~CROP(offset,0,w,h) causes honeycomb in large terrain imgs

[doofus-01]

I tried to make an animated terrain by shifting a large image that was not fully displayed, using CROP() image path function. It is supposed to be distant terrain scrolling by.(http://forums.wesnoth.org/viewtopic.php ... 66#p482866) But instead, each hex independently slides away, the pixels it vacates show the underlying images. Here are some pictures:

Spoiler:

this is with not much of an offset, big image layer is -999

this is same layer=-999, but with a larger offset (further in the animation)

this is with layer=15

On the right side of crop-error.png, there is noticeable green slash showing through the bluish chasm edge. It's like that part of the cropped image, which shouldn't show, is getting redrawn, while the parts that are supposed to be are not (the dark blue is a lower layer). Like minus sign got dropped somewhere or something like that.

This is my WML, the image names should be changed though:

Spoiler:

Code: Select all

[terrain_graphics]
map="
.,.,.,.,.,.,.,.,.
,.,.,.,*,*,.,.,.,.
.,.,.,*,*,*,.,.,.
,.,.,*,*,*,*,.,.,.
.,.,*,*,*,*,.,.,.
,.,*,*,*,*,*,.,.,.
.,.,*,*,*,*,*,.,.
,.,*,*,*,*,*,*,.,.
.,*,*,*,*,*,*,*,.
,.,*,*,*,*,*,*,*,.
.,*,*,*,*,*,*,*,.
,.,*,*,*,*,*,*,*,.
.,*,*,*,*,*,*,*,.
,.,*,.,*,*,*,*,.,.
.,.,.,.,.,*,*,.,.
,.,.,.,.,.,*,.,.,.
.,1,.,.,.,.,.,.,."

        [tile]
        pos=1
        type=Tshy
        set_no_flag=sky-hole
        [/tile]
        [image]
            layer=15
            name="backdrops/sky-map.png~CROP(0,0,700,715):500,backdrops/sky-map.png~CROP(2,0,700,715):500,backdrops/sky-map.png~CROP(4,0,700,715):500,backdrops/sky-map.png~CROP(6,0,700,715):500,
backdrops/sky-map.png~CROP(8,0,700,715):500,backdrops/sky-map.png~CROP(10,0,700,715):500,backdrops/sky-map.png~CROP(12,0,700,715):500,backdrops/sky-map.png~CROP(12,0,700,715):500"
        [/image]
        probability=100
[/terrain_graphics]
{OVERLAY_LF             Tshy                       -999      cover          ice/floor}

As I'm writing this, it occurs to me that I did not try all mainline images, but even if that has an effect, there is still a problem. The sky-map.png image is 1814X729. Everything looks fine in the first frame.

EDIT: bug report

[doofus-01]

I've got a way to more easily recreate this.

1. I needed a large image, so I copied wesnoth-icon.png into the "terrain" folder of images.
2. Edit terrain-graphics.cfg so that one of the mainline terrains uses wesnoth-icon.png and CROP() function.

example using Rp

Code: Select all

#{TERRAIN_BASE_RANDOM     Rp                                                        flat/stone-path}
#########
{DISABLE_BASE_TRANSITIONS  Rp}
    [terrain_graphics]
        map="
, * , .
* , * , .
, 1 , .
* , * , .
, * , ."

        [tile]
            pos=1
            type=Rp
            set_no_flag=base
        [/tile]

        probability=100
        [image]
            name="wesnoth-icon.png~CROP(0,0,72,72):1500,wesnoth-icon.png~CROP(5,0,72,72):500,
wesnoth-icon.png~CROP(10,0,72,72):500,wesnoth-icon.png~CROP(15,0,72,72):500"
            layer=-999
            center=86,144
        [/image]
    [/terrain_graphics]

3. Open the map editor and try it out. I used shroud hexes to push the grass transitions away. I also fiddled with the crop width and height (all value 72 in the example above) and it did not behave like I'd expected.

Left is with no offest, right is with offset in x

To be clear, what I think this should do is shift a cropped wesnoth-icon.png to the left. Instead, it is making a mess.

[zookeeper]

Looks like a bug to me...