Reduce LightCall memory usage by 50 bytes per call (#9333)

esphome/components/light/addressable_light.h

@@ -97,12 +97,12 @@ class AddressableLight : public LightOutput, public Component {
   }
   virtual ESPColorView get_view_internal(int32_t index) const = 0;
 
-  bool effect_active_{false};
   ESPColorCorrection correction_{};
+  LightState *state_parent_{nullptr};
 #ifdef USE_POWER_SUPPLY
   power_supply::PowerSupplyRequester power_;
 #endif
-  LightState *state_parent_{nullptr};
+  bool effect_active_{false};
 };
 
 class AddressableLightTransformer : public LightTransitionTransformer {
@@ -114,9 +114,9 @@ class AddressableLightTransformer : public LightTransitionTransformer {
 
  protected:
   AddressableLight &light_;
-  Color target_color_{};
   float last_transition_progress_{0.0f};
   float accumulated_alpha_{0.0f};
+  Color target_color_{};
 };
 
 }  // namespace light

esphome/components/light/esp_color_correction.h

@@ -69,8 +69,8 @@ class ESPColorCorrection {
  protected:
   uint8_t gamma_table_[256];
   uint8_t gamma_reverse_table_[256];
-  uint8_t local_brightness_{255};
   Color max_brightness_;
+  uint8_t local_brightness_{255};
 };
 
 }  // namespace light

esphome/components/light/light_call.h

@@ -1,6 +1,5 @@
 #pragma once
 
-#include "esphome/core/optional.h"
 #include "light_color_values.h"
 #include <set>
 
@@ -10,6 +9,11 @@ namespace light {
 class LightState;
 
 /** This class represents a requested change in a light state.
+ *
+ * Light state changes are tracked using a bitfield flags_ to minimize memory usage.
+ * Each possible light property has a flag indicating whether it has been set.
+ * This design keeps LightCall at ~56 bytes to minimize heap fragmentation on
+ * ESP8266 and other memory-constrained devices.
  */
 class LightCall {
  public:
@@ -131,6 +135,19 @@ class LightCall {
   /// Set whether this light call should trigger a save state to recover them at startup..
   LightCall &set_save(bool save);
 
+  // Getter methods to check if values are set
+  bool has_state() const { return (flags_ & FLAG_HAS_STATE) != 0; }
+  bool has_brightness() const { return (flags_ & FLAG_HAS_BRIGHTNESS) != 0; }
+  bool has_color_brightness() const { return (flags_ & FLAG_HAS_COLOR_BRIGHTNESS) != 0; }
+  bool has_red() const { return (flags_ & FLAG_HAS_RED) != 0; }
+  bool has_green() const { return (flags_ & FLAG_HAS_GREEN) != 0; }
+  bool has_blue() const { return (flags_ & FLAG_HAS_BLUE) != 0; }
+  bool has_white() const { return (flags_ & FLAG_HAS_WHITE) != 0; }
+  bool has_color_temperature() const { return (flags_ & FLAG_HAS_COLOR_TEMPERATURE) != 0; }
+  bool has_cold_white() const { return (flags_ & FLAG_HAS_COLD_WHITE) != 0; }
+  bool has_warm_white() const { return (flags_ & FLAG_HAS_WARM_WHITE) != 0; }
+  bool has_color_mode() const { return (flags_ & FLAG_HAS_COLOR_MODE) != 0; }
+
   /** Set the RGB color of the light by RGB values.
    *
    * Please note that this only changes the color of the light, not the brightness.
@@ -170,27 +187,62 @@ class LightCall {
   /// Some color modes also can be set using non-native parameters, transform those calls.
   void transform_parameters_();
 
-  bool has_transition_() { return this->transition_length_.has_value(); }
-  bool has_flash_() { return this->flash_length_.has_value(); }
-  bool has_effect_() { return this->effect_.has_value(); }
+  // Bitfield flags - each flag indicates whether a corresponding value has been set.
+  enum FieldFlags : uint16_t {
+    FLAG_HAS_STATE = 1 << 0,
+    FLAG_HAS_TRANSITION = 1 << 1,
+    FLAG_HAS_FLASH = 1 << 2,
+    FLAG_HAS_EFFECT = 1 << 3,
+    FLAG_HAS_BRIGHTNESS = 1 << 4,
+    FLAG_HAS_COLOR_BRIGHTNESS = 1 << 5,
+    FLAG_HAS_RED = 1 << 6,
+    FLAG_HAS_GREEN = 1 << 7,
+    FLAG_HAS_BLUE = 1 << 8,
+    FLAG_HAS_WHITE = 1 << 9,
+    FLAG_HAS_COLOR_TEMPERATURE = 1 << 10,
+    FLAG_HAS_COLD_WHITE = 1 << 11,
+    FLAG_HAS_WARM_WHITE = 1 << 12,
+    FLAG_HAS_COLOR_MODE = 1 << 13,
+    FLAG_PUBLISH = 1 << 14,
+    FLAG_SAVE = 1 << 15,
+  };
+
+  bool has_transition_() { return (this->flags_ & FLAG_HAS_TRANSITION) != 0; }
+  bool has_flash_() { return (this->flags_ & FLAG_HAS_FLASH) != 0; }
+  bool has_effect_() { return (this->flags_ & FLAG_HAS_EFFECT) != 0; }
+  bool get_publish_() { return (this->flags_ & FLAG_PUBLISH) != 0; }
+  bool get_save_() { return (this->flags_ & FLAG_SAVE) != 0; }
+
+  // Helper to set flag
+  void set_flag_(FieldFlags flag, bool value) {
+    if (value) {
+      this->flags_ |= flag;
+    } else {
+      this->flags_ &= ~flag;
+    }
+  }
 
   LightState *parent_;
-  optional<bool> state_;
-  optional<uint32_t> transition_length_;
-  optional<uint32_t> flash_length_;
-  optional<ColorMode> color_mode_;
-  optional<float> brightness_;
-  optional<float> color_brightness_;
-  optional<float> red_;
-  optional<float> green_;
-  optional<float> blue_;
-  optional<float> white_;
-  optional<float> color_temperature_;
-  optional<float> cold_white_;
-  optional<float> warm_white_;
-  optional<uint32_t> effect_;
-  bool publish_{true};
-  bool save_{true};
+
+  // Light state values - use flags_ to check if a value has been set.
+  // Group 4-byte aligned members first
+  uint32_t transition_length_;
+  uint32_t flash_length_;
+  uint32_t effect_;
+  float brightness_;
+  float color_brightness_;
+  float red_;
+  float green_;
+  float blue_;
+  float white_;
+  float color_temperature_;
+  float cold_white_;
+  float warm_white_;
+
+  // Smaller members at the end for better packing
+  uint16_t flags_{FLAG_PUBLISH | FLAG_SAVE};  // Tracks which values are set
+  ColorMode color_mode_;
+  bool state_;
 };
 
 }  // namespace light

esphome/components/light/light_color_values.h

@@ -46,8 +46,7 @@ class LightColorValues {
  public:
   /// Construct the LightColorValues with all attributes enabled, but state set to off.
   LightColorValues()
-      : color_mode_(ColorMode::UNKNOWN),
-        state_(0.0f),
+      : state_(0.0f),
         brightness_(1.0f),
         color_brightness_(1.0f),
         red_(1.0f),
@@ -56,7 +55,8 @@ class LightColorValues {
         white_(1.0f),
         color_temperature_{0.0f},
         cold_white_{1.0f},
-        warm_white_{1.0f} {}
+        warm_white_{1.0f},
+        color_mode_(ColorMode::UNKNOWN) {}
 
   LightColorValues(ColorMode color_mode, float state, float brightness, float color_brightness, float red, float green,
                    float blue, float white, float color_temperature, float cold_white, float warm_white) {
@@ -292,7 +292,6 @@ class LightColorValues {
   void set_warm_white(float warm_white) { this->warm_white_ = clamp(warm_white, 0.0f, 1.0f); }
 
  protected:
-  ColorMode color_mode_;
   float state_;  ///< ON / OFF, float for transition
   float brightness_;
   float color_brightness_;
@@ -303,6 +302,7 @@ class LightColorValues {
   float color_temperature_;  ///< Color Temperature in Mired
   float cold_white_;
   float warm_white_;
+  ColorMode color_mode_;
 };
 
 }  // namespace light

esphome/components/light/light_state.h

@@ -31,9 +31,7 @@ enum LightRestoreMode : uint8_t {
 struct LightStateRTCState {
   LightStateRTCState(ColorMode color_mode, bool state, float brightness, float color_brightness, float red, float green,
                      float blue, float white, float color_temp, float cold_white, float warm_white)
-      : color_mode(color_mode),
-        state(state),
-        brightness(brightness),
+      : brightness(brightness),
         color_brightness(color_brightness),
         red(red),
         green(green),
@@ -41,10 +39,12 @@ struct LightStateRTCState {
         white(white),
         color_temp(color_temp),
         cold_white(cold_white),
-        warm_white(warm_white) {}
+        warm_white(warm_white),
+        effect(0),
+        color_mode(color_mode),
+        state(state) {}
   LightStateRTCState() = default;
-  ColorMode color_mode{ColorMode::UNKNOWN};
-  bool state{false};
+  // Group 4-byte aligned members first
   float brightness{1.0f};
   float color_brightness{1.0f};
   float red{1.0f};
@@ -55,6 +55,9 @@ struct LightStateRTCState {
   float cold_white{1.0f};
   float warm_white{1.0f};
   uint32_t effect{0};
+  // Group smaller members at the end
+  ColorMode color_mode{ColorMode::UNKNOWN};
+  bool state{false};
 };
 
 /** This class represents the communication layer between the front-end MQTT layer and the
@@ -216,6 +219,8 @@ class LightState : public EntityBase, public Component {
   std::unique_ptr<LightTransformer> transformer_{nullptr};
   /// List of effects for this light.
   std::vector<LightEffect *> effects_;
+  /// Object used to store the persisted values of the light.
+  ESPPreferenceObject rtc_;
   /// Value for storing the index of the currently active effect. 0 if no effect is active
   uint32_t active_effect_index_{};
   /// Default transition length for all transitions in ms.
@@ -224,15 +229,11 @@ class LightState : public EntityBase, public Component {
   uint32_t flash_transition_length_{};
   /// Gamma correction factor for the light.
   float gamma_correct_{};
-
   /// Whether the light value should be written in the next cycle.
   bool next_write_{true};
   // for effects, true if a transformer (transition) is active.
   bool is_transformer_active_ = false;
 
-  /// Object used to store the persisted values of the light.
-  ESPPreferenceObject rtc_;
-
   /** Callback to call when new values for the frontend are available.
    *
    * "Remote values" are light color values that are reported to the frontend and have a lower

esphome/components/light/transformers.h

@@ -59,9 +59,9 @@ class LightTransitionTransformer : public LightTransformer {
   // transition from 0 to 1 on x = [0, 1]
   static float smoothed_progress(float x) { return x * x * x * (x * (x * 6.0f - 15.0f) + 10.0f); }
 
-  bool changing_color_mode_{false};
   LightColorValues end_values_{};
   LightColorValues intermediate_values_{};
+  bool changing_color_mode_{false};
 };
 
 class LightFlashTransformer : public LightTransformer {
@@ -117,8 +117,8 @@ class LightFlashTransformer : public LightTransformer {
 
  protected:
   LightState &state_;
-  uint32_t transition_length_;
   std::unique_ptr<LightTransformer> transformer_{nullptr};
+  uint32_t transition_length_;
   bool begun_lightstate_restore_;
 };
 

tests/integration/fixtures/light_calls.yaml

@@ -0,0 +1,80 @@
+esphome:
+  name: light-calls-test
+host:
+api:  # Port will be automatically injected
+logger:
+  level: DEBUG
+
+# Test outputs for RGBCW light
+output:
+  - platform: template
+    id: test_red
+    type: float
+    write_action:
+      - logger.log:
+          format: "Red output: %.2f"
+          args: [state]
+  - platform: template
+    id: test_green
+    type: float
+    write_action:
+      - logger.log:
+          format: "Green output: %.2f"
+          args: [state]
+  - platform: template
+    id: test_blue
+    type: float
+    write_action:
+      - logger.log:
+          format: "Blue output: %.2f"
+          args: [state]
+  - platform: template
+    id: test_cold_white
+    type: float
+    write_action:
+      - logger.log:
+          format: "Cold white output: %.2f"
+          args: [state]
+  - platform: template
+    id: test_warm_white
+    type: float
+    write_action:
+      - logger.log:
+          format: "Warm white output: %.2f"
+          args: [state]
+
+light:
+  - platform: rgbww
+    name: "Test RGBCW Light"
+    id: test_light
+    red: test_red
+    green: test_green
+    blue: test_blue
+    cold_white: test_cold_white
+    warm_white: test_warm_white
+    cold_white_color_temperature: 6536 K
+    warm_white_color_temperature: 2000 K
+    constant_brightness: true
+    effects:
+      - random:
+          name: "Random Effect"
+          transition_length: 100ms
+          update_interval: 200ms
+      - strobe:
+          name: "Strobe Effect"
+      - pulse:
+          name: "Pulse Effect"
+          transition_length: 100ms
+
+  # Additional lights to test memory with multiple instances
+  - platform: rgb
+    name: "Test RGB Light"
+    id: test_rgb_light
+    red: test_red
+    green: test_green
+    blue: test_blue
+
+  - platform: binary
+    name: "Test Binary Light"
+    id: test_binary_light
+    output: test_red

tests/integration/test_light_calls.py

@@ -0,0 +1,189 @@
+"""Integration test for all light call combinations.
+
+Tests that LightCall handles all possible light operations correctly
+including RGB, color temperature, effects, transitions, and flash.
+"""
+
+import asyncio
+from typing import Any
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_light_calls(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test all possible LightCall operations and combinations."""
+    async with run_compiled(yaml_config), api_client_connected() as client:
+        # Track state changes with futures
+        state_futures: dict[int, asyncio.Future[Any]] = {}
+        states: dict[int, Any] = {}
+
+        def on_state(state: Any) -> None:
+            states[state.key] = state
+            if state.key in state_futures and not state_futures[state.key].done():
+                state_futures[state.key].set_result(state)
+
+        client.subscribe_states(on_state)
+
+        # Get the light entities
+        entities = await client.list_entities_services()
+        lights = [e for e in entities[0] if e.object_id.startswith("test_")]
+        assert len(lights) >= 2  # Should have RGBCW and RGB lights
+
+        rgbcw_light = next(light for light in lights if "RGBCW" in light.name)
+        rgb_light = next(light for light in lights if "RGB Light" in light.name)
+
+        async def wait_for_state_change(key: int, timeout: float = 1.0) -> Any:
+            """Wait for a state change for the given entity key."""
+            loop = asyncio.get_event_loop()
+            state_futures[key] = loop.create_future()
+            try:
+                return await asyncio.wait_for(state_futures[key], timeout)
+            finally:
+                state_futures.pop(key, None)
+
+        # Test all individual parameters first
+
+        # Test 1: state only
+        client.light_command(key=rgbcw_light.key, state=True)
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.state is True
+
+        # Test 2: brightness only
+        client.light_command(key=rgbcw_light.key, brightness=0.5)
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.brightness == pytest.approx(0.5)
+
+        # Test 3: color_brightness only
+        client.light_command(key=rgbcw_light.key, color_brightness=0.8)
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.color_brightness == pytest.approx(0.8)
+
+        # Test 4-7: RGB values must be set together via rgb parameter
+        client.light_command(key=rgbcw_light.key, rgb=(0.7, 0.3, 0.9))
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.red == pytest.approx(0.7, abs=0.1)
+        assert state.green == pytest.approx(0.3, abs=0.1)
+        assert state.blue == pytest.approx(0.9, abs=0.1)
+
+        # Test 7: white value
+        client.light_command(key=rgbcw_light.key, white=0.6)
+        state = await wait_for_state_change(rgbcw_light.key)
+        # White might need more tolerance or might not be directly settable
+        if hasattr(state, "white"):
+            assert state.white == pytest.approx(0.6, abs=0.1)
+
+        # Test 8: color_temperature only
+        client.light_command(key=rgbcw_light.key, color_temperature=300)
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.color_temperature == pytest.approx(300)
+
+        # Test 9: cold_white only
+        client.light_command(key=rgbcw_light.key, cold_white=0.8)
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.cold_white == pytest.approx(0.8)
+
+        # Test 10: warm_white only
+        client.light_command(key=rgbcw_light.key, warm_white=0.2)
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.warm_white == pytest.approx(0.2)
+
+        # Test 11: transition_length with state change
+        client.light_command(key=rgbcw_light.key, state=False, transition_length=0.1)
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.state is False
+
+        # Test 12: flash_length
+        client.light_command(key=rgbcw_light.key, state=True, flash_length=0.2)
+        state = await wait_for_state_change(rgbcw_light.key)
+        # Flash starts
+        assert state.state is True
+        # Wait for flash to end
+        state = await wait_for_state_change(rgbcw_light.key)
+
+        # Test 13: effect only
+        # First ensure light is on
+        client.light_command(key=rgbcw_light.key, state=True)
+        state = await wait_for_state_change(rgbcw_light.key)
+        # Now set effect
+        client.light_command(key=rgbcw_light.key, effect="Random Effect")
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.effect == "Random Effect"
+
+        # Test 14: stop effect
+        client.light_command(key=rgbcw_light.key, effect="None")
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.effect == "None"
+
+        # Test 15: color_mode parameter
+        client.light_command(
+            key=rgbcw_light.key, state=True, color_mode=5
+        )  # COLD_WARM_WHITE
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.state is True
+
+        # Now test common combinations
+
+        # Test 16: RGB combination (set_rgb) - RGB values get normalized
+        client.light_command(key=rgbcw_light.key, rgb=(1.0, 0.0, 0.5))
+        state = await wait_for_state_change(rgbcw_light.key)
+        # RGB values get normalized - in this case red is already 1.0
+        assert state.red == pytest.approx(1.0, abs=0.1)
+        assert state.green == pytest.approx(0.0, abs=0.1)
+        assert state.blue == pytest.approx(0.5, abs=0.1)
+
+        # Test 17: Multiple RGB changes to test transitions
+        client.light_command(key=rgbcw_light.key, rgb=(0.2, 0.8, 0.4))
+        state = await wait_for_state_change(rgbcw_light.key)
+        # RGB values get normalized so green (highest) becomes 1.0
+        # Expected: (0.2/0.8, 0.8/0.8, 0.4/0.8) = (0.25, 1.0, 0.5)
+        assert state.red == pytest.approx(0.25, abs=0.01)
+        assert state.green == pytest.approx(1.0, abs=0.01)
+        assert state.blue == pytest.approx(0.5, abs=0.01)
+
+        # Test 18: State + brightness + transition
+        client.light_command(
+            key=rgbcw_light.key, state=True, brightness=0.7, transition_length=0.1
+        )
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.state is True
+        assert state.brightness == pytest.approx(0.7)
+
+        # Test 19: RGB + brightness + color_brightness
+        client.light_command(
+            key=rgb_light.key,
+            state=True,
+            brightness=0.8,
+            color_brightness=0.9,
+            rgb=(0.2, 0.4, 0.6),
+        )
+        state = await wait_for_state_change(rgb_light.key)
+        assert state.state is True
+        assert state.brightness == pytest.approx(0.8)
+
+        # Test 20: Color temp + cold/warm white
+        client.light_command(
+            key=rgbcw_light.key, color_temperature=250, cold_white=0.7, warm_white=0.3
+        )
+        state = await wait_for_state_change(rgbcw_light.key)
+        assert state.color_temperature == pytest.approx(250)
+
+        # Test 21: Turn RGB light off
+        client.light_command(key=rgb_light.key, state=False)
+        state = await wait_for_state_change(rgb_light.key)
+        assert state.state is False
+
+        # Final cleanup - turn all lights off
+        for light in lights:
+            client.light_command(
+                key=light.key,
+                state=False,
+            )
+            state = await wait_for_state_change(light.key)
+            assert state.state is False