';
// Insert divs that make up the corner.
if(round) {
var table = getTable(radius, type),
pxPos = [,];
for(var y=radius-1; y>-1; --y) {
for(var x=radius-1; x>-1; --x) {
// Go to next x if opacity is 0.
if(!table[x][y])
continue;
// Extract height and width, then calculate the position for the
.
for(var i=1; i>-1; --i)
pxPos[i] = (type==(3-2*i)||type==0||table[x][y]!=1?radius-1:0)-(i==0?x:y);
// Add a pixel row/column.
corner += '
';
}
}
}
corners += corner+'
';
}
}
return corners;
}
function getTable(radius, type) {
var table = tables[radius+''+type];
if(!table) {
var flip = !tables[radius+'0']?genTable(radius):tables[radius+'0'];
table = new Array(radius);
for(var x=radius-1; x>-1; --x) {
table[x] = new Array(radius);
for(var y=radius-1; y>-1; --y)
table[x][y] = flip[type==2||type==1?radius-1-x:x][type==2||type==3?radius-1-y:y];
}
}
return table;
}
function genTable(radius) {
// Calculates the area under the top half of a circle (0,0,radius) for [0..x].
function integral(radius, x) {
var ratio = x/radius;
return 0.5*radius*(x*Math.sqrt(1-Math.pow(ratio, 2))+radius*Math.asin(ratio));
}
// Initialize vars.
var bulk = Math.round(radius/Math.sqrt(2))-1, // The amount of whole squares that fit into the radius.
table = [],
pxPos = [,],
opacity;
// Fill in the table.
for(var x=radius-1; x>-1; --x)
table.push(new Array(radius));
for(var y=radius-1; y>=bulk; --y) {
for(var x=bulk; x>-1; --x) {
// Calculate the opacity for the current pixel w/o approximations.
if(that.antialias) {
// Calculates the positions where the circle intersects with the pixel boundaries.
for(var i=0; i<2; i++)
pxPos[i] = Math.max(x, Math.min(x+1, radius*Math.sqrt(1-Math.pow((y+1-i)/radius, 2))));
opacity = Math.round(100*((pxPos[0]>x)*(1-(pxPos[1]-pxPos[0]))+(pxPos[0]!=pxPos[1]?integral(radius, pxPos[1])-integral(radius, pxPos[0])-y*(pxPos[1]-pxPos[0]):0)))/100;
}
else
opacity = (x+0.5)*Math.sqrt(1+Math.pow((y+0.5)/(x+0.5), 2))<=radius?1:0;
// Skip fully transparent pixels.
if(opacity==0)
continue;
// Update the table based on the pixel coordinates and opacity.
table[x][y] = opacity;
table[y][x] = opacity;
// All other pixels in this row||column will also be opaque.
if(opacity==1)
break;
}
}
return table;
}
};