[PATCH] Destroy sheep corpses when constructing buildings

[elexis]

When a sheep or other animal is killed and a building is constructed in the same place, gathering units will try to reach the corpse but never reach it. When constructing buildings, these corpses should be deleted.

[fatherbushido]

I don't know if we have still the related bug: 'the ptolemaic camel archer kill a sheep wich was moving near the cc and then it tries to gather the corpse and doesn't suceed)".

[elexis]

r17156 introduced the bug, before then the entity was destroyed.

Before that commit, the obstruction of the dead animal was:

    obstruction: {
        active: true,
        blockMovement: true,
        blockPathfinding: false,
        blockFoundation: false,
        blockConstruction: true,
        disableBlockMovement: false,
        disableBlockPathfinding: false,
        shape: {
            type: "cluster"
        }

After that commit it was

    obstruction: {
        active: true,
        blockMovement: false,
        blockPathfinding: false,
        blockFoundation: false,
        blockConstruction: false,
        disableBlockMovement: false,
        disableBlockPathfinding: false,
        shape: {
            type: "static",
            width: 2,
            depth: 2
        }
    },

I have set the blockConstruction flag in the XML part of the TemplateLoader for dead gatherable animals, but that alone didn't do the trick. This is also the flag that the Foundation component checks for in the Build function (defined in GetUnitCollisions()). The blockMovement tag also wasn't it.

[elexis]

Sample replay for alpha 21 / r18804. The killed sheep is still visible and selectable in the middle of the fortress.

[wraitii]

See logs on October 8 2016 for more information on this issue.

Git branch for testing: ​https://github.com/wraitii/0ad/tree/sheepFix

Should focus on putting various stuff under foundations and seeing how it reacts, and also check if walls and gates act sanely.

[elexis]

• The flags should be accessible through the component, defined in JS, or it should become a boolean argument

[elexis]

Looks better with the most recent git commit, but I think that Obstruction.js comment wasn't intentional.

[wraitii]

Rebased branch, squashed into a single commit. Ready for review and commit.

[elexis]

Moving to the new WIP milestone.

[Itms]

Style fixes:

• the PROFILE call has a typo in the name
• the split line in GetStaticsOnObstruction has bad indentation (coming from copy-paste), see the other function and copy that indentation.
• remove the comment in GetAllOnObstruction
• you didn't replace all occurrences in the public mod of GetUnitCollisions that you removed from the API

For me the big problem of this patch is this boolean passed to GetCollisions which has an obfuscated name. It should be clear in the API what this boolean does (i.e. without having to understand the whole code in the Obstruction component).

I suggest calling the boolean onlyConstructionBlocking (and probably making it optional, with a default value of true). Then comments should be detailed more in the function (explain in the first comment that living animals have the flag while dead ones are static obstructions without the flag). Add a remark that if the boolean is false, the filter filters nothing and is equivalent to NullObstructionFilter.

Then I would add a comment in the Foundation.js code to explain that this code cleans everything under the foundation (corpses and other non foundation-blocking obstructions).

[elexis]

In 21597:

Delete sheep corpses when starting to build a foundation,

so that units don't try to gather forever while not being able to reach it and
so that the sheep corpse can't be selected and seen anymore.

Differential Revision: ​https://code.wildfiregames.com/D21
Fixes #4268
Based On Patch By: wraitii
Reviewed By: temple
Previously Reviewed By: Itms

[elexis]

Everyone who had written or reviewed the patch (me, temple wraitii, Itms) haven't considered the flag 0 well evidently.

As reported by temple in ​Phab:rP21597, placing a foundation in the fog of war yields a foundation that is never going to be constructed as it is blocked by it's own mirage.

[elexis]

​Phab:D1415

[elexis]

In 21624:

Fix mirages (and any other entity that blocks something but not BlockConstruction) blocking foundation construction following rP21597 / D21.
Clean the code by removing the animal hardcoding in the Foundation component and adding a flag DeleteUponConstruction to the Obstruction component.

Have locked gates and upgraded entities equally delete entities when transforming.
Add a workaround for trees inside walls on random maps.

Reviewed by: temple
Differential Revision: ​https://code.wildfiregames.com/D1415
Refs #4268