# Source code for tecplot.plot.rgb_coloring

    from builtins import super

    from ..constant import *
    from ..exception import *
    from ..tecutil import _tecutil_connector, sv
    from .. import legend, session, tecutil, version

    class RGBColoring(session.Style):
        """RGB coloring (multivariate contour) style control.

        .. code-block:: python
            :emphasize-lines: 39-53

            import os
            import numpy as np

            import tecplot as tp
            from tecplot.constant import *

            def normalize_variable(dataset, varname, nsigma=2):
                '''
                Normalize a variable such that the specified number of standard deviations
                are within the range [0.5, 1] and the mean is transformed to 0.5. The
                new variable will append " normalized" to the original variable's name.
                '''
                with tp.session.suspend():
                    newvarname = varname + ' normalized'
                    dataset.add_variable(newvarname)
                    data = np.concatenate([z.values(varname).as_numpy_array()
                                           for z in dataset.zones()])
                    vmin = data.mean() - nsigma * data.std()
                    vmax = data.mean() + nsigma * data.std()
                    for z in dataset.zones():
                        arr = z.values(varname).as_numpy_array()
                        z.values(newvarname)[:] = (arr - vmin) / (vmax - vmin)

            examples_dir = tp.session.tecplot_examples_directory()
            infile = os.path.join(examples_dir, 'SimpleData', 'HeatExchanger.plt')
            dataset = tp.data.load_tecplot(infile)

            frame = tp.active_frame()
            plot = frame.plot(PlotType.Cartesian2D)
            plot.show_contour = True

            # Variables must be normalized relative to each other
            # to make effective use of RGB coloring.
            normalize_variable(dataset, 'T(K)')
            normalize_variable(dataset, 'P(N)')

            plot.rgb_coloring.mode = RGBMode.SpecifyGB

            # all three channel variables must be set even if
            # we are only contouring on two of them.
            plot.rgb_coloring.red_variable = dataset.variable(0)
            plot.rgb_coloring.green_variable = dataset.variable('P(N) normalized')
            plot.rgb_coloring.blue_variable = dataset.variable('T(K) normalized')

            plot.rgb_coloring.legend.show = True
            plot.rgb_coloring.legend.use_variable_for_green_label = False
            plot.rgb_coloring.legend.green_label = 'Pressure'
            plot.rgb_coloring.legend.use_variable_for_blue_label = False
            plot.rgb_coloring.legend.blue_label = 'Temperature'

            plot.fieldmaps().contour.flood_contour_group = plot.rgb_coloring

            tp.export.save_png('rgb_coloring.png')

        .. figure:: /_static/images/rgb_coloring.png
            :width: 300px
            :figwidth: 300px
        """
        def __init__(self, plot):
            self.plot = plot
            super().__init__(sv.GLOBALRGB, **plot._kw)

        def __eq__(self, other):
            return self.plot == other.plot

        def __ne__(self, other):
            return not (self == other)

        @property
        def index(self):
            """`Index`: Color `Index` for RGB Coloring.

            This property is used internally to identify it as a contour flooding
            option.
            """
            return tecutil.Index(Color.RGBColor.value)

        @property
        def legend(self):
            """`RGBColoringLegend`: Legend placement and style control.

            Example usage::

                >>> plot.rgb_coloring.legend.show = True
            """
            return legend.RGBColoringLegend(self)

        @property
        def mode(self):
            """`RGBMode`: Which channels to use for RGB coloring.

            Example usage::

                >>> from tecplot.constant import RGBMode
                >>> plot.rgb_coloring.mode = RGBMode.SpecifyRB
            """
            return self._get_style(RGBMode, sv.RGBMODE)

        @mode.setter
        def mode(self, value):
            self._set_style(RGBMode(value), sv.RGBMODE)

        @property
        def min_intensity(self):
            """`float`: `Variable` value at minimum intensity for each channel.

            This should typically be set to the minimum value of the data being
            plotted::

                >>> plot.rgb_coloring.min_intensity = dataset.variable('P').min()
            """
            return self._get_style(float, sv.RANGEMIN)

        @min_intensity.setter
        def min_intensity(self, value):
            self._set_style(float(value), sv.RANGEMIN)

        @property
        def max_intensity(self):
            """`float`: `Variable` value at maximum intensity for each channel.

            This should typically be set to the maximum value of the data being
            plotted::

                >>> plot.rgb_coloring.max_intensity = dataset.variable('P').max()
            """
            return self._get_style(float, sv.RANGEMAX)

        @max_intensity.setter
        def max_intensity(self, value):
            self._set_style(float(value), sv.RANGEMAX)

        def _ensure_valid_rgb_variables(self, index):
            """
                Note: this is essentially a work-around for behavior in the Tecplot
                engine where setting a single RGB channel would be reverted when
                the engine goes to an on-idle state. The engine was changed to
                allow setting a single channel in 2018 R3 but this function remains
                so that setting RGB channel variables still work with 2018 R2.
                However, it requires the suspend context which was not available
                in 2018 R1.
            """
            if _tecutil_connector.connected:
                if version.sdk_version_info < (2018, 2):
                    msg = '''\
                        Setting RGB coloring variables
                        not supported in connected mode.'''
                    raise TecplotOutOfDateEngineError((2018, 2), msg)
                r = self.red_variable_index
                g = self.green_variable_index
                b = self.blue_variable_index
                if any(x < 0 for x in (r, g, b)):
                    r = tecutil.Index(index if r < 0 else r)
                    g = tecutil.Index(index if g < 0 else g)
                    b = tecutil.Index(index if b < 0 else b)
                    with session.suspend():
                        self._set_style(r, sv.REDCHANNELVAR)
                        self._set_style(g, sv.GREENCHANNELVAR)
                        self._set_style(b, sv.BLUECHANNELVAR)

        @property
        def red_variable_index(self):
            """`Index`: `Variable` `Index` to use for the red channel.

            Example usage::

                >>> plot.rgb_coloring.red_variable_index = 5

            .. note::
                In connected mode, setting this property requires Tecplot 360
                version 2018 R2 or later.
            """
            return self._get_style(tecutil.Index, sv.REDCHANNELVAR)

        @red_variable_index.setter
        def red_variable_index(self, value):
            self._ensure_valid_rgb_variables(value)
            self._set_style(tecutil.Index(value), sv.REDCHANNELVAR)

        @property
        def red_variable(self):
            """`Variable`: `Variable` to use for the red channel.

            Example usage::

                >>> plot.rgb_coloring.red_variable = dataset.variable('Gas')

            .. note::
                In connected mode, setting this property requires Tecplot 360
                version 2018 R2 or later.
            """
            return self.plot.frame.dataset.variable(self.red_variable_index)

        @red_variable.setter
        def red_variable(self, variable):
            self.red_variable_index = variable.index

        @property
        def green_variable_index(self):
            """`Index`: `Variable` `Index` to use for the green channel.

            Example usage::

                >>> plot.rgb_coloring.green_variable_index = 3

            .. note::
                In connected mode, setting this property requires Tecplot 360
                version 2018 R2 or later.
            """
            return self._get_style(tecutil.Index, sv.GREENCHANNELVAR)

        @green_variable_index.setter
        def green_variable_index(self, value):
            self._ensure_valid_rgb_variables(value)
            self._set_style(tecutil.Index(value), sv.GREENCHANNELVAR)

        @property
        def green_variable(self):
            """`Variable`: `Variable` to use for the green channel.

            Example usage::

                >>> plot.rgb_coloring.green_variable = dataset.variable('Oil')

            .. note::
                In connected mode, setting this property requires Tecplot 360
                version 2018 R2 or later.
            """
            return self.plot.frame.dataset.variable(self.green_variable_index)

        @green_variable.setter
        def green_variable(self, variable):
            self.green_variable_index = variable.index

        @property
        def blue_variable_index(self):
            """`Index`: `Variable` `Index` to use for the blue channel.

            Example usage::

                >>> plot.rgb_coloring.blue_variable_index = 4

            .. note::
                In connected mode, setting this property requires Tecplot 360
                version 2018 R2 or later.
            """
            return self._get_style(tecutil.Index, sv.BLUECHANNELVAR)

        @blue_variable_index.setter
        def blue_variable_index(self, value):
            self._ensure_valid_rgb_variables(value)
            self._set_style(tecutil.Index(value), sv.BLUECHANNELVAR)

        @property
        def blue_variable(self):
            """`Variable`: `Variable` to use for the blue channel.

            Example usage::

                >>> plot.rgb_coloring.blue_variable = dataset.variable('Water')

            .. note::
                In connected mode, setting this property requires Tecplot 360
                version 2018 R2 or later.
            """
            return self.plot.frame.dataset.variable(self.blue_variable_index)

        @blue_variable.setter
        def blue_variable(self, variable):
            self.blue_variable_index = variable.index