Hd108 (#798)

src/internal/features/DotStarL4WordFeature.h

@@ -0,0 +1,89 @@
+/*-------------------------------------------------------------------------
+DotStarL4WordFeature provides feature base class to describe color order for
+  3 color but 4 byte features when used with DotStars, exposing Luminance as W
+
+Written by Michael C. Miller.
+
+I invest time and resources providing this open source code,
+please support me by dontating (see https://github.com/Makuna/NeoPixelBus)
+
+-------------------------------------------------------------------------
+This file is part of the Makuna/NeoPixelBus library.
+
+NeoPixelBus is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as
+published by the Free Software Foundation, either version 3 of
+the License, or (at your option) any later version.
+
+NeoPixelBus is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with NeoPixel.  If not, see
+<http://www.gnu.org/licenses/>.
+-------------------------------------------------------------------------*/
+#pragma once
+
+template <uint8_t V_IC_1, uint8_t V_IC_2, uint8_t V_IC_3>
+class DotStarL4WordFeature :
+    public NeoWordElements<8, Rgbw64Color, uint32_t>
+{
+public:
+    static void applyPixelColor(uint8_t* pPixels, uint16_t indexPixel, ColorObject color)
+    {
+        uint8_t* p = getPixelAddress(pPixels, indexPixel);
+
+        uint8_t brightness = (color.W < 31 ? color.W : 31);
+
+        // upper bit is always 1 and three 5 bit brightness
+        // {1}{5}{5}{5}
+        // 1rrr rrgg gggb bbbb
+        *p++ = 0x80 | (brightness << 2) | (brightness > 3);  
+        *p++ = (brightness << 5) | (brightness);
+
+        // due to endianness the byte order must be copied to output
+        *p++ = color[V_IC_1] >> 8;
+        *p++ = color[V_IC_1] & 0xff;
+        *p++ = color[V_IC_2] >> 8;
+        *p++ = color[V_IC_2] & 0xff;
+        *p++ = color[V_IC_3] >> 8;
+        *p = color[V_IC_3] & 0xff;
+    }
+
+    static ColorObject retrievePixelColor(const uint8_t* pPixels, uint16_t indexPixel)
+    {
+        ColorObject color;
+        const uint8_t* p = getPixelAddress(pPixels, indexPixel);
+
+        p++; // ignore the first byte
+        color.W = (*p++) & 0x1F; // mask out all but lower five bits
+
+        // due to endianness the byte order must be copied to output
+        color[V_IC_1] = (static_cast<uint16_t>(*p++) << 8);
+        color[V_IC_1] |= *p++;
+        color[V_IC_2] = (static_cast<uint16_t>(*p++) << 8);
+        color[V_IC_2] |= *p++;
+        color[V_IC_3] = (static_cast<uint16_t>(*p++) << 8);
+        color[V_IC_3] |= *p;
+
+        return color;
+    }
+
+    static ColorObject retrievePixelColor_P(PGM_VOID_P pPixels, uint16_t indexPixel)
+    {
+        ColorObject color;
+        const uint16_t* p = reinterpret_cast<const uint16_t*>(getPixelAddress(reinterpret_cast<const uint8_t*>(pPixels), indexPixel));
+
+        // PROGMEM unit of storage expected to be the same size as color element
+        //    so no endianness issues to worry about
+        color.W = pgm_read_word(p++) & 0x001F; // mask out all but lower five bits
+        color[V_IC_1] = pgm_read_word(p++);
+        color[V_IC_2] = pgm_read_word(p++);
+        color[V_IC_3] = pgm_read_word(p);
+
+        return color;
+    }
+
+};