scimesh::ColorMap Struct Reference

Self-contained colormap — owns a colour lookup table and supports linearly interpolated sampling. More...

#include <colormap.h>

Public Member Functions
Color	sample (float t) const
	Sample the colormap at a normalized position using linear interpolation.
size_t	size () const
	Number of entries in the colormap.
bool	empty () const
	True if the colormap has no entries.

Static Public Member Functions
template<typename T >
static ColorMap	from_uint8_colors (const std::vector< T > &cmap)
	Build a ColorMap from a vector of scibar-style uint8_t RGBA colours.
static ColorMap	from_interleaved (const std::vector< uint8_t > &data, int channels=3)
	Build a ColorMap from a flat interleaved RGB(A) byte array.
static const ColorMap &	viridis ()
	The Viridis perceptually-uniform sequential colormap (256 entries).

Public Attributes
std::vector< Color >	colors
	The colour lookup table entries in [0, 1] float RGBA.

Detailed Description

Self-contained colormap — owns a colour lookup table and supports linearly interpolated sampling.

A ColorMap is simply a vector of Color entries plus a sample() method that performs linear interpolation between adjacent entries. The first entry corresponds to t = 0.0, the last to t = 1.0.

Note

The minimum useful size is 2 entries. Single-entry colormaps always return that single colour regardless of t.

See also

apply_colormap(), from_uint8_colors()

Definition at line 79 of file colormap.h.

Member Function Documentation

empty()

bool scimesh::ColorMap::empty ( ) const

inline

True if the colormap has no entries.

Definition at line 103 of file colormap.h.

from_interleaved()

static ColorMap scimesh::ColorMap::from_interleaved ( const std::vector< uint8_t > &  data, int  channels = 3  )

inlinestatic

Build a ColorMap from a flat interleaved RGB(A) byte array.

Parameters

data	Flat array of RGB bytes (3 × n entries) or RGBA bytes (4 × n entries).
channels	3 for RGB data, 4 for RGBA data.

Returns

A new ColorMap with data.size() / channels entries.

Example (libfs viridis output)

std::vector<uint8_t> rgb = fs::util::viridis(sulc_data);
auto cmap = ColorMap::from_interleaved(rgb, 3);

Definition at line 151 of file colormap.h.

from_uint8_colors()

template<typename T >

static ColorMap scimesh::ColorMap::from_uint8_colors ( const std::vector< T > &  cmap )

inlinestatic

Build a ColorMap from a vector of scibar-style uint8_t RGBA colours.

This is a duck-typed template — it works with any type T that has .r, .g, .b, .a fields as uint8_t in the range [0, 255]. No #include of scibar headers is required; the user simply passes their std::vector<scibar::Color> and it compiles.

Template Parameters

T	Any struct with uint8_t r, g, b, a fields.

Parameters

cmap	The source colormap (e.g., from scibar::util::viridis()).

Returns

A new ColorMap with the same entries converted to float [0, 1] RGBA.

Example (scibar → scimesh)

auto scibar_cmap = scibar::util::viridis();
auto scm_cmap = ColorMap::from_uint8_colors(scibar_cmap);

Definition at line 128 of file colormap.h.

sample()

Color scimesh::ColorMap::sample

(

float

t

)

const

Sample the colormap at a normalized position using linear interpolation.

Parameters

t	Normalized position in [0, 1]. Values outside this range are clamped: t < 0 → first entry, t > 1 → last entry.

Returns

The interpolated colour at position t, or transparent black if the colormap is empty.

Example

Color lo  = cmap.sample(0.0f);  // first colour
Color mid = cmap.sample(0.5f);  // middle
Color hi  = cmap.sample(1.0f);  // last colour

Definition at line 15 of file colormap.cpp.

size()

size_t scimesh::ColorMap::size ( ) const

inline

Number of entries in the colormap.

Definition at line 100 of file colormap.h.

viridis()

const ColorMap & scimesh::ColorMap::viridis ( )

static

The Viridis perceptually-uniform sequential colormap (256 entries).

Returns a 256-entry RGBA LUT. Viridis is perceptually uniform, colourblind-friendly, and prints well in greyscale. Identical to the matplotlib reference implementation.

Returns

A 256-entry ColorMap (cached after first call).

Definition at line 195 of file colormap.cpp.

Member Data Documentation

colors

std::vector<Color> scimesh::ColorMap::colors

The colour lookup table entries in [0, 1] float RGBA.

Definition at line 81 of file colormap.h.

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The documentation for this struct was generated from the following files:

• src/core/scimesh/colormap.h
• src/core/colormap.cpp