Add a number of helper functions

Added `lookupColor(index)`, which looks up a color in the palette, by index.
Made the `row, col` variant public, and added an `updateColor` method.

These are there to help porting FingerPainter.

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

src/Kaleidoscope/LED-Palette-Theme.cpp

@@ -56,8 +56,8 @@ LEDPaletteTheme::update (uint16_t themeBase, uint8_t theme) {
     }
 }
 
-const bool
-LEDPaletteTheme::lookupColor (uint16_t mapBase, uint16_t loc, cRGB *color) {
+const uint8_t
+LEDPaletteTheme::lookupColorIndex (uint16_t mapBase, uint16_t loc) {
     uint8_t colorIndex;
 
     colorIndex = EEPROM.read (mapBase + loc / 2);
@@ -66,6 +66,13 @@ LEDPaletteTheme::lookupColor (uint16_t mapBase, uint16_t loc, cRGB *color) {
     else
         colorIndex >>= 4;
 
+    return colorIndex;
+}
+
+const bool
+LEDPaletteTheme::lookupColor (uint16_t mapBase, uint16_t loc, cRGB *color) {
+    uint8_t colorIndex = lookupColorIndex (mapBase, loc);
+
     if (colorIndex == transparentIndex)
         return false;
 
@@ -74,6 +81,29 @@ LEDPaletteTheme::lookupColor (uint16_t mapBase, uint16_t loc, cRGB *color) {
     return true;
 }
 
+const cRGB
+LEDPaletteTheme::lookupColor (uint8_t index) {
+    cRGB color;
+
+    EEPROM.get (paletteBase + index * sizeof (cRGB), color);
+    return color;
+}
+
+void
+LEDPaletteTheme::updateColor (uint16_t mapBase, uint16_t loc, uint8_t index) {
+    uint8_t indexes;
+
+    indexes = EEPROM.read (mapBase + loc / 2);
+    if (loc % 2) {
+        uint8_t other = indexes >> 4;
+        indexes = (other << 4) + index;
+    } else {
+        uint8_t other = indexes & ~0xf0;
+        indexes = (index << 4) + other;
+    }
+    EEPROM.update (mapBase + loc / 2, indexes);
+}
+
 bool
 LEDPaletteTheme::paletteFocusHook (const char *command) {
     if (strcmp_P (command, PSTR ("palette")) != 0)

src/Kaleidoscope/LED-Palette-Theme.h

@@ -31,6 +31,11 @@ class LEDPaletteTheme : public KaleidoscopePlugin {
     static uint16_t reserveThemes (uint8_t maxThemes);
     static void update (uint16_t themeBase, uint8_t theme);
 
+    static const uint8_t lookupColorIndex (uint16_t mapBase, uint16_t loc);
+    static const cRGB lookupColor (uint8_t index);
+    static const bool lookupColor (uint16_t mapBase, uint16_t loc, cRGB *color);
+    static void updateColor (uint16_t mapBase, uint16_t loc, uint8_t index);
+
     static bool paletteFocusHook (const char *command);
     static bool themeFocusHandler (const char *command, const char *expectedCommand,
                                    uint16_t themeBase, uint8_t maxThemes);
@@ -39,8 +44,6 @@ class LEDPaletteTheme : public KaleidoscopePlugin {
 
   private:
     static uint16_t paletteBase;
-
-    static const bool lookupColor (uint16_t mapBase, uint16_t loc, cRGB *color);
 };
 };