piskel/js/drawingtools/Stroke.js
2012-09-08 15:21:22 +02:00

86 lines
3 KiB
JavaScript

/*
* @provide pskl.drawingtools.Stroke
*
* @require pskl.utils
*/
(function() {
var ns = $.namespace("pskl.drawingtools");
ns.Stroke = function() {
this.toolId = "tool-stroke"
// Stroke's first point coordinates (set in applyToolAt)
this.startCol = null;
this.startRow = null;
this.canvasOverlay = null;
};
pskl.utils.inherit(ns.Stroke, ns.BaseTool);
/**
* @override
*/
ns.Stroke.prototype.applyToolAt = function(col, row, color, drawer) {
this.startCol = col;
this.startRow = row;
// When drawing a stroke we don't change the model instantly, since the
// user can move his cursor to change the stroke direction and length
// dynamically. Instead we draw the (preview) stroke in a fake canvas that
// overlay the drawing canvas.
// We wait for the releaseToolAt callback to impact both the
// frame model and canvas rendering.
// The fake canvas where we will draw the preview of the stroke:
// Drawing the first point of the stroke in the fake overlay canvas:
drawer.overlayFrame.setPixel(col, row, color);
drawer.renderOverlay();
};
ns.Stroke.prototype.moveToolAt = function(col, row, color, drawer) {
drawer.clearOverlay();
// When the user moussemove (before releasing), we dynamically compute the
// pixel to draw the line and draw this line in the overlay canvas:
var strokePoints = this.getLinePixels_(this.startCol, col, this.startRow, row);
// Drawing current stroke:
for(var i = 0; i< strokePoints.length; i++) {
if(color == Constants.TRANSPARENT_COLOR) {
// When mousemoving the stroke tool, we draw in the canvas overlay above the drawing canvas.
// If the stroke color is transparent, we won't be
// able to see it during the movement.
// We set it to a semi-opaque white during the tool mousemove allowing to see colors below the stroke.
// When the stroke tool will be released, It will draw a transparent stroke,
// eg deleting the equivalent of a stroke.
color = Constants.SELECTION_TRANSPARENT_COLOR;
}
drawer.overlayFrame.setPixel(strokePoints[i].col, strokePoints[i].row, color);
}
drawer.renderOverlay();
};
/**
* @override
*/
ns.Stroke.prototype.releaseToolAt = function(col, row, color, drawer) {
// If the stroke tool is released outside of the canvas, we cancel the stroke:
// TODO: Mutualize this check in common method
if(drawer.frame.containsPixel(col, row)) {
// The user released the tool to draw a line. We will compute the pixel coordinate, impact
// the model and draw them in the drawing canvas (not the fake overlay anymore)
var strokePoints = this.getLinePixels_(this.startCol, col, this.startRow, row);
for(var i = 0; i< strokePoints.length; i++) {
// Change model:
drawer.frame.setPixel(strokePoints[i].col, strokePoints[i].row, color);
}
// Draw in canvas:
// TODO: Remove that when we have the centralized redraw loop
drawer.renderFrame();
}
// For now, we are done with the stroke tool and don't need an overlay anymore:
drawer.clearOverlay();
};
})();