Add breathe effect when idle

Author: ViToni

keyboards/gmmk/pro/iso/keymaps/vitoni/config.h

@@ -13,6 +13,8 @@
     #define RGB_DISABLE_WHEN_USB_SUSPENDED
     // number of milliseconds to wait until activating RGB idle effects
     #define RGB_IDLE_TIMEOUT 4500 // 4.5 seconds
+    // activate breathe effect when idle
+    #define RGB_IDLE_BREATHE
     // fade in when we have been suspended
     #define RGB_FADE_IN
 #endif

keyboards/gmmk/pro/iso/keymaps/vitoni/readme.adoc

@@ -81,7 +81,8 @@ Used to calculate lead time for fade out before suspend timeout.
 
 |===
 
-`RGB_IDLE_TIMEOUT` enables fading out after being idle for the defined time.
+`RGB_IDLE_TIMEOUT` enables fading out after being idle for the defined time and allows
+* `RGB_IDLE_BREATHE` also activates a brethe effect while idling.
 
 [%header]
 |===
@@ -93,5 +94,11 @@ Used to calculate lead time for fade out before suspend timeout.
 
 |RGB_IDLE_MINIMUM_BRIGHTNESS
 |`RGB_MATRIX_MAXIMUM_BRIGHTNESS` / 5
-|Brightness value RGB is dimmed to when starting to idle.
+|Brightness value RGB is dimmed to when starting to idle. +
+When breathing used as the lower bound of the brightness value.
+
+|RGB_IDLE_MAXIMUM_BRIGHTNESS
+|`RGB_MATRIX_MAXIMUM_BRIGHTNESS` * 2/5
+|Upper bound of brightness value of the RGB light while breathing.
+
 |===

users/vitoni/readme.adoc

@@ -8,7 +8,7 @@ Common functions are declared in link:utils.h[]. These function are not directly
 
 == rgb_matrix_effects.h
 
-Functions in link:rgb_matrix_effects.h[] make use of common function in `utils.h` and are used to create to RGB matrix effects such as fading.
+Functions in link:rgb_matrix_effects.h[] make use of common function in `utils.h` and are used to create to RGB matrix effects such as fading or breathing.
 
 == vitoni.h
 

users/vitoni/rgb_matrix_effects.c

@@ -219,4 +219,18 @@ bool idle_fade_out(const uint8_t time) {
 
     return fade_out_ranged(time, range_min, range_max);
 }
+
+#if defined(RGB_IDLE_BREATHE)
+/**
+ * @brief Changes value/brightness to create a breathing effect based on given timer.
+ * @details Brightness will breathe in the range starting from `RGB_IDLE_MINIMUM_BRIGHTNESS` to `RGB_IDLE_MAXIMUM_BRIGHTNESS`.
+ * @param[in]   time A (usually scaled) timer
+ */
+void idle_breathe(const uint8_t time) {
+    static const uint8_t range_min = RGB_IDLE_MINIMUM_BRIGHTNESS;
+    static const uint8_t range_max = RGB_IDLE_MAXIMUM_BRIGHTNESS;
+
+    rgb_matrix_config.hsv.v = scaled_sin(time, range_min, range_max);
+}
+#endif // RGB_IDLE_BREATHE
 #endif // RGB_IDLE_TIMEOUT

users/vitoni/rgb_matrix_effects.h

@@ -147,4 +147,28 @@ bool fade_out(const uint8_t time);
  * @return Returns `true` if `RGB_IDLE_MINIMUM_BRIGHTNESS` has been reached, `false` otherwise.
  */
 bool idle_fade_out(const uint8_t time);
+
+#if defined(RGB_IDLE_BREATHE)
+#   if !defined(RGB_IDLE_MAXIMUM_BRIGHTNESS)
+        // maximum brightness when idling
+#       define RGB_IDLE_MAXIMUM_BRIGHTNESS (RGB_MATRIX_MAXIMUM_BRIGHTNESS*3/5)
+#   endif
+#   if !(0 <= RGB_IDLE_MAXIMUM_BRIGHTNESS)
+#       error "RGB_IDLE_MINIMUM_BRIGHTNESS must not be less than ZERO, was: " RGB_IDLE_MAXIMUM_BRIGHTNESS
+#   endif // RGB_IDLE_MAXIMUM_BRIGHTNESS < 0
+#   if !(RGB_IDLE_MINIMUM_BRIGHTNESS < RGB_IDLE_MAXIMUM_BRIGHTNESS)
+#       error "RGB_IDLE_MINIMUM_BRIGHTNESS must be less than RGB_IDLE_MAXIMUM_BRIGHTNESS"
+#   endif // RGB_IDLE_MAXIMUM_BRIGHTNESS <= RGB_IDLE_MINIMUM_BRIGHTNESS
+#   if !(RGB_IDLE_MAXIMUM_BRIGHTNESS <= RGB_MATRIX_MAXIMUM_BRIGHTNESS)
+#       error "RGB_IDLE_MAXIMUM_BRIGHTNESS must be less than or equal to RGB_MATRIX_MAXIMUM_BRIGHTNESS"
+#   endif // RGB_MATRIX_MAXIMUM_BRIGHTNESS <= RGB_IDLE_MAXIMUM_BRIGHTNESS
+
+/**
+ * @brief Changes value/brightness to create a breathing effect based on given timer.
+ * @details Brightness will breathe in the range starting from `RGB_IDLE_MINIMUM_BRIGHTNESS` to `RGB_IDLE_MAXIMUM_BRIGHTNESS`.
+ * @param[in]   time A (usually scaled) timer
+ */
+void idle_breathe(const uint8_t time);
+#endif // RGB_IDLE_BREATHE
+
 #endif // RGB_IDLE_TIMEOUT

users/vitoni/vitoni.c

@@ -61,6 +61,14 @@ void matrix_scan_user_rgb(void) {
             }
             break;
         case IDLE:
+#if defined(RGB_IDLE_BREATHE)
+            if (calc_offset) {
+                // no need to calculate time_offset since we are aligned already due to IDLE_FADE_OUT
+                // resetting flag for subsequent calls
+                calc_offset = false;
+            }
+            idle_breathe(time + time_offset);
+#endif
             break;
 #endif
 #if defined(RGB_DISABLE_WITH_FADE_OUT)