OscillatingFields

Overview

class OscillatingFields : public omdi::examples::Sim

Built-in example simulation that animates one or more 2D scalar fields using user-supplied mathematical functions.

omdi::examples::OscillatingFields generates a regular 2D grid for each named field, evaluating a user-provided callable f(x, y, time) at every grid point on each update() call. The resulting omdi::GridXY objects are returned by get_data() and can be passed directly to omdi::PcolorPlot.

It is a convenient starting point for visualizing oscillating or time-varying 2D phenomena such as wave interference patterns, standing waves, or physical fields.

Usage example

#include <omdi.hpp>

// Define field functions (signature: float(float x, float y, double time))
auto wave = [](float x, float y, double t) -> float {
  return std::sinf(x * 6.28f + (float)t) * std::cosf(y * 6.28f + 1.5f * (float)t);
};

// Construct with a list of (name, function) pairs and grid ranges
auto sim = omdi::examples::OscillatingFields(
  { { "wave", wave } },
  { -2.0f, 2.0f, 256 },   // x: (min, max, nx)
  { -2.0f, 2.0f, 256 }    // y: (min, max, ny)
);

// Create a PcolorPlot to display the fields
auto pcolor = omdi::PcolorPlot { "Fields", sim.get_data() };

// Inside the render loop:
auto timer = omdi::Timer();

app.Render(&state, [&]() {
  sim.update(timer.elapsed(), timer.delta());
  pcolor.update_all(sim.get_data());
  pcolor.plot();
  timer.tick();
}, components, managers);

Constructor

OscillatingFields::OscillatingFields(const std::vector<std::pair<std::string, std::function<float(float, float, double)>>> &fields, const std::tuple<float, float, size_t> &x_range, const std::tuple<float, float, size_t> &y_range)

Construct an OscillatingFields simulation.

Parameters:

• fields – List of (name, function) pairs. Each function must have the signature float(float x, float y, double time) and will be evaluated at every grid point on each update() call.

• x_range – Tuple (min, max, nx) describing the X axis: minimum value, maximum value, and number of grid points.

• y_range – Tuple (min, max, ny) describing the Y axis: minimum value, maximum value, and number of grid points.

Public interface

void OscillatingFields::update(double time, double delta)

Advance the simulation by one step.

Re-evaluates each field function at all grid points using the given time value. The results are stored internally and can be retrieved with get_data().

Parameters:

• time – Absolute simulation time (seconds).

• delta – Time elapsed since the last update (seconds). Currently unused by the built-in implementation but forwarded for compatibility with omdi::examples::Sim.

auto OscillatingFields::n_groups() const -> size_t

Return the number of named field groups managed by this simulation.

Returns:

Number of (name, function) pairs passed to the constructor.

auto OscillatingFields::get_data() const -> std::map<std::string, omdi::GridXY>

Return the current field data for all groups.

Returns:

A map from field name to the corresponding omdi::GridXY, containing the most recently computed scalar values. The map is returned by value; the caller owns the result.

Notes

• The returned map from get_data() can be passed directly to omdi::PcolorPlot::update_all() to refresh all series at once.

• The grid coordinates (x, y axes) are computed once in the constructor and do not change between updates; only the z values are recomputed.

• omdi::examples::OscillatingFields is declared in examples/field.h and is included automatically via omdi.hpp.