clockwerk-guacamole – Rev 1
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/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is guacamole-common-js.
*
* The Initial Developer of the Original Code is
* Michael Jumper.
* Portions created by the Initial Developer are Copyright (C) 2010
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
// Guacamole namespace
var Guacamole = Guacamole || {};
/**
* Abstract ordered drawing surface. Each Layer contains a canvas element and
* provides simple drawing instructions for drawing to that canvas element,
* however unlike the canvas element itself, drawing operations on a Layer are
* guaranteed to run in order, even if such an operation must wait for an image
* to load before completing.
*
* @constructor
*
* @param {Number} width The width of the Layer, in pixels. The canvas element
* backing this Layer will be given this width.
*
* @param {Number} height The height of the Layer, in pixels. The canvas element
* backing this Layer will be given this height.
*/
Guacamole.Layer = function(width, height) {
/**
* Reference to this Layer.
* @private
*/
var layer = this;
/**
* The canvas element backing this Layer.
* @private
*/
var display = document.createElement("canvas");
/**
* The 2D display context of the canvas element backing this Layer.
* @private
*/
var displayContext = display.getContext("2d");
displayContext.save();
/**
* The queue of all pending Tasks. Tasks will be run in order, with new
* tasks added at the end of the queue and old tasks removed from the
* front of the queue (FIFO).
* @private
*/
var tasks = new Array();
/**
* Whether a new path should be started with the next path drawing
* operations.
*/
var pathClosed = true;
/**
* The number of states on the state stack.
*
* Note that there will ALWAYS be one element on the stack, but that
* element is not exposed. It is only used to reset the layer to its
* initial state.
*/
var stackSize = 0;
/**
* Map of all Guacamole channel masks to HTML5 canvas composite operation
* names. Not all channel mask combinations are currently implemented.
* @private
*/
var compositeOperation = {
/* 0x0 NOT IMPLEMENTED */
0x1: "destination-in",
0x2: "destination-out",
/* 0x3 NOT IMPLEMENTED */
0x4: "source-in",
/* 0x5 NOT IMPLEMENTED */
0x6: "source-atop",
/* 0x7 NOT IMPLEMENTED */
0x8: "source-out",
0x9: "destination-atop",
0xA: "xor",
0xB: "destination-over",
0xC: "copy",
/* 0xD NOT IMPLEMENTED */
0xE: "source-over",
0xF: "lighter"
};
/**
* Resizes the canvas element backing this Layer without testing the
* new size. This function should only be used internally.
*
* @private
* @param {Number} newWidth The new width to assign to this Layer.
* @param {Number} newHeight The new height to assign to this Layer.
*/
function resize(newWidth, newHeight) {
// Only preserve old data if width/height are both non-zero
var oldData = null;
if (width != 0 && height != 0) {
// Create canvas and context for holding old data
oldData = document.createElement("canvas");
oldData.width = width;
oldData.height = height;
var oldDataContext = oldData.getContext("2d");
// Copy image data from current
oldDataContext.drawImage(display,
0, 0, width, height,
0, 0, width, height);
}
// Preserve composite operation
var oldCompositeOperation = displayContext.globalCompositeOperation;
// Resize canvas
display.width = newWidth;
display.height = newHeight;
// Redraw old data, if any
if (oldData)
displayContext.drawImage(oldData,
0, 0, width, height,
0, 0, width, height);
// Restore composite operation
displayContext.globalCompositeOperation = oldCompositeOperation;
width = newWidth;
height = newHeight;
// Acknowledge reset of stack (happens on resize of canvas)
stackSize = 0;
displayContext.save();
}
/**
* Given the X and Y coordinates of the upper-left corner of a rectangle
* and the rectangle's width and height, resize the backing canvas element
* as necessary to ensure that the rectangle fits within the canvas
* element's coordinate space. This function will only make the canvas
* larger. If the rectangle already fits within the canvas element's
* coordinate space, the canvas is left unchanged.
*
* @private
* @param {Number} x The X coordinate of the upper-left corner of the
* rectangle to fit.
* @param {Number} y The Y coordinate of the upper-left corner of the
* rectangle to fit.
* @param {Number} w The width of the the rectangle to fit.
* @param {Number} h The height of the the rectangle to fit.
*/
function fitRect(x, y, w, h) {
// Calculate bounds
var opBoundX = w + x;
var opBoundY = h + y;
// Determine max width
var resizeWidth;
if (opBoundX > width)
resizeWidth = opBoundX;
else
resizeWidth = width;
// Determine max height
var resizeHeight;
if (opBoundY > height)
resizeHeight = opBoundY;
else
resizeHeight = height;
// Resize if necessary
if (resizeWidth != width || resizeHeight != height)
resize(resizeWidth, resizeHeight);
}
/**
* A container for an task handler. Each operation which must be ordered
* is associated with a Task that goes into a task queue. Tasks in this
* queue are executed in order once their handlers are set, while Tasks
* without handlers block themselves and any following Tasks from running.
*
* @constructor
* @private
* @param {function} taskHandler The function to call when this task
* runs, if any.
* @param {boolean} blocked Whether this task should start blocked.
*/
function Task(taskHandler, blocked) {
var task = this;
/**
* Whether this Task is blocked.
*
* @type boolean
*/
this.blocked = blocked;
/**
* The handler this Task is associated with, if any.
*
* @type function
*/
this.handler = taskHandler;
/**
* Unblocks this Task, allowing it to run.
*/
this.unblock = function() {
task.blocked = false;
handlePendingTasks();
}
}
/**
* If no tasks are pending or running, run the provided handler immediately,
* if any. Otherwise, schedule a task to run immediately after all currently
* running or pending tasks are complete.
*
* @private
* @param {function} handler The function to call when possible, if any.
* @param {boolean} blocked Whether the task should start blocked.
* @returns {Task} The Task created and added to the queue for future
* running, if any, or null if the handler was run
* immediately and no Task needed to be created.
*/
function scheduleTask(handler, blocked) {
// If no pending tasks, just call (if available) and exit
if (layer.isReady() && !blocked) {
if (handler) handler();
return null;
}
// If tasks are pending/executing, schedule a pending task
// and return a reference to it.
var task = new Task(handler, blocked);
tasks.push(task);
return task;
}
var tasksInProgress = false;
/**
* Run any Tasks which were pending but are now ready to run and are not
* blocked by other Tasks.
* @private
*/
function handlePendingTasks() {
if (tasksInProgress)
return;
tasksInProgress = true;
// Draw all pending tasks.
var task;
while ((task = tasks[0]) != null && !task.blocked) {
tasks.shift();
if (task.handler) task.handler();
}
tasksInProgress = false;
}
/**
* Schedules a task within the current layer just as scheduleTast() does,
* except that another specified layer will be blocked until this task
* completes, and this task will not start until the other layer is
* ready.
*
* Essentially, a task is scheduled in both layers, and the specified task
* will only be performed once both layers are ready, and neither layer may
* proceed until this task completes.
*
* Note that there is no way to specify whether the task starts blocked,
* as whether the task is blocked depends completely on whether the
* other layer is currently ready.
*
* @param {Guacamole.Layer} otherLayer The other layer which must be blocked
* until this task completes.
* @param {function} handler The function to call when possible.
*/
function scheduleTaskSynced(otherLayer, handler) {
// If we ARE the other layer, no need to sync.
// Syncing would result in deadlock.
if (layer === otherLayer)
scheduleTask(handler);
// Otherwise synchronize operation with other layer
else {
var drawComplete = false;
var layerLock = null;
function performTask() {
// Perform task
handler();
// Unblock the other layer now that draw is complete
if (layerLock != null)
layerLock.unblock();
// Flag operation as done
drawComplete = true;
}
// Currently blocked draw task
var task = scheduleTask(performTask, true);
// Unblock draw task once source layer is ready
otherLayer.sync(task.unblock);
// Block other layer until draw completes
// Note that the draw MAY have already been performed at this point,
// in which case creating a lock on the other layer will lead to
// deadlock (the draw task has already run and will thus never
// clear the lock)
if (!drawComplete)
layerLock = otherLayer.sync(null, true);
}
}
/**
* Set to true if this Layer should resize itself to accomodate the
* dimensions of any drawing operation, and false (the default) otherwise.
*
* Note that setting this property takes effect immediately, and thus may
* take effect on operations that were started in the past but have not
* yet completed. If you wish the setting of this flag to only modify
* future operations, you will need to make the setting of this flag an
* operation with sync().
*
* @example
* // Set autosize to true for all future operations
* layer.sync(function() {
* layer.autosize = true;
* });
*
* @type Boolean
* @default false
*/
this.autosize = false;
/**
* Returns the canvas element backing this Layer.
* @returns {Element} The canvas element backing this Layer.
*/
this.getCanvas = function() {
return display;
};
/**
* Returns whether this Layer is ready. A Layer is ready if it has no
* pending operations and no operations in-progress.
*
* @returns {Boolean} true if this Layer is ready, false otherwise.
*/
this.isReady = function() {
return tasks.length == 0;
};
/**
* Changes the size of this Layer to the given width and height. Resizing
* is only attempted if the new size provided is actually different from
* the current size.
*
* @param {Number} newWidth The new width to assign to this Layer.
* @param {Number} newHeight The new height to assign to this Layer.
*/
this.resize = function(newWidth, newHeight) {
scheduleTask(function() {
if (newWidth != width || newHeight != height)
resize(newWidth, newHeight);
});
};
/**
* Draws the specified image at the given coordinates. The image specified
* must already be loaded.
*
* @param {Number} x The destination X coordinate.
* @param {Number} y The destination Y coordinate.
* @param {Image} image The image to draw. Note that this is an Image
* object - not a URL.
*/
this.drawImage = function(x, y, image) {
scheduleTask(function() {
if (layer.autosize != 0) fitRect(x, y, image.width, image.height);
displayContext.drawImage(image, x, y);
});
};
/**
* Draws the image at the specified URL at the given coordinates. The image
* will be loaded automatically, and this and any future operations will
* wait for the image to finish loading.
*
* @param {Number} x The destination X coordinate.
* @param {Number} y The destination Y coordinate.
* @param {String} url The URL of the image to draw.
*/
this.draw = function(x, y, url) {
var task = scheduleTask(function() {
if (layer.autosize != 0) fitRect(x, y, image.width, image.height);
displayContext.drawImage(image, x, y);
}, true);
var image = new Image();
image.onload = task.unblock;
image.src = url;
};
/**
* Run an arbitrary function as soon as currently pending operations
* are complete.
*
* @param {function} handler The function to call once all currently
* pending operations are complete.
* @param {boolean} blocked Whether the task should start blocked.
*/
this.sync = scheduleTask;
/**
* Transfer a rectangle of image data from one Layer to this Layer using the
* specified transfer function.
*
* @param {Guacamole.Layer} srcLayer The Layer to copy image data from.
* @param {Number} srcx The X coordinate of the upper-left corner of the
* rectangle within the source Layer's coordinate
* space to copy data from.
* @param {Number} srcy The Y coordinate of the upper-left corner of the
* rectangle within the source Layer's coordinate
* space to copy data from.
* @param {Number} srcw The width of the rectangle within the source Layer's
* coordinate space to copy data from.
* @param {Number} srch The height of the rectangle within the source
* Layer's coordinate space to copy data from.
* @param {Number} x The destination X coordinate.
* @param {Number} y The destination Y coordinate.
* @param {Function} transferFunction The transfer function to use to
* transfer data from source to
* destination.
*/
this.transfer = function(srcLayer, srcx, srcy, srcw, srch, x, y, transferFunction) {
scheduleTaskSynced(srcLayer, function() {
if (layer.autosize != 0) fitRect(x, y, srcw, srch);
var srcCanvas = srcLayer.getCanvas();
if (srcCanvas.width != 0 && srcCanvas.height != 0) {
// Get image data from src and dst
var src = srcLayer.getCanvas().getContext("2d").getImageData(srcx, srcy, srcw, srch);
var dst = displayContext.getImageData(x , y, srcw, srch);
// Apply transfer for each pixel
for (var i=0; i<srcw*srch*4; i+=4) {
// Get source pixel environment
var src_pixel = new Guacamole.Layer.Pixel(
src.data[i],
src.data[i+1],
src.data[i+2],
src.data[i+3]
);
// Get destination pixel environment
var dst_pixel = new Guacamole.Layer.Pixel(
dst.data[i],
dst.data[i+1],
dst.data[i+2],
dst.data[i+3]
);
// Apply transfer function
transferFunction(src_pixel, dst_pixel);
// Save pixel data
dst.data[i ] = dst_pixel.red;
dst.data[i+1] = dst_pixel.green;
dst.data[i+2] = dst_pixel.blue;
dst.data[i+3] = dst_pixel.alpha;
}
// Draw image data
displayContext.putImageData(dst, x, y);
}
});
};
/**
* Copy a rectangle of image data from one Layer to this Layer. This
* operation will copy exactly the image data that will be drawn once all
* operations of the source Layer that were pending at the time this
* function was called are complete. This operation will not alter the
* size of the source Layer even if its autosize property is set to true.
*
* @param {Guacamole.Layer} srcLayer The Layer to copy image data from.
* @param {Number} srcx The X coordinate of the upper-left corner of the
* rectangle within the source Layer's coordinate
* space to copy data from.
* @param {Number} srcy The Y coordinate of the upper-left corner of the
* rectangle within the source Layer's coordinate
* space to copy data from.
* @param {Number} srcw The width of the rectangle within the source Layer's
* coordinate space to copy data from.
* @param {Number} srch The height of the rectangle within the source
* Layer's coordinate space to copy data from.
* @param {Number} x The destination X coordinate.
* @param {Number} y The destination Y coordinate.
*/
this.copy = function(srcLayer, srcx, srcy, srcw, srch, x, y) {
scheduleTaskSynced(srcLayer, function() {
if (layer.autosize != 0) fitRect(x, y, srcw, srch);
var srcCanvas = srcLayer.getCanvas();
if (srcCanvas.width != 0 && srcCanvas.height != 0)
displayContext.drawImage(srcCanvas, srcx, srcy, srcw, srch, x, y, srcw, srch);
});
};
/**
* Starts a new path at the specified point.
*
* @param {Number} x The X coordinate of the point to draw.
* @param {Number} y The Y coordinate of the point to draw.
*/
this.moveTo = function(x, y) {
scheduleTask(function() {
// Start a new path if current path is closed
if (pathClosed) {
displayContext.beginPath();
pathClosed = false;
}
if (layer.autosize != 0) fitRect(x, y, 0, 0);
displayContext.moveTo(x, y);
});
};
/**
* Add the specified line to the current path.
*
* @param {Number} x The X coordinate of the endpoint of the line to draw.
* @param {Number} y The Y coordinate of the endpoint of the line to draw.
*/
this.lineTo = function(x, y) {
scheduleTask(function() {
// Start a new path if current path is closed
if (pathClosed) {
displayContext.beginPath();
pathClosed = false;
}
if (layer.autosize != 0) fitRect(x, y, 0, 0);
displayContext.lineTo(x, y);
});
};
/**
* Add the specified arc to the current path.
*
* @param {Number} x The X coordinate of the center of the circle which
* will contain the arc.
* @param {Number} y The Y coordinate of the center of the circle which
* will contain the arc.
* @param {Number} radius The radius of the circle.
* @param {Number} startAngle The starting angle of the arc, in radians.
* @param {Number} endAngle The ending angle of the arc, in radians.
* @param {Boolean} negative Whether the arc should be drawn in order of
* decreasing angle.
*/
this.arc = function(x, y, radius, startAngle, endAngle, negative) {
scheduleTask(function() {
// Start a new path if current path is closed
if (pathClosed) {
displayContext.beginPath();
pathClosed = false;
}
if (layer.autosize != 0) fitRect(x, y, 0, 0);
displayContext.arc(x, y, radius, startAngle, endAngle, negative);
});
};
/**
* Starts a new path at the specified point.
*
* @param {Number} cp1x The X coordinate of the first control point.
* @param {Number} cp1y The Y coordinate of the first control point.
* @param {Number} cp2x The X coordinate of the second control point.
* @param {Number} cp2y The Y coordinate of the second control point.
* @param {Number} x The X coordinate of the endpoint of the curve.
* @param {Number} y The Y coordinate of the endpoint of the curve.
*/
this.curveTo = function(cp1x, cp1y, cp2x, cp2y, x, y) {
scheduleTask(function() {
// Start a new path if current path is closed
if (pathClosed) {
displayContext.beginPath();
pathClosed = false;
}
if (layer.autosize != 0) fitRect(x, y, 0, 0);
displayContext.bezierCurveTo(cp1x, cp1y, cp2x, cp2y, x, y);
});
};
/**
* Closes the current path by connecting the end point with the start
* point (if any) with a straight line.
*/
this.close = function() {
scheduleTask(function() {
// Close path
displayContext.closePath();
pathClosed = true;
});
};
/**
* Add the specified rectangle to the current path.
*
* @param {Number} x The X coordinate of the upper-left corner of the
* rectangle to draw.
* @param {Number} y The Y coordinate of the upper-left corner of the
* rectangle to draw.
* @param {Number} w The width of the rectangle to draw.
* @param {Number} h The height of the rectangle to draw.
*/
this.rect = function(x, y, w, h) {
scheduleTask(function() {
// Start a new path if current path is closed
if (pathClosed) {
displayContext.beginPath();
pathClosed = false;
}
if (layer.autosize != 0) fitRect(x, y, w, h);
displayContext.rect(x, y, w, h);
});
};
/**
* Clip all future drawing operations by the current path. The current path
* is implicitly closed. The current path can continue to be reused
* for other operations (such as fillColor()) but a new path will be started
* once a path drawing operation (path() or rect()) is used.
*/
this.clip = function() {
scheduleTask(function() {
// Set new clipping region
displayContext.clip();
// Path now implicitly closed
pathClosed = true;
});
};
/**
* Stroke the current path with the specified color. The current path
* is implicitly closed. The current path can continue to be reused
* for other operations (such as clip()) but a new path will be started
* once a path drawing operation (path() or rect()) is used.
*
* @param {String} cap The line cap style. Can be "round", "square",
* or "butt".
* @param {String} join The line join style. Can be "round", "bevel",
* or "miter".
* @param {Number} thickness The line thickness in pixels.
* @param {Number} r The red component of the color to fill.
* @param {Number} g The green component of the color to fill.
* @param {Number} b The blue component of the color to fill.
* @param {Number} a The alpha component of the color to fill.
*/
this.strokeColor = function(cap, join, thickness, r, g, b, a) {
scheduleTask(function() {
// Stroke with color
displayContext.lineCap = cap;
displayContext.lineJoin = join;
displayContext.lineWidth = thickness;
displayContext.strokeStyle = "rgba(" + r + "," + g + "," + b + "," + a/255.0 + ")";
displayContext.stroke();
// Path now implicitly closed
pathClosed = true;
});
};
/**
* Fills the current path with the specified color. The current path
* is implicitly closed. The current path can continue to be reused
* for other operations (such as clip()) but a new path will be started
* once a path drawing operation (path() or rect()) is used.
*
* @param {Number} r The red component of the color to fill.
* @param {Number} g The green component of the color to fill.
* @param {Number} b The blue component of the color to fill.
* @param {Number} a The alpha component of the color to fill.
*/
this.fillColor = function(r, g, b, a) {
scheduleTask(function() {
// Fill with color
displayContext.fillStyle = "rgba(" + r + "," + g + "," + b + "," + a/255.0 + ")";
displayContext.fill();
// Path now implicitly closed
pathClosed = true;
});
};
/**
* Stroke the current path with the image within the specified layer. The
* image data will be tiled infinitely within the stroke. The current path
* is implicitly closed. The current path can continue to be reused
* for other operations (such as clip()) but a new path will be started
* once a path drawing operation (path() or rect()) is used.
*
* @param {String} cap The line cap style. Can be "round", "square",
* or "butt".
* @param {String} join The line join style. Can be "round", "bevel",
* or "miter".
* @param {Number} thickness The line thickness in pixels.
* @param {Guacamole.Layer} srcLayer The layer to use as a repeating pattern
* within the stroke.
*/
this.strokeLayer = function(cap, join, thickness, srcLayer) {
scheduleTaskSynced(srcLayer, function() {
// Stroke with image data
displayContext.lineCap = cap;
displayContext.lineJoin = join;
displayContext.lineWidth = thickness;
displayContext.strokeStyle = displayContext.createPattern(
srcLayer.getCanvas(),
"repeat"
);
displayContext.stroke();
// Path now implicitly closed
pathClosed = true;
});
};
/**
* Fills the current path with the image within the specified layer. The
* image data will be tiled infinitely within the stroke. The current path
* is implicitly closed. The current path can continue to be reused
* for other operations (such as clip()) but a new path will be started
* once a path drawing operation (path() or rect()) is used.
*
* @param {Guacamole.Layer} srcLayer The layer to use as a repeating pattern
* within the fill.
*/
this.fillLayer = function(srcLayer) {
scheduleTask(function() {
// Fill with image data
displayContext.fillStyle = displayContext.createPattern(
srcLayer.getCanvas(),
"repeat"
);
displayContext.fill();
// Path now implicitly closed
pathClosed = true;
});
};
/**
* Push current layer state onto stack.
*/
this.push = function() {
scheduleTask(function() {
// Save current state onto stack
displayContext.save();
stackSize++;
});
};
/**
* Pop layer state off stack.
*/
this.pop = function() {
scheduleTask(function() {
// Restore current state from stack
if (stackSize > 0) {
displayContext.restore();
stackSize--;
}
});
};
/**
* Reset the layer, clearing the stack, the current path, and any transform
* matrix.
*/
this.reset = function() {
scheduleTask(function() {
// Clear stack
while (stackSize > 0) {
displayContext.restore();
stackSize--;
}
// Restore to initial state
displayContext.restore();
displayContext.save();
// Clear path
displayContext.beginPath();
pathClosed = false;
});
};
/**
* Sets the given affine transform (defined with six values from the
* transform's matrix).
*
* @param {Number} a The first value in the affine transform's matrix.
* @param {Number} b The second value in the affine transform's matrix.
* @param {Number} c The third value in the affine transform's matrix.
* @param {Number} d The fourth value in the affine transform's matrix.
* @param {Number} e The fifth value in the affine transform's matrix.
* @param {Number} f The sixth value in the affine transform's matrix.
*/
this.setTransform = function(a, b, c, d, e, f) {
scheduleTask(function() {
// Set transform
displayContext.setTransform(
a, b, c,
d, e, f
/*0, 0, 1*/
);
});
};
/**
* Applies the given affine transform (defined with six values from the
* transform's matrix).
*
* @param {Number} a The first value in the affine transform's matrix.
* @param {Number} b The second value in the affine transform's matrix.
* @param {Number} c The third value in the affine transform's matrix.
* @param {Number} d The fourth value in the affine transform's matrix.
* @param {Number} e The fifth value in the affine transform's matrix.
* @param {Number} f The sixth value in the affine transform's matrix.
*/
this.transform = function(a, b, c, d, e, f) {
scheduleTask(function() {
// Apply transform
displayContext.transform(
a, b, c,
d, e, f
/*0, 0, 1*/
);
});
};
/**
* Sets the channel mask for future operations on this Layer.
*
* The channel mask is a Guacamole-specific compositing operation identifier
* with a single bit representing each of four channels (in order): source
* image where destination transparent, source where destination opaque,
* destination where source transparent, and destination where source
* opaque.
*
* @param {Number} mask The channel mask for future operations on this
* Layer.
*/
this.setChannelMask = function(mask) {
scheduleTask(function() {
displayContext.globalCompositeOperation = compositeOperation[mask];
});
};
/**
* Sets the miter limit for stroke operations using the miter join. This
* limit is the maximum ratio of the size of the miter join to the stroke
* width. If this ratio is exceeded, the miter will not be drawn for that
* joint of the path.
*
* @param {Number} limit The miter limit for stroke operations using the
* miter join.
*/
this.setMiterLimit = function(limit) {
scheduleTask(function() {
displayContext.miterLimit = limit;
});
};
// Initialize canvas dimensions
display.width = width;
display.height = height;
};
/**
* Channel mask for the composite operation "rout".
*/
Guacamole.Layer.ROUT = 0x2;
/**
* Channel mask for the composite operation "atop".
*/
Guacamole.Layer.ATOP = 0x6;
/**
* Channel mask for the composite operation "xor".
*/
Guacamole.Layer.XOR = 0xA;
/**
* Channel mask for the composite operation "rover".
*/
Guacamole.Layer.ROVER = 0xB;
/**
* Channel mask for the composite operation "over".
*/
Guacamole.Layer.OVER = 0xE;
/**
* Channel mask for the composite operation "plus".
*/
Guacamole.Layer.PLUS = 0xF;
/**
* Channel mask for the composite operation "rin".
* Beware that WebKit-based browsers may leave the contents of the destionation
* layer where the source layer is transparent, despite the definition of this
* operation.
*/
Guacamole.Layer.RIN = 0x1;
/**
* Channel mask for the composite operation "in".
* Beware that WebKit-based browsers may leave the contents of the destionation
* layer where the source layer is transparent, despite the definition of this
* operation.
*/
Guacamole.Layer.IN = 0x4;
/**
* Channel mask for the composite operation "out".
* Beware that WebKit-based browsers may leave the contents of the destionation
* layer where the source layer is transparent, despite the definition of this
* operation.
*/
Guacamole.Layer.OUT = 0x8;
/**
* Channel mask for the composite operation "ratop".
* Beware that WebKit-based browsers may leave the contents of the destionation
* layer where the source layer is transparent, despite the definition of this
* operation.
*/
Guacamole.Layer.RATOP = 0x9;
/**
* Channel mask for the composite operation "src".
* Beware that WebKit-based browsers may leave the contents of the destionation
* layer where the source layer is transparent, despite the definition of this
* operation.
*/
Guacamole.Layer.SRC = 0xC;
/**
* Represents a single pixel of image data. All components have a minimum value
* of 0 and a maximum value of 255.
*
* @constructor
*
* @param {Number} r The red component of this pixel.
* @param {Number} g The green component of this pixel.
* @param {Number} b The blue component of this pixel.
* @param {Number} a The alpha component of this pixel.
*/
Guacamole.Layer.Pixel = function(r, g, b, a) {
/**
* The red component of this pixel, where 0 is the minimum value,
* and 255 is the maximum.
*/
this.red = r;
/**
* The green component of this pixel, where 0 is the minimum value,
* and 255 is the maximum.
*/
this.green = g;
/**
* The blue component of this pixel, where 0 is the minimum value,
* and 255 is the maximum.
*/
this.blue = b;
/**
* The alpha component of this pixel, where 0 is the minimum value,
* and 255 is the maximum.
*/
this.alpha = a;
};