NeoPixel_FastLED.h

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// The MIT License (MIT)
// 
// Copyright (c) 2013 FastLED
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
#ifndef NEOPIXEL_FASTLED_H
#define NEOPIXEL_FASTLED_H
 
#if defined(__arm__)
#define SCALE8_C 1
#elif defined(REELTWO_AVR)
// AVR ATmega and friends Arduino
#if !defined(LIB8_ATTINY)
#define SCALE8_AVRASM 1
#define CLEANUP_R1_AVRASM 1
#else
// On ATtiny, we just use C implementations
#define SCALE8_C 1
#define SCALE8_AVRASM 0
#endif
#else
#define SCALE8_C 1
#endif
 
enum LEDChipset
{
    WS2812B = NEO_GRB + NEO_KHZ800,
    SK6812 = NEO_GRB + NEO_KHZ800,
    SK6812CUSTOM = NEO_GRB + NEO_KHZ800
};
 
extern void hsv2rgb_rainbow( const struct CHSV& hsv, struct CRGB& rgb);
 
struct CHSV {
    union {
        struct {
            union {
                uint8_t hue;
                uint8_t h; };
            union {
                uint8_t saturation;
                uint8_t sat;
                uint8_t s; };
            union {
                uint8_t value;
                uint8_t val;
                uint8_t v; };
        };
        uint8_t raw[3];
    };
 
    inline CHSV() __attribute__((always_inline))
    {
    }
 
    inline CHSV( uint8_t ih, uint8_t is, uint8_t iv) __attribute__((always_inline))
        : h(ih), s(is), v(iv)
    {
    }
 
    inline CHSV(const CHSV& rhs) __attribute__((always_inline))
    {
        h = rhs.h;
        s = rhs.s;
        v = rhs.v;
    }
 
    inline CHSV& operator= (const CHSV& rhs) __attribute__((always_inline))
    {
        h = rhs.h;
        s = rhs.s;
        v = rhs.v;
        return *this;
    }
 
    inline CHSV& setHSV(uint8_t ih, uint8_t is, uint8_t iv) __attribute__((always_inline))
    {
        h = ih;
        s = is;
        v = iv;
        return *this;
    }
};
 
struct CRGB {
    union {
        struct {
            union {
                uint8_t g;
                uint8_t green;
            };
            union {
                uint8_t r;
                uint8_t red;
            };
            union {
                uint8_t b;
                uint8_t blue;
            };
        };
        uint8_t raw[3];
    };
 
    // default values are UNINITIALIZED
    inline CRGB() __attribute__((always_inline))
    {
    }
 
    inline CRGB( uint8_t ir, uint8_t ig, uint8_t ib)  __attribute__((always_inline))
        : g(ig), r(ir), b(ib)
    {
    }
 
    inline CRGB& setHSV (uint8_t hue, uint8_t sat, uint8_t val) __attribute__((always_inline))
    {
        hsv2rgb_rainbow( CHSV(hue, sat, val), *this);
        return *this;
    }
 
    inline CRGB& setRGB (uint8_t nr, uint8_t ng, uint8_t nb) __attribute__((always_inline))
    {
        r = nr;
        g = ng;
        b = nb;
        return *this;
    }
};
 
typedef uint8_t   fract8;   
 
#define LIB8STATIC __attribute__ ((unused)) static inline
#define LIB8STATIC_ALWAYS_INLINE __attribute__ ((always_inline)) static inline
 
#define FASTLED_RAND16_2053  ((uint16_t)(2053))
#define FASTLED_RAND16_13849 ((uint16_t)(13849))
#define RAND16_SEED  1337
 
static uint16_t rand16seed = RAND16_SEED;
 
LIB8STATIC uint8_t random8()
{
    rand16seed = (rand16seed * FASTLED_RAND16_2053) + FASTLED_RAND16_13849;
    // return the sum of the high and low bytes, for better
    //  mixing and non-sequential correlation
    return (uint8_t)(((uint8_t)(rand16seed & 0xFF)) +
                     ((uint8_t)(rand16seed >> 8)));
}
 
LIB8STATIC uint8_t random8(uint8_t lim)
{
    uint8_t r = random8();
    r = (r*lim) >> 8;
    return r;
}
 
LIB8STATIC_ALWAYS_INLINE uint8_t scale8( uint8_t i, fract8 scale)
{
#if SCALE8_C == 1
    return (((uint16_t)i) * (1+(uint16_t)(scale))) >> 8;
#elif SCALE8_AVRASM == 1
#if defined(LIB8_ATTINY)
    uint8_t work=i;
    uint8_t cnt=0x80;
    asm volatile(
        "  inc %[scale]                 \n\t"
        "  breq DONE_%=                 \n\t"
        "  clr %[work]                  \n\t"
        "LOOP_%=:                       \n\t"
        /*"  sbrc %[scale], 0             \n\t"
        "  add %[work], %[i]            \n\t"
        "  ror %[work]                  \n\t"
        "  lsr %[scale]                 \n\t"
        "  clc                          \n\t"*/
        "  sbrc %[scale], 0             \n\t"
        "  add %[work], %[i]            \n\t"
        "  ror %[work]                  \n\t"
        "  lsr %[scale]                 \n\t"
        "  lsr %[cnt]                   \n\t"
        "brcc LOOP_%=                   \n\t"
        "DONE_%=:                       \n\t"
        : [work] "+r" (work), [cnt] "+r" (cnt)
        : [scale] "r" (scale), [i] "r" (i)
        :
      );
    return work;
#else
    asm volatile(
        // Multiply 8-bit i * 8-bit scale, giving 16-bit r1,r0
        "mul %0, %1          \n\t"
        // Add i to r0, possibly setting the carry flag
        "add r0, %0         \n\t"
        // load the immediate 0 into i (note, this does _not_ touch any flags)
        "ldi %0, 0x00       \n\t"
        // walk and chew gum at the same time
        "adc %0, r1          \n\t"
         "clr __zero_reg__    \n\t"
 
         : "+a" (i)      /* writes to i */
         : "a"  (scale)  /* uses scale */
         : "r0", "r1"    /* clobbers r0, r1 */ );
 
    /* Return the result */
    return i;
#endif
#else
#error "No implementation for scale8 available."
#endif
}
 
LIB8STATIC uint8_t map8( uint8_t in, uint8_t rangeStart, uint8_t rangeEnd)
{
    uint8_t rangeWidth = rangeEnd - rangeStart;
    uint8_t out = scale8( in, rangeWidth);
    out += rangeStart;
    return out;
}
 
LIB8STATIC_ALWAYS_INLINE void cleanup_R1()
{
#if CLEANUP_R1_AVRASM == 1
    // Restore r1 to "0"; it's expected to always be that
    asm volatile( "clr __zero_reg__  \n\t" : : : "r1" );
#endif
}
 
LIB8STATIC_ALWAYS_INLINE uint8_t scale8_LEAVING_R1_DIRTY( uint8_t i, fract8 scale)
{
#if SCALE8_C == 1
    return (((uint16_t)i) * ((uint16_t)(scale)+1)) >> 8;
#elif SCALE8_AVRASM == 1
    asm volatile(
          // Multiply 8-bit i * 8-bit scale, giving 16-bit r1,r0
          "mul %0, %1          \n\t"
          // Add i to r0, possibly setting the carry flag
          "add r0, %0         \n\t"
          // load the immediate 0 into i (note, this does _not_ touch any flags)
          "ldi %0, 0x00       \n\t"
          // walk and chew gum at the same time
          "adc %0, r1          \n\t"
         /* R1 IS LEFT DIRTY HERE; YOU MUST ZERO IT OUT YOURSELF  */
         /* "clr __zero_reg__    \n\t" */
 
         : "+a" (i)      /* writes to i */
         : "a"  (scale)  /* uses scale */
         : "r0", "r1"    /* clobbers r0, r1 */ );
 
    // Return the result
    return i;
#else
#error "No implementation for scale8_LEAVING_R1_DIRTY available."
#endif
}
 
LIB8STATIC_ALWAYS_INLINE uint8_t scale8_video_LEAVING_R1_DIRTY( uint8_t i, fract8 scale)
{
#if SCALE8_C == 1 || defined(LIB8_ATTINY)
    uint8_t j = (((int)i * (int)scale) >> 8) + ((i&&scale)?1:0);
    // uint8_t nonzeroscale = (scale != 0) ? 1 : 0;
    // uint8_t j = (i == 0) ? 0 : (((int)i * (int)(scale) ) >> 8) + nonzeroscale;
    return j;
#elif SCALE8_AVRASM == 1
    uint8_t j=0;
    asm volatile(
        "  tst %[i]\n\t"
        "  breq L_%=\n\t"
        "  mul %[i], %[scale]\n\t"
        "  mov %[j], r1\n\t"
        "  breq L_%=\n\t"
        "  subi %[j], 0xFF\n\t"
        "L_%=: \n\t"
        : [j] "+a" (j)
        : [i] "a" (i), [scale] "a" (scale)
        : "r0", "r1");
 
    return j;
#else
#error "No implementation for scale8_video_LEAVING_R1_DIRTY available."
#endif
}
 
#define FORCE_REFERENCE(var)  asm volatile( "" : : "r" (var) )
 
 
#define K255 255
#define K171 171
#define K170 170
#define K85  85
 
void hsv2rgb_rainbow( const CHSV& hsv, CRGB& rgb)
{
    // Yellow has a higher inherent brightness than
    // any other color; 'pure' yellow is perceived to
    // be 93% as bright as white.  In order to make
    // yellow appear the correct relative brightness,
    // it has to be rendered brighter than all other
    // colors.
    // Level Y1 is a moderate boost, the default.
    // Level Y2 is a strong boost.
    const uint8_t Y1 = 1;
    const uint8_t Y2 = 0;
    
    // G2: Whether to divide all greens by two.
    // Depends GREATLY on your particular LEDs
    const uint8_t G2 = 0;
    
    // Gscale: what to scale green down by.
    // Depends GREATLY on your particular LEDs
    const uint8_t Gscale = 0;
    
    
    uint8_t hue = hsv.hue;
    uint8_t sat = hsv.sat;
    uint8_t val = hsv.val;
    
    uint8_t offset = hue & 0x1F; // 0..31
    
    // offset8 = offset * 8
    uint8_t offset8 = offset;
    {
#if defined(__AVR__)
        // Left to its own devices, gcc turns "x <<= 3" into a loop
        // It's much faster and smaller to just do three single-bit shifts
        // So this business is to force that.
        offset8 <<= 1;
        asm volatile("");
        offset8 <<= 1;
        asm volatile("");
        offset8 <<= 1;
#else
        // On ARM and other non-AVR platforms, we just shift 3.
        offset8 <<= 3;
#endif
    }
    
    uint8_t third = scale8( offset8, (256 / 3)); // max = 85
    
    uint8_t r, g, b;
    
    if( ! (hue & 0x80) ) {
        // 0XX
        if( ! (hue & 0x40) ) {
            // 00X
            //section 0-1
            if( ! (hue & 0x20) ) {
                // 000
                //case 0: // R -> O
                r = K255 - third;
                g = third;
                b = 0;
                FORCE_REFERENCE(b);
            } else {
                // 001
                //case 1: // O -> Y
                if( Y1 ) {
                    r = K171;
                    g = K85 + third ;
                    b = 0;
                    FORCE_REFERENCE(b);
                }
                if( Y2 ) {
                    r = K170 + third;
                    //uint8_t twothirds = (third << 1);
                    uint8_t twothirds = scale8( offset8, ((256 * 2) / 3)); // max=170
                    g = K85 + twothirds;
                    b = 0;
                    FORCE_REFERENCE(b);
                }
            }
        } else {
            //01X
            // section 2-3
            if( !  (hue & 0x20) ) {
                // 010
                //case 2: // Y -> G
                if( Y1 ) {
                    //uint8_t twothirds = (third << 1);
                    uint8_t twothirds = scale8( offset8, ((256 * 2) / 3)); // max=170
                    r = K171 - twothirds;
                    g = K170 + third;
                    b = 0;
                    FORCE_REFERENCE(b);
                }
                if( Y2 ) {
                    r = K255 - offset8;
                    g = K255;
                    b = 0;
                    FORCE_REFERENCE(b);
                }
            } else {
                // 011
                // case 3: // G -> A
                r = 0;
                FORCE_REFERENCE(r);
                g = K255 - third;
                b = third;
            }
        }
    } else {
        // section 4-7
        // 1XX
        if( ! (hue & 0x40) ) {
            // 10X
            if( ! ( hue & 0x20) ) {
                // 100
                //case 4: // A -> B
                r = 0;
                FORCE_REFERENCE(r);
                //uint8_t twothirds = (third << 1);
                uint8_t twothirds = scale8( offset8, ((256 * 2) / 3)); // max=170
                g = K171 - twothirds; //K170?
                b = K85  + twothirds;
                
            } else {
                // 101
                //case 5: // B -> P
                r = third;
                g = 0;
                FORCE_REFERENCE(g);
                b = K255 - third;
                
            }
        } else {
            if( !  (hue & 0x20)  ) {
                // 110
                //case 6: // P -- K
                r = K85 + third;
                g = 0;
                FORCE_REFERENCE(g);
                b = K171 - third;
                
            } else {
                // 111
                //case 7: // K -> R
                r = K170 + third;
                g = 0;
                FORCE_REFERENCE(g);
                b = K85 - third;
                
            }
        }
    }
    
    // This is one of the good places to scale the green down,
    // although the client can scale green down as well.
    if( G2 ) g = g >> 1;
    if( Gscale ) g = scale8_video_LEAVING_R1_DIRTY( g, Gscale);
    
    // Scale down colors if we're desaturated at all
    // and add the brightness_floor to r, g, and b.
    if( sat != 255 ) {
        if( sat == 0) {
            r = 255; b = 255; g = 255;
        } else {
            //nscale8x3_video( r, g, b, sat);
            if( r ) r = scale8_LEAVING_R1_DIRTY( r, sat);
            if( g ) g = scale8_LEAVING_R1_DIRTY( g, sat);
            if( b ) b = scale8_LEAVING_R1_DIRTY( b, sat);
            cleanup_R1();
            
            uint8_t desat = 255 - sat;
            desat = scale8( desat, desat);
            
            uint8_t brightness_floor = desat;
            r += brightness_floor;
            g += brightness_floor;
            b += brightness_floor;
        }
    }
    
    // Now scale everything down if we're at value < 255.
    if( val != 255 ) {
        
        val = scale8_video_LEAVING_R1_DIRTY( val, val);
        if( val == 0 ) {
            r=0; g=0; b=0;
        } else {
            // nscale8x3_video( r, g, b, val);
            if( r ) r = scale8_LEAVING_R1_DIRTY( r, val);
            if( g ) g = scale8_LEAVING_R1_DIRTY( g, val);
            if( b ) b = scale8_LEAVING_R1_DIRTY( b, val);
            cleanup_R1();
        }
    }
    
    // Here we have the old AVR "missing std X+n" problem again
    // It turns out that fixing it winds up costing more than
    // not fixing it.
    // To paraphrase Dr Bronner, profile! profile! profile!
    //asm volatile(  ""  :  :  : "r26", "r27" );
    //asm volatile (" movw r30, r26 \n" : : : "r30", "r31");
    rgb.r = r;
    rgb.g = g;
    rgb.b = b;
}
 
#endif