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ScatterVisualAttributes

Inherits: VisualAttributes
Namespace: TauPlot

Data-oriented per-sample style overrides for SCATTER overlays.

Description

ScatterVisualAttributes is the SCATTER specific subclass of VisualAttributes. It carries the two buffers inherited from that base class, color_buffer and alpha_buffer, and adds four scatter-specific buffers: size_buffer, shape_buffer, outline_color_buffer, and outline_width_buffer.

Assign an instance to TauXYSeriesBinding.visual_attributes when the binding targets a SCATTER overlay. Any other subclass on such a binding is a validation error and TauPlot.plot_xy() aborts. The plot reads the buffers on each draw pass and applies the per-sample values on top of the values resolved from TauScatterStyle and TauXYStyle.

Each buffer is optional. A null buffer means no per-sample override for that property, and the resolved style value applies to every sample of the series. Partial buffers are supported: a sample index past the end of the buffer takes the resolved style value as well.

The emphasized marker takes the hovered-state properties of TauScatterStyle, so size_buffer, outline_color_buffer, and outline_width_buffer shape every marker except that one.

See TauPaneOverlayConfig for the order a buffer resolves in against a ScatterVisualCallbacks callback and the style property.

Example

# Size each marker individually by building a per-sample Float32Buffer.
var series_capacity := dataset.get_series_capacity(series_id)
var marker_sizes := TauPlot.Float32Buffer.new(series_capacity)
for i in series_capacity:
    marker_sizes.append_value(8.0 + i * 0.5)

var attributes := TauPlot.ScatterVisualAttributes.new()
attributes.size_buffer = marker_sizes

var binding := TauXYSeriesBinding.new()
binding.pane_index = 0
binding.series_id = series_id
binding.overlay_type = TauXYSeriesBinding.PaneOverlayType.SCATTER
binding.y_axis_id = TauPlot.AxisId.LEFT
binding.visual_attributes = attributes

Constructor

new()

ScatterVisualAttributes.new() -> ScatterVisualAttributes

Creates a new ScatterVisualAttributes instance with all buffers set to null.

Properties

size_buffer

size_buffer: Float32Buffer

Buffer holding the marker size of each sample. Default is null.

An entry overrides the size of the marker at the same index, taking priority over TauScatterStyle.marker_sizes_px. A negative entry is treated as unset. The unit follows the active TauScatterConfig.marker_size_policy: pixels under THEME, X data units under DATA_UNITS, where the drawn size then changes with the X domain.

The resolved pixel size is raised to 1.0, so an entry of 0.0 draws a one pixel marker rather than hiding one. Hide a marker through shape_buffer instead.

Under DATA_UNITS on a categorical X axis there is no data span to convert, and the entry is not read at all: the size comes from TauScatterStyle.marker_sizes_px, with no error and no warning.

shape_buffer

shape_buffer: Int32Buffer

Buffer holding the marker shape of each sample. Default is null.

An entry overrides the shape of the marker at the same index, taking priority over TauScatterStyle.marker_shapes. A negative entry is treated as unset. Valid override values are the TauScatterStyle.MarkerShape members as integers, and any other positive entry draws a CIRCLE with no message, since the buffer is read once per sample.

An entry of NONE draws nothing for that sample. A sample that draws nothing is also left out of hover hit testing, so it reports no SampleHit and never appears in a tooltip.

outline_color_buffer

outline_color_buffer: ColorBuffer

Buffer holding the color of the outline stroked around each marker. Default is null.

An entry overrides the outline color of the marker at the same index, taking priority over TauScatterStyle.outline_color. An entry equal to ColorBuffer.NO_COLOR is treated as unset, see note 1 on the base class.

The resolved alpha of the sample is applied on top of the entry, so a marker and its outline fade together.

outline_width_buffer

outline_width_buffer: Float32Buffer

Buffer holding the thickness in pixels of the outline stroked around each marker. Default is null.

An entry overrides the outline width of the marker at the same index, taking priority over TauScatterStyle.outline_width_px. A negative entry is treated as unset. Valid override values are 0.0 or greater, where 0.0 leaves that marker unoutlined, and the drawn outline never exceeds half the resolved marker size.