function P = triangle_defaults()
% TRIANGLE_DEFAULTS Default parameters, mirroring the web app's params.ts.
% The output duration is not a parameter: it is
% (strike_count - 1) / strike_rate_hz + tail_s.

% Rod geometry (equilateral, open at the bottom-left corner)
P.side_length_m = 0.152;
P.gap_m = 0.015;
P.rod_diameter_m = 0.008;

% Rod material (steel)
P.density = 7850.0;
P.youngs_modulus = 2.0e11;
P.poisson_ratio = 0.30;
P.stiffness_trim = 1.00;

% Discretization / mode retention
P.n_elements = 60;
P.min_mode_hz = 20.0;
P.max_mode_hz = 22000.0;

% Damping
P.loss_factor = 6.0e-5;
P.loss_slope = 4.0e-10;
P.radiation_loss = 1.0;

% Beater (steel rod tip)
P.beater_radius_m = 0.0045;
P.beater_mass_kg = 0.022;
P.beater_youngs = 2.0e11;
P.restitution = 0.60;

% Strike / roll gesture
P.strike_velocity = 1.5;
P.strike_pos = 0.17;       % arclength fraction: middle of the base
P.strike_angle_deg = 20.0; % 0 = in the plane of the triangle, 90 = normal to it
P.strike_count = 12;
P.strike_rate_hz = 12.0;
P.roll_pos2 = 0.40;        % second contact point of a roll (the right leg)
P.timing_jitter_ms = 6.0;
P.velocity_spread = 0.15;
P.seed = 1;

% Radiation / listener
P.direct_gain = 1.0;
P.listener_x_m = 0.20;
P.listener_y_m = 0.10;
P.listener_z_m = 0.40;
P.speed_of_sound = 343.0;
P.air_density = 1.204;

% Rendering / output
P.sample_rate = 48000;
P.oversample = 2;
P.tail_s = 5.0;
P.pre_delay_ms = 3.0;
P.normalize = 1;
P.peak_dbfs = -3.0;
P.full_scale_pa = 2.0;
end