context.mozBackingStorePixelRatio ||
context.msBackingStorePixelRatio ||
context.oBackingStorePixelRatio ||
- context.backingStorePixelRatio;
- if (devicePixelRatio !== undefined &&
- backingStorePixelRatio !== undefined) {
+ context.backingStorePixelRatio || 1;
+ if (devicePixelRatio !== undefined) {
return devicePixelRatio / backingStoreRatio;
} else {
- // If either value is undefined, the ratio is meaningless so we want to
- // return 1.
+ // At least devicePixelRatio must be defined for this ratio to make sense.
+ // We default backingStoreRatio to 1: this does not exist on some browsers
+ // (i.e. desktop Chrome).
return 1;
}
} catch (e) {