Rotating 2D Palette effect

wled00/FX.cpp

@@ -1929,22 +1929,102 @@ static const char _data_FX_MODE_JUGGLE[] PROGMEM = "Juggle@!,Trail;;!;;sx=64,ix=
 
 
 uint16_t mode_palette() {
-  uint16_t counter = 0;
-  if (SEGMENT.speed != 0)
-  {
-    counter = (strip.now * ((SEGMENT.speed >> 3) +1)) & 0xFFFF;
-    counter = counter >> 8;
-  }
-
-  for (int i = 0; i < SEGLEN; i++)
-  {
-    uint8_t colorIndex = (i * 255 / SEGLEN) - counter;
-    SEGMENT.setPixelColor(i, SEGMENT.color_from_palette(colorIndex, false, PALETTE_MOVING_WRAP, 255));
+  // Set up some compile time constants so that we can handle integer and float based modes using the same code base.
+#ifdef ESP8266
+  using mathType = int32_t;
+  using wideMathType = int64_t;
+  using angleType = uint16_t;
+  constexpr mathType sInt16Scale             = 0x7FFF;
+  constexpr mathType maxAngle                = 0x8000;
+  constexpr mathType staticRotationScale     = 256;
+  constexpr mathType animatedRotationScale   = 1;
+  constexpr int16_t (*sinFunction)(uint16_t) = &sin16;
+  constexpr int16_t (*cosFunction)(uint16_t) = &cos16;
+#else
+  using mathType = float;
+  using wideMathType = float;
+  using angleType = float;
+  constexpr mathType sInt16Scale           = 1.0f;
+  constexpr mathType maxAngle              = M_PI / 256.0;
+  constexpr mathType staticRotationScale   = 1.0f;
+  constexpr mathType animatedRotationScale = M_TWOPI / double(0xFFFF);
+  constexpr float (*sinFunction)(float)    = &sin_t;
+  constexpr float (*cosFunction)(float)    = &cos_t;
+#endif
+  const bool isMatrix = strip.isMatrix;
+  const int cols = SEGMENT.virtualWidth();
+  const int rows = isMatrix ? SEGMENT.virtualHeight() : strip.getActiveSegmentsNum();
+
+  const int  inputShift           = SEGMENT.speed;
+  const int  inputSize            = SEGMENT.intensity;
+  const int  inputRotation        = SEGMENT.custom1;
+  const bool inputAnimateShift    = SEGMENT.check1;
+  const bool inputAnimateRotation = SEGMENT.check2;
+  const bool inputAssumeSquare    = SEGMENT.check3;
+
+  const angleType theta = (!inputAnimateRotation) ? (inputRotation * maxAngle / staticRotationScale) : (((strip.now * ((inputRotation >> 4) +1)) & 0xFFFF) * animatedRotationScale);
+  const mathType sinTheta = sinFunction(theta);
+  const mathType cosTheta = cosFunction(theta);
+
+  const mathType maxX    = std::max(1, cols-1);
+  const mathType maxY    = std::max(1, rows-1);
+  // Set up some parameters according to inputAssumeSquare, so that we can handle anamorphic mode using the same code base.
+  const mathType maxXIn  =  inputAssumeSquare ? maxX : mathType(1);
+  const mathType maxYIn  =  inputAssumeSquare ? maxY : mathType(1);
+  const mathType maxXOut = !inputAssumeSquare ? maxX : mathType(1);
+  const mathType maxYOut = !inputAssumeSquare ? maxY : mathType(1);
+  const mathType centerX = sInt16Scale * maxXOut / mathType(2);
+  const mathType centerY = sInt16Scale * maxYOut / mathType(2);
+  // The basic idea for this effect is to rotate a rectangle that is filled with the palette along one axis, then map our
+  // display to it, to find what color a pixel should have.
+  // However, we want a) no areas of solid color (in front of or behind the palette), and b) we want to make use of the full palette.
+  // So the rectangle needs to have exactly the right size. That size depends on the rotation.
+  // This scale computation here only considers one dimension. You can think of it like the rectangle is always scaled so that
+  // the left and right most points always match the left and right side of the display.
+  const mathType scale   = std::abs(sinTheta) + (std::abs(cosTheta) * maxYOut / maxXOut);
+  // 2D simulation:
+  // If we are dealing with a 1D setup, we assume that each segment represents one line on a 2-dimensional display.
+  // The function is called once per segments, so we need to handle one line at a time.
+  const int yFrom = isMatrix ? 0 : strip.getCurrSegmentId();
+  const int yTo   = isMatrix ? maxY : yFrom;
+  for (int y = yFrom; y <= yTo; ++y) {
+    // translate, scale, rotate
+    const mathType ytCosTheta = mathType((wideMathType(cosTheta) * wideMathType(y * sInt16Scale - centerY * maxYIn))/wideMathType(maxYIn * scale));
+    for (int x = 0; x < cols; ++x) {
+      // translate, scale, rotate
+      const mathType xtSinTheta = mathType((wideMathType(sinTheta) * wideMathType(x * sInt16Scale - centerX * maxXIn))/wideMathType(maxXIn * scale));
+      // Map the pixel coordinate to an imaginary-rectangle-coordinate.
+      // The y coordinate doesn't actually matter, as our imaginary rectangle is filled with the palette from left to right,
+      // so all points at a given x-coordinate have the same color.
+      const mathType sourceX = xtSinTheta + ytCosTheta + centerX;
+      // The computation was scaled just right so that the result should always be in range [0, maxXOut], but enforce this anyway
+      // to account for imprecision. Then scale it so that the range is [0, 255], which we can use with the palette.
+      int colorIndex = (std::min(std::max(sourceX, mathType(0)), maxXOut * sInt16Scale) * 255) / (sInt16Scale * maxXOut);
+      // inputSize determines by how much we want to scale the palette:
+      // values < 128 display a fraction of a palette,
+      // values > 128 display multiple palettes.
+      if (inputSize <= 128) {
+        colorIndex = (colorIndex * inputSize) / 128;
+      } else {
+        // Linear function that maps colorIndex 128=>1, 256=>9.
+        // With this function every full palette repetition is exactly 16 configuration steps wide.
+        // That allows displaying exactly 2 repetitions for example.
+        colorIndex = ((inputSize - 112) * colorIndex) / 16;
+      }
+      // Finally, shift the palette a bit.
+      const int paletteOffset = (!inputAnimateShift) ? (inputShift-128) : (((strip.now * ((inputShift >> 3) +1)) & 0xFFFF) >> 8);
+      colorIndex += paletteOffset;
+      const uint32_t color = SEGMENT.color_wheel((uint8_t)colorIndex);
+      if (isMatrix) {
+        SEGMENT.setPixelColorXY(x, y, color);
+      } else {
+        SEGMENT.setPixelColor(x, color);
+      }
+    }
   }
-
   return FRAMETIME;
 }
-static const char _data_FX_MODE_PALETTE[] PROGMEM = "Palette@Cycle speed;;!;;c3=0,o2=0";
+static const char _data_FX_MODE_PALETTE[] PROGMEM = "Palette@Shift,Size,Rotation,,,Animate Shift,Animate Rotation,Anamorphic;;!;12;c1=128,c2=128,c3=128,o1=1,o2=1,o3=0";
 
 
 // WLED limitation: Analog Clock overlay will NOT work when Fire2012 is active