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Allow subpixel anti-aliasing for most of the content.
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yurydelendik committed Nov 16, 2015
1 parent f096e4a commit 1d88003
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Showing 7 changed files with 108 additions and 52 deletions.
4 changes: 3 additions & 1 deletion src/display/api.js
Original file line number Diff line number Diff line change
Expand Up @@ -660,6 +660,8 @@ var PDFDocumentProxy = (function PDFDocumentProxyClosure() {
* calling of PDFPage.getViewport method.
* @property {string} intent - Rendering intent, can be 'display' or 'print'
* (default value is 'display').
* @property {Array} transform - (optional) Additional transform, applied
* just before viewport transform.
* @property {Object} imageLayer - (optional) An object that has beginLayout,
* endLayout and appendImage functions.
* @property {function} continueCallback - (deprecated) A function that will be
Expand Down Expand Up @@ -1732,7 +1734,7 @@ var InternalRenderTask = (function InternalRenderTaskClosure() {
this.gfx = new CanvasGraphics(params.canvasContext, this.commonObjs,
this.objs, params.imageLayer);

this.gfx.beginDrawing(params.viewport, transparency);
this.gfx.beginDrawing(params.transform, params.viewport, transparency);
this.operatorListIdx = 0;
this.graphicsReady = true;
if (this.graphicsReadyCallback) {
Expand Down
85 changes: 56 additions & 29 deletions src/display/canvas.js
Original file line number Diff line number Diff line change
Expand Up @@ -162,13 +162,15 @@ function addContextCurrentTransform(ctx) {
}

var CachedCanvases = (function CachedCanvasesClosure() {
var cache = {};
return {
function CachedCanvases() {
this.cache = Object.create(null);
}
CachedCanvases.prototype = {
getCanvas: function CachedCanvases_getCanvas(id, width, height,
trackTransform) {
var canvasEntry;
if (cache[id] !== undefined) {
canvasEntry = cache[id];
if (this.cache[id] !== undefined) {
canvasEntry = this.cache[id];
canvasEntry.canvas.width = width;
canvasEntry.canvas.height = height;
// reset canvas transform for emulated mozCurrentTransform, if needed
Expand All @@ -179,21 +181,22 @@ var CachedCanvases = (function CachedCanvasesClosure() {
if (trackTransform) {
addContextCurrentTransform(ctx);
}
cache[id] = canvasEntry = {canvas: canvas, context: ctx};
this.cache[id] = canvasEntry = {canvas: canvas, context: ctx};
}
return canvasEntry;
},
clear: function () {
for (var id in cache) {
var canvasEntry = cache[id];
for (var id in this.cache) {
var canvasEntry = this.cache[id];
// Zeroing the width and height causes Firefox to release graphics
// resources immediately, which can greatly reduce memory consumption.
canvasEntry.canvas.width = 0;
canvasEntry.canvas.height = 0;
delete cache[id];
delete this.cache[id];
}
}
};
return CachedCanvases;
})();

function compileType3Glyph(imgData) {
Expand Down Expand Up @@ -431,6 +434,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
this.smaskStack = [];
this.smaskCounter = 0;
this.tempSMask = null;
this.cachedCanvases = new CachedCanvases();
if (canvasCtx) {
// NOTE: if mozCurrentTransform is polyfilled, then the current state of
// the transformation must already be set in canvasCtx._transformMatrix.
Expand Down Expand Up @@ -707,28 +711,39 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {

CanvasGraphics.prototype = {

beginDrawing: function CanvasGraphics_beginDrawing(viewport, transparency) {
beginDrawing: function CanvasGraphics_beginDrawing(transform, viewport,
transparency) {
// For pdfs that use blend modes we have to clear the canvas else certain
// blend modes can look wrong since we'd be blending with a white
// backdrop. The problem with a transparent backdrop though is we then
// don't get sub pixel anti aliasing on text, so we fill with white if
// we can.
// don't get sub pixel anti aliasing on text, creating temporary
// transparent canvas when we have blend modes.
var width = this.ctx.canvas.width;
var height = this.ctx.canvas.height;

this.ctx.save();
this.ctx.fillStyle = 'rgb(255, 255, 255)';
this.ctx.fillRect(0, 0, width, height);
this.ctx.restore();

if (transparency) {
this.ctx.clearRect(0, 0, width, height);
} else {
this.ctx.mozOpaque = true;
var transparentCanvas = this.cachedCanvases.getCanvas(
'transparent', width, height, true);
this.compositeCtx = this.ctx;
this.transparentCanvas = transparentCanvas.canvas;
this.ctx = transparentCanvas.context;
this.ctx.save();
this.ctx.fillStyle = 'rgb(255, 255, 255)';
this.ctx.fillRect(0, 0, width, height);
this.ctx.restore();
// The transform can be applied before rendering, transferring it to
// the new canvas.
this.ctx.transform.apply(this.ctx,
this.compositeCtx.mozCurrentTransform);
}

var transform = viewport.transform;

this.ctx.save();
this.ctx.transform.apply(this.ctx, transform);
if (transform) {
this.ctx.transform.apply(this.ctx, transform);
}
this.ctx.transform.apply(this.ctx, viewport.transform);

this.baseTransform = this.ctx.mozCurrentTransform.slice();

Expand Down Expand Up @@ -810,7 +825,14 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {

endDrawing: function CanvasGraphics_endDrawing() {
this.ctx.restore();
CachedCanvases.clear();

if (this.transparentCanvas) {
this.ctx = this.compositeCtx;
this.ctx.drawImage(this.transparentCanvas, 0, 0);
this.transparentCanvas = null;
}

this.cachedCanvases.clear();
WebGLUtils.clear();

if (this.imageLayer) {
Expand Down Expand Up @@ -924,7 +946,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
var drawnWidth = activeSMask.canvas.width;
var drawnHeight = activeSMask.canvas.height;
var cacheId = 'smaskGroupAt' + this.groupLevel;
var scratchCanvas = CachedCanvases.getCanvas(
var scratchCanvas = this.cachedCanvases.getCanvas(
cacheId, drawnWidth, drawnHeight, true);

var currentCtx = this.ctx;
Expand Down Expand Up @@ -1708,7 +1730,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
// Using two cache entries is case if masks are used one after another.
cacheId += '_smask_' + ((this.smaskCounter++) % 2);
}
var scratchCanvas = CachedCanvases.getCanvas(
var scratchCanvas = this.cachedCanvases.getCanvas(
cacheId, drawnWidth, drawnHeight, true);
var groupCtx = scratchCanvas.context;

Expand Down Expand Up @@ -1849,7 +1871,8 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
return;
}

var maskCanvas = CachedCanvases.getCanvas('maskCanvas', width, height);
var maskCanvas = this.cachedCanvases.getCanvas('maskCanvas',
width, height);
var maskCtx = maskCanvas.context;
maskCtx.save();

Expand All @@ -1874,7 +1897,8 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
var fillColor = this.current.fillColor;
var isPatternFill = this.current.patternFill;

var maskCanvas = CachedCanvases.getCanvas('maskCanvas', width, height);
var maskCanvas = this.cachedCanvases.getCanvas('maskCanvas',
width, height);
var maskCtx = maskCanvas.context;
maskCtx.save();

Expand Down Expand Up @@ -1909,7 +1933,8 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
var image = images[i];
var width = image.width, height = image.height;

var maskCanvas = CachedCanvases.getCanvas('maskCanvas', width, height);
var maskCanvas = this.cachedCanvases.getCanvas('maskCanvas',
width, height);
var maskCtx = maskCanvas.context;
maskCtx.save();

Expand Down Expand Up @@ -1982,7 +2007,8 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
if (imgData instanceof HTMLElement || !imgData.data) {
imgToPaint = imgData;
} else {
tmpCanvas = CachedCanvases.getCanvas('inlineImage', width, height);
tmpCanvas = this.cachedCanvases.getCanvas('inlineImage',
width, height);
var tmpCtx = tmpCanvas.context;
putBinaryImageData(tmpCtx, imgData);
imgToPaint = tmpCanvas.canvas;
Expand All @@ -2004,7 +2030,8 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
newHeight = Math.ceil(paintHeight / 2);
heightScale /= paintHeight / newHeight;
}
tmpCanvas = CachedCanvases.getCanvas(tmpCanvasId, newWidth, newHeight);
tmpCanvas = this.cachedCanvases.getCanvas(tmpCanvasId,
newWidth, newHeight);
tmpCtx = tmpCanvas.context;
tmpCtx.clearRect(0, 0, newWidth, newHeight);
tmpCtx.drawImage(imgToPaint, 0, 0, paintWidth, paintHeight,
Expand Down Expand Up @@ -2036,7 +2063,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
var w = imgData.width;
var h = imgData.height;

var tmpCanvas = CachedCanvases.getCanvas('inlineImage', w, h);
var tmpCanvas = this.cachedCanvases.getCanvas('inlineImage', w, h);
var tmpCtx = tmpCanvas.context;
putBinaryImageData(tmpCtx, imgData);

Expand Down
12 changes: 7 additions & 5 deletions src/display/pattern_helper.js
Original file line number Diff line number Diff line change
Expand Up @@ -149,7 +149,7 @@ var createMeshCanvas = (function createMeshCanvasClosure() {
}

function createMeshCanvas(bounds, combinesScale, coords, colors, figures,
backgroundColor) {
backgroundColor, cachedCanvases) {
// we will increase scale on some weird factor to let antialiasing take
// care of "rough" edges
var EXPECTED_SCALE = 1.1;
Expand Down Expand Up @@ -183,11 +183,11 @@ var createMeshCanvas = (function createMeshCanvasClosure() {
figures, context);

// https://bugzilla.mozilla.org/show_bug.cgi?id=972126
tmpCanvas = CachedCanvases.getCanvas('mesh', width, height, false);
tmpCanvas = cachedCanvases.getCanvas('mesh', width, height, false);
tmpCanvas.context.drawImage(canvas, 0, 0);
canvas = tmpCanvas.canvas;
} else {
tmpCanvas = CachedCanvases.getCanvas('mesh', width, height, false);
tmpCanvas = cachedCanvases.getCanvas('mesh', width, height, false);
var tmpCtx = tmpCanvas.context;

var data = tmpCtx.createImageData(width, height);
Expand Down Expand Up @@ -243,7 +243,8 @@ ShadingIRs.Mesh = {
// Rasterizing on the main thread since sending/queue large canvases
// might cause OOM.
var temporaryPatternCanvas = createMeshCanvas(bounds, scale, coords,
colors, figures, shadingFill ? null : background);
colors, figures, shadingFill ? null : background,
owner.cachedCanvases);

if (!shadingFill) {
ctx.setTransform.apply(ctx, owner.baseTransform);
Expand Down Expand Up @@ -346,7 +347,8 @@ var TilingPattern = (function TilingPatternClosure() {
height = Math.min(Math.ceil(Math.abs(height * combinedScale[1])),
MAX_PATTERN_SIZE);

var tmpCanvas = CachedCanvases.getCanvas('pattern', width, height, true);
var tmpCanvas = owner.cachedCanvases.getCanvas('pattern',
width, height, true);
var tmpCtx = tmpCanvas.context;
var graphics = new CanvasGraphics(tmpCtx, commonObjs, objs);
graphics.groupLevel = owner.groupLevel;
Expand Down
18 changes: 15 additions & 3 deletions test/driver.js
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,12 @@ var SimpleTextLayerBuilder = (function SimpleTextLayerBuilderClosure() {
this.ctx = ctx;
this.viewport = viewport;
this.textCounter = 0;

// clear canvas
ctx.save();
ctx.fillStyle = 'rgb(255,255,255)';
ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
ctx.restore();
}

SimpleTextLayerBuilder.prototype = {
Expand Down Expand Up @@ -271,6 +277,7 @@ var Driver = (function DriverClosure() {
_nextPage: function Driver_nextPage(task, loadError) {
var self = this;
var failure = loadError || '';
var ctx;

if (!task.pdfDoc) {
var dataUrl = this.canvas.toDataURL('image/png');
Expand Down Expand Up @@ -301,7 +308,11 @@ var Driver = (function DriverClosure() {
// Empty the canvas
this.canvas.width = 1;
this.canvas.height = 1;
this._clearCanvas();
ctx = this.canvas.getContext('2d', {alpha: false});
ctx.save();
ctx.fillStyle = 'white';
ctx.fillRect(0, 0, 1, 1);
ctx.restore();

this._snapshot(task, '');
return;
Expand All @@ -311,7 +322,8 @@ var Driver = (function DriverClosure() {
try {
this._log(' Loading page ' + task.pageNum + '/' +
task.pdfDoc.numPages + '... ');
var ctx = this.canvas.getContext('2d');
this.canvas.mozOpaque = true;
ctx = this.canvas.getContext('2d', {alpha: false});
task.pdfDoc.getPage(task.pageNum).then(function(page) {
var viewport = page.getViewport(PDF_TO_CSS_UNITS);
self.canvas.width = viewport.width;
Expand Down Expand Up @@ -371,7 +383,7 @@ var Driver = (function DriverClosure() {
},

_clearCanvas: function Driver_clearCanvas() {
var ctx = this.canvas.getContext('2d');
var ctx = this.canvas.getContext('2d', {alpha: false});
ctx.beginPath();
ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
},
Expand Down
26 changes: 15 additions & 11 deletions web/pdf_page_view.js
Original file line number Diff line number Diff line change
Expand Up @@ -166,8 +166,7 @@ var PDFPageView = (function PDFPageViewClosure() {

var isScalingRestricted = false;
if (this.canvas && PDFJS.maxCanvasPixels > 0) {
var ctx = this.canvas.getContext('2d');
var outputScale = getOutputScale(ctx);
var outputScale = this.outputScale;
var pixelsInViewport = this.viewport.width * this.viewport.height;
var maxScale = Math.sqrt(PDFJS.maxCanvasPixels / pixelsInViewport);
if (((Math.floor(this.viewport.width) * outputScale.sx) | 0) *
Expand Down Expand Up @@ -311,17 +310,23 @@ var PDFPageView = (function PDFPageViewClosure() {

var canvas = document.createElement('canvas');
canvas.id = 'page' + this.id;
canvas.setAttribute('hidden', 'hidden');
canvasWrapper.appendChild(canvas);
if (this.annotationLayer && this.annotationLayer.div) {
// annotationLayer needs to stay on top
div.insertBefore(canvasWrapper, this.annotationLayer.div);
} else {
div.appendChild(canvasWrapper);
}
var isCanvasHidden = true;
this.canvas = canvas;

var ctx = canvas.getContext('2d');
//#if MOZCENTRAL || FIREFOX || GENERIC
canvas.mozOpaque = true;
//#endif
var ctx = canvas.getContext('2d', {alpha: false});
var outputScale = getOutputScale(ctx);
this.outputScale = outputScale;

if (PDFJS.useOnlyCssZoom) {
var actualSizeViewport = viewport.clone({scale: CSS_UNITS});
Expand Down Expand Up @@ -374,14 +379,6 @@ var PDFPageView = (function PDFPageViewClosure() {
}
this.textLayer = textLayer;

if (outputScale.scaled) {
//#if !(MOZCENTRAL || FIREFOX)
// Used by the mozCurrentTransform polyfill in src/display/canvas.js.
ctx._transformMatrix = [outputScale.sx, 0, 0, outputScale.sy, 0, 0];
//#endif
ctx.scale(outputScale.sx, outputScale.sy);
}

var resolveRenderPromise, rejectRenderPromise;
var promise = new Promise(function (resolve, reject) {
resolveRenderPromise = resolve;
Expand Down Expand Up @@ -461,12 +458,19 @@ var PDFPageView = (function PDFPageViewClosure() {
};
return;
}
if (isCanvasHidden) {
self.canvas.removeAttribute('hidden');
isCanvasHidden = false;
}
cont();
};
}

var transform = !outputScale.scaled ? null :
[outputScale.sx, 0, 0, outputScale.sy, 0, 0];
var renderContext = {
canvasContext: ctx,
transform: transform,
viewport: this.viewport,
// intent: 'default', // === 'display'
};
Expand Down
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