cleaner code with a macro, added unused functions back

Author: DedeHai

wled00/FX_fcn.cpp

@@ -1292,6 +1292,9 @@ void WS2812FX::service() {
 }
 
 // https://en.wikipedia.org/wiki/Blend_modes but using a for top layer & b for bottom layer
+static uint8_t _top       (uint8_t a, uint8_t b) { return a; } // function currently unused
+static uint8_t _bottom    (uint8_t a, uint8_t b) { return b; } // function currently unused
+static uint8_t _add       (uint8_t a, uint8_t b) { unsigned t = a + b; return t > 255 ? 255 : t; } // function currently unused
 static uint8_t _subtract  (uint8_t a, uint8_t b) { return b > a ? (b - a) : 0; }
 static uint8_t _difference(uint8_t a, uint8_t b) { return b > a ? (b - a) : (a - b); }
 static uint8_t _average   (uint8_t a, uint8_t b) { return (a + b) >> 1; }
@@ -1314,29 +1317,31 @@ static uint8_t _softlight (uint8_t a, uint8_t b) { return (b * b * (255 - 2 * a)
 static uint8_t _dodge     (uint8_t a, uint8_t b) { return _divide(~a,b); }
 static uint8_t _burn      (uint8_t a, uint8_t b) { return ~_divide(a,~b); }
 
+#define APPLY_BLEND(op) c.r = op(tC.r, bC.r); c.g = op(tC.g, bC.g); c.b = op(tC.b, bC.b); c.w = op(tC.w, bC.w)
+
 static uint32_t segblend(CRGBW tcol, CRGBW bcol, CRGBW bgcol, uint8_t blendMode) {
   CRGBW tC(tcol); CRGBW bC(bcol); CRGBW c; // note: using aliases shrinks code size for some weird compiler reasons, no speed difference in tests
                                            // note2: using CRGBW instead of uint32_t improves speed as well as code size
   switch (blendMode) {
     case 0:  return tcol.color32;                 // Top
     case 1:  return bcol.color32;                 // Bottom
     case 2:  return color_add(tcol, bcol, false); // Add
-    case 3:  c.r = _subtract(tC.r, bC.r);   c.g = _subtract(tC.g, bC.g);   c.b = _subtract(tC.b, bC.b);   c.w = _subtract(tC.w, bC.w);   break; // Subtract
-    case 4:  c.r = _difference(tC.r, bC.r); c.g = _difference(tC.g, bC.g); c.b = _difference(tC.b, bC.b); c.w = _difference(tC.w, bC.w); break; // Difference
-    case 5:  c.r = _average(tC.r, bC.r);    c.g = _average(tC.g, bC.g);    c.b = _average(tC.b, bC.b);    c.w = _average(tC.w, bC.w);    break; // Average
-    case 6:  c.r = _multiply(tC.r, bC.r);   c.g = _multiply(tC.g, bC.g);   c.b = _multiply(tC.b, bC.b);   c.w = _multiply(tC.w, bC.w);   break; // Multiply
-    case 7:  c.r = _divide(tC.r, bC.r);     c.g = _divide(tC.g, bC.g);     c.b = _divide(tC.b, bC.b);     c.w = _divide(tC.w, bC.w);     break; // Divide
-    case 8:  c.r = _lighten(tC.r, bC.r);    c.g = _lighten(tC.g, bC.g);    c.b = _lighten(tC.b, bC.b);    c.w = _lighten(tC.w, bC.w);    break; // Lighten
-    case 9:  c.r = _darken(tC.r, bC.r);     c.g = _darken(tC.g, bC.g);     c.b = _darken(tC.b, bC.b);     c.w = _darken(tC.w, bC.w);     break; // Darken
-    case 10: c.r = _screen(tC.r, bC.r);     c.g = _screen(tC.g, bC.g);     c.b = _screen(tC.b, bC.b);     c.w = _screen(tC.w, bC.w);     break; // Screen
-    case 11: c.r = _overlay(tC.r, bC.r);    c.g = _overlay(tC.g, bC.g);    c.b = _overlay(tC.b, bC.b);    c.w = _overlay(tC.w, bC.w);    break; // Overlay
-    case 12: c.r = _hardlight(tC.r, bC.r);  c.g = _hardlight(tC.g, bC.g);  c.b = _hardlight(tC.b, bC.b);  c.w = _hardlight(tC.w, bC.w);  break; // Hardlight
-    case 13: c.r = _softlight(tC.r, bC.r);  c.g = _softlight(tC.g, bC.g);  c.b = _softlight(tC.b, bC.b);  c.w = _softlight(tC.w, bC.w);  break; // Softlight
-    case 14: c.r = _dodge(tC.r, bC.r);      c.g = _dodge(tC.g, bC.g);      c.b = _dodge(tC.b, bC.b);      c.w = _dodge(tC.w, bC.w);      break; // Dodge
-    case 15: c.r = _burn(tC.r, bC.r);       c.g = _burn(tC.g, bC.g);       c.b = _burn(tC.b, bC.b);       c.w = _burn(tC.w, bC.w);       break; // Burn
+    case 3:  APPLY_BLEND(_subtract);    break;    // Subtract
+    case 4:  APPLY_BLEND(_difference);  break;    // Difference
+    case 5:  APPLY_BLEND(_average);     break;    // Average
+    case 6:  APPLY_BLEND(_multiply);    break;    // Multiply
+    case 7:  APPLY_BLEND(_divide);      break;    // Divide
+    case 8:  APPLY_BLEND(_lighten);     break;    // Lighten
+    case 9:  APPLY_BLEND(_darken);      break;    // Darken
+    case 10: APPLY_BLEND(_screen);      break;    // Screen
+    case 11: APPLY_BLEND(_overlay);     break;    // Overlay
+    case 12: APPLY_BLEND(_hardlight);   break;    // Hardlight
+    case 13: APPLY_BLEND(_softlight);   break;    // Softlight
+    case 14: APPLY_BLEND(_dodge);       break;    // Dodge
+    case 15: APPLY_BLEND(_burn);        break;    // Burn
+    case 32: return tcol.color32 == bgcol.color32 ? bcol.color32 : tcol.color32; // Stencil: backgroundcolor -> transparent, use top color otherwise
     // note: stencil mode is a special case: it works only on full color comparison and wont work correctly on a colorchannel base
     // enumerate to 32 to allow future additions above in case a function array will be used again
-    case 32: return tcol.color32 == bgcol.color32 ? bcol.color32 : tcol.color32; // Stencil: backgroundcolor -> transparent, use top color otherwise
     default: return tcol.color32; // fallback to Top
   }
   return c.color32;