Commit Graph

7 Commits

Author SHA1 Message Date
1f00af5741 Collision Detection Fix + Doodad CLI Fixes
Fix collision detection when an actor's hitbox is offset from 0,0:

* Actors having a hitbox that didn't begin at X,Y 0,0 used to experience
  clipping issues with level geometry: because the game tracks their Position
  (top left corner of their graphical sprite) and their target position wasn't
  being correctly offset by their hitbox offset.
* To resolve the issue, an "ActorOffset" struct is added: you give it the
  original game's Actor (with its offset hitbox) and it will record the offset
  and give a mocked Actor for collision detection purposes: where the Position
  and Target can be offset and where its Hitbox claims to begin at 0,0 matching
  its offsetted Position.
* The translation between your original Actor and Offset Actor is handled at the
  boundary of the CollidesWithGrid function, so the main algorithm didn't need
  to be messed with and the game itself doesn't need to care about the offset.

Make some fixes to the doodad CLI tool:

* Fix palette colors being duplicated/doubled when converting from an image.
* The --palette flag in `doodad convert` now actually functions: so you can
  supply an initial palette.json with colors and attributes to e.g. mark which
  colors should be solid or fire and give them names. The palette.json doesn't
  need to be comprehensive: it will be extended with new distinct colors as
  needed during the conversion.
2024-05-27 15:14:00 -07:00
ec0b5ba6ca Rename Go module 2022-09-24 15:17:25 -07:00
8965a7d86a Doodads: Crumbly Floor, Start Flag & State Blocks
Add new doodads:

* Start Flag: place this in a level to set the spawn point of the player
  character. If no flag is found, the player spawns at 0,0 in the top
  corner of the map. Only use one Start Flag per level, otherwise the
  player will randomly spawn at one of them.
* Crumbly Floor: a solid floor that begins to shake and then fall apart
  after a moment when a mobile character steps on it. The floor respawns
  after 5 seconds.
* State Blocks: blue and orange blocks that toggle between solid and
  pass-thru whenever a State Button is activated.
* State Button: a solid "ON/OFF" block that toggles State Blocks back
  and forth when touched. Only activates if touched on the side or bottom;
  acts as a solid floor when walked on from the top.

New features for doodad scripts:

* Actor scripts: call SetMobile(true) to mark an actor as a mobile mob
  (i.e. player character or enemy). Other doodads can check if the actor
  colliding with them IsMobile so they don't activate if placed too close
  to other (non-mobile) doodads in a level. The Blue and Red Azulians
  are the only mobile characters so far.
* Message.Broadcast allows sending a pub/sub message out to ALL doodads
  in the level, instead of only to linked doodads as Message.Publish does.
  This is used for the State Blocks to globally communicate on/off status
  without needing to link them all together manually.
2019-12-30 18:13:28 -08:00
ea0b41a781 Cut lib/render into its own package, change all imports 2019-12-22 18:21:58 -08:00
6af60f1128 Improve Collision Detection: More Active w/ Actors
* Improve the collision detection algorithm so that Actor OnCollide
  scripts get called more often WHILE an actor is moving, to prevent a
  fast-moving actor from zipping right through the "solid" hitbox and
  not giving the subject actor time to protest the movement.
* It's implemented by adding a `Settled` boolean to the OnCollide event
  object. When the game is testing out movement, Settled=false to give
  the actor a chance to say "I'm solid!" and have the moving party be
  stopped early.
* After all this is done, for any pair of actors still with overlapping
  hitboxes, OnCollide is called one last time with Settled=true. This is
  when the actor should run its actions (like publishing messages to
  other actors, changing state as in a trapdoor, etc.)
* The new collision detection algorithm works as follows:
  * Stage 1 is the same as before, all mobile actors are moved and
    tested against level geometry. They record their Original and New
    position during this phase.
  * Stage 2 is where we re-run that movement but ping actors being
    intersected each step of the way. We trace the steps between
    Original and New position, test OnCollide handler, and if it returns
    false we move the mobile actor to the Last Good Position along the
    trace.
  * Stage 3 we run the final OnCollide(Settled=true) to let actors run
    actions they wanted to for their collide handler, WITHOUT spamming
    those actions during Stage 2.
* This should now allow for tweaking of gravity speed and player speed
  without breaking all actor collision checking.
2019-07-16 21:07:38 -07:00
a2e1bd1ccb Improve OnCollide Doodad Script Handling
* Events.OnCollide now receives a CollideEvent object, which makes
  available the .Actor who collided and the .Overlap rect which is
  zero-relative to the target actor. Doodad scripts can use the .Overlap
  to see WHERE in their own box the other actor has intruded.
  * Update the LockedDoor and ElectricDoor doodads to detect when the
    player has entered their inner rect (since their doors are narrower
    than their doodad size)
  * Update the Button doodads to only press in when the player actually
    touches them (because their sizes are shorter than their doodad
    height)
  * Update the Trapdoor to only trigger its animation when the board
    along its top has been touched, not when the empty space below was
    touched from the bottom.
* Events.OnLeave now implemented and fires when an actor who was
  previously intersecting your doodad has left.
* The engine detects when an event JS callback returns false.
  Eventually, the OnCollide can return false to signify the collision is
  not accepted and the actor should be bumped away as if they hit solid
  geometry.
2019-05-06 22:58:09 -07:00
b33d93599a Unit Tests for Collision Detection 2019-04-15 20:19:52 -07:00