src/BlinkenColorizer.c (860e91b) - BlinkenLib · BlinkenArea

BlinkenColorizer.c

/* BlinkenLib
   Copyright 2004-2014 Stefan Schuermans <stefan@schuermans.info>
   Copyleft GNU public license - http://www.gnu.org/copyleft/gpl.html
   a blinkenarea.org project */

#include <string.h>

#include <BlinkenLib/BlinkenColorizer.h>

#include "Tools.h"

unsigned char BlinkenColorizerSolid(int step, int channels, int y, int x,
                                    int c) {
  int substep, updown, chan;
  step %= channels * 2 * 254;
  substep = step % 254;
  updown = (step / 254) % 2;
  chan = (step / 254) / 2;
  if (updown == 0) {
    if (c == chan)
      return 255;
    else if (c == (chan + 1) % channels)
      return substep;
    else
      return 0;
  } else {
    if (c == chan)
      return 255 - substep;
    else if (c == (chan + 1) % channels)
      return 255;
    else
      return 0;
  }
  (void)x; // keep compiler quiet
  (void)y; // keep compiler quiet
}

unsigned char BlinkenColorizerRainbow(int step, int channels, int y, int x,
                                      int c) {
  return BlinkenColorizerSolid(step + ((x + y) * 64), channels, y, x, c);
}

// type describing a colorizing modes
typedef struct _BlinkenColorizingModeDesc {
  const char *name;
  unsigned char (*func)(int step, int channels, int y, int x, int c);
} BlinkenColorizingModeDesc;

// supported colorizing modes
static const BlinkenColorizingModeDesc BlinkenColorizingModeDescs[] = {
    {"solid", BlinkenColorizerSolid},
    {"rainbow", BlinkenColorizerRainbow},
};

// convert string to colorizing mode
// returns colorizing mode (>= 0) or -1 on error
int BlinkenColorizerStr2Mode(const char *str) {
  unsigned int i;
  for (i = 0; i < arr_cnt(BlinkenColorizingModeDescs); i++)
    if (strcmp(str, BlinkenColorizingModeDescs[i].name) == 0)
      break;
  if (i < arr_cnt(BlinkenColorizingModeDescs))
    return i;
  return -1;
}

// convert colorizing mode to string
const char *BlinkenColorizerMode2Str(int mode) {
  if (mode < 0 || mode >= (int)arr_cnt(BlinkenColorizingModeDescs))
    return "(unknown)";
  return BlinkenColorizingModeDescs[mode].name;
}

// get color for colorizing
unsigned char BlinkenColorizerGetColor(int channels, int mode, int step, int y,
                                       int x, int c) {
  if (mode < 0 || mode >= (int)arr_cnt(BlinkenColorizingModeDescs))
    return 255;
  return BlinkenColorizingModeDescs[mode].func(step, channels, y, x, c);
}

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