diff --git a/src/ol/renderer/canvas/canvastilelayerrenderer.js b/src/ol/renderer/canvas/canvastilelayerrenderer.js
index 9c338b7818..717e23d879 100644
--- a/src/ol/renderer/canvas/canvastilelayerrenderer.js
+++ b/src/ol/renderer/canvas/canvastilelayerrenderer.js
@@ -1,4 +1,3 @@
-// FIXME don't redraw tiles if not needed
// FIXME find correct globalCompositeOperation
// FIXME optimize :-)
@@ -51,6 +50,12 @@ ol.renderer.canvas.TileLayer = function(mapRenderer, tileLayer) {
*/
this.transform_ = goog.vec.Mat4.createNumber();
+ /**
+ * @private
+ * @type {Array.
}
+ */
+ this.renderedTiles_ = null;
+
};
goog.inherits(ol.renderer.canvas.TileLayer, ol.renderer.canvas.Layer);
@@ -96,10 +101,11 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
var tileResolution = tileGrid.getResolution(z);
var tileRange = tileGrid.getTileRangeForExtentAndResolution(
frameState.extent, tileResolution);
+ var tileRangeWidth = tileRange.getWidth();
+ var tileRangeHeight = tileRange.getHeight();
var canvasSize = new ol.Size(
- tileSize.width * tileRange.getWidth(),
- tileSize.height * tileRange.getHeight());
+ tileSize.width * tileRangeWidth, tileSize.height * tileRangeHeight);
var canvas, context;
if (goog.isNull(this.canvas_)) {
@@ -111,6 +117,7 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
this.canvas_ = canvas;
this.canvasSize_ = canvasSize;
this.context_ = context;
+ this.renderedTiles_ = new Array(tileRangeWidth * tileRangeHeight);
} else {
canvas = this.canvas_;
context = this.context_;
@@ -118,11 +125,10 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
canvas.width = canvasSize.width;
canvas.height = canvasSize.height;
this.canvasSize_ = canvasSize;
+ this.renderedTiles_ = new Array(tileRangeWidth * tileRangeHeight);
}
}
- context.clearRect(0, 0, canvasSize.width, canvasSize.height);
-
/**
* @type {Object.>}
*/
@@ -169,9 +175,12 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
/** @type {Array.} */
var zs = goog.array.map(goog.object.getKeys(tilesToDrawByZ), Number);
goog.array.sort(zs);
+ var opaque = tileSource.getOpaque();
var origin = tileGrid.getTileCoordExtent(
new ol.TileCoord(z, tileRange.minX, tileRange.maxY)).getTopLeft();
- var currentZ, i, scale, tileCoordKey, tileExtent, tilesToDraw;
+ var currentZ, i, index, scale, tileCoordKey, tileExtent, tilesToDraw;
+ var ix, iy, interimTileExtent, interimTileRange, maxX, maxY, minX, minY;
+ var height, width;
for (i = 0; i < zs.length; ++i) {
currentZ = zs[i];
tileSize = tileGrid.getTileSize(currentZ);
@@ -179,22 +188,44 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
if (currentZ == z) {
for (tileCoordKey in tilesToDraw) {
tile = tilesToDraw[tileCoordKey];
- context.drawImage(
- tile.getImage(),
- tileSize.width * (tile.tileCoord.x - tileRange.minX),
- tileSize.height * (tileRange.maxY - tile.tileCoord.y));
+ tileCoord = tile.tileCoord;
+ index = (tileCoord.y - tileRange.minY) * tileRangeWidth +
+ (tileCoord.x - tileRange.minX);
+ if (this.renderedTiles_[index] != tile) {
+ x = tileSize.width * (tile.tileCoord.x - tileRange.minX);
+ y = tileSize.height * (tileRange.maxY - tile.tileCoord.y);
+ if (!opaque) {
+ context.clearRect(x, y, tileSize.width, tileSize.height);
+ }
+ context.drawImage(tile.getImage(), x, y);
+ this.renderedTiles_[index] = tile;
+ }
}
} else {
scale = tileGrid.getResolution(currentZ) / tileResolution;
for (tileCoordKey in tilesToDraw) {
tile = tilesToDraw[tileCoordKey];
tileExtent = tileGrid.getTileCoordExtent(tile.tileCoord);
- context.drawImage(
- tile.getImage(),
- (tileExtent.minX - origin.x) / tileResolution,
- (origin.y - tileExtent.maxY) / tileResolution,
- scale * tileSize.width,
- scale * tileSize.height);
+ x = (tileExtent.minX - origin.x) / tileResolution;
+ y = (origin.y - tileExtent.maxY) / tileResolution;
+ width = scale * tileSize.width;
+ height = scale * tileSize.height;
+ if (!opaque) {
+ context.clearRect(x, y, width, height);
+ }
+ context.drawImage(tile.getImage(), x, y, width, height);
+ interimTileRange =
+ tileGrid.getTileRangeForExtentAndZ(tileExtent, z);
+ minX = Math.max(interimTileRange.minX, tileRange.minX);
+ maxX = Math.min(interimTileRange.maxX, tileRange.maxX);
+ minY = Math.max(interimTileRange.minY, tileRange.minY);
+ maxY = Math.min(interimTileRange.maxY, tileRange.maxY);
+ for (ix = minX; ix <= maxX; ++ix) {
+ for (iy = minY; iy <= maxY; ++iy) {
+ this.renderedTiles_[(iy - tileRange.minY) * tileRangeWidth +
+ (ix - tileRange.minX)] = undefined;
+ }
+ }
}
}
}