+        const struct device *dev = DEVICE_DT_GET(DT_DRV_INST(idx));                                \
+                                                                                                   \
+        return animation_ripple_on_key_press(dev, event);                                          \
+    }                                                                                              \
+                                                                                                   \
+    ZMK_LISTENER(animation_ripple_##idx, animation_ripple_##idx##_event_handler);                  \
+    ZMK_SUBSCRIPTION(animation_ripple_##idx, zmk_position_state_changed);
+
+DT_INST_FOREACH_STATUS_OKAY(ANIMATION_RIPPLE_DEVICE);

app/src/animation/animation_solid.c

@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#define DT_DRV_COMPAT zmk_animation_solid
+
+#include <zephyr/device.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+
+#include <drivers/animation.h>
+
+#include <zmk/animation.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+struct animation_solid_config {
+    size_t *pixel_map;
+    size_t pixel_map_size;
+    struct zmk_color_hsl *colors;
+    uint8_t num_colors;
+    uint16_t duration;
+    uint16_t transition_duration;
+};
+
+struct animation_solid_data {
+    uint16_t counter;
+
+    struct zmk_color_hsl current_hsl;
+    struct zmk_color_rgb current_rgb;
+};
+
+static void animation_solid_update_color(const struct device *dev) {
+    const struct animation_solid_config *config = dev->config;
+    struct animation_solid_data *data = dev->data;
+
+    const size_t from = data->counter / config->transition_duration;
+    const size_t to = (from + 1) % config->num_colors;
+
+    struct zmk_color_hsl next_hsl;
+
+    zmk_interpolate_hsl(&config->colors[from], &config->colors[to], &next_hsl,
+                        (data->counter % config->transition_duration) /
+                            (float)config->transition_duration);
+
+    data->current_hsl = next_hsl;
+    zmk_hsl_to_rgb(&data->current_hsl, &data->current_rgb);
+
+    data->counter = (data->counter + 1) % config->duration;
+}
+
+static void animation_solid_render_frame(const struct device *dev, struct animation_pixel *pixels,
+                                         size_t num_pixels) {
+    const struct animation_solid_config *config = dev->config;
+    struct animation_solid_data *data = dev->data;
+
+    for (size_t i = 0; i < config->pixel_map_size; ++i) {
+        pixels[config->pixel_map[i]].value = data->current_rgb;
+    }
+
+    if (config->num_colors == 1) {
+        return;
+    }
+
+    // Request frames on counter reset
+    if (data->counter == 0) {
+        zmk_animation_request_frames(config->duration);
+    }
+
+    animation_solid_update_color(dev);
+}
+
+static void animation_solid_start(const struct device *dev) { zmk_animation_request_frames(1); }
+
+static void animation_solid_stop(const struct device *dev) {
+    // Nothing to do.
+}
+
+static int animation_solid_init(const struct device *dev) {
+    const struct animation_solid_config *config = dev->config;
+    struct animation_solid_data *data = dev->data;
+
+    data->counter = 0;
+    data->current_hsl = config->colors[0];
+
+    zmk_hsl_to_rgb(&data->current_hsl, &data->current_rgb);
+
+    return 0;
+}
+
+static const struct animation_api animation_solid_api = {
+    .on_start = animation_solid_start,
+    .on_stop = animation_solid_stop,
+    .render_frame = animation_solid_render_frame,
+};
+
+#define ANIMATION_SOLID_DEVICE(idx)                                                                \
+                                                                                                   \
+    static struct animation_solid_data animation_solid_##idx##_data;                               \
+                                                                                                   \
+    static size_t animation_ripple_##idx##_pixel_map[] = DT_INST_PROP(idx, pixels);                \
+                                                                                                   \
+    static uint32_t animation_solid_##idx##_colors[] = DT_INST_PROP(idx, colors);                  \
+                                                                                                   \
+    static struct animation_solid_config animation_solid_##idx##_config = {                        \
+        .pixel_map = &animation_ripple_##idx##_pixel_map[0],                                       \
+        .pixel_map_size = DT_INST_PROP_LEN(idx, pixels),                                           \
+        .colors = (struct zmk_color_hsl *)animation_solid_##idx##_colors,                          \
+        .num_colors = DT_INST_PROP_LEN(idx, colors),                                               \
+        .duration = DT_INST_PROP(idx, duration) * CONFIG_ZMK_ANIMATION_FPS,                        \
+        .transition_duration = (DT_INST_PROP(idx, duration) * CONFIG_ZMK_ANIMATION_FPS) /          \
+                               DT_INST_PROP_LEN(idx, colors),                                      \
+    };                                                                                             \
+                                                                                                   \
+    DEVICE_DT_INST_DEFINE(idx, &animation_solid_init, NULL, &animation_solid_##idx##_data,         \
+                          &animation_solid_##idx##_config, POST_KERNEL,                            \
+                          CONFIG_APPLICATION_INIT_PRIORITY, &animation_solid_api);
+
+DT_INST_FOREACH_STATUS_OKAY(ANIMATION_SOLID_DEVICE);

app/src/animation/color.c

@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <stdlib.h>
+
+#include <zmk/animation.h>
+
+static float fmod(float a, float b) {
+    float mod = a < 0 ? -a : a;
+    float x = b < 0 ? -b : b;
+
+    while (mod >= x) {
+        mod = mod - x;
+    }
+
+    return a < 0 ? -mod : mod;
+}
+
+static float fabs(float a) { return a < 0 ? -a : a; }
+
+/**
+ * HSL chosen over HSV/HSB as it shares the same parameters with LCh or HSLuv.
+ * The latter color spaces could be interesting to experiment with because of their
+ * perceptual uniformity, but it would come at the cost of some performance.
+ * Using the same parameters would make it easy to toggle any such behavior
+ * using a single config flag.
+ *
+ * Algorithm source: https://www.tlbx.app/color-converter
+ */
+void zmk_hsl_to_rgb(const struct zmk_color_hsl *hsl, struct zmk_color_rgb *rgb) {
+    float s = (float)hsl->s / 100;
+    float l = (float)hsl->l / 100;
+
+    float a = (float)hsl->h / 60;
+    float chroma = s * (1 - fabs(2 * l - 1));
+    float x = chroma * (1 - fabs(fmod(a, 2) - 1));
+    float m = l - chroma / 2;
+
+    switch ((uint8_t)a % 6) {
+    case 0:
+        rgb->r = m + chroma;
+        rgb->g = m + x;
+        rgb->b = m;
+        break;
+    case 1:
+        rgb->r = m + x;
+        rgb->g = m + chroma;
+        rgb->b = m;
+        break;
+    case 2:
+        rgb->r = m;
+        rgb->g = m + chroma;
+        rgb->b = m + x;
+        break;
+    case 3:
+        rgb->r = m;
+        rgb->g = m + x;
+        rgb->b = m + chroma;
+        break;
+    case 4:
+        rgb->r = m + x;
+        rgb->g = m;
+        rgb->b = m + chroma;
+        break;
+    case 5:
+        rgb->r = m + chroma;
+        rgb->g = m;
+        rgb->b = m + x;
+        break;
+    }
+}
+
+/**
+ * Converts ZMKs RGB (float) to Zephyr's led_rgb (uint8_t) format.
+ */
+void zmk_rgb_to_led_rgb(const struct zmk_color_rgb *rgb, struct led_rgb *led) {
+    led->r = rgb->r * 255;
+    led->g = rgb->g * 255;
+    led->b = rgb->b * 255;
+}
+
+/**
+ * Compares two HSL colors.
+ */
+bool zmk_cmp_hsl(const struct zmk_color_hsl *a, const struct zmk_color_hsl *b) {
+    return a->h == b->h && a->s == b->s && a->l == b->l;
+}
+
+/**
+ * Interpolate between two colors using the cylindrical model (HSL).
+ */
+void zmk_interpolate_hsl(const struct zmk_color_hsl *from, const struct zmk_color_hsl *to,
+                         struct zmk_color_hsl *result, float step) {
+    int16_t hue_delta;
+
+    hue_delta = from->h - to->h;
+    hue_delta = hue_delta + (180 < abs(hue_delta) ? (hue_delta < 0 ? 360 : -360) : 0);
+
+    result->h = (uint16_t)(360 + from->h - (hue_delta * step)) % 360;
+    result->s = from->s - (from->s - to->s) * step;
+    result->l = from->l - (from->l - to->l) * step;
+}
+
+struct zmk_color_rgb __zmk_apply_blending_mode(struct zmk_color_rgb base_value,
+                                               struct zmk_color_rgb blend_value, uint8_t mode) {
+    switch (mode) {
+    case ZMK_ANIMATION_BLENDING_MODE_MULTIPLY:
+        base_value.r = base_value.r * blend_value.r;
+        base_value.g = base_value.g * blend_value.g;
+        base_value.b = base_value.b * blend_value.b;
+        break;
+    case ZMK_ANIMATION_BLENDING_MODE_LIGHTEN:
+        base_value.r = base_value.r > blend_value.r ? base_value.r : blend_value.r;
+        base_value.g = base_value.g > blend_value.g ? base_value.g : blend_value.g;
+        base_value.b = base_value.b > blend_value.b ? base_value.b : blend_value.b;
+        break;
+    case ZMK_ANIMATION_BLENDING_MODE_DARKEN:
+        base_value.r = base_value.r > blend_value.r ? blend_value.r : base_value.r;
+        base_value.g = base_value.g > blend_value.g ? blend_value.g : base_value.g;
+        base_value.b = base_value.b > blend_value.b ? blend_value.b : base_value.b;
+        break;
+    case ZMK_ANIMATION_BLENDING_MODE_SCREEN:
+        base_value.r = base_value.r + (1.0f - base_value.r) * blend_value.r;
+        base_value.g = base_value.g + (1.0f - base_value.g) * blend_value.g;
+        base_value.b = base_value.b + (1.0f - base_value.b) * blend_value.b;
+        break;
+    case ZMK_ANIMATION_BLENDING_MODE_SUBTRACT:
+        base_value.r = base_value.r - base_value.r * blend_value.r;
+        base_value.g = base_value.g - base_value.g * blend_value.g;
+        base_value.b = base_value.b - base_value.b * blend_value.b;
+        break;
+    }
+
+    return base_value;
+}

app/src/behaviors/behavior_animation.c

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <zephyr/device.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+
+#include <drivers/behavior.h>
+
+#include <zmk/animation/animation_control.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#define DT_DRV_COMPAT zmk_animation_control
+
+#define DEVICE_ADDR(idx) DEVICE_DT_GET(DT_INST(idx, zmk_animation_control)),
+
+/**
+ * Control animation instance pointers.
+ */
+static const struct device *control_animations[] = {DT_INST_FOREACH_STATUS_OKAY(DEVICE_ADDR)};
+
+/**
+ * Size of control animation instance pointers array.
+ */
+static const uint8_t control_animations_size = sizeof(control_animations);
+
+/**
+ * Index of the current default control animation instance.
+ */
+static uint8_t current_zone = 0;
+
+#define DT_DRV_COMPAT zmk_behavior_animation
+
+static int
+on_keymap_binding_convert_central_state_dependent_params(struct zmk_behavior_binding *binding,
+                                                         struct zmk_behavior_binding_event event) {
+    if ((binding->param1 >> 24) == 0xff) {
+        binding->param1 = (current_zone << 24) | (binding->param1 & 0x00ffffff);
+    }
+
+    return 0;
+}
+
+static int on_keymap_binding_pressed(struct zmk_behavior_binding *binding,
+                                     struct zmk_behavior_binding_event event) {
+    uint8_t value = binding->param1 & 0xff;
+    uint8_t command = (binding->param1 >> 16) & 0xff;
+    uint8_t zone = (binding->param1 >> 24) & 0xff;
+
+    if (command == ANIMATION_CMD_NEXT_CONTROL_ZONE) {
+        current_zone++;
+
+        if (current_zone == control_animations_size) {
+            current_zone = 0;
+        }
+        return 0;
+    }
+
+    if (command == ANIMATION_CMD_PREVIOUS_CONTROL_ZONE) {
+        if (current_zone == 0) {
+            current_zone = control_animations_size;
+        }
+
+        current_zone--;
+        return 0;
+    }
+
+    if (control_animations_size <= zone) {
+        return -ENOTSUP;
+    }
+
+    return animation_control_handle_command(control_animations[zone], command, value);
+}
+
+static int on_keymap_binding_released(struct zmk_behavior_binding *binding,
+                                      struct zmk_behavior_binding_event event) {
+    return ZMK_BEHAVIOR_OPAQUE;
+}
+
+static int behavior_animation_init(const struct device *dev) { return 0; }
+
+static const struct behavior_driver_api behavior_animation_driver_api = {
+    .binding_convert_central_state_dependent_params =
+        on_keymap_binding_convert_central_state_dependent_params,
+    .binding_pressed = on_keymap_binding_pressed,
+    .binding_released = on_keymap_binding_released,
+};
+
+DEVICE_DT_INST_DEFINE(0, behavior_animation_init, NULL, NULL, NULL, APPLICATION,
+                      CONFIG_KERNEL_INIT_PRIORITY_DEFAULT, &behavior_animation_driver_api);

docs/docs/behaviors/animations.md

@@ -0,0 +1,52 @@
+---
+title: Animation Control Behavior
+sidebar_label: Animation Control
+---
+
+## Summary
+
+This page contains [Animations](../features/animations.md) behaviors supported by ZMK.
+
+## Animation Control Defines
+
+RGB actions defines are provided through the `dt-bindings/zmk/animation.h` header,
+which is added at the top of the keymap file:
+
+```
+#include <dt-bindings/zmk/animation.h>
+```
+
+This will allow you to reference the actions defined in this header such as
+`ANIMATION_TOGGLE`.
+
+Here is a table describing the action for each define:
+
+| Define                               | Action                                                        |
+| ------------------------------------ | ------------------------------------------------------------- |
+| `ANIMATION_TOGGLE`                   | Toggles active animation                                      |
+| `ANIMATION_NEXT`                     | Selects next animation within root animation node array       |
+| `ANIMATION_PREVIOUS`                 | Selects previous animation within root animation node array   |
+| `ANIMATION_SELECT(x)`                | Selects animation within root animation node at index `x`     |
+| `ANIMATION_BRIGHTEN`                 | Increases brightness (applied after other blending)           |
+| `ANIMATION_DIM`                      | Decreases brightness (applied after other blending)           |
+
+## Examples
+
+1. Toggle active animation on/off
+
+   ```
+   &animation ANIMATION_TOGGLE(0)
+   ```
+
+2. Switch to next animation
+
+   ```
+   &animation ANIMATION_NEXT(0)
+   ```
+
+3. Select animation at index 3
+
+   ```
+   &animation ANIMATION_SELECT(3)
+   ```
+

docs/docs/features/animations.md

@@ -0,0 +1,226 @@
+---
+title: RGB Animations
+sidebar_label: RGB Animations
+---
+
+ZMK supports animation effects on RGB control strips via the animation
+subsystem.
+
+## Enabling Animation Support
+
+Set `CONFIG_ZMK_ANIMATION=y` to enable animation support on your keyboard.
+See animation configuration for instructions on how to customize animation
+support.
+
+If your board does not have animation support configured, see
+[Adding Animation Support.](#adding-animation-support)
+
+## Color settings
+
+All colors are given in [HSL](https://www.w3schools.com/colors/colors_hsl.asp)
+format. The user should specify colors in this format, although they will
+be written to the LED chain driver in RGB format.
+
+## System Design
+
+This subsystem is made up of 3 key components:
+- The core animations layer
+- Animation drivers
+- Color utilites
+
+### Core Animation Layer
+
+The core animation layer is responsible for scheduling animations, kicking
+off rendering of new frames, and sending frame data to the LED strip via
+Zephyr's LED Strip API.
+
+### Animation Drivers
+
+Each animation effect is implemented as a driver. The animation API exposes
+the following functions:
+
+|       Function           |          Purpose                      |
+| ------------------------ | ------------------------------------- |
+| `animation_start`        | starts rendering the animation effect |
+| `animation_stop`         | ends rendering of the effect          |
+| `animation_render_frame` | renders a frame of the animation      |
+
+Each driver will also likely utilize `ZMK_LISTENER` to listen for keypress
+events. A driver can then request the animation subsystem render frames
+using `zmk_animation_request_frames`.
+
+
+### Color Utilities
+
+Color utilities are used by the animation drivers to perform color conversions.
+Since colors are given in HSL format, `zmk_hsl_to_rgb` is provided to
+convert user color input from devicetree to RGB data before writing to an
+animation output pixel.
+
+## Adding Animation Support
+
+Adding animation support to your board will require the following devicetree
+changes:
+- Animation core node with `zmk,animation` compatible describing
+  "pixels" within animation as well as LED drivers to write output pixels to
+- root animation node with `zmk,animation-control` compatible to cycle though
+  animations
+- animation driver nodes for all animations the user would like to implement
+
+### Animation Core Node
+
+This node describes all output "pixels" on your keyboard. These pixels
+correspond to individual LEDs on your LED chain. The animation subsystem
+will write these pixels to your LED chain driver in the order they are
+declared.
+
+Each pixel has an X and Y coordinate, which helps the animation
+subsystem determine how effects like a ripple should be rendered on your
+keyboard. X and Y coordinates can range from 0-255.
+
+The node also needs to have references to your LED strip driver nodes within
+devicetree. Multiple LED strip nodes can be provided, but each node must have
+a `chain-length` property equal to the number of pixels in the LED chain.
+When multiple LED strip nodes are provided, the `chain-length` of each will be
+used to determine how many pixels to write. Pixels are written sequentially, so
+the pixels for the second LED driver should be declared after those written
+to the first one.
+
+:::note
+
+The total number of pixels defined in your `pixel` array property should match
+the sum of all `chain-length` properties for the LED strip drivers you will be
+using.
+
+:::
+
+For example, here is a chain of 6 pixels, using two LED drivers:
+```
+animation {
+	compatible = "zmk,animation";
+	drivers = <&led_ctrl1 &led_ctrl2>;
+	pixels = <&pixel 0 0>, /* Pixel 0 is at (0,0) */
+		<&pixel 21 0>, /* Pixel 1 is (0, 21) */
+		<&pixel 42 0>,
+		<&pixel 63 0>,
+		<&pixel 84 0>,
+		<&pixel 105 0>,
+		<&pixel 255 255>; /* Max coordinate (255, 255) */
+}
+```
+
+In this case, if `led_ctrl1` has a `chain-length` of 4 and `led_ctrl2` has
+a `chain-length` of 2, then the first 4 pixels will be written to `led_ctrl1`,
+and the final two will be written to `led_ctrl2`.
+
+
+## Animation Root Node
+
+Your animation root node should be an instance of the `zmk,animation-control`
+driver. This driver allows you to cycle though other animation effects using
+a keybinding.
+
+A simple root animation node looks like this:
+
+```
+root_animation: animation_0 {
+		compatible = "zmk,animation-control";
+		label = "ANIMATION_CTRL_0";
+        /* List of all animations to cycle through */
+		animations = <&ripple_effect &solid_color>;
+};
+```
+You should set the `zmk,animation` chosen node to this root animation:
+
+```
+chosen {
+	zmk,animation = &root_animation;
+};
+```
+
+Finally, you should add a keybinding to use the animation control feature
+within your keymap:
+```
+#include <dt-bindings/zmk/animation.h>
+
+default_layer {
+    /* Basic binding, toggles animation on and off */
+    bindings = <&animation ANIMATION_TOGGLE(0)>;
+}
+```
+
+## Animation Drivers
+
+Animation drivers allow you to create custom effects on your keyboard,
+and implement different animation zones. Zone implementation is performed
+using the `pixels` property, which sets the pixels from the `pixels` property
+in the core animation node that the animation effect will apply to.
+
+### Blending Modes
+
+Several animations can utilize blending effects via the
+`zmk_apply_blending_mode` API. The following blending modes are supported:
+
+| Mode     | Affect                                                                    |
+|----------|---------------------------------------------------------------------------|
+| Multiply | Multiplies each pixel's color by the new effect's pixel color             |
+| Lighten  | Selects the highest R, G, and B values between old and new for each pixel |
+| Darken   | Selects the lowest R, G, and B values between old and new for each pixel  |
+| Screen   | Adds (1 - base {R,G,B}) * new {R,G,B} value to base {R,G,B} value         |
+
+
+### Ripple Effect
+
+Creates a ripple effect on your keyboard each time a key is pressed,
+originating at the pixel corresponding to the key. An example of
+a ripple effect node is given below.
+
+```
+ripple_effect: animation_1 {
+	compatible = "zmk,animation-ripple";
+	status = "okay";
+    /* Will only apply the effect to the first 4 pixels */
+	pixels = <0 1 2 3>;
+    /* Sets how this effect will be blended with other animations */
+	blending-mode = <BLENDING_MODE_NORMAL>;
+    /* Duration of animation in ms */
+	duration = <1000>;
+    /* Will result in a pure white */
+	color = <HSL(0, 0, 100)>;
+	ripple-width = <50>;
+};
+```
+
+### Solid Color
+
+Creates a solid color background. This effect can be combined with other
+effects such as the ripple animation to produce a static background, or
+zone specific lighting
+
+```
+solid_color: color {
+    compatible = "zmk,animation-solid";
+    status = "okay";
+    /* All pixels will be illuminated */
+    pixels = <0 1 2 3 4 5 6>;
+    colors = <HSL(236, 30, 50)>;
+};
+```
+
+### Compose Animation
+
+Composes multiple animations together, allowing you to combine animation zones
+or effects. Each animation will be rendered sequentially. If an animation has
+a blending mode set, then it will be blended onto the current state of the
+pixels
+
+```
+combine_zones: animation_1 {
+    compatible = "zmk,animation-compose";
+    status = "okay";
+    animations = <
+        &solid_color
+        &ripple_effect
+		>;
+};
+```

docs/sidebars.js

@@ -20,6 +20,7 @@ module.exports = {
       "features/backlight",
       "features/battery",
       "features/beta-testing",
+      "features/animations",
     ],
     Behaviors: [
       "behaviors/key-press",
@@ -42,6 +43,7 @@ module.exports = {
       "behaviors/underglow",
       "behaviors/backlight",
       "behaviors/power",
+      "behaviors/animations",
     ],
     Codes: [
       "codes/index",