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Use only one temp canvas for patterns

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This fixes a regression #3153 which was introduced by #2177.
The temp vanvases that are being created are not being re-used, which lead
to high memory use.
This commit is contained in:
Kalervo Kujala 2013-04-25 23:21:05 +03:00
parent ff616c830f
commit 8ac0690913
1 changed files with 87 additions and 63 deletions
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150
src/pattern.js
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@ -20,6 +20,10 @@
'use strict';
// This global variable is used to minimize the memory usage when patterns are
// used.
var temporaryPatternCanvas = null;
var PatternType = {
AXIAL: 2,
RADIAL: 3
@ -268,68 +272,24 @@ var TilingPattern = (function TilingPatternClosure() {
COLORED: 1,
UNCOLORED: 2
};
var MAX_PATTERN_SIZE = 4096;
var MAX_PATTERN_SIZE = 8192;
function TilingPattern(IR, color, ctx, objs, commonObjs) {
var operatorList = IR[2];
this.name = IR[1][0].name;
this.operatorList = IR[2];
this.matrix = IR[3] || [1, 0, 0, 1, 0, 0];
var bbox = IR[4];
var xstep = IR[5];
var ystep = IR[6];
var paintType = IR[7];
var tilingType = IR[8];
TODO('TilingType: ' + tilingType);
this.bbox = IR[4];
this.xstep = IR[5];
this.ystep = IR[6];
this.paintType = IR[7];
this.tilingType = IR[8];
this.color = color;
this.objs = objs;
this.commonObjs = commonObjs;
this.curMatrix = ctx.mozCurrentTransform;
this.ctx = ctx;
this.type = 'Pattern';
var x0 = bbox[0], y0 = bbox[1], x1 = bbox[2], y1 = bbox[3];
var topLeft = [x0, y0];
// we want the canvas to be as large as the step size
var botRight = [x0 + xstep, y0 + ystep];
var width = botRight[0] - topLeft[0];
var height = botRight[1] - topLeft[1];
// Obtain scale from matrix and current transformation matrix.
var matrixScale = Util.singularValueDecompose2dScale(this.matrix);
var curMatrixScale = Util.singularValueDecompose2dScale(this.curMatrix);
var combinedScale = [matrixScale[0] * curMatrixScale[0],
matrixScale[1] * curMatrixScale[1]];
// MAX_PATTERN_SIZE is used to avoid OOM situation.
// Use width and height values that are as close as possible to the end
// result when the pattern is used. Too low value makes the pattern look
// blurry. Too large value makes it look too crispy.
width = Math.min(Math.ceil(Math.abs(width * combinedScale[0])),
MAX_PATTERN_SIZE);
height = Math.min(Math.ceil(Math.abs(height * combinedScale[1])),
MAX_PATTERN_SIZE);
var tmpCanvas = createScratchCanvas(width, height);
// set the new canvas element context as the graphics context
var tmpCtx = tmpCanvas.getContext('2d');
var graphics = new CanvasGraphics(tmpCtx, commonObjs, objs);
this.setFillAndStrokeStyleToContext(tmpCtx, paintType, color);
this.setScale(width, height, xstep, ystep);
this.transformToScale(graphics);
// transform coordinates to pattern space
var tmpTranslate = [1, 0, 0, 1, -topLeft[0], -topLeft[1]];
graphics.transform.apply(graphics, tmpTranslate);
this.clipBbox(graphics, bbox, x0, y0, x1, y1);
graphics.executeOperatorList(operatorList);
this.canvas = tmpCanvas;
this.ctx = ctx;
}
TilingPattern.getIR = function TilingPattern_getIR(operatorList, dict, args) {
@ -347,6 +307,66 @@ var TilingPattern = (function TilingPatternClosure() {
};
TilingPattern.prototype = {
createPatternCanvas: function TilinPattern_createPatternCanvas(tmpCanvas) {
var operatorList = this.operatorList;
var bbox = this.bbox;
var xstep = this.xstep;
var ystep = this.ystep;
var paintType = this.paintType;
var tilingType = this.tilingType;
var color = this.color;
var objs = this.objs;
var commonObjs = this.commonObjs;
var ctx = this.ctx;
TODO('TilingType: ' + tilingType);
var x0 = bbox[0], y0 = bbox[1], x1 = bbox[2], y1 = bbox[3];
var topLeft = [x0, y0];
// we want the canvas to be as large as the step size
var botRight = [x0 + xstep, y0 + ystep];
var width = botRight[0] - topLeft[0];
var height = botRight[1] - topLeft[1];
// Obtain scale from matrix and current transformation matrix.
var matrixScale = Util.singularValueDecompose2dScale(this.matrix);
var curMatrixScale = Util.singularValueDecompose2dScale(this.curMatrix);
var combinedScale = [matrixScale[0] * curMatrixScale[0],
matrixScale[1] * curMatrixScale[1]];
// MAX_PATTERN_SIZE is used to avoid OOM situation.
// Use width and height values that are as close as possible to the end
// result when the pattern is used. Too low value makes the pattern look
// blurry. Too large value makes it look too crispy.
width = Math.min(Math.ceil(Math.abs(width * combinedScale[0])),
MAX_PATTERN_SIZE);
height = Math.min(Math.ceil(Math.abs(height * combinedScale[1])),
MAX_PATTERN_SIZE);
tmpCanvas.width = width;
tmpCanvas.height = height;
// set the new canvas element context as the graphics context
var tmpCtx = tmpCanvas.getContext('2d');
var graphics = new CanvasGraphics(tmpCtx, commonObjs, objs);
this.setFillAndStrokeStyleToContext(tmpCtx, paintType, color);
this.setScale(width, height, xstep, ystep);
this.transformToScale(graphics);
// transform coordinates to pattern space
var tmpTranslate = [1, 0, 0, 1, -topLeft[0], -topLeft[1]];
graphics.transform.apply(graphics, tmpTranslate);
this.clipBbox(graphics, bbox, x0, y0, x1, y1);
graphics.executeOperatorList(operatorList);
},
setScale: function TilingPattern_setScale(width, height, xstep, ystep) {
this.scale = [width / xstep, height / ystep];
},
@ -392,15 +412,19 @@ var TilingPattern = (function TilingPatternClosure() {
},
getPattern: function TilingPattern_getPattern() {
var matrix = this.matrix;
var curMatrix = this.curMatrix;
var ctx = this.ctx;
// The temporary canvas is created only because the memory is released
// more quickly than creating multiple temporary canvases.
if (temporaryPatternCanvas === null) {
temporaryPatternCanvas = createScratchCanvas(0, 0);
}
this.createPatternCanvas(temporaryPatternCanvas);
ctx.setTransform.apply(ctx, curMatrix);
ctx.transform.apply(ctx, matrix);
var ctx = this.ctx;
ctx.setTransform.apply(ctx, this.curMatrix);
ctx.transform.apply(ctx, this.matrix);
this.scaleToContext();
return ctx.createPattern(this.canvas, 'repeat');
return ctx.createPattern(temporaryPatternCanvas, 'repeat');
}
};