switched background rendering to use patterns

src/Generate.js

@@ -323,16 +323,14 @@
   _html2canvas.Generate.Gradient = function(src, bounds) {
     var canvas = document.createElement('canvas'),
     ctx = canvas.getContext('2d'),
-    gradient, grad, i, len, img;
+    gradient, grad, i, len;
 
     canvas.width = bounds.width;
     canvas.height = bounds.height;
 
-    // TODO: add support for multi defined background gradients (like radial gradient example in background.html)
+    // TODO: add support for multi defined background gradients
     gradient = _html2canvas.Generate.parseGradient(src, bounds);
 
-    img = new Image();
-
     if(gradient) {
       if(gradient.type === 'linear') {
         grad = ctx.createLinearGradient(gradient.x0, gradient.y0, gradient.x1, gradient.y1);
@@ -349,7 +347,6 @@
         ctx.fillStyle = grad;
         ctx.fillRect(0, 0, bounds.width, bounds.height);
 
-        img.src = canvas.toDataURL();
       } else if(gradient.type === 'circle') {
 
         grad = ctx.createRadialGradient(gradient.cx, gradient.cy, 0, gradient.cx, gradient.cy, gradient.rx);
@@ -366,7 +363,6 @@
         ctx.fillStyle = grad;
         ctx.fillRect(0, 0, bounds.width, bounds.height);
 
-        img.src = canvas.toDataURL();
       } else if(gradient.type === 'ellipse') {
 
         // draw circle
@@ -393,21 +389,12 @@
 
         ctx.fillStyle = gradient.colorStops[i - 1].color;
         ctx.fillRect(0, 0, canvas.width, canvas.height);
+        ctx.drawImage(canvasRadial, gradient.cx - gradient.rx, gradient.cy - gradient.ry, 2 * gradient.rx, 2 * gradient.ry);
 
-        imgRadial = new Image();
-        imgRadial.onload = function() { // wait until the image is filled
-
-          // transform circle to ellipse
-          ctx.drawImage(imgRadial, gradient.cx - gradient.rx, gradient.cy - gradient.ry, 2 * gradient.rx, 2 * gradient.ry);
-
-          img.src = canvas.toDataURL();
-
-        };
-        imgRadial.src = canvasRadial.toDataURL();
       }
     }
 
-    return img;
+    return canvas;
   };
 
   _html2canvas.Generate.ListAlpha = function(number) {

src/Parse.js

@@ -740,118 +740,27 @@ _html2canvas.Parse = function (images, options) {
     numDraws+=1;
   }
 
-  function renderBackgroundSlice (ctx, image, x, y, width, height, elx, ely){
-    var sourceX = (elx - x > 0) ? elx-x :0,
-    sourceY= (ely - y > 0) ? ely-y : 0;
-
-    drawImage(
-      ctx,
-      image,
-      Math.floor(sourceX), // source X
-      Math.floor(sourceY), // source Y
-      Math.ceil(width-sourceX), // source Width
-      Math.ceil(height-sourceY), // source Height
-      Math.ceil(x+sourceX), // destination X
-      Math.ceil(y+sourceY), // destination Y
-      Math.ceil(width-sourceX), // destination width
-      Math.ceil(height-sourceY) // destination height
-      );
-  }
-
   function renderBackgroundRepeat(ctx, image, backgroundPosition, bounds) {
-    var bgy,
+    var offsetX = Math.round(bounds.left + backgroundPosition.left),
-    height,
+    offsetY = Math.round(bounds.top + backgroundPosition.top);
-    add,
-    h;
 
-    backgroundPosition.top -= Math.ceil(backgroundPosition.top / image.height) * image.height;
+    ctx.createPattern(image);
-
+    ctx.translate(offsetX, offsetY);
-    for(bgy = (bounds.top + backgroundPosition.top); bgy < (bounds.height + bounds.top); bgy = Math.floor(bgy+image.height) - add) {
+    ctx.fill();
-      h = Math.min(image.height,(bounds.height + bounds.top) - bgy);
+    ctx.translate(-offsetX, -offsetY);
-
-      height = (Math.floor(bgy + image.height) > h + bgy) ? (h + bgy) - bgy : image.height;
-
-      if (bgy < bounds.top){
-        add = bounds.top - bgy;
-        bgy = bounds.top;
-      } else {
-        add = 0;
   }
 
-      renderBackgroundRepeatX(ctx, image, backgroundPosition, bounds.left, bgy, bounds.width, height);
+  function backgroundRepeatShape(ctx, image, backgroundPosition, bounds, left, top, width, height) {
-
+    var args = [];
-      if (add > 0){
+    args.push(["line", Math.round(left), Math.round(top)]);
-        backgroundPosition.top += add;
+    args.push(["line", Math.round(left + width), Math.round(top)]);
-      }
+    args.push(["line", Math.round(left + width), Math.round(height + top)]);
-    }
+    args.push(["line", Math.round(left), Math.round(height + top)]);
-  }
+    createShape(ctx, args);
-
+    ctx.save();
-  function renderBackgroundNoRepeat(ctx, image, backgroundPosition, x, y, w, h) {
+    ctx.clip();
-    var bgdw = w - backgroundPosition.left,
+    renderBackgroundRepeat(ctx, image, backgroundPosition, bounds);
-    bgdh = h - backgroundPosition.top,
+    ctx.restore();
-    bgsx = backgroundPosition.left,
-    bgsy = backgroundPosition.top,
-    bgdx = backgroundPosition.left + x,
-    bgdy = backgroundPosition.top + y;
-
-    if (bgsx<0){
-      bgsx = Math.abs(bgsx);
-      bgdx += bgsx;
-      bgdw = Math.min(w,image.width-bgsx);
-    } else {
-      bgdw = Math.min(bgdw,image.width);
-      bgsx = 0;
-    }
-
-    if (bgsy < 0){
-      bgsy = Math.abs(bgsy);
-      bgdy += bgsy;
-      bgdh = Math.min(h, image.height - bgsy);
-    } else {
-      bgdh = Math.min(bgdh, image.height);
-      bgsy = 0;
-    }
-
-    if (bgdh > 0 && bgdw > 0){
-      drawImage(
-        ctx,
-        image,
-        bgsx,
-        bgsy,
-        bgdw,
-        bgdh,
-        bgdx,
-        bgdy,
-        bgdw,
-        bgdh
-        );
-    }
-  }
-
-  function renderBackgroundRepeatY (ctx, image, backgroundPosition, x, y, w, h){
-    var height,
-    width = Math.min(image.width, w),
-    bgy;
-
-    backgroundPosition.top -= Math.ceil(backgroundPosition.top / image.height) * image.height;
-
-    for (bgy = y + backgroundPosition.top; bgy < h + y; bgy = Math.round(bgy + image.height)){
-      height = (Math.floor(bgy + image.height) > h + y) ? (h+y) - bgy : image.height;
-      renderBackgroundSlice(ctx, image, x + backgroundPosition.left, bgy,width, height, x, y);
-    }
-  }
-
-  function renderBackgroundRepeatX(ctx, image, backgroundPosition, x, y, w, h){
-    var height = Math.min(image.height, h),
-    width,
-    bgx;
-
-    backgroundPosition.left -= Math.ceil(backgroundPosition.left / image.width) * image.width;
-
-    for (bgx = x + backgroundPosition.left; bgx < w + x; bgx = Math.round(bgx + image.width)) {
-      width = (Math.floor(bgx + image.width) > w + x) ? (w + x) - bgx : image.width;
-      renderBackgroundSlice(ctx, image, bgx,(y + backgroundPosition.top), width, height, x, y);
-    }
   }
 
   function renderBackgroundColor(ctx, backgroundBounds, bgcolor) {
@@ -870,15 +779,18 @@ _html2canvas.Parse = function (images, options) {
     backgroundRepeat = getCSS(el, "backgroundRepeat").split(",")[0];
     switch (backgroundRepeat) {
       case "repeat-x":
-        renderBackgroundRepeatX(ctx, image, backgroundPosition, bounds.left, bounds.top, bounds.width, bounds.height);
+        backgroundRepeatShape(ctx, image, backgroundPosition, bounds,
+          bounds.left, bounds.top + backgroundPosition.top, 99999, image.height);
         break;
 
       case "repeat-y":
-        renderBackgroundRepeatY(ctx, image, backgroundPosition, bounds.left, bounds.top, bounds.width, bounds.height);
+        backgroundRepeatShape(ctx, image, backgroundPosition, bounds,
+          bounds.left + backgroundPosition.left, bounds.top, image.width, 99999);
         break;
 
       case "no-repeat":
-        renderBackgroundNoRepeat(ctx, image, backgroundPosition, bounds.left, bounds.top, bounds.width, bounds.height);
+        backgroundRepeatShape(ctx, image, backgroundPosition, bounds,
+          bounds.left + backgroundPosition.left, bounds.top + backgroundPosition.top, image.width, image.height);
         break;
 
       default:
@@ -960,8 +872,9 @@ _html2canvas.Parse = function (images, options) {
     borders = stack.borders,
     ctx = stack.ctx,
     backgroundBounds = getBackgroundBounds(borders, bounds, stack.clip),
-    borderData = parseBorders(element, bounds, borders),
+    borderData = parseBorders(element, bounds, borders);
-    clipPath = createShape(ctx, borderData.clip);
+
+    createShape(ctx, borderData.clip);
 
     ctx.save();
     ctx.clip();

src/Preload.js

@@ -123,11 +123,9 @@ _html2canvas.Preload = function( options ) {
         h2clog("html2canvas: failed to get background-image - Exception: " + e.message);
       }
       if (background_image && background_image !== "1" && background_image !== "none") {
-
         // TODO add multi image background support
 
         if (/^(-webkit|-o|-moz|-ms|linear)-/.test( background_image )) {
-
           img = _html2canvas.Generate.Gradient(background_image, _html2canvas.Util.Bounds( el ) );
 
           if ( img !== undefined ){

src/Queue.js

@@ -11,6 +11,13 @@ function h2cRenderContext(width, height) {
         'arguments': arguments
       });
     },
+    translate: function() {
+      storage.push({
+        type: "function",
+        name: "translate",
+        'arguments': arguments
+      });
+    },
     fill: function() {
       storage.push({
         type: "function",
@@ -39,6 +46,13 @@ function h2cRenderContext(width, height) {
         'arguments': arguments
       });
     },
+    createPattern: function() {
+      storage.push({
+        type: "function",
+        name: "createPattern",
+        'arguments': arguments
+      });
+    },
     drawShape: function() {
 
       var shape = [];

src/renderers/Canvas.js

@@ -145,6 +145,8 @@ _html2canvas.Renderer.Canvas = function( options ) {
                     if (!usingFlashcanvas || renderItem['arguments'][0] + renderItem['arguments'][2] < flashMaxSize  && renderItem['arguments'][1] + renderItem['arguments'][3] < flashMaxSize) {
                       ctx.fillRect.apply( ctx, renderItem['arguments'] );
                     }
+                  } else if (renderItem.name === "createPattern") {
+                    ctx.fillStyle = ctx.createPattern(renderItem['arguments'][0], "repeat");
                   } else if (renderItem.name === "drawShape") {
                     createShape(renderItem['arguments']);
                   } else if (renderItem.name === "fillText") {

tests/test.js

@@ -13,7 +13,7 @@ var h2cSelector, h2cOptions;
     document.write(srcStart + '/tests/assets/jquery.plugin.html2canvas.js' + scrEnd);
     var html2canvas = ['Core', 'Generate', 'Parse', 'Preload', 'Queue', 'Renderer', 'Util', 'Support', 'Font', 'renderers/Canvas'], i;
     for (i = 0; i < html2canvas.length; ++i) {
-        document.write(srcStart + '/src/' + html2canvas[i] + '.js' + scrEnd);
+        document.write(srcStart + '/src/' + html2canvas[i] + '.js?' + Math.random() + scrEnd);
     }
     window.onload = function() {
         h2cSelector = [document.body];