Zoom level error with non-baselayer TMS layers (resolution floats) [#1165350]

since #1159328: TMS baselayer functionality we have the baselayer switcher available when defining TMS layers. this enables to define a layer as either baselayer or overlay layer.

when i use the overlay functionality with a custom MBTiles tilemill export with zoom levels 0-8 there is a problem that the map won't work for certain zoom levels. for zoom levels great than 4, the zoom-level part of the tile image links being generated will be set to -1 instead of the correct value from 5-8:
http://mysite/1.0.0/my_map/-1/18/20.png

as tmcw stated in the #mapbox irc channel there seems to be some PHP number conversion problem in D7 but we couldn't really figure out how exactly that's being caused...

Comment	File	Size	Author
#10	zoom-level-error-1165350-10.patch	755 bytes	mgifford
#10

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Comments

Comment #1

zzolo CreditAttribution: zzolo commented 22 May 2011 at 18:53

Title:

Zoom level error with non-baselayer TMS layers

» Zoom level error with non-baselayer TMS layers (resolution floats)

From this old issue, it seems like it is a general problem with floats and resolutions. #842026: Resolutions arrays must be cast to strings for export (marking other as duplicate)

Comment #2

dasjo

he/him

German

Zurich

CreditAttribution: dasjo commented 26 May 2011 at 08:18

interesting, do you think there is an easy fix to that issue?

Comment #3

dasjo

he/him

German

Zurich

CreditAttribution: dasjo commented 15 July 2011 at 01:30

i'm currently travelling central america to do some presentations about drupal and i would love to show tilemill integration as well. would be great if there was some fix / workarround to the issue described above as it basically prevents custom tilemill maps from being shown using openlayers.

zzolo, can you think of a way to tackle this? i am happy to do some testing here

Comment #4

MW CreditAttribution: MW commented 21 July 2011 at 16:51

i have modified the following file
all\modules\openlayers\js\openlayer.js at lines 64 and 70 for tms basemaps

// TODO: work around this scary code
if (map.projection === '900913') {
options.maxExtent = new OpenLayers.Bounds(
-20037508.34, -20037508.34, 20037508.34, 20037508.34);
options.units = "m";
}
if (map.projection === '4326') {
options.maxExtent = new OpenLayers.Bounds(-180, -90, 180, 90);
}

options.maxResolution = "auto"; //1.40625;
options.controls = [];