Stack effects. Keep their scope.

export function validateSmartFilters(filters:SmartFilter[]){if(!Array.isArray(filters)||filters.length>16)throw Error('Use up to 16 Smart Filters.');const ids=new Set();for(const f of filters){if(!f||typeof f.id!=='string'||ids.has(f.id)||!Object.hasOwn(filterNames,f.type)||!Number.isFinite(f.radius)||f.radius<0||f.radius>50||!Number.isFinite(f.amount)||f.amount<0||f.amount>500||!Number.isFinite(f.threshold)||f.threshold<0||f.threshold>255||!Number.isFinite(f.opacity)||f.opacity<0||f.opacity>1||!Object.hasOwn(blendNames,f.blend)||typeof f.enabled!=='boolean')throw Error('Invalid Smart Filter.');if(f.angle!==undefined&&(!Number.isFinite(f.angle)||f.angle < -180||f.angle>180)||f.seed!==undefined&&(!Number.isInteger(f.seed)||f.seed<1||f.seed>2147483647)||f.distribution!==undefined&&!['uniform','gaussian'].includes(f.distribution)||f.monochromatic!==undefined&&typeof f.monochromatic!=='boolean')throw Error('Invalid Smart Filter options.');if(f.edge!==undefined&&!['wrap','clamp','transparent'].includes(f.edge)||f.type==='shear'&&(!Array.isArray(f.shear)||f.shear.length!==5||f.shear.some(n=>!Number.isFinite(n)||Math.abs(n)>100)))throw Error('Invalid geometric Smart Filter.');ids.add(f.id);}}

export function nativeSmartFilters(filters:SmartFilter[],mask?:LayerMask){validateSmartFilters(filters);const unsupported=filters.find(f=>!filterCapabilities[f.type].native);if(unsupported)throw Error(filterNames[unsupported.type]+' Smart Filter is editable in Photoshot projects. Native PSD export for this operation is not supported yet; save a project or rasterize a duplicate.');return {enabled:true,validAtPosition:true,maskEnabled:!!mask?.enabled,maskLinked:mask?.linked!==false,maskExtendWithWhite:!mask,list:filters.map(f=>({type:filterCapabilities[f.type].native,name:filterNames[f.type],enabled:f.enabled,hasOptions:!simpleSmartTypes.includes(f.type as any),opacity:f.opacity,blendMode:f.blend.replaceAll('-',' '),foregroundColor:{r:0,g:0,b:0},backgroundColor:{r:255,g:255,b:255},filter:simpleSmartTypes.includes(f.type as any)?undefined:f.type==='twirl'?{angle:f.angle??0}:f.type==='motion'?{angle:f.angle??0,distance:{units:'Pixels',value:f.radius}}:f.type==='mosaic'?{cellSize:{units:'Pixels',value:Math.max(1,Math.round(f.radius))}}:f.type==='noise'?{amount:f.amount/100,distribution:f.distribution??'uniform',monochromatic:f.monochromatic??true,randomSeed:f.seed??1}:{radius:{units:'Pixels',value:f.radius},...(f.type==='unsharp'?{amount:f.amount/100,threshold:f.threshold}:{})}}))};}

export async function filterMaskGuard(cache:any){if(!cache?.extra)return undefined;const m=cache.extra,w=m.right-m.left,h=m.bottom-m.top;if(w<=0||h<=0||w*h>64*1024*1024||cache.depth!==8)return {unsupported:true};const pixels=decodePlane(m.data,m.compressionMode,w,h,true);return {bounds:[m.left,m.top,m.right,m.bottom],hash:Array.from(new Uint8Array(await crypto.subtle.digest('SHA-256',new Uint8Array(pixels)))).map(n=>n.toString(16).padStart(2,'0')).join('')};}
export function editableNativeFilters(doc:StudioDoc,layer:Layer):Layer{if(layer.smartFilters!==undefined){validateSmartFilters(layer.smartFilters);return layer;}const native=unpackMetadata(layer.psdData??{}).placedLayer?.filter,cache=filterCache(doc,layer);if(!native?.list?.length)return layer;const names=Object.fromEntries(Object.entries(filterCapabilities).filter(([,c])=>c.native).map(([id,c])=>[c.native,id])) as Record<string,SmartFilter['type']>;if(native.list.some((f:any)=>!names[f.type]))throw Error('This stack contains filters that cannot yet be edited. Its original pixels and settings are preserved.');if(!cache||![8,16,32].includes(cache.depth)||cache.depth!==8&&!doc.precision)throw Error('This file has no supported unfiltered pixel cache. Open and save it in Photoshop before editing its Smart Filters.');const w=cache.right-cache.left,h=cache.bottom-cache.top;if(w<=0||h<=0||w*h>64*1024*1024)throw Error('The filter cache exceeds the supported size.');const filters:SmartFilter[]=native.list.map((f:any)=>({id:crypto.randomUUID(),type:names[f.type],radius:f.filter?.radius?.value??f.filter?.distance?.value??f.filter?.cellSize?.value??0,amount:['unsharp mask','add noise'].includes(f.type)?(f.filter.amount??0)*100:100,...(['motion blur','twirl'].includes(f.type)?{angle:f.filter.angle}:{}),...(f.type==='add noise'?{seed:Math.max(1,(f.filter.randomSeed??1)&2147483647),distribution:f.filter.distribution,monochromatic:f.filter.monochromatic}:{}),threshold:f.filter?.threshold??0,opacity:f.opacity??1,blend:(f.blendMode??'normal').replaceAll(' ','-'),enabled:native.enabled!==false&&f.enabled!==false}));validateSmartFilters(filters);let smartFilterMask:Layer['smartFilterMask'];if(cache.extra){const m=cache.extra,mw=m.right-m.left,mh=m.bottom-m.top;if(mw<=0||mh<=0||mw*mh>64*1024*1024)throw Error('Invalid filter mask size.');const a=cache.depth===8?decodePlane(m.data,m.compressionMode,mw,mh,true):Uint8Array.from(decodePrecisionPlane(m.data,m.compressionMode,mw,mh,cache.depth,true),v=>Math.round(Math.max(0,Math.min(1,v))*255)),mc=surface(mw,mh),mg=mc.getContext('2d')!,im=mg.createImageData(mw,mh);for(let p=0;p<a.length;p++){im.data[p*4]=im.data[p*4+1]=im.data[p*4+2]=a[p];im.data[p*4+3]=255;}mg.putImageData(im,0,0);const result=surface(layer.width,layer.height),rg=result.getContext('2d')!;rg.fillStyle=native.maskExtendWithWhite?'#fff':'#000';rg.fillRect(0,0,result.width,result.height);rg.drawImage(mc,m.left-layer.x,m.top-layer.y);const values=rg.getImageData(0,0,result.width,result.height).data;smartFilterMask={width:layer.width,height:layer.height,enabled:native.maskEnabled!==false,inverted:false,linked:native.maskLinked!==false,strokes:[],raster:{width:result.width,height:result.height,alpha:Array.from({length:result.width*result.height},(_,i)=>values[i*4])}};}if(doc.precision){let r=precisionLayerPixels({left:cache.left,top:cache.top,right:cache.right,bottom:cache.bottom,rawData:{large:true,channels:cache.channels.map((c:any,i:number)=>c?{id:i===25?-1:i,data:c.data,compression:c.compressionMode}:null).filter(Boolean)}},doc.precision.space,cache.depth as PrecisionDepth,profileBytes(doc.precision.profile));if(!r)throw Error('Missing native filter cache pixels.');if(w!==Math.round(layer.width)||h!==Math.round(layer.height)||cache.left!==layer.x||cache.top!==layer.y)r=resamplePrecision(r,Math.round(layer.width),Math.round(layer.height),(x,y)=>({x:x+layer.x-cache.left,y:y+layer.y-cache.top}));return {...layer,precision:packPrecision(r),precisionSource:precisionSource(layer.src),smartFilters:filters,smartFilterMask};}const c=surface(w,h),g=c.getContext('2d')!,data=g.createImageData(w,h);for(const [i,index]of [0,1,2,25].entries()){const ch=cache.channels[index];if(!ch&&index!==25)throw Error('The unfiltered cache is incomplete.');const plane=ch?(cache.depth===8?decodePlane(ch.data,ch.compressionMode,w,h,true):Uint8Array.from(decodePrecisionPlane(ch.data,ch.compressionMode,w,h,cache.depth,true),v=>Math.round(Math.max(0,Math.min(1,v))*255))):new Uint8Array(w*h).fill(255);for(let p=0;p<w*h;p++)data.data[p*4+i]=plane[p];}g.putImageData(data,0,0);const local=surface(layer.width,layer.height);local.getContext('2d')!.drawImage(c,cache.left-layer.x,cache.top-layer.y);const src=local.toDataURL();return {...layer,src,smartFilters:filters,smartFilterMask};}