Rework the plugin, to have customisable effects

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>

README.md

@@ -6,16 +6,13 @@
  [st:broken]: https://img.shields.io/badge/broken-X-black.png?style=flat&colorA=e05d44&colorB=494e52
  [st:experimental]: https://img.shields.io/badge/experimental----black.png?style=flat&colorA=dfb317&colorB=494e52
 
-A haunting effect, where the lights follow your fingers as you keep typing.
-Always behind, always watching, always stalking the fingertips...
-
-The plugin simply lights up the LED below keys you press, and fades them away
-soon after, producing a haunting trail effect.
+The `StalkerEffect` plugin provides an interesting new typing experience: the
+LEDs light up as you tap keys, and play one of the selected effects: a haunting
+trail of ghostly white lights, or a blazing trail of fire.
 
 ## Using the plugin
 
-To use the plugin, one needs to include the header, and activate the effect. It
-is also possible to use a custom color instead of the white-ish default.
+To use the plugin, one needs to include the header, and select the effect.
 
 ```c++
 #include <Akela-LED-Stalker.h>
@@ -23,6 +20,7 @@ is also possible to use a custom color instead of the white-ish default.
 void setup () {
   Keyboardio.setup (KEYMAP_SIZE);
 
+  StalkerEffect.configure (STALKER (Haunt, {0xff, 0, 0}));
   Keyboardio.use (&StalkerEffect, NULL);
   
   StalkerEffect.configure ({0x00, 0xff, 0xff});
@@ -31,13 +29,37 @@ void setup () {
 
 It is recommended to place the activation of the plugin (the `Keyboardio.use`
 call) as early as possible, so the plugin can catch all relevant key presses.
+The configuration can happen at any time, but using the `STALKER` macro is
+highly recommended.
 
 ## Plugin methods
 
 The plugin provides the `StalkerEffect` object, which has the following
 method:
 
-### `.configure(color)`
+### `.configure(effect)`
+
+> Set the effect to use with the plugin. See below for a list.
+>
+> It is recommended to use the `STALKER` macro to declare the effect itself.
+
+## Plugin helpers
+
+### `STALKER(effect, params...)`
+
+> Returns an effect, to be used by the `.configure` method of the
+> `StalkerEffect` object. Any arguments given to the macro, are also passed on
+> to the effect. If the effect takes no arguments, use `NULL`.
+
+## Plugin effects
+
+The plugin provides the following effects:
+
+### `Haunt([color])`
+
+> A ghostly haunt effect, that trails the key taps with a ghostly white color
+> (or any other color, if specified).
+
+### `BlazingTrail()`
 
-> Set the color to use for highlighting pressed keys. If unset, will use the
-> default white-ish color.
+> A blazing trail of fire will follow our fingers!

src/Akela/LED-Stalker.cpp

@@ -20,21 +20,21 @@
 
 namespace Akela {
   namespace LEDEffects {
-    cRGB StalkerEffect::highlightColor = (cRGB) {64, 128, 128};
     uint8_t StalkerEffect::map[ROWS][COLS];
+    StalkerEffect::ColorComputer *StalkerEffect::colorComputer;
 
     StalkerEffect::StalkerEffect (void) {
     }
 
     void
-    StalkerEffect::begin (void) {
-      event_handler_hook_add (eventHandlerHook);
-      loop_hook_add (loopHook);
+    StalkerEffect::configure (ColorComputer *colorComputer_) {
+      colorComputer = colorComputer_;
     }
 
     void
-    StalkerEffect::configure (const cRGB highlightColor_) {
-      highlightColor = highlightColor_;
+    StalkerEffect::begin (void) {
+      event_handler_hook_add (eventHandlerHook);
+      loop_hook_add (loopHook);
     }
 
      Key
@@ -53,18 +53,13 @@ namespace Akela {
       if (postClear)
         return;
 
-      float mb = highlightColor.b / 255.0;
-      float mg = highlightColor.g / 255.0;
-      float mr = highlightColor.r / 255.0;
+      if (!colorComputer)
+        return;
 
       for (byte r = 0; r < ROWS; r++) {
         for (byte c = 0; c < COLS; c++) {
-          cRGB color = {(uint8_t)min(map[r][c] * mb, 255),
-                        (uint8_t)min(map[r][c] * mg, 255),
-                        (uint8_t)min(map[r][c] * mr, 255)};
-
           if (map[r][c])
-            led_set_crgb_at (r, c, color);
+            led_set_crgb_at (r, c, colorComputer->compute (map[r][c]));
 
           if (map[r][c] >= 0xf0)
             map[r][c]--;
@@ -78,6 +73,50 @@ namespace Akela {
       }
     }
 
+    namespace Stalker {
+
+      // Haunt
+      float Haunt::mb;
+      float Haunt::mg;
+      float Haunt::mr;
+
+      Haunt::Haunt (const cRGB highlightColor) {
+        mb = highlightColor.b / 255.0;
+        mg = highlightColor.g / 255.0;
+        mr = highlightColor.r / 255.0;
+      }
+
+      cRGB
+      Haunt::compute (uint8_t step) {
+        cRGB color = {(uint8_t)min(step * mb, 255),
+                      (uint8_t)min(step * mg, 255),
+                      (uint8_t)min(step * mr, 255)};
+
+        return color;
+      }
+
+      // BlazingTrail
+      BlazingTrail::BlazingTrail (...) {
+      }
+
+      cRGB
+      BlazingTrail::compute (uint8_t step) {
+        cRGB color;
+
+        color.b = 0;
+        color.r = step;
+
+        if (step >= 0xf0) {
+        } else if (step >= 0x80) {
+          color.g = 0xa0 - step / 2;
+        } else
+          color.g = step;
+
+        return color;
+      }
+
+    };
+
   };
 };
 

src/Akela/LED-Stalker.h

@@ -18,22 +18,53 @@
 
 #include <Akela-Core.h>
 
+#define STALKER(n, ...) (({static Akela::LEDEffects::Stalker::n _effect (__VA_ARGS__); &_effect;}))
+
 namespace Akela {
   namespace LEDEffects {
     class StalkerEffect : public KeyboardioPlugin {
     public:
+      class ColorComputer {
+      public:
+        virtual cRGB compute (uint8_t step) = 0;
+      };
+
       StalkerEffect (void);
 
-      static void configure (const cRGB highlightColor);
       virtual void begin (void) final;
+      static void configure (ColorComputer *colorComputer);
 
     private:
-      static cRGB highlightColor;
+      static ColorComputer *colorComputer;
       static uint8_t map[ROWS][COLS];
 
       static Key eventHandlerHook (Key mappedKey, byte row, byte col, uint8_t keyState);
       static void loopHook (bool postClear);
     };
+
+    namespace Stalker {
+
+      class Haunt : public StalkerEffect::ColorComputer {
+      public:
+        Haunt (const cRGB highlightColor);
+        Haunt (void) : Haunt ({0x40, 0x80, 0x80}) {};
+        Haunt (void *) : Haunt () {};
+
+        virtual cRGB compute (uint8_t step) final;
+
+      private:
+        static float mr, mg, mb;
+      };
+
+      class BlazingTrail : public StalkerEffect::ColorComputer {
+      public:
+        BlazingTrail (...);
+
+        virtual cRGB compute (uint8_t step) final;
+      };
+
+    };
+
   };
 };