text: #
  # RGBMap.py -- color mapping
  #
  # This is open-source software licensed under a BSD license.
  # Please see the file LICENSE.txt for details.
  #
  import numpy as np
  
  from ginga.misc import Callback
  from ginga import ColorDist
  
  
  class RGBMapError(Exception):
      pass
  
  
  class RGBPlanes(object):
  
      def __init__(self, rgbarr, order):
          self.rgbarr = rgbarr
          order = order.upper()
          self.order = order
          self.hasAlpha = 'A' in order
  
      def get_slice(self, ch):
          return self.rgbarr[..., self.order.index(ch.upper())]
  
      def has_slice(self, ch):
          return ch.upper() in self.order
  
      def get_order(self):
          return self.order
  
      def get_order_indexes(self, cs):
          cs = cs.upper()
          return [self.order.index(c) for c in cs]
  
      def get_array(self, order, dtype=None):
          """Get Numpy array that represents the RGB layers.
  
          Parameters
          ----------
          order : str
              The desired order of RGB color layers.
  
          Returns
          -------
          arr : ndarray
              Numpy array that represents the RGB layers.
  
          dtype : numpy array dtype (optional)
              Type of the numpy array desired.
  
          """
          if dtype is None:
              dtype = self.rgbarr.dtype
          order = order.upper()
          if order == self.order:
              return self.rgbarr.astype(dtype, copy=False)
  
          l = [self.get_slice(c) for c in order]
          res = np.concatenate([arr[..., np.newaxis].astype(dtype, copy=False,
                                                            casting='unsafe')
                                for arr in l], axis=-1)
          return res
  
      def get_size(self):
          """Returns (height, width) tuple of slice size."""
          return self.get_slice('R').shape
  
  
  class RGBMapper(Callback.Callbacks):
  
      ############################################################
      # CODE NOTES
      #
      # [A] Some numpy routines have been optomized by using the out=
      # parameter, which avoids having to allocate a new array for the
      # result
      #
  
      def __init__(self, logger, dist=None, bpp=None):
          Callback.Callbacks.__init__(self)
  
          self.logger = logger
  
          # For color and intensity maps
          self.cmap = None
          self.imap = None
          self.arr = None
          self.iarr = None
          self.carr = None
          self.sarr = None
          self.scale_pct = 1.0
          # length of the color map
          self.maxc = 255
  
          # targeted bit depth per-pixel band of the output RGB array
          # (can be less than the data size of the output array)
          if bpp is None:
              bpp = 8
          self.bpp = bpp
          # maximum value that we can generate in this range
          self.maxv = 2 ** self.bpp - 1
          # data size per pixel band in the output RGB array
          self._set_dtype()
  
          # For scaling algorithms
          hashsize = 65536
          if dist is None:
              dist = ColorDist.LinearDist(hashsize)
          self.dist = dist
  
          self.reset_sarr(callback=False)
  
          # For callbacks
          for name in ('changed', ):
              self.enable_callback(name)
  
      def _set_dtype(self):
          if self.bpp <= 8:
              self.dtype = np.uint8
          elif self.bpp <= 16:
              self.dtype = np.uint16
          else:
              self.dtype = np.uint32
  
      def set_bpp(self, bpp):
          """
          Set the bit depth (per band) for the output.
          A typical "32-bit RGBA" image would be 8; a 48-bit image would
          be 16, etc.
          """
          self.bpp = bpp
          self.maxv = 2 ** self.bpp - 1
          self._set_dtype()
          self.calc_cmap()
          self.recalc(callback=False)
  
      def set_cmap(self, cmap, callback=True):
          """
          Set the color map used by this RGBMapper.
  
          `cmap` specifies a ColorMap object.  If `callback` is True, then
          any callbacks associated with this change will be invoked.
          """
          self.cmap = cmap
          self.calc_cmap()
          self.recalc(callback=callback)
  
      def get_cmap(self):
          """
          Return the color map used by this RGBMapper.
          """
          return self.cmap
  
      def calc_cmap(self):
          clst = self.cmap.clst
          arr = np.array(clst).transpose() * float(self.maxv)
          # does this really need to be the same type as rgbmap output type?
          self.carr = np.round(arr).astype(self.dtype, copy=False)
          self.maxc = len(clst) - 1
  
      def invert_cmap(self, callback=True):
          self.carr = np.fliplr(self.carr)
          self.recalc(callback=callback)
  
      def rotate_cmap(self, num, callback=True):
          self.carr = np.roll(self.carr, num, axis=1)
          self.recalc(callback=callback)
  
      def restore_cmap(self, callback=True):
          self.reset_sarr(callback=False)
          self.calc_cmap()
          self.recalc(callback=callback)
  
      def get_rgb(self, index):
          """
          Return a tuple of (R, G, B) values in the 0-maxc range associated
          mapped by the value of `index`.
          """
          return tuple(self.arr[index])
  
      def get_rgbval(self, index):
          """
          Return a tuple of (R, G, B) values in the 0-maxv range associated
          mapped by the value of `index`.
          """
          assert (index >= 0) and (index <= self.maxc), \
              RGBMapError("Index must be in range 0-%d !" % (self.maxc))
          index = self.sarr[index].clip(0, self.maxc)
          return (self.arr[0][index],
                  self.arr[1][index],
                  self.arr[2][index])
  
      def set_imap(self, imap, callback=True):
          """
          Set the intensity map used by this RGBMapper.
  
          `imap` specifies an IntensityMap object.  If `callback` is True, then
          any callbacks associated with this change will be invoked.
          """
          self.imap = imap
          self.calc_imap()
          self.recalc(callback=callback)
  
      def get_imap(self):
          """
          Return the intensity map used by this RGBMapper.
          """
          return self.imap
  
      def calc_imap(self):
          arr = np.array(self.imap.ilst) * float(self.maxc)
          self.iarr = np.round(arr).astype(np.uint, copy=False)
  
      def reset_sarr(self, callback=True):
          maxlen = self.maxc + 1
          self.sarr = np.arange(maxlen)
          self.scale_pct = 1.0
          if callback:
              self.make_callback('changed')
  
      def set_sarr(self, sarr, callback=True):
          maxlen = self.maxc + 1
          assert len(sarr) == maxlen, \
              RGBMapError("shift map length %d != %d" % (len(sarr), maxlen))
          self.sarr = sarr.astype(np.uint, copy=False)
          self.scale_pct = 1.0
  
          if callback:
              self.make_callback('changed')
  
      def get_sarr(self):
          return self.sarr
  
      def recalc(self, callback=True):
          self.arr = np.copy(self.carr)
          # Apply intensity map to rearrange colors
          if self.iarr is not None:
              idx = self.iarr
              self.arr[0] = self.arr[0][idx]
              self.arr[1] = self.arr[1][idx]
              self.arr[2] = self.arr[2][idx]
  
          # NOTE: don't reset shift array
          #self.reset_sarr(callback=False)
          if callback:
              self.make_callback('changed')
  
      def get_hash_size(self):
          return self.dist.get_hash_size()
  
      def set_hash_size(self, size, callback=True):
          self.dist.set_hash_size(size)
          if callback:
              self.make_callback('changed')
  
      def get_hash_algorithms(self):
          return ColorDist.get_dist_names()
  
      def get_hash_algorithm(self):
          return str(self.dist)
  
      def get_dist(self):
          """
          Return the color distribution used by this RGBMapper.
          """
          return self.dist
  
      def set_dist(self, dist, callback=True):
          self.dist = dist
          if callback:
              self.make_callback('changed')
  
      def set_hash_algorithm(self, name, callback=True, **kwdargs):
          hashsize = self.dist.get_hash_size()
          dist = ColorDist.get_dist(name)(hashsize, **kwdargs)
          self.set_dist(dist, callback=callback)
  
      def get_order_indexes(self, order, cs):
          order = order.upper()
          if order == '':
              # assume standard RGB order if we don't find an order
              # explicitly set
              return [0, 1, 2]
          cs = cs.upper()
          return [order.index(c) for c in cs]
  
      def _get_rgbarray(self, idx, rgbobj, image_order=''):
          # NOTE: data is assumed to be in the range 0-maxv at this point
          # but clip as a precaution
          # See NOTE [A]: idx is always an array calculated in the caller and
          #    discarded afterwards
          # idx = idx.clip(0, self.maxc)
          idx.clip(0, self.maxc, out=idx)
  
          # run it through the shift array and clip the result
          # See NOTE [A]
          # idx = self.sarr[idx].clip(0, self.maxc)
          idx = self.sarr[idx]
          idx.clip(0, self.maxc, out=idx)
  
          ri, gi, bi = self.get_order_indexes(rgbobj.get_order(), 'RGB')
          out = rgbobj.rgbarr
  
          # change [A]
          if (image_order is None) or (len(image_order) < 3):
              out[..., ri] = self.arr[0][idx]
              out[..., gi] = self.arr[1][idx]
              out[..., bi] = self.arr[2][idx]
          else:
              # <== indexes already contain RGB info.
              rj, gj, bj = self.get_order_indexes(image_order, 'RGB')
              out[..., ri] = self.arr[0][idx[..., rj]]
              out[..., gi] = self.arr[1][idx[..., gj]]
              out[..., bi] = self.arr[2][idx[..., bj]]
  
      def get_rgbarray(self, idx, out=None, order='RGB', image_order=''):
          """
          Parameters
          ----------
          idx : index array
  
          out : output array or None
              The output array.  If `None` one of the correct size and depth
              will be created.
  
          order : str
              The order of the color planes in the output array (e.g. "ARGB")
  
          image_order : str or None
              The order of channels if indexes already contain RGB info.
          """
          # prepare output array
          shape = idx.shape
          depth = len(order)
  
          if (image_order is not None) and (len(image_order) > 1):
              # indexes contain RGB axis, so omit this
              res_shape = shape[:-1] + (depth, )
          else:
              res_shape = shape + (depth, )
  
          if out is None:
              out = np.empty(res_shape, dtype=self.dtype, order='C')
          else:
              # TODO: assertion check on shape of out
              assert res_shape == out.shape, \
                  RGBMapError("Output array shape %s doesn't match result "
                              "shape %s" % (str(out.shape), str(res_shape)))
  
          res = RGBPlanes(out, order)
  
          # set alpha channel
          if res.hasAlpha:
              aa = res.get_slice('A')
              aa.fill(self.maxv)
  
          idx = self.get_hasharray(idx)
  
          self._get_rgbarray(idx, res, image_order=image_order)
  
          return res
  
      def get_hasharray(self, idx):
          return self.dist.hash_array(idx)
  
      def _shift(self, sarr, pct, rotate=False):
          n = len(sarr)
          num = int(n * pct)
          arr = np.roll(sarr, num)
          if not rotate:
              if num > 0:
                  arr[0:num] = sarr[0]
              elif num < 0:
                  arr[n + num:n] = sarr[-1]
          return arr
  
      def _stretch(self, sarr, scale):
          old_wd = len(sarr)
          new_wd = int(round(scale * old_wd))
  
          # Is there a more efficient way to do this?
          xi = np.mgrid[0:new_wd]
          iscale_x = float(old_wd) / float(new_wd)
  
          xi = (xi * iscale_x).astype('int', copy=False)
          xi = xi.clip(0, old_wd - 1)
          newdata = sarr[xi]
          return newdata
  
      def shift(self, pct, rotate=False, callback=True):
          work = self._shift(self.sarr, pct, rotate=rotate)
          maxlen = self.maxc + 1
          assert len(work) == maxlen, \
              RGBMapError("shifted shift map is != %d" % maxlen)
          self.sarr = work
          if callback:
              self.make_callback('changed')
  
      def scale_and_shift(self, scale_pct, shift_pct, callback=True):
          """Stretch and/or shrink the color map via altering the shift map.
          """
          maxlen = self.maxc + 1
          self.sarr = np.arange(maxlen)
  
          # limit shrinkage to 5% of original size
          scale = max(scale_pct, 0.050)
          self.scale_pct = scale
  
          work = self._stretch(self.sarr, scale)
          n = len(work)
          if n < maxlen:
              # pad on the lowest and highest values of the shift map
              m = (maxlen - n) // 2 + 1
              barr = np.array([0] * m)
              tarr = np.array([self.maxc] * m)
              work = np.concatenate([barr, work, tarr])
              work = work[:maxlen]
  
          # we are mimicing ds9's stretch and shift algorithm here.
          # ds9 seems to cut the center out of the stretched array
          # BEFORE shifting
          n = len(work) // 2
          halflen = maxlen // 2
          work = work[n - halflen:n + halflen].astype(np.uint, copy=False)
          assert len(work) == maxlen, \
              RGBMapError("scaled shift map is != %d" % maxlen)
  
          # shift map according to the shift_pct
          work = self._shift(work, shift_pct)
          assert len(work) == maxlen, \
              RGBMapError("shifted shift map is != %d" % maxlen)
  
          self.sarr = work
          if callback:
              self.make_callback('changed')
  
      def stretch(self, scale_factor, callback=True):
          """Stretch the color map via altering the shift map.
          """
          self.scale_pct *= scale_factor
          self.scale_and_shift(self.scale_pct, 0.0, callback=callback)
  
      def copy_attributes(self, dst_rgbmap):
          dst_rgbmap.set_cmap(self.cmap, callback=False)
          dst_rgbmap.set_imap(self.imap, callback=False)
          dst_rgbmap.set_hash_algorithm(str(self.dist), callback=False)
          # TODO: set hash size
          dst_rgbmap.carr = np.copy(self.carr)
          dst_rgbmap.sarr = np.copy(self.sarr)
          dst_rgbmap.recalc()
  
      def reset_cmap(self):
          self.recalc()
  
  
  class NonColorMapper(RGBMapper):
      """
      A kind of color mapper for data that is already in RGB form.
  
      This mapper allows changing of color distribution and contrast
      adjustment, but does no coloring.
      """
      def __init__(self, logger, dist=None, bpp=None):
          super(NonColorMapper, self).__init__(logger, dist=dist, bpp=bpp)
  
          maxlen = self.maxv + 1
          self.dist.set_hash_size(maxlen)
          self.reset_sarr(callback=False)
  
      def _get_rgbarray(self, idx, rgbobj, image_order='RGB'):
          # NOTE: data is assumed to be in the range 0-maxv at this point
          # but clip as a precaution
          # See NOTE [A]: idx is always an array calculated in the caller and
          #    discarded afterwards
          idx.clip(0, self.maxc, out=idx)
  
          # run it through the shift array and clip the result
          # See NOTE [A]
          idx = self.sarr[idx]
          idx.clip(0, self.maxc, out=idx)
  
          ri, gi, bi = self.get_order_indexes(rgbobj.get_order(), 'RGB')
          rj, gj, bj = self.get_order_indexes(image_order, 'RGB')
          out = rgbobj.rgbarr
  
          out[..., ri] = idx[..., rj]
          out[..., gi] = idx[..., gj]
          out[..., bi] = idx[..., bj]
  
  
  class PassThruRGBMapper(RGBMapper):
      """
      A kind of color mapper for data that is already in RGB form.
  
      This mapper bypasses color distribution, contrast adjustment and
      coloring.  It is thus the most efficient one to use for maximum
      speed rendering of "finished" RGB data.
      """
      def __init__(self, logger, dist=None, bpp=None):
          super(PassThruRGBMapper, self).__init__(logger, bpp=bpp)
  
          # ignore passed in distribution
          maxlen = self.maxv + 1
          self.dist = ColorDist.LinearDist(maxlen)
  
      def get_hasharray(self, idx):
          # data is already constrained to 0..maxv and we want to
          # bypass color redistribution
          return idx
  
      def _get_rgbarray(self, idx, rgbobj, image_order='RGB'):
          # NOTE: data is assumed to be in the range 0-maxv at this point
          # but clip as a precaution
          # See NOTE [A]: idx is always an array calculated in the caller and
          #    discarded afterwards
          idx.clip(0, self.maxc, out=idx)
  
          # bypass the shift array and skip color mapping,
          # index is the final data
          ri, gi, bi = self.get_order_indexes(rgbobj.get_order(), 'RGB')
          rj, gj, bj = self.get_order_indexes(image_order, 'RGB')
          out = rgbobj.rgbarr
  
          out[..., ri] = idx[..., rj]
          out[..., gi] = idx[..., gj]
          out[..., bi] = idx[..., bj]
  
  
  #END
  