优化开关机Gamma渐变

project/example/ble/ble_peripheral/app/src/light_transition.c

@@ -7,6 +7,13 @@ volatile uint8_t Light_Transition_FadeActive;
 #define LIGHT_FADE_STEP 1U
 #define BRIGHTNESS_SMOOTH_SHIFT 4U
 #define BREATH_MIN_OUTPUT 1U
+#define POWER_FADE_Q12_MAX 4096U
+#define POWER_FADE_ON_TICKS 140U
+#define POWER_FADE_OFF_TICKS 160U
+#define POWER_FADE_ON_STEP (POWER_FADE_Q12_MAX / POWER_FADE_ON_TICKS)
+#define POWER_FADE_ON_REMAINDER (POWER_FADE_Q12_MAX % POWER_FADE_ON_TICKS)
+#define POWER_FADE_OFF_STEP (POWER_FADE_Q12_MAX / POWER_FADE_OFF_TICKS)
+#define POWER_FADE_OFF_REMAINDER (POWER_FADE_Q12_MAX % POWER_FADE_OFF_TICKS)
 
 /*
  * Gamma 1.8, mapping APP levels 1..100 to a stable physical range of
@@ -26,7 +33,30 @@ static const uint16_t brightness_gamma_q12[100] = {
     3515U, 3577U, 3640U, 3704U, 3768U, 3832U, 3897U, 3963U, 4029U, 4096U
 };
 
+/*
+ * Gamma 1.8 envelope for power-on/off. The transition progress is advanced
+ * independently of the requested brightness, so every turn-on takes about
+ * 700 ms and every turn-off takes about 800 ms. Linear interpolation between
+ * table entries prevents visible 1% steps.
+ */
+static const uint16_t power_fade_gamma_q12[101] = {
+    0U, 1U, 4U, 7U, 12U, 19U, 26U, 34U, 43U, 54U,
+    65U, 77U, 90U, 104U, 119U, 135U, 151U, 169U, 187U, 206U,
+    226U, 247U, 268U, 291U, 314U, 338U, 363U, 388U, 414U, 441U,
+    469U, 498U, 527U, 557U, 588U, 619U, 651U, 684U, 718U, 752U,
+    787U, 823U, 859U, 897U, 934U, 973U, 1012U, 1052U, 1093U, 1134U,
+    1176U, 1219U, 1262U, 1306U, 1351U, 1396U, 1442U, 1489U, 1536U, 1585U,
+    1633U, 1682U, 1732U, 1783U, 1834U, 1886U, 1939U, 1992U, 2046U, 2100U,
+    2155U, 2211U, 2268U, 2325U, 2382U, 2440U, 2499U, 2559U, 2619U, 2680U,
+    2741U, 2803U, 2866U, 2929U, 2993U, 3057U, 3122U, 3188U, 3254U, 3321U,
+    3388U, 3456U, 3525U, 3594U, 3664U, 3735U, 3806U, 3877U, 3950U, 4023U,
+    4096U
+};
+
 static uint16_t current_brightness_q12;
+static uint16_t power_fade_progress_q12;
+static uint16_t power_fade_remainder;
+static uint8_t power_fade_direction;
 
 static uint16_t brightness_scale_for_level(uint8_t level)
 {
@@ -71,32 +101,115 @@ static uint16_t approach_target(uint16_t current, uint16_t target)
     return current;
 }
 
+static uint16_t power_fade_scale(uint16_t progress_q12)
+{
+    uint32_t position;
+    uint16_t index;
+    uint16_t fraction;
+    uint16_t lower;
+    uint16_t upper;
+
+    if(progress_q12 >= POWER_FADE_Q12_MAX) return POWER_FADE_Q12_MAX;
+
+    position = (uint32_t)progress_q12 * 100U;
+    index = (uint16_t)(position >> 12);
+    fraction = (uint16_t)(position & 0x0FFFU);
+    lower = power_fade_gamma_q12[index];
+    upper = power_fade_gamma_q12[index + 1U];
+
+    return (uint16_t)(lower +
+        (((uint32_t)(upper - lower) * fraction + 2048U) >> 12));
+}
+
+static void update_power_fade(uint8_t powered_on)
+{
+    uint16_t step;
+
+    if(powered_on)
+    {
+        if(power_fade_direction != 1U)
+        {
+            power_fade_direction = 1U;
+            power_fade_remainder = 0U;
+        }
+        if(power_fade_progress_q12 >= POWER_FADE_Q12_MAX) return;
+
+        step = POWER_FADE_ON_STEP;
+        power_fade_remainder += POWER_FADE_ON_REMAINDER;
+        if(power_fade_remainder >= POWER_FADE_ON_TICKS)
+        {
+            power_fade_remainder -= POWER_FADE_ON_TICKS;
+            step++;
+        }
+        if(step >= POWER_FADE_Q12_MAX - power_fade_progress_q12)
+            power_fade_progress_q12 = POWER_FADE_Q12_MAX;
+        else
+            power_fade_progress_q12 += step;
+    }
+    else
+    {
+        if(power_fade_direction != 2U)
+        {
+            power_fade_direction = 2U;
+            power_fade_remainder = 0U;
+        }
+        if(power_fade_progress_q12 == 0U) return;
+
+        step = POWER_FADE_OFF_STEP;
+        power_fade_remainder += POWER_FADE_OFF_REMAINDER;
+        if(power_fade_remainder >= POWER_FADE_OFF_TICKS)
+        {
+            power_fade_remainder -= POWER_FADE_OFF_TICKS;
+            step++;
+        }
+        if(step >= power_fade_progress_q12)
+            power_fade_progress_q12 = 0U;
+        else
+            power_fade_progress_q12 -= step;
+    }
+}
+
 void Light_Transition_SyncBrightness(uint8_t level)
 {
     current_brightness_q12 = brightness_scale_for_level(level);
+    power_fade_progress_q12 =
+        level == 0U ? 0U : POWER_FADE_Q12_MAX;
+    power_fade_remainder = 0U;
+    power_fade_direction = 0U;
 }
 
 void Light_Transition_Task(void)
 {
-    uint8_t target_brightness = 0U;
+    uint8_t powered_on = deviceStatus != POWEROFF;
     uint16_t target_w;
     uint16_t target_c;
     uint16_t target_brightness_scale;
     uint16_t brightness_scale;
+    uint16_t fade_scale;
+    uint8_t power_transitioning;
 
-    if(deviceStatus != POWEROFF) target_brightness = Brightness;
+    /*
-    target_brightness_scale = brightness_scale_for_level(target_brightness);
+     * Keep APP brightness tracking while off. Power fading is a separate
+     * envelope, so on/off duration does not change with the saved brightness.
+     */
+    target_brightness_scale = brightness_scale_for_level(Brightness);
     current_brightness_q12 =
         approach_brightness_scale(current_brightness_q12,
                                   target_brightness_scale);
-    brightness_scale = current_brightness_q12;
+    update_power_fade(powered_on);
+    fade_scale = power_fade_scale(power_fade_progress_q12);
+    brightness_scale = (uint16_t)(
+        ((uint32_t)current_brightness_q12 * fade_scale + 2048U) >> 12);
+    power_transitioning =
+        powered_on ? (power_fade_progress_q12 < POWER_FADE_Q12_MAX)
+                   : (power_fade_progress_q12 != 0U);
 
     target_w =
         (uint16_t)(((uint32_t)W_PWM * brightness_scale + 2048U) >> 12);
     target_c =
         (uint16_t)(((uint32_t)C_PWM * brightness_scale + 2048U) >> 12);
 
-    if(Mode == mode1 && target_brightness != 0U)
+    if(Mode == mode1 && powered_on && !power_transitioning)
     {
         if(W_PWM != 0U && target_w < BREATH_MIN_OUTPUT)
             target_w = BREATH_MIN_OUTPUT;
@@ -104,7 +217,7 @@ void Light_Transition_Task(void)
             target_c = BREATH_MIN_OUTPUT;
     }
 
-    if(Mode == mode2 && deviceStatus != POWEROFF)
+    if((Mode == mode2 && powered_on) || power_transitioning)
     {
         W_PWM_duty = target_w;
         C_PWM_duty = target_c;
@@ -116,5 +229,6 @@ void Light_Transition_Task(void)
     }
 
     Light_Transition_FadeActive =
-        deviceStatus == POWEROFF && (W_PWM_duty != 0U || C_PWM_duty != 0U);
+        !powered_on && (power_fade_progress_q12 != 0U ||
+                        W_PWM_duty != 0U || C_PWM_duty != 0U);
 }