controller.h

#ifndef __INC_CONTROLLER_H
#define __INC_CONTROLLER_H

#include "led_sysdefs.h"
#include "pixeltypes.h"
#include "color.h"

#define RO(X) RGB_BYTE(RGB_ORDER, X)
#define RGB_BYTE(RO,X) (((RO)>>(3*(2-(X)))) & 0x3)

#define RGB_BYTE0(RO) ((RO>>6) & 0x3)
#define RGB_BYTE1(RO) ((RO>>3) & 0x3)
#define RGB_BYTE2(RO) ((RO) & 0x3)

// operator byte *(struct CRGB[] arr) { return (byte*)arr; }

#define DISABLE_DITHER 0x00
#define BINARY_DITHER 0x01
typedef uint8_t EDitherMode;

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// LED Controller interface definition
//
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

/// Base definition for an LED controller.  Pretty much the methods that every LED controller object will make available.
/// Note that the showARGB method is not impelemented for all controllers yet.   Note also the methods for eventual checking
/// of background writing of data (I'm looking at you, teensy 3.0 DMA controller!).  If you want to pass LED controllers around
/// to methods, make them references to this type, keeps your code saner.  However, most people won't be seeing/using these objects
/// directly at all
class CLEDController {
protected:
    friend class CFastLED;
    CRGB *m_Data;
    CLEDController *m_pNext;
    CRGB m_ColorCorrection;
    CRGB m_ColorTemperature;
    EDitherMode m_DitherMode;
    int m_nLeds;
    static CLEDController *m_pHead;
    static CLEDController *m_pTail;

    // set all the leds on the controller to a given color
    virtual void showColor(const struct CRGB & data, int nLeds, CRGB scale) = 0;

    // note that the uint8_ts will be in the order that you want them sent out to the device.
    // nLeds is the number of RGB leds being written to
    virtual void show(const struct CRGB *data, int nLeds, CRGB scale) = 0;

#ifdef SUPPORT_ARGB
    // as above, but every 4th uint8_t is assumed to be alpha channel data, and will be skipped
    virtual void show(const struct CARGB *data, int nLeds, CRGB scale) = 0;
#endif
public:
    CLEDController() : m_Data(NULL), m_ColorCorrection(UncorrectedColor), m_ColorTemperature(UncorrectedTemperature), m_DitherMode(BINARY_DITHER), m_nLeds(0) {
        m_pNext = NULL;
        if(m_pHead==NULL) { m_pHead = this; }
        if(m_pTail != NULL) { m_pTail->m_pNext = this; }
        m_pTail = this;
    }

	// initialize the LED controller
	virtual void init() = 0;

	// clear out/zero out the given number of leds.
	virtual void clearLeds(int nLeds) = 0;

    // show function w/integer brightness, will scale for color correction and temperature
    void show(const struct CRGB *data, int nLeds, uint8_t brightness) {
        show(data, nLeds, getAdjustment(brightness));
    }

    // show function w/integer brightness, will scale for color correction and temperature
    void showColor(const struct CRGB &data, int nLeds, uint8_t brightness) {
        showColor(data, nLeds, getAdjustment(brightness));
    }

    // show function using the "attached to this controller" led data
    void showLeds(uint8_t brightness=255) {
        show(m_Data, m_nLeds, getAdjustment(brightness));
    }

    void showColor(const struct CRGB & data, uint8_t brightness=255) {
        showColor(data, m_nLeds, getAdjustment(brightness));
    }

    // navigating the list of controllers
    static CLEDController *head() { return m_pHead; }
    CLEDController *next() { return m_pNext; }

 #ifdef SUPPORT_ARGB
    // as above, but every 4th uint8_t is assumed to be alpha channel data, and will be skipped
    void show(const struct CARGB *data, int nLeds, uint8_t brightness) {
        show(data, nLeds, getAdjustment(brightness))
    }
#endif

    CLEDController & setLeds(CRGB *data, int nLeds) {
        m_Data = data;
        m_nLeds = nLeds;
        return *this;
    }

    void clearLedData() {
        if(m_Data) {
            memset8((void*)m_Data, 0, sizeof(struct CRGB) * m_nLeds);
        }
    }

    // How many leds does this controller manage?
    int size() { return m_nLeds; }

    // Pointer to the CRGB array for this controller
    CRGB* leds() { return m_Data; }

    // Reference to the n'th item in the controller
    CRGB &operator[](int x) { return m_Data[x]; }

    inline CLEDController & setDither(uint8_t ditherMode = BINARY_DITHER) { m_DitherMode = ditherMode; return *this; }
    inline uint8_t getDither() { return m_DitherMode; }

    CLEDController & setCorrection(CRGB correction) { m_ColorCorrection = correction; return *this; }
    CLEDController & setCorrection(LEDColorCorrection correction) { m_ColorCorrection = correction; return *this; }
    CRGB getCorrection() { return m_ColorCorrection; }

    CLEDController & setTemperature(CRGB temperature) { m_ColorTemperature = temperature; return *this; }
    CLEDController & setTemperature(ColorTemperature temperature) { m_ColorTemperature = temperature; return *this; }
    CRGB getTemperature() { return m_ColorTemperature; }

    CRGB getAdjustment(uint8_t scale) {
#if defined(NO_CORRECTION) && (NO_CORRECTION==1)
        return CRGB(scale,scale,scale);
#else
        CRGB adj(0,0,0);

        if(scale > 0) {
            for(uint8_t i = 0; i < 3; i++) {
                uint8_t cc = m_ColorCorrection.raw[i];
                uint8_t ct = m_ColorTemperature.raw[i];
                if(cc > 0 && ct > 0) {
                    uint32_t work = (((uint32_t)cc)+1) * (((uint32_t)ct)+1) * scale;
                    work /= 0x10000L;
                    adj.raw[i] = work & 0xFF;
                }
            }
        }

        return adj;
#endif
    }
};

// Pixel controller class.  This is the class that we use to centralize pixel access in a block of data, including
// support for things like RGB reordering, scaling, dithering, skipping (for ARGB data), and eventually, we will
// centralize 8/12/16 conversions here as well.
template<EOrder RGB_ORDER>
struct PixelController {
        const uint8_t *mData;
        int mLen;
        uint8_t d[3];
        uint8_t e[3];
        CRGB mScale;
        uint8_t mAdvance;

        PixelController(const PixelController & other) {
            d[0] = other.d[0];
            d[1] = other.d[1];
            d[2] = other.d[2];
            e[0] = other.e[0];
            e[1] = other.e[1];
            e[2] = other.e[2];
            mData = other.mData;
            mScale = other.mScale;
            mAdvance = other.mAdvance;
            mLen = other.mLen;
        }

        PixelController(const uint8_t *d, int len, CRGB & s, EDitherMode dither = BINARY_DITHER, bool advance=true, uint8_t skip=0) : mData(d), mLen(len), mScale(s) {
            enable_dithering(dither);
            mData += skip;
            mAdvance = (advance) ? 3+skip : 0;
        }

        PixelController(const CRGB *d, int len, CRGB & s, EDitherMode dither = BINARY_DITHER) : mData((const uint8_t*)d), mLen(len), mScale(s) {
            enable_dithering(dither);
            mAdvance = 3;
        }

        PixelController(const CRGB &d, int len, CRGB & s, EDitherMode dither = BINARY_DITHER) : mData((const uint8_t*)&d), mLen(len), mScale(s) {
            enable_dithering(dither);
            mAdvance = 0;
        }

#ifdef SUPPORT_ARGB
        PixelController(const CARGB &d, int len, CRGB & s, EDitherMode dither = BINARY_DITHER) : mData((const uint8_t*)&d), mLen(len), mScale(s) {
            enable_dithering(dither);
            // skip the A in CARGB
            mData += 1;
            mAdvance = 0;
        }

        PixelController(const CARGB *d, int len, CRGB & s, EDitherMode dither = BINARY_DITHER) : mData((const uint8_t*)d), mLen(len), mScale(s) {
            enable_dithering(dither);
            // skip the A in CARGB
            mData += 1;
            mAdvance = 4;
        }
#endif

        void init_binary_dithering() {
#if !defined(NO_DITHERING) || (NO_DITHERING != 1)

            // Set 'virtual bits' of dithering to the highest level
            // that is not likely to cause excessive flickering at
            // low brightness levels + low update rates.
            // These pre-set values are a little ambitious, since
            // a 400Hz update rate for WS2811-family LEDs is only
            // possible with 85 pixels or fewer.
            // Once we have a 'number of milliseconds since last update'
            // value available here, we can quickly calculate the correct
            // number of 'virtual bits' on the fly with a couple of 'if'
            // statements -- no division required.  At this point,
            // the division is done at compile time, so there's no runtime
            // cost, but the values are still hard-coded.
#define MAX_LIKELY_UPDATE_RATE_HZ     400
#define MIN_ACCEPTABLE_DITHER_RATE_HZ  50
#define UPDATES_PER_FULL_DITHER_CYCLE (MAX_LIKELY_UPDATE_RATE_HZ / MIN_ACCEPTABLE_DITHER_RATE_HZ)
#define RECOMMENDED_VIRTUAL_BITS ((UPDATES_PER_FULL_DITHER_CYCLE>1) + \
                                  (UPDATES_PER_FULL_DITHER_CYCLE>2) + \
                                  (UPDATES_PER_FULL_DITHER_CYCLE>4) + \
                                  (UPDATES_PER_FULL_DITHER_CYCLE>8) + \
                                  (UPDATES_PER_FULL_DITHER_CYCLE>16) + \
                                  (UPDATES_PER_FULL_DITHER_CYCLE>32) + \
                                  (UPDATES_PER_FULL_DITHER_CYCLE>64) + \
                                  (UPDATES_PER_FULL_DITHER_CYCLE>128) )
#define VIRTUAL_BITS RECOMMENDED_VIRTUAL_BITS
            // R is the digther signal 'counter'.
            static byte R = 0;
            R++;

            // R is wrapped around at 2^ditherBits,
            // so if ditherBits is 2, R will cycle through (0,1,2,3)
            byte ditherBits = VIRTUAL_BITS;
            R &= (0x01 << ditherBits) - 1;

            // Q is the "unscaled dither signal" itself.
            // It's initialized to the reversed bits of R.
            // If 'ditherBits' is 2, Q here will cycle through (0,128,64,192)
            byte Q = 0;

            // Reverse bits in a byte
            {
                if(R & 0x01) { Q |= 0x80; }
                if(R & 0x02) { Q |= 0x40; }
                if(R & 0x04) { Q |= 0x20; }
                if(R & 0x08) { Q |= 0x10; }
                if(R & 0x10) { Q |= 0x08; }
                if(R & 0x20) { Q |= 0x04; }
                if(R & 0x40) { Q |= 0x02; }
                if(R & 0x80) { Q |= 0x01; }
            }

            // Now we adjust Q to fall in the center of each range,
            // instead of at the start of the range.
            // If ditherBits is 2, Q will be (0, 128, 64, 192) at first,
            // and this adjustment makes it (31, 159, 95, 223).
            if( ditherBits < 8) {
                Q += 0x01 << (7 - ditherBits);
            }

            // D and E form the "scaled dither signal"
            // which is added to pixel values to affect the
            // actual dithering.

            // Setup the initial D and E values
            for(int i = 0; i < 3; i++) {
                    byte s = mScale.raw[i];
                    e[i] = s ? (256/s) + 1 : 0;
                    d[i] = scale8(Q, e[i]);
                    if(e[i]) e[i]--;
            }
#endif
        }

        // Do we have n pixels left to process?
        __attribute__((always_inline)) inline bool has(int n) {
            return mLen >= n;
        }

        // toggle dithering enable
        void enable_dithering(EDitherMode dither) {
            switch(dither) {
                case BINARY_DITHER: init_binary_dithering(); break;
                default: d[0]=d[1]=d[2]=e[0]=e[1]=e[2]=0; break;
            }
        }

        // get the amount to advance the pointer by
        __attribute__((always_inline)) inline int advanceBy() { return mAdvance; }

        // advance the data pointer forward, adjust position counter
         __attribute__((always_inline)) inline void advanceData() { mData += mAdvance; mLen--;}

        // step the dithering forward
         __attribute__((always_inline)) inline void stepDithering() {
         		// IF UPDATING HERE, BE SURE TO UPDATE THE ASM VERSION IN
         		// clockless_trinket.h!
                d[0] = e[0] - d[0];
                d[1] = e[1] - d[1];
                d[2] = e[2] - d[2];
        }

        // Some chipsets pre-cycle the first byte, which means we want to cycle byte 0's dithering separately
        __attribute__((always_inline)) inline void preStepFirstByteDithering() {
            d[RO(0)] = e[RO(0)] - d[RO(0)];
        }

        template<int SLOT>  __attribute__((always_inline)) inline static uint8_t loadByte(PixelController & pc) { return pc.mData[RO(SLOT)]; }
        template<int SLOT>  __attribute__((always_inline)) inline static uint8_t dither(PixelController & pc, uint8_t b) { return b ? qadd8(b, pc.d[RO(SLOT)]) : 0; }
        template<int SLOT>  __attribute__((always_inline)) inline static uint8_t scale(PixelController & pc, uint8_t b) { return scale8(b, pc.mScale.raw[RO(SLOT)]); }

        // composite shortcut functions for loading, dithering, and scaling
        template<int SLOT>  __attribute__((always_inline)) inline static uint8_t loadAndScale(PixelController & pc) { return scale<SLOT>(pc, pc.dither<SLOT>(pc, pc.loadByte<SLOT>(pc))); }
        template<int SLOT>  __attribute__((always_inline)) inline static uint8_t advanceAndLoadAndScale(PixelController & pc) { pc.advanceData(); return pc.loadAndScale<SLOT>(pc); }

		// Helper functions to get around gcc stupidities
		__attribute__((always_inline)) inline uint8_t loadAndScale0() { return loadAndScale<0>(*this); }
		__attribute__((always_inline)) inline uint8_t loadAndScale1() { return loadAndScale<1>(*this); }
		__attribute__((always_inline)) inline uint8_t loadAndScale2() { return loadAndScale<2>(*this); }
		__attribute__((always_inline)) inline uint8_t advanceAndLoadAndScale0() { return advanceAndLoadAndScale<0>(*this); }
        __attribute__((always_inline)) inline uint8_t stepAdvanceAndLoadAndScale0() { stepDithering(); return advanceAndLoadAndScale<0>(*this); }
};

#endif