// Predefined design scripts, selectable from the interface. Each is a
// MATLAB-syntax script that fills in the `design` struct; see design.ts for
// the fields. A script is self-contained: the shape functions it uses are
// ordinary MATLAB functions written at the bottom of the script itself.

export interface Preset {
  id: string;
  label: string;
  source: string;
}

const flatRectangle = `% A flat rectangular sheet of stainless steel, hanging freely (no stand).
% The script is an ordinary MATLAB program that fills in a struct named
% design. Lengths are meters; the constants at the top are the only units.
% A field can be a number or a function handle @(x, y, r, theta) of the
% point, measured from the center of the bounding box; the handles are
% applied to whole grid matrices, so use elementwise operators (.*, ./, .^)
% inside them. Anything else a script needs it defines itself, as MATLAB
% functions at the bottom; the other presets show how.
inch = 0.0254;                  % m
mm = 1e-3;                      % m

design.name = 'Flat steel rectangle';
design.material.E = 170e9;      % Young's modulus [Pa]
design.material.nu = 0.29;      % Poisson ratio
design.material.rho = 7900;     % density [kg/m^3]
design.bounds.width = 12*inch;  % bounding box [m]
design.bounds.height = 18*inch;
design.thickness = 0.79*mm;
design.stand = [];              % free plate
design.loss.T60 = @(f) 3 ./ (1 + f/1500);   % decay time [s] as a function of frequency [Hz]
`;

const bowedRectangle = `% The same steel sheet with a 3 mm parabolic bow across its width, the
% kind of bow that rolling and handling leave in real sheet metal. The bow
% makes the sheet a shallow shell: the linear modes couple bending to
% stretching, and the full simulation oil-cans and wobbles when struck.
inch = 0.0254; mm = 1e-3;
W = 12*inch; H = 18*inch;

design.name = 'Bowed steel rectangle';
design.material.E = 170e9;
design.material.nu = 0.29;
design.material.rho = 7900;
design.bounds.width = W;
design.bounds.height = H;
design.thickness = 0.79*mm;
design.profile = @(x, y, r, theta) bow(x, W, 3*mm, 0.3);   % stress-free height [m]
design.stand = [];
design.loss.T60 = @(f) 3 ./ (1 + f/1500);

function v = bow(s, span, sag, offset)
% A parabola of the given sag across a span centered on 0; s runs along the
% span, and the offset in -1..1 moves the crest toward one end.
t = 2*s/span;
v = sag * (1 - t.^2) .* (1 + offset*t);
end
`;

const flatDisc = `% A flat 16 inch bronze disc with a center hole on a cymbal stand. The
% stand is a rod through the hole with a felt pad below the plate and
% another above it under the wing nut; each pad is an annulus of felt of
% the given radii and thickness, and its stiffness per unit area is E over
% the thickness. The pads hold the disc level and let it bounce and rock.
inch = 0.0254; mm = 1e-3;
D = 16*inch; hole = 13*mm;

design.name = 'Flat bronze disc';
design.material.E = 110e9;      % bronze
design.material.nu = 0.34;
design.material.rho = 8800;
design.bounds.width = D;
design.bounds.height = D;
design.inside = @(x, y, r, theta) (r <= D/2) & (r >= hole/2);
design.thickness = 1.0*mm;
design.stand.pad.innerRadius = 7*mm;    % the felt sits on the plastic sleeve of the rod
design.stand.pad.outerRadius = 20*mm;
design.stand.pad.thickness = 12*mm;
design.stand.pad.E = 0.5e6;             % Pa, felt in compression
design.stand.pad.lossFactor = 0.3;
design.stand.topPad = true;
design.stand.preload = 1*mm;            % compression of the top pad by the wing nut
design.loss.T60 = @(f) 4 ./ (1 + f/2000);
`;

const crash16 = `% A 16 inch flat crash: bronze, lathed to a taper from 1.2 mm at the
% center to 0.7 mm at the edge, on a stand. Flat, so the linear modes are
% pure bending modes; the tapered profile is what makes it a crash rather
% than a ride.
inch = 0.0254; mm = 1e-3;
D = 16*inch; R = D/2; hole = 13*mm;
tCenter = 1.2*mm; tEdge = 0.7*mm;

design.name = '16 inch flat crash';
design.material.E = 110e9;
design.material.nu = 0.34;
design.material.rho = 8800;
design.bounds.width = D;
design.bounds.height = D;
design.inside = @(x, y, r, theta) (r <= R) & (r >= hole/2);
design.thickness = @(x, y, r, theta) tCenter + (tEdge - tCenter) * ramp(40*mm, R, r);
design.stand.pad.innerRadius = 7*mm;
design.stand.pad.outerRadius = 20*mm;
design.stand.pad.thickness = 12*mm;
design.stand.pad.E = 0.5e6;
design.stand.pad.lossFactor = 0.3;
design.stand.topPad = true;
design.stand.preload = 1*mm;
design.loss.T60 = [100 5; 1000 3.5; 5000 1.2; 15000 0.4];   % table of [Hz seconds], interpolated

function v = ramp(a, b, x)
% 0 at x = a, 1 at x = b, clamped to that range outside.
v = min(max((x - a) ./ (b - a), 0), 1);
end
`;

const ride20 = `% A 20 inch flat ride: thicker bronze, 2.2 mm at the center to 1.4 mm at
% the edge, on a stand with a loose wing nut (a small preload). The
% thickness raises every frequency in proportion, and the ride has a
% clearer ping and a longer decay than the crash.
inch = 0.0254; mm = 1e-3;
D = 20*inch; R = D/2; hole = 13*mm;

design.name = '20 inch flat ride';
design.material.E = 110e9;
design.material.nu = 0.34;
design.material.rho = 8800;
design.bounds.width = D;
design.bounds.height = D;
design.inside = @(x, y, r, theta) (r <= R) & (r >= hole/2);
design.thickness = @(x, y, r, theta) 2.2*mm + (1.4*mm - 2.2*mm) * ramp(50*mm, R, r);
design.stand.pad.innerRadius = 7*mm;
design.stand.pad.outerRadius = 22*mm;
design.stand.pad.thickness = 12*mm;
design.stand.pad.E = 0.5e6;
design.stand.pad.lossFactor = 0.3;
design.stand.topPad = true;
design.stand.preload = 0.3*mm;
design.loss.T60 = @(f) 8 ./ (1 + f/2500);

function v = ramp(a, b, x)
v = min(max((x - a) ./ (b - a), 0), 1);
end
`;

const crashBell16 = `% A 16 inch crash with a shallow bow and a cosine bell, on a stand. The
% profile makes the cymbal a shallow shell: the linear model couples the
% bending to the stretching (a larger eigenproblem, so the modes take
% longer), and the full simulation shows the asymmetric nonlinearity of a
% curved plate. The slopes are kept small; the interface reports the
% largest one.
inch = 0.0254; mm = 1e-3;
D = 16*inch; R = D/2; hole = 13*mm;
bellR = 55*mm; bellH = 8*mm; bowH = 10*mm;
tCenter = 1.2*mm; tEdge = 0.7*mm;

design.name = '16 inch crash with bell';
design.material.E = 110e9;
design.material.nu = 0.34;
design.material.rho = 8800;
design.bounds.width = D;
design.bounds.height = D;
design.inside = @(x, y, r, theta) (r <= R) & (r >= hole/2);
design.thickness = @(x, y, r, theta) tCenter + (tEdge - tCenter) * ramp(bellR, R, r);
design.profile = @(x, y, r, theta) bowH * (1 - (r/R).^2) + dome(r, bellR, bellH);
design.stand.pad.innerRadius = 7*mm;
design.stand.pad.outerRadius = 20*mm;
design.stand.pad.thickness = 12*mm;
design.stand.pad.E = 0.5e6;
design.stand.pad.lossFactor = 0.3;
design.stand.topPad = true;
design.stand.preload = 1*mm;
design.loss.T60 = [100 5; 1000 3.5; 5000 1.2; 15000 0.4];

function v = ramp(a, b, x)
v = min(max((x - a) ./ (b - a), 0), 1);
end

function v = dome(d, radius, height)
% A cosine dome of the given height and base radius, with zero slope both at
% its rim and at its apex; d is the distance from its center.
v = 0.5 * height * (1 + cos(pi * d / radius)) .* (d < radius);
end
`;

const ellipse = `% A free elliptical steel plate. The outline is any test on the point;
% an ellipse inscribed in the bounding box here. The degenerate mode pairs
% of a disc split on an ellipse, which the mode browser shows.
inch = 0.0254; mm = 1e-3;
A = 14*inch; B = 10*inch;

design.name = 'Steel ellipse';
design.material.E = 170e9;
design.material.nu = 0.29;
design.material.rho = 7900;
design.bounds.width = A;
design.bounds.height = B;
design.inside = @(x, y, r, theta) (x/(A/2)).^2 + (y/(B/2)).^2 <= 1;
design.thickness = 1.0*mm;
design.stand = [];
design.loss.T60 = @(f) 3 ./ (1 + f/1500);
`;

const thunderSheet = `% A thunder sheet: a large thin steel sheet hung from one corner. Its modes
% are dense and low, and the full simulation turns a hard hit into a roar.
% Long at the default spacing; a coarser grid keeps it interactive.
inch = 0.0254; mm = 1e-3;

design.name = 'Thunder sheet';
design.material.E = 200e9;
design.material.nu = 0.3;
design.material.rho = 7850;
design.bounds.width = 24*inch;
design.bounds.height = 36*inch;
design.thickness = 0.5*mm;
design.stand = [];
design.loss.T60 = @(f) 2.5 ./ (1 + f/1000);
`;

export const PRESETS: Preset[] = [
  { id: "flat-rectangle", label: "Flat steel rectangle", source: flatRectangle },
  { id: "bowed-rectangle", label: "Bowed steel rectangle", source: bowedRectangle },
  { id: "flat-disc", label: "Flat bronze disc on a stand", source: flatDisc },
  { id: "crash-16", label: "16 inch flat crash", source: crash16 },
  { id: "ride-20", label: "20 inch flat ride", source: ride20 },
  { id: "crash-bell-16", label: "16 inch crash with bell", source: crashBell16 },
  { id: "ellipse", label: "Steel ellipse", source: ellipse },
  { id: "thunder-sheet", label: "Thunder sheet", source: thunderSheet },
];

export const DEFAULT_PRESET = "crash-16";

export function presetById(id: string): Preset | undefined {
  return PRESETS.find((p) => p.id === id);
}