Add shift-to-invert to remaining directional RGB_* keycode pairs (#7484)

* Add shift-to-invert to remaining directional RGB_* keycode pairs

RGB_MODE_FORWARD / RGB_MODE_REVERSE invert their functions when shift is held.
This change adds the same capabilities to the remaining directional RGB_*
keycode pairs.  This improves consistency and provides full RGB control in a
keymap containing only one keycode from each pair.

* remove redundant variable

* fix typo

* Fix more typos

Flyspell is on now I swear!

4 files changed, 79 insertions, 43 deletions

diff --git a/docs/feature_rgb_matrix.md b/docs/feature_rgb_matrix.md
index 3e69361fbd..5b834a99d5 100644
--- a/docs/feature_rgb_matrix.md
+++ b/docs/feature_rgb_matrix.md
@@ -173,16 +173,20 @@ As mentioned earlier, the center of the keyboard by default is expected to be `{
 
 All RGB keycodes are currently shared with the RGBLIGHT system:
 
-* `RGB_TOG` - toggle
-* `RGB_MOD` - cycle through modes
-* `RGB_HUI` - increase hue
-* `RGB_HUD` - decrease hue
-* `RGB_SAI` - increase saturation
-* `RGB_SAD` - decrease saturation
-* `RGB_VAI` - increase value
-* `RGB_VAD` - decrease value
-* `RGB_SPI` - increase speed effect (no EEPROM support)
-* `RGB_SPD` - decrease speed effect (no EEPROM support)
+|Key                |Aliases   |Description                                                                           |
+|-------------------|----------|--------------------------------------------------------------------------------------|
+|`RGB_TOG`          |          |Toggle RGB lighting on or off                                                         |
+|`RGB_MODE_FORWARD` |`RGB_MOD` |Cycle through modes, reverse direction when Shift is held                             |
+|`RGB_MODE_REVERSE` |`RGB_RMOD`|Cycle through modes in reverse, forward direction when Shift is held                  |
+|`RGB_HUI`          |          |Increase hue, decrease hue when Shift is held                                         |
+|`RGB_HUD`          |          |Decrease hue, increase hue when Shift is held                                         |
+|`RGB_SAI`          |          |Increase saturation, decrease saturation when Shift is held                           |
+|`RGB_SAD`          |          |Decrease saturation, increase saturation when Shift is held                           |
+|`RGB_VAI`          |          |Increase value (brightness), decrease value when Shift is held                        |
+|`RGB_VAD`          |          |Decrease value (brightness), increase value when Shift is held                        |
+|`RGB_SPI`          |          |Increase effect speed (does not support eeprom yet), decrease speed when Shift is held|
+|`RGB_SPD`          |          |Decrease effect speed (does not support eeprom yet), increase speed when Shift is held|
+
 * `RGB_MODE_*` keycodes will generally work, but are not currently mapped to the correct effects for the RGB Matrix system
 
 ## RGB Matrix Effects
diff --git a/docs/feature_rgblight.md b/docs/feature_rgblight.md
index 2e9610163b..69a6aaaed6 100644
--- a/docs/feature_rgblight.md
+++ b/docs/feature_rgblight.md
@@ -48,12 +48,12 @@ Changing the **Value** sets the overall brightness.<br>
 |`RGB_TOG`          |          |Toggle RGB lighting on or off                                       |
 |`RGB_MODE_FORWARD` |`RGB_MOD` |Cycle through modes, reverse direction when Shift is held           |
 |`RGB_MODE_REVERSE` |`RGB_RMOD`|Cycle through modes in reverse, forward direction when Shift is held|
-|`RGB_HUI`          |          |Increase hue                                                        |
-|`RGB_HUD`          |          |Decrease hue                                                        |
-|`RGB_SAI`          |          |Increase saturation                                                 |
-|`RGB_SAD`          |          |Decrease saturation                                                 |
-|`RGB_VAI`          |          |Increase value (brightness)                                         |
-|`RGB_VAD`          |          |Decrease value (brightness)                                         |
+|`RGB_HUI`          |          |Increase hue, decrease hue when Shift is held                       |
+|`RGB_HUD`          |          |Decrease hue, increase hue when Shift is held                       |
+|`RGB_SAI`          |          |Increase saturation, decrease saturation when Shift is held         |
+|`RGB_SAD`          |          |Decrease saturation, increase saturation when Shift is held         |
+|`RGB_VAI`          |          |Increase value (brightness), decrease value when Shift is held      |
+|`RGB_VAD`          |          |Decrease value (brightness), increase value when Shift is held      |
 |`RGB_MODE_PLAIN`   |`RGB_M_P `|Static (no animation) mode                                          |
 |`RGB_MODE_BREATHE` |`RGB_M_B` |Breathing animation mode                                            |
 |`RGB_MODE_RAINBOW` |`RGB_M_R` |Rainbow animation mode                                              |
diff --git a/docs/keycodes.md b/docs/keycodes.md
index fa01df63dc..d777246f68 100644
--- a/docs/keycodes.md
+++ b/docs/keycodes.md
@@ -389,12 +389,12 @@ This is a reference only. Each group of keys links to the page documenting their
 |`RGB_TOG`          |          |Toggle RGB lighting on or off                                       |
 |`RGB_MODE_FORWARD` |`RGB_MOD` |Cycle through modes, reverse direction when Shift is held           |
 |`RGB_MODE_REVERSE` |`RGB_RMOD`|Cycle through modes in reverse, forward direction when Shift is held|
-|`RGB_HUI`          |          |Increase hue                                                        |
-|`RGB_HUD`          |          |Decrease hue                                                        |
-|`RGB_SAI`          |          |Increase saturation                                                 |
-|`RGB_SAD`          |          |Decrease saturation                                                 |
-|`RGB_VAI`          |          |Increase value (brightness)                                         |
-|`RGB_VAD`          |          |Decrease value (brightness)                                         |
+|`RGB_HUI`          |          |Increase hue, decrease hue when Shift is held                       |
+|`RGB_HUD`          |          |Decrease hue, increase hue when Shift is held                       |
+|`RGB_SAI`          |          |Increase saturation, decrease saturation when Shift is held         |
+|`RGB_SAD`          |          |Decrease saturation, increase saturation when Shift is held         |
+|`RGB_VAI`          |          |Increase value (brightness), decrease value when Shift is held      |
+|`RGB_VAD`          |          |Decrease value (brightness), increase value when Shift is held      |
 |`RGB_MODE_PLAIN`   |`RGB_M_P `|Static (no animation) mode                                          |
 |`RGB_MODE_BREATHE` |`RGB_M_B` |Breathing animation mode                                            |
 |`RGB_MODE_RAINBOW` |`RGB_M_R` |Rainbow animation mode                                              |
@@ -407,19 +407,19 @@ This is a reference only. Each group of keys links to the page documenting their
 
 ## [RGB Matrix Lighting](feature_rgb_matrix.md)
 
-|Key                |Aliases   |Description                                                         |
-|-------------------|----------|--------------------------------------------------------------------|
-|`RGB_TOG`          |          |Toggle RGB lighting on or off                                       |
-|`RGB_MODE_FORWARD` |`RGB_MOD` |Cycle through modes, reverse direction when Shift is held           |
-|`RGB_MODE_REVERSE` |`RGB_RMOD`|Cycle through modes in reverse, forward direction when Shift is held|
-|`RGB_HUI`          |          |Increase hue                                                        |
-|`RGB_HUD`          |          |Decrease hue                                                        |
-|`RGB_SAI`          |          |Increase saturation                                                 |
-|`RGB_SAD`          |          |Decrease saturation                                                 |
-|`RGB_VAI`          |          |Increase value (brightness)                                         |
-|`RGB_VAD`          |          |Decrease value (brightness)                                         |
-|`RGB_SPI`          |          |Increase effect speed (does no support eeprom yet)                  |
-|`RGB_SPD`          |          |Decrease effect speed (does no support eeprom yet)                  |
+|Key                |Aliases   |Description                                                                           |
+|-------------------|----------|--------------------------------------------------------------------------------------|
+|`RGB_TOG`          |          |Toggle RGB lighting on or off                                                         |
+|`RGB_MODE_FORWARD` |`RGB_MOD` |Cycle through modes, reverse direction when Shift is held                             |
+|`RGB_MODE_REVERSE` |`RGB_RMOD`|Cycle through modes in reverse, forward direction when Shift is held                  |
+|`RGB_HUI`          |          |Increase hue, decrease hue when Shift is held                                         |
+|`RGB_HUD`          |          |Decrease hue, increase hue when Shift is held                                         |
+|`RGB_SAI`          |          |Increase saturation, decrease saturation when Shift is held                           |
+|`RGB_SAD`          |          |Decrease saturation, increase saturation when Shift is held                           |
+|`RGB_VAI`          |          |Increase value (brightness), decrease value when Shift is held                        |
+|`RGB_VAD`          |          |Decrease value (brightness), increase value when Shift is held                        |
+|`RGB_SPI`          |          |Increase effect speed (does not support eeprom yet), decrease speed when Shift is held|
+|`RGB_SPD`          |          |Decrease effect speed (does not support eeprom yet), increase speed when Shift is held|
 
 ## [Thermal Printer](feature_thermal_printer.md)
 
diff --git a/quantum/quantum.c b/quantum/quantum.c
index f768f86bc2..dd57d7a5e9 100644
--- a/quantum/quantum.c
+++ b/quantum/quantum.c
@@ -346,28 +346,60 @@ bool process_record_quantum(keyrecord_t *record) {
                 }
                 return false;
             case RGB_HUI:
-                rgblight_increase_hue();
+                if (shifted) {
+                    rgblight_decrease_hue();
+                } else {
+                    rgblight_increase_hue();
+                }
                 return false;
             case RGB_HUD:
-                rgblight_decrease_hue();
+                if (shifted) {
+                    rgblight_increase_hue();
+                } else {
+                    rgblight_decrease_hue();
+                }
                 return false;
             case RGB_SAI:
-                rgblight_increase_sat();
+                if (shifted) {
+                    rgblight_decrease_sat();
+                } else {
+                    rgblight_increase_sat();
+                }
                 return false;
             case RGB_SAD:
-                rgblight_decrease_sat();
+                if (shifted) {
+                    rgblight_increase_sat();
+                } else {
+                    rgblight_decrease_sat();
+                }
                 return false;
             case RGB_VAI:
-                rgblight_increase_val();
+                if (shifted) {
+                    rgblight_decrease_val();
+                } else {
+                    rgblight_increase_val();
+                }
                 return false;
             case RGB_VAD:
-                rgblight_decrease_val();
+                if (shifted) {
+                    rgblight_increase_val();
+                } else {
+                    rgblight_decrease_val();
+                }
                 return false;
             case RGB_SPI:
-                rgblight_increase_speed();
+                if (shifted) {
+                    rgblight_decrease_speed();
+                } else {
+                    rgblight_increase_speed();
+                }
                 return false;
             case RGB_SPD:
-                rgblight_decrease_speed();
+                if (shifted) {
+                    rgblight_increase_speed();
+                } else {
+                    rgblight_decrease_speed();
+                }
                 return false;
             case RGB_MODE_PLAIN:
                 rgblight_mode(RGBLIGHT_MODE_STATIC_LIGHT);