implementing transform matrix to getTextContent

src/core/evaluator.js

@@ -725,14 +725,18 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
       var bidiTexts;
       var SPACE_FACTOR = 0.35;
       var MULTI_SPACE_FACTOR = 1.5;
+      var textState;
 
       if (!state) {
+        textState = new TextState();
         bidiTexts = [];
         state = {
+          textState: textState,
           bidiTexts: bidiTexts
         };
       } else {
         bidiTexts = state.bidiTexts;
+        textState = state.textState;
       }
 
       var self = this;
@@ -752,6 +756,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
 
       var chunk = '';
       var font = null;
+      var charSpace = 0, wordSpace = 0;
       while (!isEOF(obj = parser.getObj())) {
         if (isCmd(obj)) {
           var cmd = obj.cmd;
@@ -759,6 +764,49 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
             // TODO: Add support for SAVE/RESTORE and XFORM here.
             case 'Tf':
               font = handleSetFont(args[0].name).translated;
+              textState.fontSize = args[1];
+              break;
+            case 'Ts':
+              textState.textRise = args[0];
+              break;
+            case 'Tz':
+              textState.textHScale = args[0] / 100;
+              break;
+            case 'TL':
+              textState.leading = args[0];
+              break;
+            case 'Td':
+              textState.translateTextMatrix(args[0], args[1]);
+              break;
+            case 'TD':
+              textState.leading = -args[1];
+              textState.translateTextMatrix(args[0], args[1]);
+              break;
+            case 'T*':
+              textState.translateTextMatrix(0, -textState.leading);
+              break;
+            case 'Tm':
+              textState.setTextMatrix(args[0], args[1],
+                                       args[2], args[3], args[4], args[5]);
+              break;
+            case 'Tc':
+              charSpace = args[0];
+              break;
+            case 'Tw':
+              wordSpace = args[0];
+              break;
+            case 'q':
+              textState.push();
+              break;
+            case 'Q':
+              textState.pop();
+              break;
+            case 'BT':
+              textState.initialiseTextObj();
+              break;
+            case 'cm':
+              textState.transformCTM(args[0], args[1], args[2],
+                                args[3], args[4], args[5]);
               break;
             case 'TJ':
               var items = args[0];
@@ -844,6 +892,15 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
 
           if (chunk !== '') {
             var bidiText = PDFJS.bidi(chunk, -1, font.vertical);
+            var renderParams = textState.calcRenderParams();
+            bidiText.x = renderParams.renderMatrix[4] - (textState.fontSize *
+                           renderParams.vScale * Math.sin(renderParams.angle));
+            bidiText.y = renderParams.renderMatrix[5] + (textState.fontSize *
+                           renderParams.vScale * Math.cos(renderParams.angle));
+            if (bidiText.dir == 'ttb') {
+              bidiText.x += renderParams.vScale / 2;
+              bidiText.y -= renderParams.vScale;
+            }
             bidiTexts.push(bidiText);
 
             chunk = '';
@@ -1552,6 +1609,78 @@ var OperatorList = (function OperatorListClosure() {
 
   return OperatorList;
 })();
+var TextState = (function TextStateClosure() {
+  function TextState() {
+    this.fontSize = 0;
+    this.ctm = [1, 0, 0, 1, 0, 0];
+    this.textMatrix = [1, 0, 0, 1, 0, 0];
+    this.stateStack = [];
+    //textState variables
+    this.leading = 0;
+    this.textHScale = 1;
+    this.textRise = 0;
+  }
+  TextState.prototype = {
+    push: function TextState_push() {
+      this.stateStack.push(this.ctm.slice());
+    },
+    pop: function TextStae_pop() {
+      this.ctm = this.stateStack.pop();
+    },
+    initialiseTextObj: function TextState_initialiseTextObj() {
+      var m = this.textMatrix;
+      m[0] = 1, m[1] = 0, m[2] = 0, m[3] = 1, m[4] = 0, m[5] = 0;
+    },
+    setTextMatrix: function TextState_setTextMatrix(a, b, c, d, e, f) {
+      var m = this.textMatrix;
+      m[0] = a, m[1] = b, m[2] = c, m[3] = d, m[4] = e, m[5] = f;
+    },
+    transformCTM: function TextState_transformCTM(a, b, c, d, e, f) {
+      var m = this.ctm;
+      var m0 = m[0], m1 = m[1], m2 = m[2], m3 = m[3], m4 = m[4], m5 = m[5];
+      m[0] = m0 * a + m2 * b;
+      m[1] = m1 * a + m3 * b;
+      m[2] = m0 * c + m2 * d;
+      m[3] = m1 * c + m3 * d;
+      m[4] = m0 * e + m2 * f + m4;
+      m[5] = m1 * e + m3 * f + m5;
+    },
+    translateTextMatrix: function TextState_translateTextMatrix(x, y) {
+      var m = this.textMatrix;
+      m[4] = m[0] * x + m[2] * y + m[4];
+      m[5] = m[1] * x + m[3] * y + m[5];
+    },
+    calcRenderParams: function TextState_calcRenderingParams() {
+      var tm = this.textMatrix;
+      var cm = this.ctm;
+      var a = this.fontSize;
+      var b = a * this.textHScale;
+      var c = this.textRise;
+      var vScale = Math.sqrt((tm[2] * tm[2]) + (tm[3] * tm[3]));
+      var angle = Math.atan2(tm[1], tm[0]);
+      var m0 = tm[0] * cm[0] + tm[1] * cm[2];
+      var m1 = tm[0] * cm[1] + tm[1] * cm[3];
+      var m2 = tm[2] * cm[0] + tm[3] * cm[2];
+      var m3 = tm[2] * cm[1] + tm[3] * cm[3];
+      var m4 = tm[4] * cm[0] + tm[5] * cm[2] + cm[4];
+      var m5 = tm[4] * cm[1] + tm[5] * cm[3] + cm[5];
+      var renderMatrix = [
+        b * m0,
+        b * m1,
+        a * m2,
+        a * m3,
+        c * m2 + m4,
+        c * m3 + m5
+      ];
+      return {
+        renderMatrix: renderMatrix,
+        vScale: vScale,
+        angle: angle
+      };
+    },
+  };
+  return TextState;
+})();
 
 var EvalState = (function EvalStateClosure() {
   function EvalState() {

web/text_layer_builder.js

@@ -36,6 +36,7 @@ var TextLayerBuilder = function textLayerBuilder(options) {
   this.pageIdx = options.pageIndex;
   this.matches = [];
   this.lastScrollSource = options.lastScrollSource;
+  this.viewport = options.viewport;
   this.isViewerInPresentationMode = options.isViewerInPresentationMode;
 
   if(typeof PDFFindController === 'undefined') {
@@ -158,6 +159,12 @@ var TextLayerBuilder = function textLayerBuilder(options) {
       }
 
       textDiv.textContent = bidiText.str;
+      // TODO refactor text layer to use text content position
+      /**
+       * var arr = this.viewport.convertToViewportPoint(bidiText.x, bidiText.y);
+       * textDiv.style.left = arr[0] + 'px';
+       * textDiv.style.top = arr[1] + 'px';
+       */
       // bidiText.dir may be 'ttb' for vertical texts.
       textDiv.dir = bidiText.dir;
     }

web/viewer.js

@@ -1912,6 +1912,7 @@ var PageView = function pageView(container, id, scale,
         textLayerDiv: textLayerDiv,
         pageIndex: this.id - 1,
         lastScrollSource: PDFView,
+        viewport: this.viewport,
         isViewerInPresentationMode: PDFView.isPresentationMode
       }) : null;