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add boundary #8

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2 changes: 2 additions & 0 deletions .gitignore
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Original file line number Diff line number Diff line change
Expand Up @@ -45,3 +45,5 @@ $RECYCLE.BIN/
Network Trash Folder
Temporary Items
.apdisk

*.sh
3 changes: 2 additions & 1 deletion example/example.html
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Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,8 @@
maxZoom: 18,
cellSize: 10,
exp: 3,
max: 1200
max: 1200,
range: 20.0
}).addTo(map);
</script>
</html>
235 changes: 160 additions & 75 deletions src/leaflet-idw.js
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@
this._height = canvas.height;

this._max = 1;
this._range = 0.0;
this._data = [];
}

Expand Down Expand Up @@ -49,6 +50,11 @@
return this;
},

range: function (range) {
this._range = range;
return this;
},

add: function (point) {
this._data.push(point);
return this;
Expand Down Expand Up @@ -110,8 +116,8 @@
ctx.clearRect(0, 0, this._width, this._height);

// draw a grayscale idwmap by putting a cell at each data point
for (var i = 0, len = this._data.length, p; i < len; i++) {
p = this._data[i];
for (var i = this._data.length - 1; i >= 0; i--) {
var p = this._data[i];
ctx.globalAlpha = p[2] / this._max;
ctx.drawImage(this._cell, p[0] - this._r, p[1] - this._r);
}
Expand All @@ -127,12 +133,12 @@

_colorize: function (pixels, gradient, opacity) {
for (var i = 0, len = pixels.length, j; i < len; i += 4) {
j = pixels[i + 3] * 4;

pixels[i] = gradient[j];
pixels[i + 1] = gradient[j + 1];
pixels[i + 2] = gradient[j + 2];
pixels[i + 3] = opacity*256;
j = pixels[i + 3] * 4;
if(this._range > 0.0 && j === 0) continue;
pixels[i] = gradient[j];
pixels[i + 1] = gradient[j + 1];
pixels[i + 2] = gradient[j + 2];
pixels[i + 3] = opacity * 256;
}
}
},
Expand Down Expand Up @@ -232,12 +238,9 @@ L.IdwLayer = (L.Layer ? L.Layer : L.Class).extend({
_updateOptions: function () {
this._idw.cellSize(this.options.cellSize || this._idw.defaultCellSize);

if (this.options.gradient) {
this._idw.gradient(this.options.gradient);
}
if (this.options.max) {
this._idw.max(this.options.max);
}
if(this.options.gradient) this._idw.gradient(this.options.gradient);
if(this.options.max) this._idw.max(this.options.max);
if(this.options.range) this._idw.range(this.options.range);
},

_reset: function () {
Expand All @@ -257,81 +260,120 @@ L.IdwLayer = (L.Layer ? L.Layer : L.Class).extend({
},

_redraw: function () {
if (!this._map) {
return;
}
var data = [],
if (!this._map) return;

var map = this._map,
data = [],
// side length of a cell
r = this._idw._r,
// map size in pixel
size = this._map.getSize(),
// bounds of pixel coordinate on the screen
bounds = new L.Bounds(
L.point([-r, -r]),
size.add([r, r])),

size.add([r, r])
),
// power parameter
exp = this.options.exp === undefined ? 1 : this.options.exp,
max = this.options.max === undefined ? 1 : this.options.max,
// max idw value
maxVal = this.options.max === undefined ? 1 : this.options.max,
maxZoom = this.options.maxZoom === undefined ? this._map.getMaxZoom() : this.options.maxZoom,
v = 1,
range = this.options.range === undefined ? 0.0 : this.options.range,
cellCen = r / 2,
grid = [],
nCellX = Math.ceil((bounds.max.x-bounds.min.x)/r)+1,
nCellY = Math.ceil((bounds.max.y-bounds.min.y)/r)+1,
panePos = this._map._getMapPanePos(),

offsetX = 0,
offsetY = 0,
i, len, p, cell, x, y, j, len2, k;

console.log(nCellX);
console.log(nCellY);
nCellX = Math.ceil((bounds.max.x - bounds.min.x) / r) + 1,
nCellY = Math.ceil((bounds.max.y - bounds.min.y) / r) + 1;

console.time('process');

for (i = 0, len = nCellY; i < len; i++) {
for (j = 0, len2 = nCellX; j < len2; j++) {

var x=i*r,y=j*r;
var numerator=0,denominator=0;

for (k = 0, len3 = this._latlngs.length; k < len3; k++) {

var p = this._map.latLngToContainerPoint(this._latlngs[k]);
var cp = L.point((y-cellCen), (x-cellCen));
var dist = cp.distanceTo(p);

var val =
this._latlngs[k].alt !== undefined ? this._latlngs[k].alt :
this._latlngs[k][2] !== undefined ? +this._latlngs[k][2] : 1;

if(dist===0){
numerator = val;
denominator = 1;
break;
}

var dist2 = Math.pow(dist, exp);
var cellsn = new Array(nCellY),
cellsd = new Array(nCellY);
// initialize cellsn and cellsd to 0
for (var i = 0; i < nCellY; i++) {
cellsn[i] = new Array(nCellX);
cellsd[i] = new Array(nCellX);
for (var j = 0; j < nCellX; j++) {
cellsn[i][j] = 0.0;
cellsd[i][j] = 0.0;
}
}
console.log("number of cell on x-axis:", nCellX);
console.log("number of cell on y-axis:", nCellY);
console.time("process IDW");
if(range > 0.0) {
// left top lat lon coordinate of the screen
var leftTop = map.containerPointToLatLng([0, 0]),
// right bottom lat lon coordinate of the screen
rightBottom = map.containerPointToLatLng([map.getSize().x, map.getSize().y]),
// km per pixel on x-axis
offsetX = Math.abs(leftTop.lng - rightBottom.lng) * 104.64 / map.getSize().x,
// km per pixel on y-axis
offsetY = Math.abs(leftTop.lat - rightBottom.lat) * 110.69 / map.getSize().y
for(var index = this._latlngs.length - 1; index >= 0; index--) {
var p = this._map.latLngToContainerPoint(
L.latLng(this._latlngs[index][0], this._latlngs[index][1])
),
// left pixel coordinate of the cell
x1 = p.x - range / offsetX,
// right
x2 = p.x + range / offsetX,
// top
y1 = p.y - range / offsetY,
// bottom
y2 = p.y + range / offsetY;

// cell coordinate
x1 = Math.round(x1 / r + 0.5);
x2 = Math.ceil(x2 / r - 0.5);
y1 = Math.round(y1 / r + 0.5);
y2 = Math.ceil(y2 / r - 0.5);

// check if x1, x2, y1, y2 out of cellsn, cellsd bounds
if (x2 < 0) continue;
if (x1 >= nCellX) continue;
if (y2 < 0) continue;
if (y1 >= nCellY) continue;

if (x1 < 0) x1 = 0;
if (x2 >= nCellX) x2 = nCellX - 1;
if (y1 < 0) y1 = 0;
if (y2 >= nCellY) y2 = nCellY - 1;
this._idwCalculation(p, r, exp, index, x1, x2, y1, y2, cellCen, cellsd, cellsn,
range, offsetX, offsetY);
}
} else {
for(var index = this._latlngs.length - 1; index >= 0; index--) {
var p = this._map.latLngToContainerPoint(L.latLng(this._latlngs[index][0], this._latlngs[index][1]));
this._idwCalculation(p, r, exp, index,
0, nCellX - 1, 0, nCellY - 1, cellCen, cellsd, cellsn, range);
}
}

numerator += (val/dist2);
denominator += (1/dist2);

for (var i = 0; i < nCellY; i++) {
for (var j = 0; j < nCellX; j++) {
if (cellsd[i][j] < 0.0) {
cellsd[i][j] = 1.0;
}

interpolVal = numerator/denominator;

cell = [j*r, i*r, interpolVal];

if (cell) {
data.push([
Math.round(cell[0]),
Math.round(cell[1]),
Math.min(cell[2], max)
]);
var interpolVal = 0.0
if (cellsd[i][j] === 0.0) {
// cell not used
interpolVal = 0.0;
} else {
interpolVal = cellsn[i][j] / cellsd[i][j];
}
// IDW value
var cell = [
Math.round(j * r),
Math.round(i * r),
Math.min(interpolVal, maxVal)
];

if (cell !== undefined) {
data.push(cell);
}
}
}
console.timeEnd('process');
console.time('draw ' + data.length);
console.timeEnd('process IDW');
console.time("draw " + data.length + " cells");
this._idw.data(data).draw(this.options.opacity);
console.timeEnd('draw ' + data.length);
console.timeEnd("draw " + data.length + " cells");

this._frame = null;
},
Expand All @@ -346,6 +388,49 @@ L.IdwLayer = (L.Layer ? L.Layer : L.Class).extend({
} else {
this._canvas.style[L.DomUtil.TRANSFORM] = L.DomUtil.getTranslateString(offset) + ' scale(' + scale + ')';
}
},

_idwCalculation: function(p, r, exp, index, x1, x2, y1, y2, cellCen, cellsd, cellsn,
range, offsetX, offsetY) {
// array are passed by reference
for (var j = x1; j <= x2; j++) {
for (var i = y1; i <= y2; i++) {
if (cellsd[i][j] < 0.0) {
// center of the cell
// cellsd = -1
continue;
}
// estimated point pixel coordinate
var cp = L.point((j * r + cellCen), (i * r + cellCen));

if(range > 0.0) {
// distance in km on x-axis
var x = (p.x - cp.x) * offsetX;
// distance in km on y-axis
var y = (p.y - cp.y) * offsetY;
var dist = Math.sqrt(x * x + y * y);
if (dist > range) {
// point out of effective range
continue;
}
}
// IDW value
var val = this._latlngs[index].alt !== undefined ? this._latlngs[index].alt :
this._latlngs[index][2] !== undefined ? +this._latlngs[index][2] : 1;
// pixel distance
var d = cp.distanceTo(p);

if (d === 0.0) {
// cell center fills in original value
cellsn[i][j] = val;
cellsd[i][j] = -1;
} else {
var dExp = Math.pow(d, exp);
cellsn[i][j] += (val / dExp);
cellsd[i][j] += (1.0 / dExp);
}
}
}
}
});

Expand Down