import{fft2,frequency,intensity}from'./fft.mjs';export{fft2,frequency,intensity};export const MODEL_VERSION='1.0.0',EXPERIMENT_ID='course-04/holography',DEFAULTS=Object.freeze({wavelength_nm:632.8,recording_distance_mm:300,reconstruction_distance_mm:300,reference_amplitude:1,field_length_mm:4,grid_size:256,carrier_per_mm:10,sideband_radius_per_mm:3.5});
export function validateParameters(p){for(const[k,l,h]of[['wavelength_nm',500,700],['recording_distance_mm',100,500],['reconstruction_distance_mm',100,500],['reference_amplitude',.5,2]])if(!Number.isFinite(p[k])||p[k]<l||p[k]>h)throw new RangeError(`${k}须在${l}–${h}`);if(![128,256,512].includes(p.grid_size)||p.field_length_mm!==4||p.carrier_per_mm!==10||p.sideband_radius_per_mm!==3.5)throw new RangeError('网格128/256/512、L4mm、载频10mm⁻¹、边带3.5mm⁻¹');if(p.carrier_per_mm+p.sideband_radius_per_mm>=p.grid_size/(2*p.field_length_mm))throw new RangeError('载频边带超过Nyquist');return{...p};}
export function objectField(p){validateParameters(p);const n=p.grid_size,re=new Float64Array(n*n),im=new Float64Array(n*n);for(let j=0;j<n;j++)for(let i=0;i<n;i++){const x=(i/n-.5)*4,y=(j/n-.5)*4,g1=.7*Math.exp(-((x+.5)**2+y*y)/(2*.18**2)),g2=.4*Math.exp(-((x-.45)**2+(y-.25)**2)/(2*.24**2)),k=j*n+i;re[k]=g1+.5*g2;im[k]=Math.sqrt(3)/2*g2;}return{n,re,im};}
export function propagate(field,distance_mm,p){validateParameters(p);if(!Number.isFinite(distance_mm)||Math.abs(distance_mm)>500)throw new RangeError('传播距离绝对值不超过500mm');const spectrum=fft2(field),n=field.n,lambda=p.wavelength_nm*1e-6;for(let j=0;j<n;j++)for(let i=0;i<n;i++){const k=j*n+i,fx=frequency(i,n,4),fy=frequency(j,n,4),phase=-Math.PI*lambda*distance_mm*(fx*fx+fy*fy),co=Math.cos(phase),si=Math.sin(phase),re=spectrum.re[k],im=spectrum.im[k];spectrum.re[k]=re*co-im*si;spectrum.im[k]=re*si+im*co;}return fft2(spectrum,true);}
export function analyze(p){validateParameters(p);const object=objectField(p),sensor=propagate(object,p.recording_distance_mm,p),n=p.grid_size,hologram=new Float64Array(n*n);for(let j=0;j<n;j++)for(let i=0;i<n;i++){const k=j*n+i,x=(i/n-.5)*4,phase=2*Math.PI*p.carrier_per_mm*x,re=sensor.re[k]+p.reference_amplitude*Math.cos(phase),im=sensor.im[k]+p.reference_amplitude*Math.sin(phase);hologram[k]=re*re+im*im;}const spectrum=fft2({n,re:hologram,im:new Float64Array(n*n)}),selected={n,re:Float64Array.from(spectrum.re),im:Float64Array.from(spectrum.im)},mask=new Uint8Array(n*n);for(let j=0;j<n;j++)for(let i=0;i<n;i++){const k=j*n+i,fx=frequency(i,n,4),fy=frequency(j,n,4),pass=Math.hypot(fx+p.carrier_per_mm,fy)<=p.sideband_radius_per_mm;mask[k]=pass?1:0;if(!pass)selected.re[k]=selected.im[k]=0;}const cross=fft2(selected,true);for(let j=0;j<n;j++)for(let i=0;i<n;i++){const k=j*n+i,x=(i/n-.5)*4,phase=2*Math.PI*p.carrier_per_mm*x,co=Math.cos(phase),si=Math.sin(phase),re=cross.re[k],im=cross.im[k];cross.re[k]=(re*co-im*si)/p.reference_amplitude;cross.im[k]=(re*si+im*co)/p.reference_amplitude;}const reconstruction=propagate(cross,-p.reconstruction_distance_mm,p),inputIntensity=intensity(object),outputIntensity=intensity(reconstruction),inputEnergy=inputIntensity.reduce((a,b)=>a+b,0),outputEnergy=outputIntensity.reduce((a,b)=>a+b,0);let error=0;for(let k=0;k<n*n;k++)error+=(reconstruction.re[k]-object.re[k])**2+(reconstruction.im[k]-object.im[k])**2;return{object,sensor,hologram,spectrum,mask,reconstruction,inputIntensity,outputIntensity,metrics:{relative_complex_error:Math.sqrt(error/inputEnergy),reconstructed_energy_fraction:outputEnergy/inputEnergy,reference_angle_deg:Math.asin(p.wavelength_nm*1e-6*p.carrier_per_mm)*180/Math.PI,hologram_min:hologram.reduce((a,b)=>Math.min(a,b),Infinity),hologram_max:hologram.reduce((a,b)=>Math.max(a,b),0)}};}