allow customizing decrease delay of rgb heatmap (#11322)

* allow customizing decrease delay of rgb heatmap

* rename rgb typing heatmap decrease delay variable

* address review comments

* nix-shell: add clang-tools required for formatting the C code

* heatmap: use real timer to track decrement rate

* heatmap: fix ifndef var name typo

* heatmap: add docs

* Update docs/feature_rgb_matrix.md

Co-authored-by: Drashna Jaelre <drashna@live.com>

Co-authored-by: Drashna Jaelre <drashna@live.com>

1 files changed, 24 insertions, 1 deletions

diff --git a/quantum/rgb_matrix_animations/typing_heatmap_anim.h b/quantum/rgb_matrix_animations/typing_heatmap_anim.h
index b855fdc19..e06437bf7 100644
--- a/quantum/rgb_matrix_animations/typing_heatmap_anim.h
+++ b/quantum/rgb_matrix_animations/typing_heatmap_anim.h
@@ -2,6 +2,10 @@
 RGB_MATRIX_EFFECT(TYPING_HEATMAP)
 #    ifdef RGB_MATRIX_CUSTOM_EFFECT_IMPLS
 
+#        ifndef RGB_MATRIX_TYPING_HEATMAP_DECREASE_DELAY_MS
+#            define RGB_MATRIX_TYPING_HEATMAP_DECREASE_DELAY_MS 25
+#        endif
+
 void process_rgb_matrix_typing_heatmap(keyrecord_t* record) {
     uint8_t row   = record->event.key.row;
     uint8_t col   = record->event.key.col;
@@ -27,6 +31,11 @@ void process_rgb_matrix_typing_heatmap(keyrecord_t* record) {
     }
 }
 
+// A timer to track the last time we decremented all heatmap values.
+static uint16_t heatmap_decrease_timer;
+// Whether we should decrement the heatmap values during the next update.
+static bool decrease_heatmap_values;
+
 bool TYPING_HEATMAP(effect_params_t* params) {
     // Modified version of RGB_MATRIX_USE_LIMITS to work off of matrix row / col size
     uint8_t led_min = RGB_MATRIX_LED_PROCESS_LIMIT * params->iter;
@@ -38,6 +47,18 @@ bool TYPING_HEATMAP(effect_params_t* params) {
         memset(g_rgb_frame_buffer, 0, sizeof g_rgb_frame_buffer);
     }
 
+    // The heatmap animation might run in several iterations depending on
+    // `RGB_MATRIX_LED_PROCESS_LIMIT`, therefore we only want to update the
+    // timer when the animation starts.
+    if (params->iter == 0) {
+        decrease_heatmap_values = timer_elapsed(heatmap_decrease_timer) >= RGB_MATRIX_TYPING_HEATMAP_DECREASE_DELAY_MS;
+
+        // Restart the timer if we are going to decrease the heatmap this frame.
+        if (decrease_heatmap_values) {
+            heatmap_decrease_timer = timer_read();
+        }
+    }
+
     // Render heatmap & decrease
     for (int i = led_min; i < led_max; i++) {
         uint8_t row = i % MATRIX_ROWS;
@@ -55,7 +76,9 @@ bool TYPING_HEATMAP(effect_params_t* params) {
             rgb_matrix_set_color(led[j], rgb.r, rgb.g, rgb.b);
         }
 
-        g_rgb_frame_buffer[row][col] = qsub8(val, 1);
+        if (decrease_heatmap_values) {
+            g_rgb_frame_buffer[row][col] = qsub8(val, 1);
+        }
     }
 
     return led_max < sizeof(g_rgb_frame_buffer);