Drawing ‘Straight’ label with LABEL_NO_CLIP, if “Follow” label drawing fails.

[nnikolov]

When ANGLE “Follow” option is set for label rendering, if a “follow” label drawing fails (in msPolylineLabelPath()) under some circumstances, it defaults to drawing ‘straight’ labels (using msPolylineLabelPoint()). However, when LABEL_NO_CLIP option is ON, the code does not follow the above logic. There are two identical places in mapdraw.c file (line 1403 - 1407 and 1605-1609) where the problem is:

if(layer->class[c]->label.autofollow == MS_TRUE ) {

annopath = msPolylineLabelPath(&annoshape, layer->class[c]->label.minfeaturesize, &(map->fontset), shape->text, &(layer->class[c]->label), layer->scalefactor, &status);

} else {

annocallret = msPolylineLabelPoint(&annoshape, &annopnt, layer->class[c]->label.minfeaturesize, &angle, &length);

}

The proposed fix is to replace the above lines (in both places) with the following lines:

if(layer->class[c]->label.autofollow == MS_TRUE ) {

annopath = msPolylineLabelPath(&annoshape, layer->class[c]->label.minfeaturesize, &(map->fontset), labelshapePtr->text, &(layer->class[c]->label), layer->scalefactor, &status);

}

/* Use regular label algorithm if angle is AUTO or a number, or if ANGLE FOLLOW failed */

if ( layer->class[c]->label.autofollow == MS_FALSE

(!annopath && status != MS_FAILURE) ) {

annocallret = msPolylineLabelPoint(&annoshape, &annopnt, layer->class[c]->label.minfeaturesize, &angle, &length);

}

[aboudreault]

Steve, Do you want I take care of this one?

[sdlime]

Alan: This looks to still be an issue, can you take a peek? The label path code is more complex in 6.0 and it's not clear at first glance how you detect failure. Must be a 0 in one of the counters.

Steve

[aboudreault]

Will take a look.

[aboudreault]

nnikolov, could you attach a test case to test this easily?