Fast and advanced PNG (APNG) decoder and encoder (lossy / lossless)
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/452821/1103227/UPNGjs.js
var UPNG = {};
UPNG.toRGBA8 = function(out)
{
var w = out.width, h = out.height;
if(out.tabs.acTL==null) return [UPNG.toRGBA8.decodeImage(out.data, w, h, out).buffer];
var frms = [];
if(out.frames[0].data==null) out.frames[0].data = out.data;
var len = w*h*4, img = new Uint8Array(len), empty = new Uint8Array(len), prev=new Uint8Array(len);
for(var i=0; i<out.frames.length; i++)
{
var frm = out.frames[i];
var fx=frm.rect.x, fy=frm.rect.y, fw = frm.rect.width, fh = frm.rect.height;
var fdata = UPNG.toRGBA8.decodeImage(frm.data, fw,fh, out);
if(i!=0) for(var j=0; j<len; j++) prev[j]=img[j];
if (frm.blend==0) UPNG._copyTile(fdata, fw, fh, img, w, h, fx, fy, 0);
else if(frm.blend==1) UPNG._copyTile(fdata, fw, fh, img, w, h, fx, fy, 1);
frms.push(img.buffer.slice(0));
if (frm.dispose==0) {}
else if(frm.dispose==1) UPNG._copyTile(empty, fw, fh, img, w, h, fx, fy, 0);
else if(frm.dispose==2) for(var j=0; j<len; j++) img[j]=prev[j];
}
return frms;
}
UPNG.toRGBA8.decodeImage = function(data, w, h, out)
{
var area = w*h, bpp = UPNG.decode._getBPP(out);
var bpl = Math.ceil(w*bpp/8); // bytes per line
var bf = new Uint8Array(area*4), bf32 = new Uint32Array(bf.buffer);
var ctype = out.ctype, depth = out.depth;
var rs = UPNG._bin.readUshort;
//console.log(ctype, depth);
var time = Date.now();
if (ctype==6) { // RGB + alpha
var qarea = area<<2;
if(depth== 8) for(var i=0; i<qarea;i+=4) { bf[i] = data[i]; bf[i+1] = data[i+1]; bf[i+2] = data[i+2]; bf[i+3] = data[i+3]; }
if(depth==16) for(var i=0; i<qarea;i++ ) { bf[i] = data[i<<1]; }
}
else if(ctype==2) { // RGB
var ts=out.tabs["tRNS"];
if(ts==null) {
if(depth== 8) for(var i=0; i<area; i++) { var ti=i*3; bf32[i] = (255<<24)|(data[ti+2]<<16)|(data[ti+1]<<8)|data[ti]; }
if(depth==16) for(var i=0; i<area; i++) { var ti=i*6; bf32[i] = (255<<24)|(data[ti+4]<<16)|(data[ti+2]<<8)|data[ti]; }
}
else { var tr=ts[0], tg=ts[1], tb=ts[2];
if(depth== 8) for(var i=0; i<area; i++) { var qi=i<<2, ti=i*3; bf32[i] = (255<<24)|(data[ti+2]<<16)|(data[ti+1]<<8)|data[ti];
if(data[ti] ==tr && data[ti+1] ==tg && data[ti+2] ==tb) bf[qi+3] = 0; }
if(depth==16) for(var i=0; i<area; i++) { var qi=i<<2, ti=i*6; bf32[i] = (255<<24)|(data[ti+4]<<16)|(data[ti+2]<<8)|data[ti];
if(rs(data,ti)==tr && rs(data,ti+2)==tg && rs(data,ti+4)==tb) bf[qi+3] = 0; }
}
}
else if(ctype==3) { // palette
var p=out.tabs["PLTE"], ap=out.tabs["tRNS"], tl=ap?ap.length:0;
//console.log(p, ap);
if(depth==1) for(var y=0; y<h; y++) { var s0 = y*bpl, t0 = y*w;
for(var i=0; i<w; i++) { var qi=(t0+i)<<2, j=((data[s0+(i>>3)]>>(7-((i&7)<<0)))& 1), cj=3*j; bf[qi]=p[cj]; bf[qi+1]=p[cj+1]; bf[qi+2]=p[cj+2]; bf[qi+3]=(j<tl)?ap[j]:255; }
}
if(depth==2) for(var y=0; y<h; y++) { var s0 = y*bpl, t0 = y*w;
for(var i=0; i<w; i++) { var qi=(t0+i)<<2, j=((data[s0+(i>>2)]>>(6-((i&3)<<1)))& 3), cj=3*j; bf[qi]=p[cj]; bf[qi+1]=p[cj+1]; bf[qi+2]=p[cj+2]; bf[qi+3]=(j<tl)?ap[j]:255; }
}
if(depth==4) for(var y=0; y<h; y++) { var s0 = y*bpl, t0 = y*w;
for(var i=0; i<w; i++) { var qi=(t0+i)<<2, j=((data[s0+(i>>1)]>>(4-((i&1)<<2)))&15), cj=3*j; bf[qi]=p[cj]; bf[qi+1]=p[cj+1]; bf[qi+2]=p[cj+2]; bf[qi+3]=(j<tl)?ap[j]:255; }
}
if(depth==8) for(var i=0; i<area; i++ ) { var qi=i<<2, j=data[i] , cj=3*j; bf[qi]=p[cj]; bf[qi+1]=p[cj+1]; bf[qi+2]=p[cj+2]; bf[qi+3]=(j<tl)?ap[j]:255; }
}
else if(ctype==4) { // gray + alpha
if(depth== 8) for(var i=0; i<area; i++) { var qi=i<<2, di=i<<1, gr=data[di]; bf[qi]=gr; bf[qi+1]=gr; bf[qi+2]=gr; bf[qi+3]=data[di+1]; }
if(depth==16) for(var i=0; i<area; i++) { var qi=i<<2, di=i<<2, gr=data[di]; bf[qi]=gr; bf[qi+1]=gr; bf[qi+2]=gr; bf[qi+3]=data[di+2]; }
}
else if(ctype==0) { // gray
var tr = out.tabs["tRNS"] ? out.tabs["tRNS"] : -1;
for(var y=0; y<h; y++) {
var off = y*bpl, to = y*w;
if (depth== 1) for(var x=0; x<w; x++) { var gr=255*((data[off+(x>>>3)]>>>(7 -((x&7) )))& 1), al=(gr==tr*255)?0:255; bf32[to+x]=(al<<24)|(gr<<16)|(gr<<8)|gr; }
else if(depth== 2) for(var x=0; x<w; x++) { var gr= 85*((data[off+(x>>>2)]>>>(6 -((x&3)<<1)))& 3), al=(gr==tr* 85)?0:255; bf32[to+x]=(al<<24)|(gr<<16)|(gr<<8)|gr; }
else if(depth== 4) for(var x=0; x<w; x++) { var gr= 17*((data[off+(x>>>1)]>>>(4 -((x&1)<<2)))&15), al=(gr==tr* 17)?0:255; bf32[to+x]=(al<<24)|(gr<<16)|(gr<<8)|gr; }
else if(depth== 8) for(var x=0; x<w; x++) { var gr=data[off+ x], al=(gr ==tr)?0:255; bf32[to+x]=(al<<24)|(gr<<16)|(gr<<8)|gr; }
else if(depth==16) for(var x=0; x<w; x++) { var gr=data[off+(x<<1)], al=(rs(data,off+(x<<1))==tr)?0:255; bf32[to+x]=(al<<24)|(gr<<16)|(gr<<8)|gr; }
}
}
//console.log(Date.now()-time);
return bf;
}
UPNG.decode = function(buff)
{
var data = new Uint8Array(buff), offset = 8, bin = UPNG._bin, rUs = bin.readUshort, rUi = bin.readUint;
var out = {tabs:{}, frames:[]};
var dd = new Uint8Array(data.length), doff = 0; // put all IDAT data into it
var fd, foff = 0; // frames
var mgck = [0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a];
for(var i=0; i<8; i++) if(data[i]!=mgck[i]) throw "The input is not a PNG file!";
while(offset<data.length)
{
var len = bin.readUint(data, offset); offset += 4;
var type = bin.readASCII(data, offset, 4); offset += 4;
//console.log(type,len);
if (type=="IHDR") { UPNG.decode._IHDR(data, offset, out); }
else if(type=="CgBI") { out.tabs[type] = data.slice(offset,offset+4); }
else if(type=="IDAT") {
for(var i=0; i<len; i++) dd[doff+i] = data[offset+i];
doff += len;
}
else if(type=="acTL") {
out.tabs[type] = { num_frames:rUi(data, offset), num_plays:rUi(data, offset+4) };
fd = new Uint8Array(data.length);
}
else if(type=="fcTL") {
if(foff!=0) { var fr = out.frames[out.frames.length-1];
fr.data = UPNG.decode._decompress(out, fd.slice(0,foff), fr.rect.width, fr.rect.height); foff=0;
}
var rct = {x:rUi(data, offset+12),y:rUi(data, offset+16),width:rUi(data, offset+4),height:rUi(data, offset+8)};
var del = rUs(data, offset+22); del = rUs(data, offset+20) / (del==0?100:del);
var frm = {rect:rct, delay:Math.round(del*1000), dispose:data[offset+24], blend:data[offset+25]};
//console.log(frm);
out.frames.push(frm);
}
else if(type=="fdAT") {
for(var i=0; i<len-4; i++) fd[foff+i] = data[offset+i+4];
foff += len-4;
}
else if(type=="pHYs") {
out.tabs[type] = [bin.readUint(data, offset), bin.readUint(data, offset+4), data[offset+8]];
}
else if(type=="cHRM") {
out.tabs[type] = [];
for(var i=0; i<8; i++) out.tabs[type].push(bin.readUint(data, offset+i*4));
}
else if(type=="tEXt" || type=="zTXt") {
if(out.tabs[type]==null) out.tabs[type] = {};
var nz = bin.nextZero(data, offset);
var keyw = bin.readASCII(data, offset, nz-offset);
var text, tl=offset+len-nz-1;
if(type=="tEXt") text = bin.readASCII(data, nz+1, tl);
else {
var bfr = UPNG.decode._inflate(data.slice(nz+2,nz+2+tl));
text = bin.readUTF8(bfr,0,bfr.length);
}
out.tabs[type][keyw] = text;
}
else if(type=="iTXt") {
if(out.tabs[type]==null) out.tabs[type] = {};
var nz = 0, off = offset;
nz = bin.nextZero(data, off);
var keyw = bin.readASCII(data, off, nz-off); off = nz + 1;
var cflag = data[off], cmeth = data[off+1]; off+=2;
nz = bin.nextZero(data, off);
var ltag = bin.readASCII(data, off, nz-off); off = nz + 1;
nz = bin.nextZero(data, off);
var tkeyw = bin.readUTF8(data, off, nz-off); off = nz + 1;
var text, tl=len-(off-offset);
if(cflag==0) text = bin.readUTF8(data, off, tl);
else {
var bfr = UPNG.decode._inflate(data.slice(off,off+tl));
text = bin.readUTF8(bfr,0,bfr.length);
}
out.tabs[type][keyw] = text;
}
else if(type=="PLTE") {
out.tabs[type] = bin.readBytes(data, offset, len);
}
else if(type=="hIST") {
var pl = out.tabs["PLTE"].length/3;
out.tabs[type] = []; for(var i=0; i<pl; i++) out.tabs[type].push(rUs(data, offset+i*2));
}
else if(type=="tRNS") {
if (out.ctype==3) out.tabs[type] = bin.readBytes(data, offset, len);
else if(out.ctype==0) out.tabs[type] = rUs(data, offset);
else if(out.ctype==2) out.tabs[type] = [ rUs(data,offset),rUs(data,offset+2),rUs(data,offset+4) ];
//else console.log("tRNS for unsupported color type",out.ctype, len);
}
else if(type=="gAMA") out.tabs[type] = bin.readUint(data, offset)/100000;
else if(type=="sRGB") out.tabs[type] = data[offset];
else if(type=="bKGD")
{
if (out.ctype==0 || out.ctype==4) out.tabs[type] = [rUs(data, offset)];
else if(out.ctype==2 || out.ctype==6) out.tabs[type] = [rUs(data, offset), rUs(data, offset+2), rUs(data, offset+4)];
else if(out.ctype==3) out.tabs[type] = data[offset];
}
else if(type=="IEND") {
break;
}
//else { console.log("unknown chunk type", type, len); out.tabs[type]=data.slice(offset,offset+len); }
offset += len;
var crc = bin.readUint(data, offset); offset += 4;
}
if(foff!=0) { var fr = out.frames[out.frames.length-1];
fr.data = UPNG.decode._decompress(out, fd.slice(0,foff), fr.rect.width, fr.rect.height);
}
out.data = UPNG.decode._decompress(out, dd, out.width, out.height);
delete out.compress; delete out.interlace; delete out.filter;
return out;
}
UPNG.decode._decompress = function(out, dd, w, h) {
var time = Date.now();
var bpp = UPNG.decode._getBPP(out), bpl = Math.ceil(w*bpp/8), buff = new Uint8Array((bpl+1+out.interlace)*h);
if(out.tabs["CgBI"]) dd = UPNG.inflateRaw(dd,buff);
else dd = UPNG.decode._inflate(dd,buff);
//console.log(dd.length, buff.length);
//console.log(Date.now()-time);
var time=Date.now();
if (out.interlace==0) dd = UPNG.decode._filterZero(dd, out, 0, w, h);
else if(out.interlace==1) dd = UPNG.decode._readInterlace(dd, out);
//console.log(Date.now()-time);
return dd;
}
UPNG.decode._inflate = function(data, buff) { var out=UPNG["inflateRaw"](new Uint8Array(data.buffer, 2,data.length-6),buff); return out; }
UPNG.inflateRaw=function(){var H={};H.H={};H.H.N=function(N,W){var R=Uint8Array,i=0,m=0,J=0,h=0,Q=0,X=0,u=0,w=0,d=0,v,C;
if(N[0]==3&&N[1]==0)return W?W:new R(0);var V=H.H,n=V.b,A=V.e,l=V.R,M=V.n,I=V.A,e=V.Z,b=V.m,Z=W==null;
if(Z)W=new R(N.length>>>2<<5);while(i==0){i=n(N,d,1);m=n(N,d+1,2);d+=3;if(m==0){if((d&7)!=0)d+=8-(d&7);
var D=(d>>>3)+4,q=N[D-4]|N[D-3]<<8;if(Z)W=H.H.W(W,w+q);W.set(new R(N.buffer,N.byteOffset+D,q),w);d=D+q<<3;
w+=q;continue}if(Z)W=H.H.W(W,w+(1<<17));if(m==1){v=b.J;C=b.h;X=(1<<9)-1;u=(1<<5)-1}if(m==2){J=A(N,d,5)+257;
h=A(N,d+5,5)+1;Q=A(N,d+10,4)+4;d+=14;var E=d,j=1;for(var c=0;c<38;c+=2){b.Q[c]=0;b.Q[c+1]=0}for(var c=0;
c<Q;c++){var K=A(N,d+c*3,3);b.Q[(b.X[c]<<1)+1]=K;if(K>j)j=K}d+=3*Q;M(b.Q,j);I(b.Q,j,b.u);v=b.w;C=b.d;
d=l(b.u,(1<<j)-1,J+h,N,d,b.v);var r=V.V(b.v,0,J,b.C);X=(1<<r)-1;var S=V.V(b.v,J,h,b.D);u=(1<<S)-1;M(b.C,r);
I(b.C,r,v);M(b.D,S);I(b.D,S,C)}while(!0){var T=v[e(N,d)&X];d+=T&15;var p=T>>>4;if(p>>>8==0){W[w++]=p}else if(p==256){break}else{var z=w+p-254;
if(p>264){var _=b.q[p-257];z=w+(_>>>3)+A(N,d,_&7);d+=_&7}var $=C[e(N,d)&u];d+=$&15;var s=$>>>4,Y=b.c[s],a=(Y>>>4)+n(N,d,Y&15);
d+=Y&15;while(w<z){W[w]=W[w++-a];W[w]=W[w++-a];W[w]=W[w++-a];W[w]=W[w++-a]}w=z}}}return W.length==w?W:W.slice(0,w)};
H.H.W=function(N,W){var R=N.length;if(W<=R)return N;var V=new Uint8Array(R<<1);V.set(N,0);return V};
H.H.R=function(N,W,R,V,n,A){var l=H.H.e,M=H.H.Z,I=0;while(I<R){var e=N[M(V,n)&W];n+=e&15;var b=e>>>4;
if(b<=15){A[I]=b;I++}else{var Z=0,m=0;if(b==16){m=3+l(V,n,2);n+=2;Z=A[I-1]}else if(b==17){m=3+l(V,n,3);
n+=3}else if(b==18){m=11+l(V,n,7);n+=7}var J=I+m;while(I<J){A[I]=Z;I++}}}return n};H.H.V=function(N,W,R,V){var n=0,A=0,l=V.length>>>1;
while(A<R){var M=N[A+W];V[A<<1]=0;V[(A<<1)+1]=M;if(M>n)n=M;A++}while(A<l){V[A<<1]=0;V[(A<<1)+1]=0;A++}return n};
H.H.n=function(N,W){var R=H.H.m,V=N.length,n,A,l,M,I,e=R.j;for(var M=0;M<=W;M++)e[M]=0;for(M=1;M<V;M+=2)e[N[M]]++;
var b=R.K;n=0;e[0]=0;for(A=1;A<=W;A++){n=n+e[A-1]<<1;b[A]=n}for(l=0;l<V;l+=2){I=N[l+1];if(I!=0){N[l]=b[I];
b[I]++}}};H.H.A=function(N,W,R){var V=N.length,n=H.H.m,A=n.r;for(var l=0;l<V;l+=2)if(N[l+1]!=0){var M=l>>1,I=N[l+1],e=M<<4|I,b=W-I,Z=N[l]<<b,m=Z+(1<<b);
while(Z!=m){var J=A[Z]>>>15-W;R[J]=e;Z++}}};H.H.l=function(N,W){var R=H.H.m.r,V=15-W;for(var n=0;n<N.length;
n+=2){var A=N[n]<<W-N[n+1];N[n]=R[A]>>>V}};H.H.M=function(N,W,R){R=R<<(W&7);var V=W>>>3;N[V]|=R;N[V+1]|=R>>>8};
H.H.I=function(N,W,R){R=R<<(W&7);var V=W>>>3;N[V]|=R;N[V+1]|=R>>>8;N[V+2]|=R>>>16};H.H.e=function(N,W,R){return(N[W>>>3]|N[(W>>>3)+1]<<8)>>>(W&7)&(1<<R)-1};
H.H.b=function(N,W,R){return(N[W>>>3]|N[(W>>>3)+1]<<8|N[(W>>>3)+2]<<16)>>>(W&7)&(1<<R)-1};H.H.Z=function(N,W){return(N[W>>>3]|N[(W>>>3)+1]<<8|N[(W>>>3)+2]<<16)>>>(W&7)};
H.H.i=function(N,W){return(N[W>>>3]|N[(W>>>3)+1]<<8|N[(W>>>3)+2]<<16|N[(W>>>3)+3]<<24)>>>(W&7)};H.H.m=function(){var N=Uint16Array,W=Uint32Array;
return{K:new N(16),j:new N(16),X:[16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15],S:[3,4,5,6,7,8,9,10,11,13,15,17,19,23,27,31,35,43,51,59,67,83,99,115,131,163,195,227,258,999,999,999],T:[0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0,0,0,0],q:new N(32),p:[1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,65535,65535],z:[0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,0,0],c:new W(32),J:new N(512),_:[],h:new N(32),$:[],w:new N(32768),C:[],v:[],d:new N(32768),D:[],u:new N(512),Q:[],r:new N(1<<15),s:new W(286),Y:new W(30),a:new W(19),t:new W(15e3),k:new N(1<<16),g:new N(1<<15)}}();
(function(){var N=H.H.m,W=1<<15;for(var R=0;R<W;R++){var V=R;V=(V&2863311530)>>>1|(V&1431655765)<<1;
V=(V&3435973836)>>>2|(V&858993459)<<2;V=(V&4042322160)>>>4|(V&252645135)<<4;V=(V&4278255360)>>>8|(V&16711935)<<8;
N.r[R]=(V>>>16|V<<16)>>>17}function n(A,l,M){while(l--!=0)A.push(0,M)}for(var R=0;R<32;R++){N.q[R]=N.S[R]<<3|N.T[R];
N.c[R]=N.p[R]<<4|N.z[R]}n(N._,144,8);n(N._,255-143,9);n(N._,279-255,7);n(N._,287-279,8);H.H.n(N._,9);
H.H.A(N._,9,N.J);H.H.l(N._,9);n(N.$,32,5);H.H.n(N.$,5);H.H.A(N.$,5,N.h);H.H.l(N.$,5);n(N.Q,19,0);n(N.C,286,0);
n(N.D,30,0);n(N.v,320,0)}());return H.H.N}()
UPNG.decode._readInterlace = function(data, out)
{
var w = out.width, h = out.height;
var bpp = UPNG.decode._getBPP(out), cbpp = bpp>>3, bpl = Math.ceil(w*bpp/8);
var img = new Uint8Array( h * bpl );
var di = 0;
var starting_row = [ 0, 0, 4, 0, 2, 0, 1 ];
var starting_col = [ 0, 4, 0, 2, 0, 1, 0 ];
var row_increment = [ 8, 8, 8, 4, 4, 2, 2 ];
var col_increment = [ 8, 8, 4, 4, 2, 2, 1 ];
var pass=0;
while(pass<7)
{
var ri = row_increment[pass], ci = col_increment[pass];
var sw = 0, sh = 0;
var cr = starting_row[pass]; while(cr<h) { cr+=ri; sh++; }
var cc = starting_col[pass]; while(cc<w) { cc+=ci; sw++; }
var bpll = Math.ceil(sw*bpp/8);
UPNG.decode._filterZero(data, out, di, sw, sh);
var y=0, row = starting_row[pass];
while(row<h)
{
var col = starting_col[pass];
var cdi = (di+y*bpll)<<3;
while(col<w)
{
if(bpp==1) {
var val = data[cdi>>3]; val = (val>>(7-(cdi&7)))&1;
img[row*bpl + (col>>3)] |= (val << (7-((col&7)<<0)));
}
if(bpp==2) {
var val = data[cdi>>3]; val = (val>>(6-(cdi&7)))&3;
img[row*bpl + (col>>2)] |= (val << (6-((col&3)<<1)));
}
if(bpp==4) {
var val = data[cdi>>3]; val = (val>>(4-(cdi&7)))&15;
img[row*bpl + (col>>1)] |= (val << (4-((col&1)<<2)));
}
if(bpp>=8) {
var ii = row*bpl+col*cbpp;
for(var j=0; j<cbpp; j++) img[ii+j] = data[(cdi>>3)+j];
}
cdi+=bpp; col+=ci;
}
y++; row += ri;
}
if(sw*sh!=0) di += sh * (1 + bpll);
pass = pass + 1;
}
return img;
}
UPNG.decode._getBPP = function(out) {
var noc = [1,null,3,1,2,null,4][out.ctype];
return noc * out.depth;
}
UPNG.decode._filterZero = function(data, out, off, w, h)
{
var bpp = UPNG.decode._getBPP(out), bpl = Math.ceil(w*bpp/8), paeth = UPNG.decode._paeth;
bpp = Math.ceil(bpp/8);
var i,di, type=data[off], x=0;
if(type>1) data[off]=[0,0,1][type-2];
if(type==3) for(x=bpp; x<bpl; x++) data[x+1] = (data[x+1] + (data[x+1-bpp]>>>1) )&255;
for(var y=0; y<h; y++) {
i = off+y*bpl; di = i+y+1;
type = data[di-1]; x=0;
if (type==0) for(; x<bpl; x++) data[i+x] = data[di+x];
else if(type==1) { for(; x<bpp; x++) data[i+x] = data[di+x];
for(; x<bpl; x++) data[i+x] = (data[di+x] + data[i+x-bpp]); }
else if(type==2) { for(; x<bpl; x++) data[i+x] = (data[di+x] + data[i+x-bpl]); }
else if(type==3) { for(; x<bpp; x++) data[i+x] = (data[di+x] + ( data[i+x-bpl]>>>1));
for(; x<bpl; x++) data[i+x] = (data[di+x] + ((data[i+x-bpl]+data[i+x-bpp])>>>1) ); }
else { for(; x<bpp; x++) data[i+x] = (data[di+x] + paeth(0, data[i+x-bpl], 0));
for(; x<bpl; x++) data[i+x] = (data[di+x] + paeth(data[i+x-bpp], data[i+x-bpl], data[i+x-bpp-bpl]) ); }
}
return data;
}
UPNG.decode._paeth = function(a,b,c)
{
var p = a+b-c, pa = (p-a), pb = (p-b), pc = (p-c);
if (pa*pa <= pb*pb && pa*pa <= pc*pc) return a;
else if (pb*pb <= pc*pc) return b;
return c;
}
UPNG.decode._IHDR = function(data, offset, out)
{
var bin = UPNG._bin;
out.width = bin.readUint(data, offset); offset += 4;
out.height = bin.readUint(data, offset); offset += 4;
out.depth = data[offset]; offset++;
out.ctype = data[offset]; offset++;
out.compress = data[offset]; offset++;
out.filter = data[offset]; offset++;
out.interlace = data[offset]; offset++;
}
UPNG._bin = {
nextZero : function(data,p) { while(data[p]!=0) p++; return p; },
readUshort : function(buff,p) { return (buff[p]<< 8) | buff[p+1]; },
writeUshort: function(buff,p,n){ buff[p] = (n>>8)&255; buff[p+1] = n&255; },
readUint : function(buff,p) { return (buff[p]*(256*256*256)) + ((buff[p+1]<<16) | (buff[p+2]<< 8) | buff[p+3]); },
writeUint : function(buff,p,n){ buff[p]=(n>>24)&255; buff[p+1]=(n>>16)&255; buff[p+2]=(n>>8)&255; buff[p+3]=n&255; },
readASCII : function(buff,p,l){ var s = ""; for(var i=0; i<l; i++) s += String.fromCharCode(buff[p+i]); return s; },
writeASCII : function(data,p,s){ for(var i=0; i<s.length; i++) data[p+i] = s.charCodeAt(i); },
readBytes : function(buff,p,l){ var arr = []; for(var i=0; i<l; i++) arr.push(buff[p+i]); return arr; },
pad : function(n) { return n.length < 2 ? "0" + n : n; },
readUTF8 : function(buff, p, l) {
var s = "", ns;
for(var i=0; i<l; i++) s += "%" + UPNG._bin.pad(buff[p+i].toString(16));
try { ns = decodeURIComponent(s); }
catch(e) { return UPNG._bin.readASCII(buff, p, l); }
return ns;
}
}
UPNG._copyTile = function(sb, sw, sh, tb, tw, th, xoff, yoff, mode)
{
var w = Math.min(sw,tw), h = Math.min(sh,th);
var si=0, ti=0;
for(var y=0; y<h; y++)
for(var x=0; x<w; x++)
{
if(xoff>=0 && yoff>=0) { si = (y*sw+x)<<2; ti = (( yoff+y)*tw+xoff+x)<<2; }
else { si = ((-yoff+y)*sw-xoff+x)<<2; ti = (y*tw+x)<<2; }
if (mode==0) { tb[ti] = sb[si]; tb[ti+1] = sb[si+1]; tb[ti+2] = sb[si+2]; tb[ti+3] = sb[si+3]; }
else if(mode==1) {
var fa = sb[si+3]*(1/255), fr=sb[si]*fa, fg=sb[si+1]*fa, fb=sb[si+2]*fa;
var ba = tb[ti+3]*(1/255), br=tb[ti]*ba, bg=tb[ti+1]*ba, bb=tb[ti+2]*ba;
var ifa=1-fa, oa = fa+ba*ifa, ioa = (oa==0?0:1/oa);
tb[ti+3] = 255*oa;
tb[ti+0] = (fr+br*ifa)*ioa;
tb[ti+1] = (fg+bg*ifa)*ioa;
tb[ti+2] = (fb+bb*ifa)*ioa;
}
else if(mode==2){ // copy only differences, otherwise zero
var fa = sb[si+3], fr=sb[si], fg=sb[si+1], fb=sb[si+2];
var ba = tb[ti+3], br=tb[ti], bg=tb[ti+1], bb=tb[ti+2];
if(fa==ba && fr==br && fg==bg && fb==bb) { tb[ti]=0; tb[ti+1]=0; tb[ti+2]=0; tb[ti+3]=0; }
else { tb[ti]=fr; tb[ti+1]=fg; tb[ti+2]=fb; tb[ti+3]=fa; }
}
else if(mode==3){ // check if can be blended
var fa = sb[si+3], fr=sb[si], fg=sb[si+1], fb=sb[si+2];
var ba = tb[ti+3], br=tb[ti], bg=tb[ti+1], bb=tb[ti+2];
if(fa==ba && fr==br && fg==bg && fb==bb) continue;
//if(fa!=255 && ba!=0) return false;
if(fa<220 && ba>20) return false;
}
}
return true;
}
UPNG.encode = function(bufs, w, h, ps, dels, tabs, forbidPlte)
{
if(ps==null) ps=0;
if(forbidPlte==null) forbidPlte = false;
var nimg = UPNG.encode.compress(bufs, w, h, ps, [false, false, false, 0, forbidPlte,false]);
UPNG.encode.compressPNG(nimg, -1);
return UPNG.encode._main(nimg, w, h, dels, tabs);
}
UPNG.encodeLL = function(bufs, w, h, cc, ac, depth, dels, tabs) {
var nimg = { ctype: 0 + (cc==1 ? 0 : 2) + (ac==0 ? 0 : 4), depth: depth, frames: [] };
var time = Date.now();
var bipp = (cc+ac)*depth, bipl = bipp * w;
for(var i=0; i<bufs.length; i++)
nimg.frames.push({ rect:{x:0,y:0,width:w,height:h}, img:new Uint8Array(bufs[i]), blend:0, dispose:1, bpp:Math.ceil(bipp/8), bpl:Math.ceil(bipl/8) });
UPNG.encode.compressPNG(nimg, 0, true);
var out = UPNG.encode._main(nimg, w, h, dels, tabs);
return out;
}
UPNG.encode._main = function(nimg, w, h, dels, tabs) {
if(tabs==null) tabs={};
var crc = UPNG.crc.crc, wUi = UPNG._bin.writeUint, wUs = UPNG._bin.writeUshort, wAs = UPNG._bin.writeASCII;
var offset = 8, anim = nimg.frames.length>1, pltAlpha = false;
var leng = 8 + (16+5+4) /*+ (9+4)*/ + (anim ? 20 : 0);
if(tabs["sRGB"]!=null) leng += 8+1+4;
if(tabs["pHYs"]!=null) leng += 8+9+4;
if(nimg.ctype==3) {
var dl = nimg.plte.length;
for(var i=0; i<dl; i++) if((nimg.plte[i]>>>24)!=255) pltAlpha = true;
leng += (8 + dl*3 + 4) + (pltAlpha ? (8 + dl*1 + 4) : 0);
}
for(var j=0; j<nimg.frames.length; j++)
{
var fr = nimg.frames[j];
if(anim) leng += 38;
leng += fr.cimg.length + 12;
if(j!=0) leng+=4;
}
leng += 12;
var data = new Uint8Array(leng);
var wr=[0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a];
for(var i=0; i<8; i++) data[i]=wr[i];
wUi(data,offset, 13); offset+=4;
wAs(data,offset,"IHDR"); offset+=4;
wUi(data,offset,w); offset+=4;
wUi(data,offset,h); offset+=4;
data[offset] = nimg.depth; offset++; // depth
data[offset] = nimg.ctype; offset++; // ctype
data[offset] = 0; offset++; // compress
data[offset] = 0; offset++; // filter
data[offset] = 0; offset++; // interlace
wUi(data,offset,crc(data,offset-17,17)); offset+=4; // crc
// 13 bytes to say, that it is sRGB
if(tabs["sRGB"]!=null) {
wUi(data,offset, 1); offset+=4;
wAs(data,offset,"sRGB"); offset+=4;
data[offset] = tabs["sRGB"]; offset++;
wUi(data,offset,crc(data,offset-5,5)); offset+=4; // crc
}
if(tabs["pHYs"]!=null) {
wUi(data,offset, 9); offset+=4;
wAs(data,offset,"pHYs"); offset+=4;
wUi(data,offset, tabs["pHYs"][0]); offset+=4;
wUi(data,offset, tabs["pHYs"][1]); offset+=4;
data[offset]=tabs["pHYs"][2]; offset++;
wUi(data,offset,crc(data,offset-13,13)); offset+=4; // crc
}
if(anim) {
wUi(data,offset, 8); offset+=4;
wAs(data,offset,"acTL"); offset+=4;
wUi(data,offset, nimg.frames.length); offset+=4;
wUi(data,offset, tabs["loop"]!=null?tabs["loop"]:0); offset+=4;
wUi(data,offset,crc(data,offset-12,12)); offset+=4; // crc
}
if(nimg.ctype==3) {
var dl = nimg.plte.length;
wUi(data,offset, dl*3); offset+=4;
wAs(data,offset,"PLTE"); offset+=4;
for(var i=0; i<dl; i++){
var ti=i*3, c=nimg.plte[i], r=(c)&255, g=(c>>>8)&255, b=(c>>>16)&255;
data[offset+ti+0]=r; data[offset+ti+1]=g; data[offset+ti+2]=b;
}
offset+=dl*3;
wUi(data,offset,crc(data,offset-dl*3-4,dl*3+4)); offset+=4; // crc
if(pltAlpha) {
wUi(data,offset, dl); offset+=4;
wAs(data,offset,"tRNS"); offset+=4;
for(var i=0; i<dl; i++) data[offset+i]=(nimg.plte[i]>>>24)&255;
offset+=dl;
wUi(data,offset,crc(data,offset-dl-4,dl+4)); offset+=4; // crc
}
}
var fi = 0;
for(var j=0; j<nimg.frames.length; j++)
{
var fr = nimg.frames[j];
if(anim) {
wUi(data, offset, 26); offset+=4;
wAs(data, offset,"fcTL"); offset+=4;
wUi(data, offset, fi++); offset+=4;
wUi(data, offset, fr.rect.width ); offset+=4;
wUi(data, offset, fr.rect.height); offset+=4;
wUi(data, offset, fr.rect.x); offset+=4;
wUi(data, offset, fr.rect.y); offset+=4;
wUs(data, offset, dels[j]); offset+=2;
wUs(data, offset, 1000); offset+=2;
data[offset] = fr.dispose; offset++; // dispose
data[offset] = fr.blend ; offset++; // blend
wUi(data,offset,crc(data,offset-30,30)); offset+=4; // crc
}
var imgd = fr.cimg, dl = imgd.length;
wUi(data,offset, dl+(j==0?0:4)); offset+=4;
var ioff = offset;
wAs(data,offset,(j==0)?"IDAT":"fdAT"); offset+=4;
if(j!=0) { wUi(data, offset, fi++); offset+=4; }
data.set(imgd,offset);
offset += dl;
wUi(data,offset,crc(data,ioff,offset-ioff)); offset+=4; // crc
}
wUi(data,offset, 0); offset+=4;
wAs(data,offset,"IEND"); offset+=4;
wUi(data,offset,crc(data,offset-4,4)); offset+=4; // crc
return data.buffer;
}
UPNG.encode.compressPNG = function(out, filter, levelZero) {
for(var i=0; i<out.frames.length; i++) {
var frm = out.frames[i], nw=frm.rect.width, nh=frm.rect.height;
var fdata = new Uint8Array(nh*frm.bpl+nh);
frm.cimg = UPNG.encode._filterZero(frm.img,nh,frm.bpp,frm.bpl,fdata, filter, levelZero);
}
}
UPNG.encode.compress = function(bufs, w, h, ps, prms) // prms: onlyBlend, minBits, forbidPlte
{
//var time = Date.now();
var onlyBlend = prms[0], evenCrd = prms[1], forbidPrev = prms[2], minBits = prms[3], forbidPlte = prms[4], dither=prms[5];
var ctype = 6, depth = 8, alphaAnd=255
for(var j=0; j<bufs.length; j++) { // when not quantized, other frames can contain colors, that are not in an initial frame
var img = new Uint8Array(bufs[j]), ilen = img.length;
for(var i=0; i<ilen; i+=4) alphaAnd &= img[i+3];
}
var gotAlpha = (alphaAnd!=255);
//console.log("alpha check", Date.now()-time); time = Date.now();
//var brute = gotAlpha && forGIF; // brute : frames can only be copied, not "blended"
var frms = UPNG.encode.framize(bufs, w, h, onlyBlend, evenCrd, forbidPrev);
//console.log("framize", Date.now()-time); time = Date.now();
var cmap={}, plte=[], inds=[];
if(ps!=0) {
var nbufs = []; for(var i=0; i<frms.length; i++) nbufs.push(frms[i].img.buffer);
var abuf = UPNG.encode.concatRGBA(nbufs), qres = UPNG.quantize(abuf, ps);
for(var i=0; i<qres.plte.length; i++) plte.push(qres.plte[i].est.rgba);
var cof = 0;
for(var i=0; i<frms.length; i++) {
var frm=frms[i], bln=frm.img.length, ind = new Uint8Array(qres.inds.buffer, cof>>2, bln>>2); inds.push(ind);
var bb = new Uint8Array(qres.abuf,cof,bln);
//console.log(frm.img, frm.width, frm.height);
//var time = Date.now();
if(dither) UPNG.encode.dither(frm.img, frm.rect.width, frm.rect.height, plte, bb, ind);
//console.log(Date.now()-time);
frm.img.set(bb); cof+=bln;
}
//console.log("quantize", Date.now()-time); time = Date.now();
}
else {
// what if ps==0, but there are <=256 colors? we still need to detect, if the palette could be used
for(var j=0; j<frms.length; j++) { // when not quantized, other frames can contain colors, that are not in an initial frame
var frm = frms[j], img32 = new Uint32Array(frm.img.buffer), nw=frm.rect.width, ilen = img32.length;
var ind = new Uint8Array(ilen); inds.push(ind);
for(var i=0; i<ilen; i++) {
var c = img32[i];
if (i!=0 && c==img32[i- 1]) ind[i]=ind[i-1];
else if(i>nw && c==img32[i-nw]) ind[i]=ind[i-nw];
else {
var cmc = cmap[c];
if(cmc==null) { cmap[c]=cmc=plte.length; plte.push(c); if(plte.length>=300) break; }
ind[i]=cmc;
}
}
}
//console.log("make palette", Date.now()-time); time = Date.now();
}
var cc=plte.length; //console.log("colors:",cc);
if(cc<=256 && forbidPlte==false) {
if(cc<= 2) depth=1; else if(cc<= 4) depth=2; else if(cc<=16) depth=4; else depth=8;
depth = Math.max(depth, minBits);
}
for(var j=0; j<frms.length; j++)
{
var frm = frms[j], nx=frm.rect.x, ny=frm.rect.y, nw=frm.rect.width, nh=frm.rect.height;
var cimg = frm.img, cimg32 = new Uint32Array(cimg.buffer);
var bpl = 4*nw, bpp=4;
if(cc<=256 && forbidPlte==false) {
bpl = Math.ceil(depth*nw/8);
var nimg = new Uint8Array(bpl*nh);
var inj = inds[j];
for(var y=0; y<nh; y++) { var i=y*bpl, ii=y*nw;
if (depth==8) for(var x=0; x<nw; x++) nimg[i+(x) ] = (inj[ii+x] );
else if(depth==4) for(var x=0; x<nw; x++) nimg[i+(x>>1)] |= (inj[ii+x]<<(4-(x&1)*4));
else if(depth==2) for(var x=0; x<nw; x++) nimg[i+(x>>2)] |= (inj[ii+x]<<(6-(x&3)*2));
else if(depth==1) for(var x=0; x<nw; x++) nimg[i+(x>>3)] |= (inj[ii+x]<<(7-(x&7)*1));
}
cimg=nimg; ctype=3; bpp=1;
}
else if(gotAlpha==false && frms.length==1) { // some next "reduced" frames may contain alpha for blending
var nimg = new Uint8Array(nw*nh*3), area=nw*nh;
for(var i=0; i<area; i++) { var ti=i*3, qi=i*4; nimg[ti]=cimg[qi]; nimg[ti+1]=cimg[qi+1]; nimg[ti+2]=cimg[qi+2]; }
cimg=nimg; ctype=2; bpp=3; bpl=3*nw;
}
frm.img=cimg; frm.bpl=bpl; frm.bpp=bpp;
}
//console.log("colors => palette indices", Date.now()-time); time = Date.now();
return {ctype:ctype, depth:depth, plte:plte, frames:frms };
}
UPNG.encode.framize = function(bufs,w,h,alwaysBlend,evenCrd,forbidPrev) {
/* DISPOSE
- 0 : no change
- 1 : clear to transparent
- 2 : retstore to content before rendering (previous frame disposed)
BLEND
- 0 : replace
- 1 : blend
*/
var frms = [];
for(var j=0; j<bufs.length; j++) {
var cimg = new Uint8Array(bufs[j]), cimg32 = new Uint32Array(cimg.buffer);
var nimg;
var nx=0, ny=0, nw=w, nh=h, blend=alwaysBlend?1:0;
if(j!=0) {
var tlim = (forbidPrev || alwaysBlend || j==1 || frms[j-2].dispose!=0)?1:2, tstp = 0, tarea = 1e9;
for(var it=0; it<tlim; it++)
{
var pimg = new Uint8Array(bufs[j-1-it]), p32 = new Uint32Array(bufs[j-1-it]);
var mix=w,miy=h,max=-1,may=-1;
for(var y=0; y<h; y++) for(var x=0; x<w; x++) {
var i = y*w+x;
if(cimg32[i]!=p32[i]) {
if(x<mix) mix=x; if(x>max) max=x;
if(y<miy) miy=y; if(y>may) may=y;
}
}
if(max==-1) mix=miy=max=may=0;
if(evenCrd) { if((mix&1)==1)mix--; if((miy&1)==1)miy--; }
var sarea = (max-mix+1)*(may-miy+1);
if(sarea<tarea) {
tarea = sarea; tstp = it;
nx = mix; ny = miy; nw = max-mix+1; nh = may-miy+1;
}
}
// alwaysBlend: pokud zjistím, že blendit nelze, nastavím předchozímu snímku dispose=1. Zajistím, aby obsahoval můj obdélník.
var pimg = new Uint8Array(bufs[j-1-tstp]);
if(tstp==1) frms[j-1].dispose = 2;
nimg = new Uint8Array(nw*nh*4);
UPNG._copyTile(pimg,w,h, nimg,nw,nh, -nx,-ny, 0);
blend = UPNG._copyTile(cimg,w,h, nimg,nw,nh, -nx,-ny, 3) ? 1 : 0;
if(blend==1) UPNG.encode._prepareDiff(cimg,w,h,nimg,{x:nx,y:ny,width:nw,height:nh});
else UPNG._copyTile(cimg,w,h, nimg,nw,nh, -nx,-ny, 0);
//UPNG._copyTile(cimg,w,h, nimg,nw,nh, -nx,-ny, blend==1?2:0);
}
else nimg = cimg.slice(0); // img may be rewritten further ... don't rewrite input
frms.push({rect:{x:nx,y:ny,width:nw,height:nh}, img:nimg, blend:blend, dispose:0});
}
if(alwaysBlend) for(var j=0; j<frms.length; j++) {
var frm = frms[j]; if(frm.blend==1) continue;
var r0 = frm.rect, r1 = frms[j-1].rect
var miX = Math.min(r0.x, r1.x), miY = Math.min(r0.y, r1.y);
var maX = Math.max(r0.x+r0.width, r1.x+r1.width), maY = Math.max(r0.y+r0.height, r1.y+r1.height);
var r = {x:miX, y:miY, width:maX-miX, height:maY-miY};
frms[j-1].dispose = 1;
if(j-1!=0)
UPNG.encode._updateFrame(bufs, w,h,frms, j-1,r, evenCrd);
UPNG.encode._updateFrame(bufs, w,h,frms, j ,r, evenCrd);
}
var area = 0;
if(bufs.length!=1) for(var i=0; i<frms.length; i++) {
var frm = frms[i];
area += frm.rect.width*frm.rect.height;
//if(i==0 || frm.blend!=1) continue;
//var ob = new Uint8Array(
//console.log(frm.blend, frm.dispose, frm.rect);
}
//if(area!=0) console.log(area);
return frms;
}
UPNG.encode._updateFrame = function(bufs, w,h, frms, i, r, evenCrd) {
var U8 = Uint8Array, U32 = Uint32Array;
var pimg = new U8(bufs[i-1]), pimg32 = new U32(bufs[i-1]), nimg = i+1<bufs.length ? new U8(bufs[i+1]):null;
var cimg = new U8(bufs[i]), cimg32 = new U32(cimg.buffer);
var mix=w,miy=h,max=-1,may=-1;
for(var y=0; y<r.height; y++) for(var x=0; x<r.width; x++) {
var cx = r.x+x, cy = r.y+y;
var j = cy*w+cx, cc = cimg32[j];
// no need to draw transparency, or to dispose it. Or, if writing the same color and the next one does not need transparency.
if(cc==0 || (frms[i-1].dispose==0 && pimg32[j]==cc && (nimg==null || nimg[j*4+3]!=0))/**/) {}
else {
if(cx<mix) mix=cx; if(cx>max) max=cx;
if(cy<miy) miy=cy; if(cy>may) may=cy;
}
}
if(max==-1) mix=miy=max=may=0;
if(evenCrd) { if((mix&1)==1)mix--; if((miy&1)==1)miy--; }
r = {x:mix, y:miy, width:max-mix+1, height:may-miy+1};
var fr = frms[i]; fr.rect = r; fr.blend = 1; fr.img = new Uint8Array(r.width*r.height*4);
if(frms[i-1].dispose==0) {
UPNG._copyTile(pimg,w,h, fr.img,r.width,r.height, -r.x,-r.y, 0);
UPNG.encode._prepareDiff(cimg,w,h,fr.img,r);
//UPNG._copyTile(cimg,w,h, fr.img,r.width,r.height, -r.x,-r.y, 2);
}
else
UPNG._copyTile(cimg,w,h, fr.img,r.width,r.height, -r.x,-r.y, 0);
}
UPNG.encode._prepareDiff = function(cimg, w,h, nimg, rec) {
UPNG._copyTile(cimg,w,h, nimg,rec.width,rec.height, -rec.x,-rec.y, 2);
/*
var n32 = new Uint32Array(nimg.buffer);
var og = new Uint8Array(rec.width*rec.height*4), o32 = new Uint32Array(og.buffer);
UPNG._copyTile(cimg,w,h, og,rec.width,rec.height, -rec.x,-rec.y, 0);
for(var i=4; i<nimg.length; i+=4) {
if(nimg[i-1]!=0 && nimg[i+3]==0 && o32[i>>>2]==o32[(i>>>2)-1]) {
n32[i>>>2]=o32[i>>>2];
//var j = i, c=p32[(i>>>2)-1];
//while(p32[j>>>2]==c) { n32[j>>>2]=c; j+=4; }
}
}
for(var i=nimg.length-8; i>0; i-=4) {
if(nimg[i+7]!=0 && nimg[i+3]==0 && o32[i>>>2]==o32[(i>>>2)+1]) {
n32[i>>>2]=o32[i>>>2];
//var j = i, c=p32[(i>>>2)-1];
//while(p32[j>>>2]==c) { n32[j>>>2]=c; j+=4; }
}
}*/
}
UPNG.encode._filterZero = function(img,h,bpp,bpl,data, filter, levelZero)
{
var fls = [], ftry=[0,1,2,3,4];
if (filter!=-1) ftry=[filter];
else if(h*bpl>500000 || bpp==1) ftry=[0];
var opts; if(levelZero) opts={level:0};
var CMPR = (data.length>10e6 && UZIP!=null) ? UZIP : pako;
var time = Date.now();
for(var i=0; i<ftry.length; i++) {
for(var y=0; y<h; y++) UPNG.encode._filterLine(data, img, y, bpl, bpp, ftry[i]);
//var nimg = new Uint8Array(data.length);
//var sz = UZIP.F.deflate(data, nimg); fls.push(nimg.slice(0,sz));
//var dfl = pako["deflate"](data), dl=dfl.length-4;
//var crc = (dfl[dl+3]<<24)|(dfl[dl+2]<<16)|(dfl[dl+1]<<8)|(dfl[dl+0]<<0);
//console.log(crc, UZIP.adler(data,2,data.length-6));
fls.push(CMPR["deflate"](data,opts));
}
var ti, tsize=1e9;
for(var i=0; i<fls.length; i++) if(fls[i].length<tsize) { ti=i; tsize=fls[i].length; }
return fls[ti];
}
UPNG.encode._filterLine = function(data, img, y, bpl, bpp, type)
{
var i = y*bpl, di = i+y, paeth = UPNG.decode._paeth
data[di]=type; di++;
if(type==0) {
if(bpl<500) for(var x=0; x<bpl; x++) data[di+x] = img[i+x];
else data.set(new Uint8Array(img.buffer,i,bpl),di);
}
else if(type==1) {
for(var x= 0; x<bpp; x++) data[di+x] = img[i+x];
for(var x=bpp; x<bpl; x++) data[di+x] = (img[i+x]-img[i+x-bpp]+256)&255;
}
else if(y==0) {
for(var x= 0; x<bpp; x++) data[di+x] = img[i+x];
if(type==2) for(var x=bpp; x<bpl; x++) data[di+x] = img[i+x];
if(type==3) for(var x=bpp; x<bpl; x++) data[di+x] = (img[i+x] - (img[i+x-bpp]>>1) +256)&255;
if(type==4) for(var x=bpp; x<bpl; x++) data[di+x] = (img[i+x] - paeth(img[i+x-bpp], 0, 0) +256)&255;
}
else {
if(type==2) { for(var x= 0; x<bpl; x++) data[di+x] = (img[i+x]+256 - img[i+x-bpl])&255; }
if(type==3) { for(var x= 0; x<bpp; x++) data[di+x] = (img[i+x]+256 - (img[i+x-bpl]>>1))&255;
for(var x=bpp; x<bpl; x++) data[di+x] = (img[i+x]+256 - ((img[i+x-bpl]+img[i+x-bpp])>>1))&255; }
if(type==4) { for(var x= 0; x<bpp; x++) data[di+x] = (img[i+x]+256 - paeth(0, img[i+x-bpl], 0))&255;
for(var x=bpp; x<bpl; x++) data[di+x] = (img[i+x]+256 - paeth(img[i+x-bpp], img[i+x-bpl], img[i+x-bpp-bpl]))&255; }
}
}
UPNG.crc = {
table : ( function() {
var tab = new Uint32Array(256);
for (var n=0; n<256; n++) {
var c = n;
for (var k=0; k<8; k++) {
if (c & 1) c = 0xedb88320 ^ (c >>> 1);
else c = c >>> 1;
}
tab[n] = c; }
return tab; })(),
update : function(c, buf, off, len) {
for (var i=0; i<len; i++) c = UPNG.crc.table[(c ^ buf[off+i]) & 0xff] ^ (c >>> 8);
return c;
},
crc : function(b,o,l) { return UPNG.crc.update(0xffffffff,b,o,l) ^ 0xffffffff; }
}
UPNG.quantize = function(abuf, ps)
{
var sb = new Uint8Array(abuf), tb = sb.slice(0), tb32 = new Uint32Array(tb.buffer);
var KD = UPNG.quantize.getKDtree(tb, ps);
var root = KD[0], leafs = KD[1];
var planeDst = UPNG.quantize.planeDst;
var len=sb.length;
var inds = new Uint8Array(len>>2), nd;
if(sb.length<20e6) // precise, but slow :(
for(var i=0; i<len; i+=4) {
var r=sb[i]*(1/255), g=sb[i+1]*(1/255), b=sb[i+2]*(1/255), a=sb[i+3]*(1/255);
nd = UPNG.quantize.getNearest(root, r, g, b, a);
inds[i>>2] = nd.ind; tb32[i>>2] = nd.est.rgba;
}
else
for(var i=0; i<len; i+=4) {
var r=sb[i]*(1/255), g=sb[i+1]*(1/255), b=sb[i+2]*(1/255), a=sb[i+3]*(1/255);
nd = root; while(nd.left) nd = (planeDst(nd.est,r,g,b,a)<=0) ? nd.left : nd.right;
inds[i>>2] = nd.ind; tb32[i>>2] = nd.est.rgba;
}
return { abuf:tb.buffer, inds:inds, plte:leafs };
}
UPNG.quantize.getKDtree = function(nimg, ps, err) {
if(err==null) err = 0.0001;
var nimg32 = new Uint32Array(nimg.buffer);
var root = {i0:0, i1:nimg.length, bst:null, est:null, tdst:0, left:null, right:null }; // basic statistic, extra statistic
root.bst = UPNG.quantize.stats( nimg,root.i0, root.i1 ); root.est = UPNG.quantize.estats( root.bst );
var leafs = [root];
while(leafs.length<ps)
{
var maxL = 0, mi=0;
for(var i=0; i<leafs.length; i++) if(leafs[i].est.L > maxL) { maxL=leafs[i].est.L; mi=i; }
if(maxL<err) break;
var node = leafs[mi];
var s0 = UPNG.quantize.splitPixels(nimg,nimg32, node.i0, node.i1, node.est.e, node.est.eMq255);
var s0wrong = (node.i0>=s0 || node.i1<=s0);
//console.log(maxL, leafs.length, mi);
if(s0wrong) { node.est.L=0; continue; }
var ln = {i0:node.i0, i1:s0, bst:null, est:null, tdst:0, left:null, right:null }; ln.bst = UPNG.quantize.stats( nimg, ln.i0, ln.i1 );
ln.est = UPNG.quantize.estats( ln.bst );
var rn = {i0:s0, i1:node.i1, bst:null, est:null, tdst:0, left:null, right:null }; rn.bst = {R:[], m:[], N:node.bst.N-ln.bst.N};
for(var i=0; i<16; i++) rn.bst.R[i] = node.bst.R[i]-ln.bst.R[i];
for(var i=0; i< 4; i++) rn.bst.m[i] = node.bst.m[i]-ln.bst.m[i];
rn.est = UPNG.quantize.estats( rn.bst );
node.left = ln; node.right = rn;
leafs[mi]=ln; leafs.push(rn);
}
leafs.sort(function(a,b) { return b.bst.N-a.bst.N; });
for(var i=0; i<leafs.length; i++) leafs[i].ind=i;
return [root, leafs];
}
UPNG.quantize.getNearest = function(nd, r,g,b,a)
{
if(nd.left==null) { nd.tdst = UPNG.quantize.dist(nd.est.q,r,g,b,a); return nd; }
var planeDst = UPNG.quantize.planeDst(nd.est,r,g,b,a);
var node0 = nd.left, node1 = nd.right;
if(planeDst>0) { node0=nd.right; node1=nd.left; }
var ln = UPNG.quantize.getNearest(node0, r,g,b,a);
if(ln.tdst<=planeDst*planeDst) return ln;
var rn = UPNG.quantize.getNearest(node1, r,g,b,a);
return rn.tdst<ln.tdst ? rn : ln;
}
UPNG.quantize.planeDst = function(est, r,g,b,a) { var e = est.e; return e[0]*r + e[1]*g + e[2]*b + e[3]*a - est.eMq; }
UPNG.quantize.dist = function(q, r,g,b,a) { var d0=r-q[0], d1=g-q[1], d2=b-q[2], d3=a-q[3]; return d0*d0+d1*d1+d2*d2+d3*d3; }
UPNG.quantize.splitPixels = function(nimg, nimg32, i0, i1, e, eMq)
{
var vecDot = UPNG.quantize.vecDot;
i1-=4;
var shfs = 0;
while(i0<i1)
{
while(vecDot(nimg, i0, e)<=eMq) i0+=4;
while(vecDot(nimg, i1, e)> eMq) i1-=4;
if(i0>=i1) break;
var t = nimg32[i0>>2]; nimg32[i0>>2] = nimg32[i1>>2]; nimg32[i1>>2]=t;
i0+=4; i1-=4;
}
while(vecDot(nimg, i0, e)>eMq) i0-=4;
return i0+4;
}
UPNG.quantize.vecDot = function(nimg, i, e)
{
return nimg[i]*e[0] + nimg[i+1]*e[1] + nimg[i+2]*e[2] + nimg[i+3]*e[3];
}
UPNG.quantize.stats = function(nimg, i0, i1){
var R = [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0];
var m = [0,0,0,0];
var N = (i1-i0)>>2;
for(var i=i0; i<i1; i+=4)
{
var r = nimg[i]*(1/255), g = nimg[i+1]*(1/255), b = nimg[i+2]*(1/255), a = nimg[i+3]*(1/255);
//var r = nimg[i], g = nimg[i+1], b = nimg[i+2], a = nimg[i+3];
m[0]+=r; m[1]+=g; m[2]+=b; m[3]+=a;
R[ 0] += r*r; R[ 1] += r*g; R[ 2] += r*b; R[ 3] += r*a;
R[ 5] += g*g; R[ 6] += g*b; R[ 7] += g*a;
R[10] += b*b; R[11] += b*a;
R[15] += a*a;
}
R[4]=R[1]; R[8]=R[2]; R[9]=R[6]; R[12]=R[3]; R[13]=R[7]; R[14]=R[11];
return {R:R, m:m, N:N};
}
UPNG.quantize.estats = function(stats){
var R = stats.R, m = stats.m, N = stats.N;
// when all samples are equal, but N is large (millions), the Rj can be non-zero ( 0.0003.... - precission error)
var m0 = m[0], m1 = m[1], m2 = m[2], m3 = m[3], iN = (N==0 ? 0 : 1/N);
var Rj = [
R[ 0] - m0*m0*iN, R[ 1] - m0*m1*iN, R[ 2] - m0*m2*iN, R[ 3] - m0*m3*iN,
R[ 4] - m1*m0*iN, R[ 5] - m1*m1*iN, R[ 6] - m1*m2*iN, R[ 7] - m1*m3*iN,
R[ 8] - m2*m0*iN, R[ 9] - m2*m1*iN, R[10] - m2*m2*iN, R[11] - m2*m3*iN,
R[12] - m3*m0*iN, R[13] - m3*m1*iN, R[14] - m3*m2*iN, R[15] - m3*m3*iN
];
var A = Rj, M = UPNG.M4;
var b = [Math.random(),Math.random(),Math.random(),Math.random()], mi = 0, tmi = 0;
if(N!=0)
for(var i=0; i<16; i++) {
b = M.multVec(A, b); tmi = Math.sqrt(M.dot(b,b)); b = M.sml(1/tmi, b);
if(i!=0 && Math.abs(tmi-mi)<1e-9) break; mi = tmi;
}
//b = [0,0,1,0]; mi=N;
var q = [m0*iN, m1*iN, m2*iN, m3*iN];
var eMq255 = M.dot(M.sml(255,q),b);
return { Cov:Rj, q:q, e:b, L:mi, eMq255:eMq255, eMq : M.dot(b,q),
rgba: (((Math.round(255*q[3])<<24) | (Math.round(255*q[2])<<16) | (Math.round(255*q[1])<<8) | (Math.round(255*q[0])<<0))>>>0) };
}
UPNG.M4 = {
multVec : function(m,v) {
return [
m[ 0]*v[0] + m[ 1]*v[1] + m[ 2]*v[2] + m[ 3]*v[3],
m[ 4]*v[0] + m[ 5]*v[1] + m[ 6]*v[2] + m[ 7]*v[3],
m[ 8]*v[0] + m[ 9]*v[1] + m[10]*v[2] + m[11]*v[3],
m[12]*v[0] + m[13]*v[1] + m[14]*v[2] + m[15]*v[3]
];
},
dot : function(x,y) { return x[0]*y[0]+x[1]*y[1]+x[2]*y[2]+x[3]*y[3]; },
sml : function(a,y) { return [a*y[0],a*y[1],a*y[2],a*y[3]]; }
}
UPNG.encode.concatRGBA = function(bufs) {
var tlen = 0;
for(var i=0; i<bufs.length; i++) tlen += bufs[i].byteLength;
var nimg = new Uint8Array(tlen), noff=0;
for(var i=0; i<bufs.length; i++) {
var img = new Uint8Array(bufs[i]), il = img.length;
for(var j=0; j<il; j+=4) {
var r=img[j], g=img[j+1], b=img[j+2], a = img[j+3];
if(a==0) r=g=b=0;
nimg[noff+j]=r; nimg[noff+j+1]=g; nimg[noff+j+2]=b; nimg[noff+j+3]=a; }
noff += il;
}
return nimg.buffer;
}
UPNG.encode.dither = function(sb, w, h, plte, tb, oind) {
function addErr(er, tg, ti, f) {
tg[ti]+=(er[0]*f)>>4; tg[ti+1]+=(er[1]*f)>>4; tg[ti+2]+=(er[2]*f)>>4; tg[ti+3]+=(er[3]*f)>>4;
}
function N(x) { return Math.max(0, Math.min(255, x)); }
function D(a,b) { var dr=a[0]-b[0], dg=a[1]-b[1], db=a[2]-b[2], da=a[3]-b[3]; return (dr*dr + dg*dg + db*db + da*da); }
var pc=plte.length, nplt = [], rads=[];
for(var i=0; i<pc; i++) {
var c = plte[i];
nplt.push([((c>>>0)&255), ((c>>>8)&255), ((c>>>16)&255), ((c>>>24)&255)]);
}
for(var i=0; i<pc; i++) {
var ne=0xffffffff, ni=0;
for(var j=0; j<pc; j++) { var ce=D(nplt[i],nplt[j]); if(j!=i && ce<ne) { ne=ce; ni=j; } }
var hd = Math.sqrt(ne)/2;
rads[i] = ~~(hd*hd);
}
var tb32 = new Uint32Array(tb.buffer);
var err = new Int16Array(w*h*4);
for(var y=0; y<h; y++) {
for(var x=0; x<w; x++) {
var i = (y*w+x)*4;
var cc = [N(sb[i]+err[i]), N(sb[i+1]+err[i+1]), N(sb[i+2]+err[i+2]), N(sb[i+3]+err[i+3])];
var ni=0, nd = 0xffffff;
for(var j=0; j<pc; j++) {
var cd = D(cc,nplt[j]);
if(cd<nd) { nd=cd; ni=j; }
}
//ni = oind[i>>2];
var nc = nplt[ni];
var er = [cc[0]-nc[0], cc[1]-nc[1], cc[2]-nc[2], cc[3]-nc[3]];
//addErr(er, err, i+4, 16);
//*
if(x!=w-1) addErr(er, err, i+4 , 7);
if(y!=h-1) {
if(x!= 0) addErr(er, err, i+4*w-4, 3);
addErr(er, err, i+4*w , 5);
if(x!=w-1) addErr(er, err, i+4*w+4, 1); //*/
}
oind[i>>2] = ni; tb32[i>>2] = plte[ni];
}
}
}