From 777becd99e2962c611be19002e1f4e522881d480 Mon Sep 17 00:00:00 2001
From: Svetlana Linuxenko <linuxenko@yahoo.com>
Date: Wed, 30 Nov 2016 18:37:13 +0200
Subject: [PATCH] png rendering example

---
 examples/png/png-decoder.js | 344 ++++++++++++++++++++++++++++++++++++
 examples/png/screen.png     | Bin 0 -> 5408 bytes
 examples/png/test1.js       |  80 +++++++++
 3 files changed, 424 insertions(+)
 create mode 100644 examples/png/png-decoder.js
 create mode 100644 examples/png/screen.png
 create mode 100644 examples/png/test1.js

diff --git a/examples/png/png-decoder.js b/examples/png/png-decoder.js
new file mode 100644
index 0000000..28f120f
--- /dev/null
+++ b/examples/png/png-decoder.js
@@ -0,0 +1,344 @@
+/*
+ * Simple png decoder 
+ * https://github.com/b37t1td/png-decoder
+ */
+
+var CRCTable = new Int32Array([
+  0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
+  0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+  0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
+  0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+  0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+  0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+  0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
+  0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+  0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
+  0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+  0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
+  0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+  0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
+  0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+  0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+  0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+  0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
+  0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+  0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
+  0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+  0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
+  0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+  0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
+  0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+  0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+  0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+  0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
+  0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+  0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
+  0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+  0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
+  0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+  0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
+  0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+  0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+  0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+  0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
+  0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+  0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
+  0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+  0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
+  0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+  0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+]);
+
+var crc32 = function(buf) {
+  var crc = -1;
+  for (var i = 0; i < buf.length; i++) {
+    crc = CRCTable[(crc ^ buf[i]) & 0xff] ^ (crc >>> 8);
+  }
+  return crc ^ -1;
+};
+
+/*
+ * BE byteArray implementation
+ * by Svetlana Linuxenko <linuxenko@yahoo.com>
+ */
+
+/* eslint no-undef: 0 */
+var byteArray = Uint8Array;
+
+var cmp = function(a, b) {
+  if (!b) b = a; a = this;
+  return a.filter(function(c,i) { return c === b[i]; }).length === a.length;
+};
+
+var toInt = function(a) {
+  if (!a) a = this.slice(this.off, 4);
+  return (a[0] << 24) | (a[1] << 16) | (a[2] << 8) | a[3];
+  //return a[0] | (a[1] << 8) | (a[2] << 16) | (a[3] << 24);
+};
+
+var toBytes = function(int) {
+  return new byteArray([
+    (int >> 24) & 0xff,
+    (int >> 16) & 0xff,
+    (int >> 8) & 0xff,
+    int & 0xff
+  ]);
+};
+
+var nextInt = function() {
+  return this.toInt(this.slice(this.off, (this.off += 4)));
+};
+
+var nextIntBytes = function() {
+  return this.nextBytes(4);
+};
+
+var nextBytes = function(size) {
+  return this.slice(this.off, (this.off += size));
+};
+
+var nextByte = function() {
+  return this.nextBytes(1)[0];
+};
+
+var insertInt = function(int) {
+  this.insertBytes(this.toBytes(int));
+};
+
+var insertBytes = function(bytes, length) {
+  length = length || 4;
+  this.set(bytes, this.off, length);
+  this.off += length;
+};
+
+var insertByte = function(byte) {
+  this.set([byte], this.off, (this.off += 1));
+};
+
+byteArray.prototype.cmp = cmp;
+byteArray.prototype.toInt = toInt;
+byteArray.prototype.nextInt = nextInt;
+byteArray.prototype.nextIntBytes = nextIntBytes;
+byteArray.prototype.toBytes = toBytes;
+byteArray.prototype.insertInt = insertInt;
+byteArray.prototype.insertBytes = insertBytes;
+byteArray.prototype.nextBytes = nextBytes;
+byteArray.prototype.nextByte = nextByte;
+byteArray.prototype.insertByte = insertByte;
+
+Object.defineProperty(byteArray.prototype , 'off', {
+  enumerable: false,
+  configurable: false,
+  writable: true,
+  value : 0
+});
+
+
+var SIGNATURE = new byteArray([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]);
+var IHDR = new byteArray([0x49, 0x48, 0x44, 0x52]);
+var IDAT = new byteArray([0x49, 0x44, 0x41, 0x54]);
+var IEND = new byteArray([0x49, 0x45, 0x4e, 0x44]);
+
+
+/*
+ * Decoder
+ */
+var zlib = require('zlib');
+
+var inflateFunction = function(data) {
+  return zlib.inflateSync(Buffer.from(data));
+};
+
+
+var Decoder = function() { };
+
+Decoder.prototype.parse = function(data) {
+  if (!(data instanceof byteArray)) {
+    data = new byteArray(data);
+  }
+
+  if (!SIGNATURE.cmp(data.nextBytes(SIGNATURE.length))) {
+    throw new Error('Not png');
+  }
+
+  while (data.off < data.length) {
+    var len = data.nextInt();
+    var hdr = data.nextBytes(len + 4);
+
+    if (crc32(hdr) !== data.nextInt()) {
+      throw new Error('Crc error');
+    }
+
+    if (IHDR.cmp(hdr)) {
+      this._IHDR = this._chunkIHDR(hdr.slice(4, len + 4));
+
+      if (this._IHDR.palette !== 8) {
+        throw new Error('Depth error');
+      }
+
+      if (this._IHDR.compression !== 0) {
+        throw new Error('Compression error');
+      }
+
+      if (this._IHDR.filter !== 0) {
+        throw new Error('Filter error');
+      }
+
+      if (this._IHDR.interlace !== 0) {
+        throw new Error('Interlace error');
+      }
+
+      switch (this._IHDR.colorType){
+        case 0: this.bpp = 1; break;
+        case 2: this.bpp = 3; break;
+        case 3: this.bpp = 1; break;
+        case 4: this.bpp = 2; break;
+        case 6: this.bpp = 4; break;
+        default: throw new Error('ColorType error');
+      }
+      this.chunks = [];
+    }
+
+    if (IDAT.cmp(hdr)) {
+      if (!this._IHDR) {
+        throw new Error('IHDR error');
+      }
+
+      this._chunkIDAT(hdr.slice(4, len + 4));
+    }
+
+    if (IEND.cmp(hdr)) {
+      return this._chunkIEND();
+    }
+  }
+
+  throw new Error('Data error');
+};
+
+Decoder.prototype._chunkIEND = function() {
+  var tmp = [];
+  for (var i = 0; i < this.chunks.length; i++) {
+    for (var j = 0; j < this.chunks[i].length; j++) {
+      tmp.push(this.chunks[i][j]);
+    }
+  }
+  return this.filter(inflateFunction(tmp));
+};
+
+Decoder.prototype._chunkIDAT = function(chunk) {
+  this.chunks.push(chunk);
+};
+
+Decoder.prototype._chunkIHDR = function(chunk) {
+  return {
+    width : chunk.nextInt(),
+    height : chunk.nextInt(),
+    palette : chunk.nextByte(),
+    colorType : chunk.nextByte(),
+    compression : chunk.nextByte(),
+    filter : chunk.nextByte(),
+    interlace : chunk.nextByte()
+  };
+};
+
+Decoder.prototype.filter = function(data) {
+  var bpp = this.bpp;
+  var width = this._IHDR.width, height = this._IHDR.height;
+  var pixels = new byteArray((width * height) * bpp);
+  var filter, line, left, leftup, up, pixel;
+  var lineWidth = width * bpp, byte, off;
+
+  for (var y = 0; y < height; y++) {
+
+    filter = data.nextByte();
+    line = data.nextBytes(lineWidth);
+
+    for (var x = 0; x < lineWidth; x++) {
+
+      if (filter !== 0) {
+        off = (y * lineWidth) + x;
+      }
+
+      byte = line.nextByte();
+
+      switch(filter) {
+        case 0: //None
+          pixel = byte;
+          break;
+        case 1: // Sub  Raw(x) + Raw(x - bpp)
+          if (x < bpp) {
+            pixel = byte;
+            break;
+          }
+          pixel = pixels[off - bpp] + byte & 0xff;
+          break;
+        case 2: // Up(x) = Raw(x) + Prior(x)
+          if (y === 0) {
+            pixel = byte;
+            break;
+          }
+          pixel = pixels[off - lineWidth] + byte & 0xff;
+          break;
+        case 3: // Average(x) = Raw(x) + floor((Raw(x-bpp)+Prior(x))/2)
+          if (y === 0) {
+            if (x < bpp) {
+              pixel = byte;
+            } else {
+              pixel = (byte + (pixels[off - bpp] >> 1)) & 0xff;
+            }
+            break;
+          }
+
+          if (x < bpp) {
+            pixel = (byte + (pixels[off - lineWidth] >> 1)) & 0xff;
+            break;
+          }
+
+          pixel = (byte + (pixels[off - bpp] + pixels[off - lineWidth] >> 1)) & 0xff;
+          break;
+        case 4: // Paeth
+          if (y === 0) {
+            if (x < bpp) {
+              pixel = byte;
+            } else {
+              pixel = (byte + (pixels[off - bpp])) & 0xff;
+            }
+            break;
+          }
+
+          if (x < bpp) {
+            pixel = (byte + (pixels[off - lineWidth])) & 0xff;
+            break;
+          }
+
+          up =  pixels[off - lineWidth];
+          left =  pixels[off - bpp];
+          leftup = pixels[(off - lineWidth) - bpp];
+
+          var p = left + up - leftup,
+            pleft = Math.abs(p - left),
+            pup = Math.abs(p - up),
+            pleftup = Math.abs(p - leftup);
+
+          if (pleft <= pup && pleft <= pleftup){
+            pixel = byte + left & 0xff;
+            break;
+          } else if (pup <= pleftup) {
+            pixel = byte + up & 0xff;
+            break;
+          }
+
+          pixel = byte + leftup & 0xff;
+          break;
+        default:
+          throw new Error('Filter error: ' + filter);
+      }
+
+      pixels.insertByte(pixel);
+    }
+  }
+
+  return pixels;
+};
+
+module.exports = Decoder;
\ No newline at end of file
diff --git a/examples/png/screen.png b/examples/png/screen.png
new file mode 100644
index 0000000000000000000000000000000000000000..f9009de490420c107e0b7047b6fd06020d68ecf2
GIT binary patch
literal 5408
zcmeHKSy)rawyuCUfHFt`0X2vq4hYhyfDB37fGCXtMU=_VL~&qLhCmpCqCye|X<JcS
zz((=N5Ks{!G6W?g+A1^%1PC!2hA>0GKmsA$9c;hT=U&h7a3Ai&eb`^^RIR;g)%ySS
zuL{xi;J#IgI*I^*Rr{Un4*?)Y001_(d?_?jlPrD+4J*Q&Ji`G{QkOk2aQn_0XmVM^
zeiw&jAC=at>aP4v@6vGq;I#er-@8Y5jdEO4efwhS1pGU(<8fWjE-ekxW9+s(==Jc>
zryH)z6|Oyf=@4A#vDG)?Xy>-7Dic?C){#qjA%$HB4848x$t}Ly@*PJn8ssm(-E|<(
zbuTtmy=4je{7vl){%}IJiA{xonab?3%86~7o7?a7YDejKe4`n^DRyjM6pv2yAF0n}
zvTCPi&P|UDo^Bm>E9!#*)WUGYp5~zPo{|jCI>JOUVQnWnl;$hp99`J7iP7Yk!*343
z<*~Q_s0i-Loh`Q+5_;|YmGW$=5tBMgs1f5Ol99oOtUxmh)^{5~qT(5<HDvGacUSFH
zQx0)<rWR*BX_FC97Q6=ljkchQyyH#x5@uTqHj_f&m%VEMIC2E;&>ORT=v}{0>)9CN
z{CQGd%G6<VGiz%tiih=cPDpRe`ZPz|E6K~S5hpf3F~&^F4>XhmP+0hW(7t9f$*|@H
z79X&?(dEYmKEeml6y$|aDe+bhOx7{8Vv}%24|uvp$dsd8YYkknw|aejl7&y8zyH<>
zn`ed<K_B45?HuhNevmh_W~UN~g6Q$y*OoE7nq#<MS#sdvlMrgk$P8heO18no9Su5v
zeowoj+FZ_TM9}(@ea&Yb;hdDblvhtuj5CVORE_?|e!NhQpo@*ky8<0GeTq_SauQ}O
zun`dkUK9_wgPMbz{f(2ECp~xSq*)?&X>e!z3HCXWp>MnZ*z&4YR7GZT-@f%ped;Zs
zqC?5MvMW;>^+Q({v|+zPq#)<|Rj>hf)#`spVimWI!3CGO_}!!si#^$mFP+=YX7+hX
z=4drKX^tL4kh_A1!E?Pygj**&BNu*hgPYmeX=7r7uyNJa>JH(%Ne5#;(YoHP8K~f8
zR<Rmr)v^5~cCmvSy+d@uM%bzjh4|EqG7wdzByAgv$lFZnc=RbJnxEZccBn-bYXPR(
z1#kQQy}97?m0bd2mrq1Mz(#%l2Z!l%??*c-D$WgZ=eVyug4Px=!$$Yo+wHJ~qdDfQ
z_ZgkSo;Wek;x)r15LPNHJC=3&v?M{~GuycnKEuU@rl!R|8}KTvolR3<bw2L7r2s*o
zN|*}ZdkK1(SMHhb(r&H^^A<7>b2?^{h|%YUyP{9{+SVeQ)3egi3@N&lj81Rl+J#Vg
z;kZ?FLXIu&%uHxhiH7d(ZuRi+vgXmKED7NEKYyH1e?|1MwLrH-D4C*#ziT4Q4=?Cs
zi@n=e-bw%^c^61!KQ8!?J~k5JBQd^73EbCXnj>+Sv;~gS5tLFUGW#r(j1D4GM$4MB
zZ#|z#^3?oQrygRx3563vh0bW{MVWSqf8ci`5(5A9{=l@fwCxi%dz4BPfS$Bp!-0PK
z)b8iu=2?WtR=RA*+X5pMt`=r~49!C$Doqn&`cF0A%Bkj^Vx5SIsLEp1iWna~h9{4{
zsuA~7wc`A8=SNC0vvV(AT+l7iP|J!El}tBdX!z|Qk<K&KlqB+v-|&3O)(x8^6u+q+
z&(+Q#hz3uLNZ&F<%mp#6BRbS5;pAr$B9$0mJt>*YIO(bR{(V{I$#Yw(qim|MFP24x
z`14wtTwLCL2&1IDv5q@hRXv3pg@7kEa9>vWm3yr>de9{(N*lY}BqXQwn0v<cof1Y1
zSnE?Tzi+}$O)ul+FG$_u20ugvt*bqDD(243L3@e^?P(O{2D38!+T(zCuktava})Kt
zc6G*Y{3j*ut!K*}SfmsM<X9iC6cf4~0D(nm^FwAJc2xA%)`1>}iuWJA-LcSN<UiGl
zzGoY0Vz&#wZ-fvOUW{1S4}Ui`RTLoTidIWw^oas@4xJnNJlOHwWL;kFYg}+*JMVMB
zduOj<Yp!@Kl69KOmcek<T@tBPIc~kfHN#?4S#-iCvP-#s-T<SnTimfT;k!Lkp<@Gg
zbjdE1fCzrTy@4qGCpHHU@&yd{?d`?E_PB)63m5RI8EFmT46a5}Qj#;NREdf^<sTHJ
z-(IrLGlIe-^avDKx7HvqVGu6AoWO`Ahsg=``-<Aq%ik4<CT9na=~5an##txLw9}#m
zNtriw)}}e$OL*rs8fCP;Yu2yVv-UIy@YLkw=`sn?`Z{S|1%WVdKd<8C6hndbX`{Y=
z)6~tee!*;|amA{N9<9lP_V6qkduC&E<de3Ptj1JECBt>)P92tS5qpr)S%zRtOoa7{
zFS9=QiZ-SDOMRbdeW06}n`<HWh<jcIy3NW|<5dnvQ0ah^nw*71{LZgr=F$f}f=>ZK
zXLe$P+tXg_XQ)#yL}T%KwHzHH<0ES4kWjZ|mjx@eIWzMama`73<25nI$stsA^Rn=B
zAv~WS(P(C!Urz;;a96R2EqHs)nM6|}ovzr^d<NG~^SqamB5Mv_HJWMo?V4<dkqnux
z2R7s8j-#=54>aFCQY@C041i<+fD|MEcyno7({_N``s8H=#wzLEG`F2wx_Md~zlGVn
z60$1x?<MXPECW3B2=V*Bj;7*|>KAz`KyXTxxHMN4PJrCKNd9x&hu^SS3VofIaY^4*
z0@IV)BUU)v70II{M7z}_lwet+NIl*FenIxV(X7*ExdsF{a!m=jRvkDE=x~~>33B(4
zpQlXjW+Or2gHW9GQZ7~j823Ey4z(ui&7%p~i%ay}fsMZ{hqiWi!E{e+Bxp!z%1k(*
z=Q^n-0@Q03_jt|dwv{a{MbrzNX@$FI@#pzyk)epNA>9hx*CyzrfE*ywbIHg?7}zZK
zVs9%Ihd1-@;rn(aTB{S9x!c^v2<xZqyQXZ9O~$Dh*l}wNn`WGNQykC9xC|pZF2%5s
zY7`~CglJp=p4kqWOnk<J=_#DNJgU^QJRA8bIa~p(CL*=M@0f$DPLj%$o^Dv8J+G-j
zm#+#8RufFREVF>#Zz6f1mnkYcoD{COXny97_oBJwMgW5r!rdH!97<on_fG{&WS={%
zfh`9spp?mi&(`wzHCz>F9>q0}u5x(XWOH=Fry8FF>J%Bdu9cOKybE&8aFBh`YC<=D
zghC(RxD=My(t{4`{_xRz2pi@zB88#02#iGdg~uzt2YwDb(}srw%<TKW{P4#Z0{EQi
zL<oQOvWGX+9<aARl9L>+0d6pZxrX#Z*K@OW$R$2C4&<9&_jCFw+4#CIDpLu(Nu|L}
z@(MUQE`4G}6bNI_++IE@aaax9J6%R4N30a9H||XHT<#6%h?h-2LfyfaLbBepC1Hdp
z?wE%dVyL_OrUpo%4L|HUNW5ugUL|9eT2d!0QB>5TOpG?GFU(<sNB#mMuN}_7$v|58
z#9ZIw?b9K?B`9{15aDk%AqH5!NQK=!D`1UN>+Ol2rq{h`i*%=BXpe?Z^@BPWItIyI
zs=gtBwl-v5?rMaDsIpdmu`1lROJ{}CS?i3LJdaAD66$A&^@*b4Gg0#pJN>i;tPE<6
z{S|E4&)u^MdIb=6D2dRxDj{7BT!p9(9=#O}Q(1dD-Od;P&Wj`f1GPUZjm{l9|Au8I
z4?;Fbs~IawdYhI&S2c@^-l>;f;b#RJZkA4<&M+RwW{uWM`#PZG%3Q<1)i_CIaL2;h
zAHcCb(Nu}!Gdsd=@bH908@g%kiEC9d=4l|VA1+Ml_b#k~o^0r$^n2f~?G#UWJst`(
zhRK|KEqP<IMO^Wf>yo{Gm=8*zdx<p^98`p0@r<(lC~FXkKDOywzGMrc7_^#rmVvo3
zio3s+VW#kR%fCC7=?LTi<<OSqrvZ0cBL^Po%m(nAlI4yjV^@G8W+TFwSGkX6I4{9i
z?RFcQja^@3Jt$sp6ZN1~sABWnY*0LAJDpH4jEIQ{Y?<Q3j6_54gwLPu^Q(j%-uaZ#
zT~L@SUX%TEx70<7%3vtNp3>a)#VnE#$y9}S^d-vPo~Gc%%+(D|xtUU5@ps9Cd4r4z
zC}o?5=5K+!zYAEQ-F6XgLE@!9&s=w?r<8lVr+0TA_K0TbjJzK43!Xcx2w(9GQ-TmL
zjeJtp+fi&FGbs?MYg=ww%;>|j65(*LskKXb1Lgc1twe(!St?mtBT}oSpzb?fX>KTi
zs8WVerpCdX_DJoQ2PiM*vyg$IahH~<pKN#TyI~4x>o0x`$RT}2fD+J1rxkW9t8WSL
z5{9n@9tKjnV!#UMrhvH~<!DdV_7HY2P1GPG1s6MED1X7x@^!1#umMr?5Ow{RmdODD
z&P@Y%;7Jhe(f%;I#c6$}>f0rN&TT8K#_C74+`R0I1c#1VTnxNt)P_>61FrEF@obCB
zI}VJNCl=UXsuCayvn2WF)m%2D93uLBS_ZV9jaJbuCq0t^O2c@LQ(G{4-@UK>Gzk%k
zWvKv@s{CwPUPqRXQ`~3qw6pvD>NiFb;HS`I8d<aUV#u%@$fsjSRfHOyi|O^{{7vA|
zO93-&V{!3vwOCMBNYCZayfdB_$v4}C&fi%A4v>(r=vX;5XkY49%<Bf92(^SSm38%)
zq%-EHa?2Uury&zT$b#6AOE!C{0#=ieS|=|dfPp5#q|uTJ^d5`CGZ|J2kO4#v$SPas
zj<d{5<>{Waa?rI-Cc(;!<~++&i{@s`N;yz;?}L(-(3m~$q&Evb?j9g!;Ll|;tzdw<
z5Bk5+Y_7sk*0a@2@a&HUuG?*e8=9hG!;}GPuYk`pmB_A(=q1aM;I56W@HTDO4pk}-
zk1xVYtsH^7^M_%TKhm#G$b;1+WTqZueEt0tHNG^aE<~PO%f{DQ1;}L1sqY?I0&_hQ
zL$eE`u3EPZeC!vFHgYx4FHP<aY#Z%9zZUlJMztdPW#i9SIbiH!7$q%<-WvsT;F5CC
zP}M>K91;(xFG{A<-ex0N6V|_aDGzcAHDSHX54u)Rx$w}-73~(A`9B+1l57{(zm9N{
z4fNY0HkiEGN*ZODAhhuri$-*nn+ytSW25t0g}Ll<sEljRi{=lpxMjmo>Bde>c;}Z8
z{8;Myn{eZwSkAr+uS&9^cmAi1(0m+A33?y?l;!Mg&7uJ?D7%sTgB1Ov!2DU|U-jqf
z{pG(+|5fW`vIH%E)zPmK_~-Pu_WJkEzJB!|IQvV4-wMG4t?3450C08b|Ipz7rGuk>
z9?D-(PJZ&#sJd!%q&Qibll?iG%ZZ0XH`n@eSj$xW$r%VC8vl=U2(7T0A_$d_f5=c7
zAIp-V^;?Y$tuc9MUh+rQwVd&G4rXg`uq@scvaa_3XnpC>|AGvEA;G^%*B7+*l|g9L
z$k0j;`4L||9zvkW(3-WEp*1%wLu&v+Xy)Uz457MaBpP2EOI?VB`lS_q2h>NqYyZ|N
z%s|ZZq23uer{(O;ZbU!=^?#raApQ7O9ekta{zZj;BcI>Meq!4-2l!<(0PeqlPX8b7
uD)aM=V7}pAra}K?`dfQ_<KUlD7M5w^hcb)We}Z-eV86pb`;xtW7yk>47i_x#

literal 0
HcmV?d00001

diff --git a/examples/png/test1.js b/examples/png/test1.js
new file mode 100644
index 0000000..ed8bef5
--- /dev/null
+++ b/examples/png/test1.js
@@ -0,0 +1,80 @@
+//var logo = require('./node-png').readPng('./node-logo.png');
+var fs = require('fs');
+var Decoder = require('./png-decoder');
+var decoder = new Decoder();
+
+var logo = {
+  data : Buffer.from(decoder.parse(fs.readFileSync('./screen.png'))),
+  width : decoder._IHDR.width,
+  height : decoder._IHDR.height
+};
+
+var x11 = require('../../lib');
+
+var Exposure = x11.eventMask.Exposure;
+
+x11.createClient(function(err, display)
+{
+  var X = display.client;
+  X.require('render', function(err, Render) {
+    var root = display.screen[0].root;
+    main(root, X, Render, display);
+  });
+});
+
+
+function main(root, X, Render, display) {
+
+  var win, picWin, pic, gc;
+
+  win = X.AllocID();
+  X.CreateWindow(
+     win, root,
+     0, 0, logo.width, logo.height,
+     0, 0, 0, 0,
+     { eventMask: Exposure }
+  );
+  X.MapWindow(win);
+
+  gc = X.AllocID();
+  X.CreateGC(gc, win);
+
+  var logoPixmap = X.AllocID();
+  X.CreatePixmap(logoPixmap, win, 24, logo.width, logo.height);
+
+  var rscreen = display.screen[0];
+  var screen =
+    rscreen.depths[rscreen.root_depth][
+      Object.keys(rscreen.depths[rscreen.root_depth])[0]];
+
+  var rmask = parseInt(screen.red_mask, 10);
+  var gmask = parseInt(screen.green_mask, 10);
+  var bmask = parseInt(screen.blue_mask, 10);
+
+  for (var y = 0; y < logo.height; y++) {
+    for (var x = 0; x < logo.width; x++) {
+      var pixel = Buffer.from([
+        logo.data[(x + logo.width * y) * 4],
+        logo.data[(x + logo.width * y) * 4 + 1],
+        logo.data[(x + logo.width * y) * 4 + 2], 0]).readInt32LE();
+
+      logo.data[(x + logo.width * y) * 4 ] = (pixel & rmask) >> 16;
+      logo.data[(x + logo.width * y) * 4 + 1] = (pixel & gmask) >> 8;
+      logo.data[(x + logo.width * y) * 4 + 2] = (pixel & bmask) >> 0;
+      logo.data[(x + logo.width * y) * 4 + 3] = 0x00;
+    }
+  }
+
+  X.PutImage(2, logoPixmap, gc, logo.width, logo.height, 0, 0, 0, 24, logo.data);
+
+  var logoPicture = X.AllocID();
+  Render.CreatePicture(logoPicture, logoPixmap, Render.rgb24);
+  var winPicture = X.AllocID();
+  Render.CreatePicture(winPicture, win, Render.rgb24);
+
+  X.on('event', function(ev) {
+    if (ev.name == 'Expose') {
+      Render.Composite(3, logoPicture, 0, winPicture, 0, 0, 0, 0, 0, 0, logo.width, logo.height);
+    }
+  });
+}