Only evaluate CrossFaded properties at integer zooms (#6430)

* validate non-integer stops for crossfaded properties * add to style spec docs * remove validation errors, only evalutate CrossFaded props at integer zooms * reword spec
mapbox · Apr 13, 2018 · 9090d10 · 9090d10
1 parent 6997943
commit 9090d10
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Showing 2 changed files with 8 additions and 8 deletions.
diff --git a/src/style-spec/reference/v8.json b/src/style-spec/reference/v8.json
@@ -2860,7 +2860,7 @@
       "function": "piecewise-constant",
       "zoom-function": true,
       "transition": true,
-      "doc": "Name of image in sprite to use for drawing image fills. For seamless patterns, image width and height must be a factor of two (2, 4, 8, ..., 512).",
+      "doc": "Name of image in sprite to use for drawing image fills. For seamless patterns, image width and height must be a factor of two (2, 4, 8, ..., 512). Note that zoom-dependent expressions will be evaluated only at integer zoom levels.",
       "sdk-support": {
         "basic functionality": {
           "js": "0.10.0",
@@ -2975,7 +2975,7 @@
       "function": "piecewise-constant",
       "zoom-function": true,
       "transition": true,
-      "doc": "Name of image in sprite to use for drawing images on extruded fills. For seamless patterns, image width and height must be a factor of two (2, 4, 8, ..., 512).",
+      "doc": "Name of image in sprite to use for drawing images on extruded fills. For seamless patterns, image width and height must be a factor of two (2, 4, 8, ..., 512). Note that zoom-dependent expressions will be evaluated only at integer zoom levels.",
       "sdk-support": {
         "basic functionality": {
           "js": "0.27.0",
@@ -3245,7 +3245,7 @@
       "value": "number",
       "function": "piecewise-constant",
       "zoom-function": true,
-      "doc": "Specifies the lengths of the alternating dashes and gaps that form the dash pattern. The lengths are later scaled by the line width. To convert a dash length to pixels, multiply the length by the current line width. Note that GeoJSON sources with `lineMetrics: true` specified won't render dashed lines to the expected scale.",
+      "doc": "Specifies the lengths of the alternating dashes and gaps that form the dash pattern. The lengths are later scaled by the line width. To convert a dash length to pixels, multiply the length by the current line width. Note that GeoJSON sources with `lineMetrics: true` specified won't render dashed lines to the expected scale. Also note that zoom-dependent expressions will be evaluated only at integer zoom levels.",
       "minimum": 0,
       "transition": true,
       "units": "line widths",
@@ -3269,7 +3269,7 @@
       "function": "piecewise-constant",
       "zoom-function": true,
       "transition": true,
-      "doc": "Name of image in sprite to use for drawing image lines. For seamless patterns, image width must be a factor of two (2, 4, 8, ..., 512).",
+      "doc": "Name of image in sprite to use for drawing image lines. For seamless patterns, image width must be a factor of two (2, 4, 8, ..., 512). Note that zoom-dependent expressions will be evaluated only at integer zoom levels.",
       "sdk-support": {
         "basic functionality": {
           "js": "0.10.0",
@@ -4313,7 +4313,7 @@
       "function": "piecewise-constant",
       "zoom-function": true,
       "transition": true,
-      "doc": "Name of image in sprite to use for drawing an image background. For seamless patterns, image width and height must be a factor of two (2, 4, 8, ..., 512).",
+      "doc": "Name of image in sprite to use for drawing an image background. For seamless patterns, image width and height must be a factor of two (2, 4, 8, ..., 512). Note that zoom-dependent expressions will be evaluated only at integer zoom levels.",
       "sdk-support": {
         "basic functionality": {
           "js": "0.10.0",

diff --git a/src/style/properties.js b/src/style/properties.js
@@ -598,9 +598,9 @@ export class CrossFadedProperty<T> implements Property<T, ?CrossFaded<T>> {
         } else {
             assert(!value.isDataDriven());
             return this._calculate(
-                value.expression.evaluate({zoom: parameters.zoom - 1.0}),
-                value.expression.evaluate({zoom: parameters.zoom}),
-                value.expression.evaluate({zoom: parameters.zoom + 1.0}),
+                value.expression.evaluate({zoom: Math.floor(parameters.zoom - 1.0)}),
+                value.expression.evaluate({zoom: Math.floor(parameters.zoom)}),
+                value.expression.evaluate({zoom: Math.floor(parameters.zoom + 1.0)}),
                 parameters);
         }
     }