Drop transparency support

Supporting transparency is very, very expensive in terms of speed, while the
benefits are marginal at best. Drop support for it for now.

Signed-off-by: Gergely Nagy <kaleidoscope@gergo.csillger.hu>

README.md

@@ -10,7 +10,7 @@
  [st:experimental]: https://img.shields.io/badge/experimental----black.svg?style=flat&colorA=dfb317&colorB=494e52
 
 A common base for plugins that want to provide themes, or theme-related
-capabilities, using a 15+1 color palette. In other words, this is for plugin
+capabilities, using a 16 color palette. In other words, this is for plugin
 authors primarily. The primary aim of the plugin is to provide not only a common
 palette, but tools that make it easier to use it too.
 
@@ -112,17 +112,6 @@ The plugin provides the `LEDPaletteTheme` object, which has the following method
 > The palette can be set via the `palette` focus command, implemented by the
 > `FOCUS_HOOK_LEDPALETTETHEME` hook explained below.
 
-### `.transparent_index`
-
-> The plugin supports transparent colors too: by default, the last color (index
-> 15) is treated as transparent. If a pixel is found to be transparent,
-> `.updateHandler` will not change its color, but leave it as is. This way one
-> can create layers of themes, if so desired.
->
-> This property can be set to a number between 0 and 15 to make that index
-> transparent, or to a number higher than 15 to disable transparency support,
-> and gain another color on the palette.
-
 ## Focus commands
 
 The plugin provides a single `Focus` hook, `FOCUS_HOOK_LEDPALETTETHEME`,

src/Kaleidoscope/LED-Palette-Theme.cpp

@@ -24,10 +24,6 @@
 namespace kaleidoscope {
 
 uint16_t LEDPaletteTheme::palette_base_;
-uint8_t LEDPaletteTheme::transparent_index = 15;
-
-LEDPaletteTheme::LEDPaletteTheme(void) {
-}
 
 void LEDPaletteTheme::begin(void) {
   Kaleidoscope.use(&::EEPROMSettings);
@@ -44,11 +40,7 @@ void LEDPaletteTheme::updateHandler(uint16_t theme_base, uint8_t theme) {
   uint16_t map_base = theme_base + (theme * ROWS * COLS / 2);
 
   for (uint16_t pos = 0; pos < ROWS * COLS; pos++) {
-    cRGB color;
-
-    if (!lookupColorAtPosition(map_base, pos, &color))
-      continue;
-
+    cRGB color = lookupColorAtPosition(map_base, pos);
     ::LEDControl.setCrgbAt(pos, color);
   }
 }
@@ -57,11 +49,7 @@ void LEDPaletteTheme::refreshAt(uint16_t theme_base, uint8_t theme, byte row, by
   uint16_t map_base = theme_base + (theme * ROWS * COLS / 2);
   uint16_t pos = KeyboardHardware.getLedIndex(row, col);
 
-  cRGB color;
-
-  if (!lookupColorAtPosition(map_base, pos, &color))
-    return;
-
+  cRGB color = lookupColorAtPosition(map_base, pos);
   ::LEDControl.setCrgbAt(pos, color);
 }
 
@@ -78,15 +66,10 @@ const uint8_t LEDPaletteTheme::lookupColorIndexAtPosition(uint16_t map_base, uin
   return color_index;
 }
 
-const bool LEDPaletteTheme::lookupColorAtPosition(uint16_t map_base, uint16_t position, cRGB *color) {
+const cRGB LEDPaletteTheme::lookupColorAtPosition(uint16_t map_base, uint16_t position) {
   uint8_t color_index = lookupColorIndexAtPosition(map_base, position);
 
-  if (color_index == transparent_index)
-    return false;
-
-  *color = lookupPaletteColor(color_index);
-
-  return true;
+  return lookupPaletteColor(color_index);
 }
 
 const cRGB LEDPaletteTheme::lookupPaletteColor(uint8_t color_index) {

src/Kaleidoscope/LED-Palette-Theme.h

@@ -25,7 +25,7 @@ namespace kaleidoscope {
 
 class LEDPaletteTheme : public KaleidoscopePlugin {
  public:
-  LEDPaletteTheme(void);
+  LEDPaletteTheme(void) {};
 
   void begin(void) final;
 
@@ -34,7 +34,7 @@ class LEDPaletteTheme : public KaleidoscopePlugin {
   static void refreshAt(uint16_t theme_base, uint8_t theme, byte row, byte col);
 
   static const uint8_t lookupColorIndexAtPosition(uint16_t theme_base, uint16_t position);
-  static const bool lookupColorAtPosition(uint16_t theme_base, uint16_t position, cRGB *color);
+  static const cRGB lookupColorAtPosition(uint16_t theme_base, uint16_t position);
   static void updateColorIndexAtPosition(uint16_t theme_base, uint16_t position, uint8_t color_index);
 
   static const cRGB lookupPaletteColor(uint8_t palette_index);
@@ -43,8 +43,6 @@ class LEDPaletteTheme : public KaleidoscopePlugin {
   static bool themeFocusHandler(const char *command, const char *expected_command,
                                 uint16_t theme_base, uint8_t max_themes);
 
-  static uint8_t transparent_index;
-
  private:
   static uint16_t palette_base_;
 };