diff options
Diffstat (limited to 'lib/lib8tion/lib8tion.h')
| -rw-r--r-- | lib/lib8tion/lib8tion.h | 934 |
1 files changed, 934 insertions, 0 deletions
diff --git a/lib/lib8tion/lib8tion.h b/lib/lib8tion/lib8tion.h new file mode 100644 index 000000000..d93c748e6 --- /dev/null +++ b/lib/lib8tion/lib8tion.h | |||
| @@ -0,0 +1,934 @@ | |||
| 1 | #ifndef __INC_LIB8TION_H | ||
| 2 | #define __INC_LIB8TION_H | ||
| 3 | |||
| 4 | /* | ||
| 5 | |||
| 6 | Fast, efficient 8-bit math functions specifically | ||
| 7 | designed for high-performance LED programming. | ||
| 8 | |||
| 9 | Because of the AVR(Arduino) and ARM assembly language | ||
| 10 | implementations provided, using these functions often | ||
| 11 | results in smaller and faster code than the equivalent | ||
| 12 | program using plain "C" arithmetic and logic. | ||
| 13 | |||
| 14 | |||
| 15 | Included are: | ||
| 16 | |||
| 17 | |||
| 18 | - Saturating unsigned 8-bit add and subtract. | ||
| 19 | Instead of wrapping around if an overflow occurs, | ||
| 20 | these routines just 'clamp' the output at a maxumum | ||
| 21 | of 255, or a minimum of 0. Useful for adding pixel | ||
| 22 | values. E.g., qadd8( 200, 100) = 255. | ||
| 23 | |||
| 24 | qadd8( i, j) == MIN( (i + j), 0xFF ) | ||
| 25 | qsub8( i, j) == MAX( (i - j), 0 ) | ||
| 26 | |||
| 27 | - Saturating signed 8-bit ("7-bit") add. | ||
| 28 | qadd7( i, j) == MIN( (i + j), 0x7F) | ||
| 29 | |||
| 30 | |||
| 31 | - Scaling (down) of unsigned 8- and 16- bit values. | ||
| 32 | Scaledown value is specified in 1/256ths. | ||
| 33 | scale8( i, sc) == (i * sc) / 256 | ||
| 34 | scale16by8( i, sc) == (i * sc) / 256 | ||
| 35 | |||
| 36 | Example: scaling a 0-255 value down into a | ||
| 37 | range from 0-99: | ||
| 38 | downscaled = scale8( originalnumber, 100); | ||
| 39 | |||
| 40 | A special version of scale8 is provided for scaling | ||
| 41 | LED brightness values, to make sure that they don't | ||
| 42 | accidentally scale down to total black at low | ||
| 43 | dimming levels, since that would look wrong: | ||
| 44 | scale8_video( i, sc) = ((i * sc) / 256) +? 1 | ||
| 45 | |||
| 46 | Example: reducing an LED brightness by a | ||
| 47 | dimming factor: | ||
| 48 | new_bright = scale8_video( orig_bright, dimming); | ||
| 49 | |||
| 50 | |||
| 51 | - Fast 8- and 16- bit unsigned random numbers. | ||
| 52 | Significantly faster than Arduino random(), but | ||
| 53 | also somewhat less random. You can add entropy. | ||
| 54 | random8() == random from 0..255 | ||
| 55 | random8( n) == random from 0..(N-1) | ||
| 56 | random8( n, m) == random from N..(M-1) | ||
| 57 | |||
| 58 | random16() == random from 0..65535 | ||
| 59 | random16( n) == random from 0..(N-1) | ||
| 60 | random16( n, m) == random from N..(M-1) | ||
| 61 | |||
| 62 | random16_set_seed( k) == seed = k | ||
| 63 | random16_add_entropy( k) == seed += k | ||
| 64 | |||
| 65 | |||
| 66 | - Absolute value of a signed 8-bit value. | ||
| 67 | abs8( i) == abs( i) | ||
| 68 | |||
| 69 | |||
| 70 | - 8-bit math operations which return 8-bit values. | ||
| 71 | These are provided mostly for completeness, | ||
| 72 | not particularly for performance. | ||
| 73 | mul8( i, j) == (i * j) & 0xFF | ||
| 74 | add8( i, j) == (i + j) & 0xFF | ||
| 75 | sub8( i, j) == (i - j) & 0xFF | ||
| 76 | |||
| 77 | |||
| 78 | - Fast 16-bit approximations of sin and cos. | ||
| 79 | Input angle is a uint16_t from 0-65535. | ||
| 80 | Output is a signed int16_t from -32767 to 32767. | ||
| 81 | sin16( x) == sin( (x/32768.0) * pi) * 32767 | ||
| 82 | cos16( x) == cos( (x/32768.0) * pi) * 32767 | ||
| 83 | Accurate to more than 99% in all cases. | ||
| 84 | |||
| 85 | - Fast 8-bit approximations of sin and cos. | ||
| 86 | Input angle is a uint8_t from 0-255. | ||
| 87 | Output is an UNsigned uint8_t from 0 to 255. | ||
| 88 | sin8( x) == (sin( (x/128.0) * pi) * 128) + 128 | ||
| 89 | cos8( x) == (cos( (x/128.0) * pi) * 128) + 128 | ||
| 90 | Accurate to within about 2%. | ||
| 91 | |||
| 92 | |||
| 93 | - Fast 8-bit "easing in/out" function. | ||
| 94 | ease8InOutCubic(x) == 3(x^i) - 2(x^3) | ||
| 95 | ease8InOutApprox(x) == | ||
| 96 | faster, rougher, approximation of cubic easing | ||
| 97 | ease8InOutQuad(x) == quadratic (vs cubic) easing | ||
| 98 | |||
| 99 | - Cubic, Quadratic, and Triangle wave functions. | ||
| 100 | Input is a uint8_t representing phase withing the wave, | ||
| 101 | similar to how sin8 takes an angle 'theta'. | ||
| 102 | Output is a uint8_t representing the amplitude of | ||
| 103 | the wave at that point. | ||
| 104 | cubicwave8( x) | ||
| 105 | quadwave8( x) | ||
| 106 | triwave8( x) | ||
| 107 | |||
| 108 | - Square root for 16-bit integers. About three times | ||
| 109 | faster and five times smaller than Arduino's built-in | ||
| 110 | generic 32-bit sqrt routine. | ||
| 111 | sqrt16( uint16_t x ) == sqrt( x) | ||
| 112 | |||
| 113 | - Dimming and brightening functions for 8-bit | ||
| 114 | light values. | ||
| 115 | dim8_video( x) == scale8_video( x, x) | ||
| 116 | dim8_raw( x) == scale8( x, x) | ||
| 117 | dim8_lin( x) == (x<128) ? ((x+1)/2) : scale8(x,x) | ||
| 118 | brighten8_video( x) == 255 - dim8_video( 255 - x) | ||
| 119 | brighten8_raw( x) == 255 - dim8_raw( 255 - x) | ||
| 120 | brighten8_lin( x) == 255 - dim8_lin( 255 - x) | ||
| 121 | The dimming functions in particular are suitable | ||
| 122 | for making LED light output appear more 'linear'. | ||
| 123 | |||
| 124 | |||
| 125 | - Linear interpolation between two values, with the | ||
| 126 | fraction between them expressed as an 8- or 16-bit | ||
| 127 | fixed point fraction (fract8 or fract16). | ||
| 128 | lerp8by8( fromU8, toU8, fract8 ) | ||
| 129 | lerp16by8( fromU16, toU16, fract8 ) | ||
| 130 | lerp15by8( fromS16, toS16, fract8 ) | ||
| 131 | == from + (( to - from ) * fract8) / 256) | ||
| 132 | lerp16by16( fromU16, toU16, fract16 ) | ||
| 133 | == from + (( to - from ) * fract16) / 65536) | ||
| 134 | map8( in, rangeStart, rangeEnd) | ||
| 135 | == map( in, 0, 255, rangeStart, rangeEnd); | ||
| 136 | |||
| 137 | - Optimized memmove, memcpy, and memset, that are | ||
| 138 | faster than standard avr-libc 1.8. | ||
| 139 | memmove8( dest, src, bytecount) | ||
| 140 | memcpy8( dest, src, bytecount) | ||
| 141 | memset8( buf, value, bytecount) | ||
| 142 | |||
| 143 | - Beat generators which return sine or sawtooth | ||
| 144 | waves in a specified number of Beats Per Minute. | ||
| 145 | Sine wave beat generators can specify a low and | ||
| 146 | high range for the output. Sawtooth wave beat | ||
| 147 | generators always range 0-255 or 0-65535. | ||
| 148 | beatsin8( BPM, low8, high8) | ||
| 149 | = (sine(beatphase) * (high8-low8)) + low8 | ||
| 150 | beatsin16( BPM, low16, high16) | ||
| 151 | = (sine(beatphase) * (high16-low16)) + low16 | ||
| 152 | beatsin88( BPM88, low16, high16) | ||
| 153 | = (sine(beatphase) * (high16-low16)) + low16 | ||
| 154 | beat8( BPM) = 8-bit repeating sawtooth wave | ||
| 155 | beat16( BPM) = 16-bit repeating sawtooth wave | ||
| 156 | beat88( BPM88) = 16-bit repeating sawtooth wave | ||
| 157 | BPM is beats per minute in either simple form | ||
| 158 | e.g. 120, or Q8.8 fixed-point form. | ||
| 159 | BPM88 is beats per minute in ONLY Q8.8 fixed-point | ||
| 160 | form. | ||
| 161 | |||
| 162 | Lib8tion is pronounced like 'libation': lie-BAY-shun | ||
| 163 | |||
| 164 | */ | ||
| 165 | |||
| 166 | |||
| 167 | |||
| 168 | #include <stdint.h> | ||
| 169 | |||
| 170 | #define LIB8STATIC __attribute__ ((unused)) static inline | ||
| 171 | #define LIB8STATIC_ALWAYS_INLINE __attribute__ ((always_inline)) static inline | ||
| 172 | |||
| 173 | #if !defined(__AVR__) | ||
| 174 | #include <string.h> | ||
| 175 | // for memmove, memcpy, and memset if not defined here | ||
| 176 | #endif | ||
| 177 | |||
| 178 | #if defined(__arm__) | ||
| 179 | |||
| 180 | #if defined(FASTLED_TEENSY3) | ||
| 181 | // Can use Cortex M4 DSP instructions | ||
| 182 | #define QADD8_C 0 | ||
| 183 | #define QADD7_C 0 | ||
| 184 | #define QADD8_ARM_DSP_ASM 1 | ||
| 185 | #define QADD7_ARM_DSP_ASM 1 | ||
| 186 | #else | ||
| 187 | // Generic ARM | ||
| 188 | #define QADD8_C 1 | ||
| 189 | #define QADD7_C 1 | ||
| 190 | #endif | ||
| 191 | |||
| 192 | #define QSUB8_C 1 | ||
| 193 | #define SCALE8_C 1 | ||
| 194 | #define SCALE16BY8_C 1 | ||
| 195 | #define SCALE16_C 1 | ||
| 196 | #define ABS8_C 1 | ||
| 197 | #define MUL8_C 1 | ||
| 198 | #define QMUL8_C 1 | ||
| 199 | #define ADD8_C 1 | ||
| 200 | #define SUB8_C 1 | ||
| 201 | #define EASE8_C 1 | ||
| 202 | #define AVG8_C 1 | ||
| 203 | #define AVG7_C 1 | ||
| 204 | #define AVG16_C 1 | ||
| 205 | #define AVG15_C 1 | ||
| 206 | #define BLEND8_C 1 | ||
| 207 | |||
| 208 | |||
| 209 | #elif defined(__AVR__) | ||
| 210 | |||
| 211 | // AVR ATmega and friends Arduino | ||
| 212 | |||
| 213 | #define QADD8_C 0 | ||
| 214 | #define QADD7_C 0 | ||
| 215 | #define QSUB8_C 0 | ||
| 216 | #define ABS8_C 0 | ||
| 217 | #define ADD8_C 0 | ||
| 218 | #define SUB8_C 0 | ||
| 219 | #define AVG8_C 0 | ||
| 220 | #define AVG7_C 0 | ||
| 221 | #define AVG16_C 0 | ||
| 222 | #define AVG15_C 0 | ||
| 223 | |||
| 224 | #define QADD8_AVRASM 1 | ||
| 225 | #define QADD7_AVRASM 1 | ||
| 226 | #define QSUB8_AVRASM 1 | ||
| 227 | #define ABS8_AVRASM 1 | ||
| 228 | #define ADD8_AVRASM 1 | ||
| 229 | #define SUB8_AVRASM 1 | ||
| 230 | #define AVG8_AVRASM 1 | ||
| 231 | #define AVG7_AVRASM 1 | ||
| 232 | #define AVG16_AVRASM 1 | ||
| 233 | #define AVG15_AVRASM 1 | ||
| 234 | |||
| 235 | // Note: these require hardware MUL instruction | ||
| 236 | // -- sorry, ATtiny! | ||
| 237 | #if !defined(LIB8_ATTINY) | ||
| 238 | #define SCALE8_C 0 | ||
| 239 | #define SCALE16BY8_C 0 | ||
| 240 | #define SCALE16_C 0 | ||
| 241 | #define MUL8_C 0 | ||
| 242 | #define QMUL8_C 0 | ||
| 243 | #define EASE8_C 0 | ||
| 244 | #define BLEND8_C 0 | ||
| 245 | #define SCALE8_AVRASM 1 | ||
| 246 | #define SCALE16BY8_AVRASM 1 | ||
| 247 | #define SCALE16_AVRASM 1 | ||
| 248 | #define MUL8_AVRASM 1 | ||
| 249 | #define QMUL8_AVRASM 1 | ||
| 250 | #define EASE8_AVRASM 1 | ||
| 251 | #define CLEANUP_R1_AVRASM 1 | ||
| 252 | #define BLEND8_AVRASM 1 | ||
| 253 | #else | ||
| 254 | // On ATtiny, we just use C implementations | ||
| 255 | #define SCALE8_C 1 | ||
| 256 | #define SCALE16BY8_C 1 | ||
| 257 | #define SCALE16_C 1 | ||
| 258 | #define MUL8_C 1 | ||
| 259 | #define QMUL8_C 1 | ||
| 260 | #define EASE8_C 1 | ||
| 261 | #define BLEND8_C 1 | ||
| 262 | #define SCALE8_AVRASM 0 | ||
| 263 | #define SCALE16BY8_AVRASM 0 | ||
| 264 | #define SCALE16_AVRASM 0 | ||
| 265 | #define MUL8_AVRASM 0 | ||
| 266 | #define QMUL8_AVRASM 0 | ||
| 267 | #define EASE8_AVRASM 0 | ||
| 268 | #define BLEND8_AVRASM 0 | ||
| 269 | #endif | ||
| 270 | |||
| 271 | #else | ||
| 272 | |||
| 273 | // unspecified architecture, so | ||
| 274 | // no ASM, everything in C | ||
| 275 | #define QADD8_C 1 | ||
| 276 | #define QADD7_C 1 | ||
| 277 | #define QSUB8_C 1 | ||
| 278 | #define SCALE8_C 1 | ||
| 279 | #define SCALE16BY8_C 1 | ||
| 280 | #define SCALE16_C 1 | ||
| 281 | #define ABS8_C 1 | ||
| 282 | #define MUL8_C 1 | ||
| 283 | #define QMUL8_C 1 | ||
| 284 | #define ADD8_C 1 | ||
| 285 | #define SUB8_C 1 | ||
| 286 | #define EASE8_C 1 | ||
| 287 | #define AVG8_C 1 | ||
| 288 | #define AVG7_C 1 | ||
| 289 | #define AVG16_C 1 | ||
| 290 | #define AVG15_C 1 | ||
| 291 | #define BLEND8_C 1 | ||
| 292 | |||
| 293 | #endif | ||
| 294 | |||
| 295 | ///@defgroup lib8tion Fast math functions | ||
| 296 | ///A variety of functions for working with numbers. | ||
| 297 | ///@{ | ||
| 298 | |||
| 299 | |||
| 300 | /////////////////////////////////////////////////////////////////////// | ||
| 301 | // | ||
| 302 | // typdefs for fixed-point fractional types. | ||
| 303 | // | ||
| 304 | // sfract7 should be interpreted as signed 128ths. | ||
| 305 | // fract8 should be interpreted as unsigned 256ths. | ||
| 306 | // sfract15 should be interpreted as signed 32768ths. | ||
| 307 | // fract16 should be interpreted as unsigned 65536ths. | ||
| 308 | // | ||
| 309 | // Example: if a fract8 has the value "64", that should be interpreted | ||
| 310 | // as 64/256ths, or one-quarter. | ||
| 311 | // | ||
| 312 | // | ||
| 313 | // fract8 range is 0 to 0.99609375 | ||
| 314 | // in steps of 0.00390625 | ||
| 315 | // | ||
| 316 | // sfract7 range is -0.9921875 to 0.9921875 | ||
| 317 | // in steps of 0.0078125 | ||
| 318 | // | ||
| 319 | // fract16 range is 0 to 0.99998474121 | ||
| 320 | // in steps of 0.00001525878 | ||
| 321 | // | ||
| 322 | // sfract15 range is -0.99996948242 to 0.99996948242 | ||
| 323 | // in steps of 0.00003051757 | ||
| 324 | // | ||
| 325 | |||
| 326 | /// ANSI unsigned short _Fract. range is 0 to 0.99609375 | ||
| 327 | /// in steps of 0.00390625 | ||
| 328 | typedef uint8_t fract8; ///< ANSI: unsigned short _Fract | ||
| 329 | |||
| 330 | /// ANSI: signed short _Fract. range is -0.9921875 to 0.9921875 | ||
| 331 | /// in steps of 0.0078125 | ||
| 332 | typedef int8_t sfract7; ///< ANSI: signed short _Fract | ||
| 333 | |||
| 334 | /// ANSI: unsigned _Fract. range is 0 to 0.99998474121 | ||
| 335 | /// in steps of 0.00001525878 | ||
| 336 | typedef uint16_t fract16; ///< ANSI: unsigned _Fract | ||
| 337 | |||
| 338 | /// ANSI: signed _Fract. range is -0.99996948242 to 0.99996948242 | ||
| 339 | /// in steps of 0.00003051757 | ||
| 340 | typedef int16_t sfract15; ///< ANSI: signed _Fract | ||
| 341 | |||
| 342 | |||
| 343 | // accumXY types should be interpreted as X bits of integer, | ||
| 344 | // and Y bits of fraction. | ||
| 345 | // E.g., accum88 has 8 bits of int, 8 bits of fraction | ||
| 346 | |||
| 347 | typedef uint16_t accum88; ///< ANSI: unsigned short _Accum. 8 bits int, 8 bits fraction | ||
| 348 | typedef int16_t saccum78; ///< ANSI: signed short _Accum. 7 bits int, 8 bits fraction | ||
| 349 | typedef uint32_t accum1616;///< ANSI: signed _Accum. 16 bits int, 16 bits fraction | ||
| 350 | typedef int32_t saccum1516;///< ANSI: signed _Accum. 15 bits int, 16 bits fraction | ||
| 351 | typedef uint16_t accum124; ///< no direct ANSI counterpart. 12 bits int, 4 bits fraction | ||
| 352 | typedef int32_t saccum114;///< no direct ANSI counterpart. 1 bit int, 14 bits fraction | ||
| 353 | |||
| 354 | |||
| 355 | |||
| 356 | #include "math8.h" | ||
| 357 | #include "scale8.h" | ||
| 358 | #include "random8.h" | ||
| 359 | #include "trig8.h" | ||
| 360 | |||
| 361 | /////////////////////////////////////////////////////////////////////// | ||
| 362 | |||
| 363 | |||
| 364 | |||
| 365 | |||
| 366 | |||
| 367 | |||
| 368 | |||
| 369 | /////////////////////////////////////////////////////////////////////// | ||
| 370 | // | ||
| 371 | // float-to-fixed and fixed-to-float conversions | ||
| 372 | // | ||
| 373 | // Note that anything involving a 'float' on AVR will be slower. | ||
| 374 | |||
| 375 | /// sfract15ToFloat: conversion from sfract15 fixed point to | ||
| 376 | /// IEEE754 32-bit float. | ||
| 377 | LIB8STATIC float sfract15ToFloat( sfract15 y) | ||
| 378 | { | ||
| 379 | return y / 32768.0; | ||
| 380 | } | ||
| 381 | |||
| 382 | /// conversion from IEEE754 float in the range (-1,1) | ||
| 383 | /// to 16-bit fixed point. Note that the extremes of | ||
| 384 | /// one and negative one are NOT representable. The | ||
| 385 | /// representable range is basically | ||
| 386 | LIB8STATIC sfract15 floatToSfract15( float f) | ||
| 387 | { | ||
| 388 | return f * 32768.0; | ||
| 389 | } | ||
| 390 | |||
| 391 | |||
| 392 | |||
| 393 | /////////////////////////////////////////////////////////////////////// | ||
| 394 | // | ||
| 395 | // memmove8, memcpy8, and memset8: | ||
| 396 | // alternatives to memmove, memcpy, and memset that are | ||
| 397 | // faster on AVR than standard avr-libc 1.8 | ||
| 398 | |||
| 399 | #if defined(__AVR__) | ||
| 400 | void * memmove8( void * dst, const void * src, uint16_t num ); | ||
| 401 | void * memcpy8 ( void * dst, const void * src, uint16_t num ) __attribute__ ((noinline)); | ||
| 402 | void * memset8 ( void * ptr, uint8_t value, uint16_t num ) __attribute__ ((noinline)) ; | ||
| 403 | #else | ||
| 404 | // on non-AVR platforms, these names just call standard libc. | ||
| 405 | #define memmove8 memmove | ||
| 406 | #define memcpy8 memcpy | ||
| 407 | #define memset8 memset | ||
| 408 | #endif | ||
| 409 | |||
| 410 | |||
| 411 | /////////////////////////////////////////////////////////////////////// | ||
| 412 | // | ||
| 413 | // linear interpolation, such as could be used for Perlin noise, etc. | ||
| 414 | // | ||
| 415 | |||
| 416 | // A note on the structure of the lerp functions: | ||
| 417 | // The cases for b>a and b<=a are handled separately for | ||
| 418 | // speed: without knowing the relative order of a and b, | ||
| 419 | // the value (a-b) might be overflow the width of a or b, | ||
| 420 | // and have to be promoted to a wider, slower type. | ||
| 421 | // To avoid that, we separate the two cases, and are able | ||
| 422 | // to do all the math in the same width as the arguments, | ||
| 423 | // which is much faster and smaller on AVR. | ||
| 424 | |||
| 425 | /// linear interpolation between two unsigned 8-bit values, | ||
| 426 | /// with 8-bit fraction | ||
| 427 | LIB8STATIC uint8_t lerp8by8( uint8_t a, uint8_t b, fract8 frac) | ||
| 428 | { | ||
| 429 | uint8_t result; | ||
| 430 | if( b > a) { | ||
| 431 | uint8_t delta = b - a; | ||
| 432 | uint8_t scaled = scale8( delta, frac); | ||
| 433 | result = a + scaled; | ||
| 434 | } else { | ||
| 435 | uint8_t delta = a - b; | ||
| 436 | uint8_t scaled = scale8( delta, frac); | ||
| 437 | result = a - scaled; | ||
| 438 | } | ||
| 439 | return result; | ||
| 440 | } | ||
| 441 | |||
| 442 | /// linear interpolation between two unsigned 16-bit values, | ||
| 443 | /// with 16-bit fraction | ||
| 444 | LIB8STATIC uint16_t lerp16by16( uint16_t a, uint16_t b, fract16 frac) | ||
| 445 | { | ||
| 446 | uint16_t result; | ||
| 447 | if( b > a ) { | ||
| 448 | uint16_t delta = b - a; | ||
| 449 | uint16_t scaled = scale16(delta, frac); | ||
| 450 | result = a + scaled; | ||
| 451 | } else { | ||
| 452 | uint16_t delta = a - b; | ||
| 453 | uint16_t scaled = scale16( delta, frac); | ||
| 454 | result = a - scaled; | ||
| 455 | } | ||
| 456 | return result; | ||
| 457 | } | ||
| 458 | |||
| 459 | /// linear interpolation between two unsigned 16-bit values, | ||
| 460 | /// with 8-bit fraction | ||
| 461 | LIB8STATIC uint16_t lerp16by8( uint16_t a, uint16_t b, fract8 frac) | ||
| 462 | { | ||
| 463 | uint16_t result; | ||
| 464 | if( b > a) { | ||
| 465 | uint16_t delta = b - a; | ||
| 466 | uint16_t scaled = scale16by8( delta, frac); | ||
| 467 | result = a + scaled; | ||
| 468 | } else { | ||
| 469 | uint16_t delta = a - b; | ||
| 470 | uint16_t scaled = scale16by8( delta, frac); | ||
| 471 | result = a - scaled; | ||
| 472 | } | ||
| 473 | return result; | ||
| 474 | } | ||
| 475 | |||
| 476 | /// linear interpolation between two signed 15-bit values, | ||
| 477 | /// with 8-bit fraction | ||
| 478 | LIB8STATIC int16_t lerp15by8( int16_t a, int16_t b, fract8 frac) | ||
| 479 | { | ||
| 480 | int16_t result; | ||
| 481 | if( b > a) { | ||
| 482 | uint16_t delta = b - a; | ||
| 483 | uint16_t scaled = scale16by8( delta, frac); | ||
| 484 | result = a + scaled; | ||
| 485 | } else { | ||
| 486 | uint16_t delta = a - b; | ||
| 487 | uint16_t scaled = scale16by8( delta, frac); | ||
| 488 | result = a - scaled; | ||
| 489 | } | ||
| 490 | return result; | ||
| 491 | } | ||
| 492 | |||
| 493 | /// linear interpolation between two signed 15-bit values, | ||
| 494 | /// with 8-bit fraction | ||
| 495 | LIB8STATIC int16_t lerp15by16( int16_t a, int16_t b, fract16 frac) | ||
| 496 | { | ||
| 497 | int16_t result; | ||
| 498 | if( b > a) { | ||
| 499 | uint16_t delta = b - a; | ||
| 500 | uint16_t scaled = scale16( delta, frac); | ||
| 501 | result = a + scaled; | ||
| 502 | } else { | ||
| 503 | uint16_t delta = a - b; | ||
| 504 | uint16_t scaled = scale16( delta, frac); | ||
| 505 | result = a - scaled; | ||
| 506 | } | ||
| 507 | return result; | ||
| 508 | } | ||
| 509 | |||
| 510 | /// map8: map from one full-range 8-bit value into a narrower | ||
| 511 | /// range of 8-bit values, possibly a range of hues. | ||
| 512 | /// | ||
| 513 | /// E.g. map myValue into a hue in the range blue..purple..pink..red | ||
| 514 | /// hue = map8( myValue, HUE_BLUE, HUE_RED); | ||
| 515 | /// | ||
| 516 | /// Combines nicely with the waveform functions (like sin8, etc) | ||
| 517 | /// to produce continuous hue gradients back and forth: | ||
| 518 | /// | ||
| 519 | /// hue = map8( sin8( myValue), HUE_BLUE, HUE_RED); | ||
| 520 | /// | ||
| 521 | /// Mathematically simiar to lerp8by8, but arguments are more | ||
| 522 | /// like Arduino's "map"; this function is similar to | ||
| 523 | /// | ||
| 524 | /// map( in, 0, 255, rangeStart, rangeEnd) | ||
| 525 | /// | ||
| 526 | /// but faster and specifically designed for 8-bit values. | ||
| 527 | LIB8STATIC uint8_t map8( uint8_t in, uint8_t rangeStart, uint8_t rangeEnd) | ||
| 528 | { | ||
| 529 | uint8_t rangeWidth = rangeEnd - rangeStart; | ||
| 530 | uint8_t out = scale8( in, rangeWidth); | ||
| 531 | out += rangeStart; | ||
| 532 | return out; | ||
| 533 | } | ||
| 534 | |||
| 535 | |||
| 536 | /////////////////////////////////////////////////////////////////////// | ||
| 537 | // | ||
| 538 | // easing functions; see http://easings.net | ||
| 539 | // | ||
| 540 | |||
| 541 | /// ease8InOutQuad: 8-bit quadratic ease-in / ease-out function | ||
| 542 | /// Takes around 13 cycles on AVR | ||
| 543 | #if EASE8_C == 1 | ||
| 544 | LIB8STATIC uint8_t ease8InOutQuad( uint8_t i) | ||
| 545 | { | ||
| 546 | uint8_t j = i; | ||
| 547 | if( j & 0x80 ) { | ||
| 548 | j = 255 - j; | ||
| 549 | } | ||
| 550 | uint8_t jj = scale8( j, j); | ||
| 551 | uint8_t jj2 = jj << 1; | ||
| 552 | if( i & 0x80 ) { | ||
| 553 | jj2 = 255 - jj2; | ||
| 554 | } | ||
| 555 | return jj2; | ||
| 556 | } | ||
| 557 | |||
| 558 | #elif EASE8_AVRASM == 1 | ||
| 559 | // This AVR asm version of ease8InOutQuad preserves one more | ||
| 560 | // low-bit of precision than the C version, and is also slightly | ||
| 561 | // smaller and faster. | ||
| 562 | LIB8STATIC uint8_t ease8InOutQuad(uint8_t val) { | ||
| 563 | uint8_t j=val; | ||
| 564 | asm volatile ( | ||
| 565 | "sbrc %[val], 7 \n" | ||
| 566 | "com %[j] \n" | ||
| 567 | "mul %[j], %[j] \n" | ||
| 568 | "add r0, %[j] \n" | ||
| 569 | "ldi %[j], 0 \n" | ||
| 570 | "adc %[j], r1 \n" | ||
| 571 | "lsl r0 \n" // carry = high bit of low byte of mul product | ||
| 572 | "rol %[j] \n" // j = (j * 2) + carry // preserve add'l bit of precision | ||
| 573 | "sbrc %[val], 7 \n" | ||
| 574 | "com %[j] \n" | ||
| 575 | "clr __zero_reg__ \n" | ||
| 576 | : [j] "+&a" (j) | ||
| 577 | : [val] "a" (val) | ||
| 578 | : "r0", "r1" | ||
| 579 | ); | ||
| 580 | return j; | ||
| 581 | } | ||
| 582 | |||
| 583 | #else | ||
| 584 | #error "No implementation for ease8InOutQuad available." | ||
| 585 | #endif | ||
| 586 | |||
| 587 | /// ease16InOutQuad: 16-bit quadratic ease-in / ease-out function | ||
| 588 | // C implementation at this point | ||
| 589 | LIB8STATIC uint16_t ease16InOutQuad( uint16_t i) | ||
| 590 | { | ||
| 591 | uint16_t j = i; | ||
| 592 | if( j & 0x8000 ) { | ||
| 593 | j = 65535 - j; | ||
| 594 | } | ||
| 595 | uint16_t jj = scale16( j, j); | ||
| 596 | uint16_t jj2 = jj << 1; | ||
| 597 | if( i & 0x8000 ) { | ||
| 598 | jj2 = 65535 - jj2; | ||
| 599 | } | ||
| 600 | return jj2; | ||
| 601 | } | ||
| 602 | |||
| 603 | |||
| 604 | /// ease8InOutCubic: 8-bit cubic ease-in / ease-out function | ||
| 605 | /// Takes around 18 cycles on AVR | ||
| 606 | LIB8STATIC fract8 ease8InOutCubic( fract8 i) | ||
| 607 | { | ||
| 608 | uint8_t ii = scale8_LEAVING_R1_DIRTY( i, i); | ||
| 609 | uint8_t iii = scale8_LEAVING_R1_DIRTY( ii, i); | ||
| 610 | |||
| 611 | uint16_t r1 = (3 * (uint16_t)(ii)) - ( 2 * (uint16_t)(iii)); | ||
| 612 | |||
| 613 | /* the code generated for the above *'s automatically | ||
| 614 | cleans up R1, so there's no need to explicitily call | ||
| 615 | cleanup_R1(); */ | ||
| 616 | |||
| 617 | uint8_t result = r1; | ||
| 618 | |||
| 619 | // if we got "256", return 255: | ||
| 620 | if( r1 & 0x100 ) { | ||
| 621 | result = 255; | ||
| 622 | } | ||
| 623 | return result; | ||
| 624 | } | ||
| 625 | |||
| 626 | /// ease8InOutApprox: fast, rough 8-bit ease-in/ease-out function | ||
| 627 | /// shaped approximately like 'ease8InOutCubic', | ||
| 628 | /// it's never off by more than a couple of percent | ||
| 629 | /// from the actual cubic S-curve, and it executes | ||
| 630 | /// more than twice as fast. Use when the cycles | ||
| 631 | /// are more important than visual smoothness. | ||
| 632 | /// Asm version takes around 7 cycles on AVR. | ||
| 633 | |||
| 634 | #if EASE8_C == 1 | ||
| 635 | LIB8STATIC fract8 ease8InOutApprox( fract8 i) | ||
| 636 | { | ||
| 637 | if( i < 64) { | ||
| 638 | // start with slope 0.5 | ||
| 639 | i /= 2; | ||
| 640 | } else if( i > (255 - 64)) { | ||
| 641 | // end with slope 0.5 | ||
| 642 | i = 255 - i; | ||
| 643 | i /= 2; | ||
| 644 | i = 255 - i; | ||
| 645 | } else { | ||
| 646 | // in the middle, use slope 192/128 = 1.5 | ||
| 647 | i -= 64; | ||
| 648 | i += (i / 2); | ||
| 649 | i += 32; | ||
| 650 | } | ||
| 651 | |||
| 652 | return i; | ||
| 653 | } | ||
| 654 | |||
| 655 | #elif EASE8_AVRASM == 1 | ||
| 656 | LIB8STATIC uint8_t ease8InOutApprox( fract8 i) | ||
| 657 | { | ||
| 658 | // takes around 7 cycles on AVR | ||
| 659 | asm volatile ( | ||
| 660 | " subi %[i], 64 \n\t" | ||
| 661 | " cpi %[i], 128 \n\t" | ||
| 662 | " brcc Lshift_%= \n\t" | ||
| 663 | |||
| 664 | // middle case | ||
| 665 | " mov __tmp_reg__, %[i] \n\t" | ||
| 666 | " lsr __tmp_reg__ \n\t" | ||
| 667 | " add %[i], __tmp_reg__ \n\t" | ||
| 668 | " subi %[i], 224 \n\t" | ||
| 669 | " rjmp Ldone_%= \n\t" | ||
| 670 | |||
| 671 | // start or end case | ||
| 672 | "Lshift_%=: \n\t" | ||
| 673 | " lsr %[i] \n\t" | ||
| 674 | " subi %[i], 96 \n\t" | ||
| 675 | |||
| 676 | "Ldone_%=: \n\t" | ||
| 677 | |||
| 678 | : [i] "+&a" (i) | ||
| 679 | : | ||
| 680 | : "r0", "r1" | ||
| 681 | ); | ||
| 682 | return i; | ||
| 683 | } | ||
| 684 | #else | ||
| 685 | #error "No implementation for ease8 available." | ||
| 686 | #endif | ||
| 687 | |||
| 688 | |||
| 689 | |||
| 690 | /// triwave8: triangle (sawtooth) wave generator. Useful for | ||
| 691 | /// turning a one-byte ever-increasing value into a | ||
| 692 | /// one-byte value that oscillates up and down. | ||
| 693 | /// | ||
| 694 | /// input output | ||
| 695 | /// 0..127 0..254 (positive slope) | ||
| 696 | /// 128..255 254..0 (negative slope) | ||
| 697 | /// | ||
| 698 | /// On AVR this function takes just three cycles. | ||
| 699 | /// | ||
| 700 | LIB8STATIC uint8_t triwave8(uint8_t in) | ||
| 701 | { | ||
| 702 | if( in & 0x80) { | ||
| 703 | in = 255 - in; | ||
| 704 | } | ||
| 705 | uint8_t out = in << 1; | ||
| 706 | return out; | ||
| 707 | } | ||
| 708 | |||
| 709 | |||
| 710 | // quadwave8 and cubicwave8: S-shaped wave generators (like 'sine'). | ||
| 711 | // Useful for turning a one-byte 'counter' value into a | ||
| 712 | // one-byte oscillating value that moves smoothly up and down, | ||
| 713 | // with an 'acceleration' and 'deceleration' curve. | ||
| 714 | // | ||
| 715 | // These are even faster than 'sin8', and have | ||
| 716 | // slightly different curve shapes. | ||
| 717 | // | ||
| 718 | |||
| 719 | /// quadwave8: quadratic waveform generator. Spends just a little more | ||
| 720 | /// time at the limits than 'sine' does. | ||
| 721 | LIB8STATIC uint8_t quadwave8(uint8_t in) | ||
| 722 | { | ||
| 723 | return ease8InOutQuad( triwave8( in)); | ||
| 724 | } | ||
| 725 | |||
| 726 | /// cubicwave8: cubic waveform generator. Spends visibly more time | ||
| 727 | /// at the limits than 'sine' does. | ||
| 728 | LIB8STATIC uint8_t cubicwave8(uint8_t in) | ||
| 729 | { | ||
| 730 | return ease8InOutCubic( triwave8( in)); | ||
| 731 | } | ||
| 732 | |||
| 733 | /// squarewave8: square wave generator. Useful for | ||
| 734 | /// turning a one-byte ever-increasing value | ||
| 735 | /// into a one-byte value that is either 0 or 255. | ||
| 736 | /// The width of the output 'pulse' is | ||
| 737 | /// determined by the pulsewidth argument: | ||
| 738 | /// | ||
| 739 | ///~~~ | ||
| 740 | /// If pulsewidth is 255, output is always 255. | ||
| 741 | /// If pulsewidth < 255, then | ||
| 742 | /// if input < pulsewidth then output is 255 | ||
| 743 | /// if input >= pulsewidth then output is 0 | ||
| 744 | ///~~~ | ||
| 745 | /// | ||
| 746 | /// the output looking like: | ||
| 747 | /// | ||
| 748 | ///~~~ | ||
| 749 | /// 255 +--pulsewidth--+ | ||
| 750 | /// . | | | ||
| 751 | /// 0 0 +--------(256-pulsewidth)-------- | ||
| 752 | ///~~~ | ||
| 753 | /// | ||
| 754 | /// @param in | ||
| 755 | /// @param pulsewidth | ||
| 756 | /// @returns square wave output | ||
| 757 | LIB8STATIC uint8_t squarewave8( uint8_t in, uint8_t pulsewidth) | ||
| 758 | { | ||
| 759 | if( in < pulsewidth || (pulsewidth == 255)) { | ||
| 760 | return 255; | ||
| 761 | } else { | ||
| 762 | return 0; | ||
| 763 | } | ||
| 764 | } | ||
| 765 | |||
| 766 | |||
| 767 | // Beat generators - These functions produce waves at a given | ||
| 768 | // number of 'beats per minute'. Internally, they use | ||
| 769 | // the Arduino function 'millis' to track elapsed time. | ||
| 770 | // Accuracy is a bit better than one part in a thousand. | ||
| 771 | // | ||
| 772 | // beat8( BPM ) returns an 8-bit value that cycles 'BPM' times | ||
| 773 | // per minute, rising from 0 to 255, resetting to zero, | ||
| 774 | // rising up again, etc.. The output of this function | ||
| 775 | // is suitable for feeding directly into sin8, and cos8, | ||
| 776 | // triwave8, quadwave8, and cubicwave8. | ||
| 777 | // beat16( BPM ) returns a 16-bit value that cycles 'BPM' times | ||
| 778 | // per minute, rising from 0 to 65535, resetting to zero, | ||
| 779 | // rising up again, etc. The output of this function is | ||
| 780 | // suitable for feeding directly into sin16 and cos16. | ||
| 781 | // beat88( BPM88) is the same as beat16, except that the BPM88 argument | ||
| 782 | // MUST be in Q8.8 fixed point format, e.g. 120BPM must | ||
| 783 | // be specified as 120*256 = 30720. | ||
| 784 | // beatsin8( BPM, uint8_t low, uint8_t high) returns an 8-bit value that | ||
| 785 | // rises and falls in a sine wave, 'BPM' times per minute, | ||
| 786 | // between the values of 'low' and 'high'. | ||
| 787 | // beatsin16( BPM, uint16_t low, uint16_t high) returns a 16-bit value | ||
| 788 | // that rises and falls in a sine wave, 'BPM' times per | ||
| 789 | // minute, between the values of 'low' and 'high'. | ||
| 790 | // beatsin88( BPM88, ...) is the same as beatsin16, except that the | ||
| 791 | // BPM88 argument MUST be in Q8.8 fixed point format, | ||
| 792 | // e.g. 120BPM must be specified as 120*256 = 30720. | ||
| 793 | // | ||
| 794 | // BPM can be supplied two ways. The simpler way of specifying BPM is as | ||
| 795 | // a simple 8-bit integer from 1-255, (e.g., "120"). | ||
| 796 | // The more sophisticated way of specifying BPM allows for fractional | ||
| 797 | // "Q8.8" fixed point number (an 'accum88') with an 8-bit integer part and | ||
| 798 | // an 8-bit fractional part. The easiest way to construct this is to multiply | ||
| 799 | // a floating point BPM value (e.g. 120.3) by 256, (e.g. resulting in 30796 | ||
| 800 | // in this case), and pass that as the 16-bit BPM argument. | ||
| 801 | // "BPM88" MUST always be specified in Q8.8 format. | ||
| 802 | // | ||
| 803 | // Originally designed to make an entire animation project pulse with brightness. | ||
| 804 | // For that effect, add this line just above your existing call to "FastLED.show()": | ||
| 805 | // | ||
| 806 | // uint8_t bright = beatsin8( 60 /*BPM*/, 192 /*dimmest*/, 255 /*brightest*/ )); | ||
| 807 | // FastLED.setBrightness( bright ); | ||
| 808 | // FastLED.show(); | ||
| 809 | // | ||
| 810 | // The entire animation will now pulse between brightness 192 and 255 once per second. | ||
| 811 | |||
| 812 | |||
| 813 | // The beat generators need access to a millisecond counter. | ||
| 814 | // On Arduino, this is "millis()". On other platforms, you'll | ||
| 815 | // need to provide a function with this signature: | ||
| 816 | // uint32_t get_millisecond_timer(); | ||
| 817 | // that provides similar functionality. | ||
| 818 | // You can also force use of the get_millisecond_timer function | ||
| 819 | // by #defining USE_GET_MILLISECOND_TIMER. | ||
| 820 | #if (defined(ARDUINO) || defined(SPARK) || defined(FASTLED_HAS_MILLIS)) && !defined(USE_GET_MILLISECOND_TIMER) | ||
| 821 | // Forward declaration of Arduino function 'millis'. | ||
| 822 | //uint32_t millis(); | ||
| 823 | #define GET_MILLIS millis | ||
| 824 | #else | ||
| 825 | uint32_t get_millisecond_timer(void); | ||
| 826 | #define GET_MILLIS get_millisecond_timer | ||
| 827 | #endif | ||
| 828 | |||
| 829 | // beat16 generates a 16-bit 'sawtooth' wave at a given BPM, | ||
| 830 | /// with BPM specified in Q8.8 fixed-point format; e.g. | ||
| 831 | /// for this function, 120 BPM MUST BE specified as | ||
| 832 | /// 120*256 = 30720. | ||
| 833 | /// If you just want to specify "120", use beat16 or beat8. | ||
| 834 | LIB8STATIC uint16_t beat88( accum88 beats_per_minute_88, uint32_t timebase) | ||
| 835 | { | ||
| 836 | // BPM is 'beats per minute', or 'beats per 60000ms'. | ||
| 837 | // To avoid using the (slower) division operator, we | ||
| 838 | // want to convert 'beats per 60000ms' to 'beats per 65536ms', | ||
| 839 | // and then use a simple, fast bit-shift to divide by 65536. | ||
| 840 | // | ||
| 841 | // The ratio 65536:60000 is 279.620266667:256; we'll call it 280:256. | ||
| 842 | // The conversion is accurate to about 0.05%, more or less, | ||
| 843 | // e.g. if you ask for "120 BPM", you'll get about "119.93". | ||
| 844 | return (((GET_MILLIS()) - timebase) * beats_per_minute_88 * 280) >> 16; | ||
| 845 | } | ||
| 846 | |||
| 847 | /// beat16 generates a 16-bit 'sawtooth' wave at a given BPM | ||
| 848 | LIB8STATIC uint16_t beat16( accum88 beats_per_minute, uint32_t timebase) | ||
| 849 | { | ||
| 850 | // Convert simple 8-bit BPM's to full Q8.8 accum88's if needed | ||
| 851 | if( beats_per_minute < 256) beats_per_minute <<= 8; | ||
| 852 | return beat88(beats_per_minute, timebase); | ||
| 853 | } | ||
| 854 | |||
| 855 | /// beat8 generates an 8-bit 'sawtooth' wave at a given BPM | ||
| 856 | LIB8STATIC uint8_t beat8( accum88 beats_per_minute, uint32_t timebase) | ||
| 857 | { | ||
| 858 | return beat16( beats_per_minute, timebase) >> 8; | ||
| 859 | } | ||
| 860 | |||
| 861 | /// beatsin88 generates a 16-bit sine wave at a given BPM, | ||
| 862 | /// that oscillates within a given range. | ||
| 863 | /// For this function, BPM MUST BE SPECIFIED as | ||
| 864 | /// a Q8.8 fixed-point value; e.g. 120BPM must be | ||
| 865 | /// specified as 120*256 = 30720. | ||
| 866 | /// If you just want to specify "120", use beatsin16 or beatsin8. | ||
| 867 | LIB8STATIC uint16_t beatsin88( accum88 beats_per_minute_88, uint16_t lowest, uint16_t highest, uint32_t timebase, uint16_t phase_offset) | ||
| 868 | { | ||
| 869 | uint16_t beat = beat88( beats_per_minute_88, timebase); | ||
| 870 | uint16_t beatsin = (sin16( beat + phase_offset) + 32768); | ||
| 871 | uint16_t rangewidth = highest - lowest; | ||
| 872 | uint16_t scaledbeat = scale16( beatsin, rangewidth); | ||
| 873 | uint16_t result = lowest + scaledbeat; | ||
| 874 | return result; | ||
| 875 | } | ||
| 876 | |||
| 877 | /// beatsin16 generates a 16-bit sine wave at a given BPM, | ||
| 878 | /// that oscillates within a given range. | ||
| 879 | LIB8STATIC uint16_t beatsin16(accum88 beats_per_minute, uint16_t lowest, uint16_t highest, uint32_t timebase, uint16_t phase_offset) | ||
| 880 | { | ||
| 881 | uint16_t beat = beat16( beats_per_minute, timebase); | ||
| 882 | uint16_t beatsin = (sin16( beat + phase_offset) + 32768); | ||
| 883 | uint16_t rangewidth = highest - lowest; | ||
| 884 | uint16_t scaledbeat = scale16( beatsin, rangewidth); | ||
| 885 | uint16_t result = lowest + scaledbeat; | ||
| 886 | return result; | ||
| 887 | } | ||
| 888 | |||
| 889 | /// beatsin8 generates an 8-bit sine wave at a given BPM, | ||
| 890 | /// that oscillates within a given range. | ||
| 891 | LIB8STATIC uint8_t beatsin8( accum88 beats_per_minute, uint8_t lowest, uint8_t highest, uint32_t timebase, uint8_t phase_offset) | ||
| 892 | { | ||
| 893 | uint8_t beat = beat8( beats_per_minute, timebase); | ||
| 894 | uint8_t beatsin = sin8( beat + phase_offset); | ||
| 895 | uint8_t rangewidth = highest - lowest; | ||
| 896 | uint8_t scaledbeat = scale8( beatsin, rangewidth); | ||
| 897 | uint8_t result = lowest + scaledbeat; | ||
| 898 | return result; | ||
| 899 | } | ||
| 900 | |||
| 901 | |||
| 902 | /// Return the current seconds since boot in a 16-bit value. Used as part of the | ||
| 903 | /// "every N time-periods" mechanism | ||
| 904 | LIB8STATIC uint16_t seconds16(void) | ||
| 905 | { | ||
| 906 | uint32_t ms = GET_MILLIS(); | ||
| 907 | uint16_t s16; | ||
| 908 | s16 = ms / 1000; | ||
| 909 | return s16; | ||
| 910 | } | ||
| 911 | |||
| 912 | /// Return the current minutes since boot in a 16-bit value. Used as part of the | ||
| 913 | /// "every N time-periods" mechanism | ||
| 914 | LIB8STATIC uint16_t minutes16(void) | ||
| 915 | { | ||
| 916 | uint32_t ms = GET_MILLIS(); | ||
| 917 | uint16_t m16; | ||
| 918 | m16 = (ms / (60000L)) & 0xFFFF; | ||
| 919 | return m16; | ||
| 920 | } | ||
| 921 | |||
| 922 | /// Return the current hours since boot in an 8-bit value. Used as part of the | ||
| 923 | /// "every N time-periods" mechanism | ||
| 924 | LIB8STATIC uint8_t hours8(void) | ||
| 925 | { | ||
| 926 | uint32_t ms = GET_MILLIS(); | ||
| 927 | uint8_t h8; | ||
| 928 | h8 = (ms / (3600000L)) & 0xFF; | ||
| 929 | return h8; | ||
| 930 | } | ||
| 931 | |||
| 932 | ///@} | ||
| 933 | |||
| 934 | #endif | ||
