Commit Graph

3 Commits

Author SHA1 Message Date
08e65c32b5 Overhaul the Platformer Physics System
* Player character now experiences acceleration and friction when
  walking around the map!
* Actor position and movement had to be converted from int's
  (render.Point) to float64's to support fine-grained acceleration
  steps.
* Added "physics" package and physics.Vector to be a float64 counterpart
  for render.Point. Vector is used for uix.Actor.Position() for the sake
  of movement math. Vector is flattened back to a render.Point for
  collision purposes, since the levels and hitboxes are pixel-bound.
* Refactor the uix.Actor to no longer extend the doodads.Drawing (so it
  can have a Position that's a Vector instead of a Point). This broke
  some code that expected `.Doodad` to directly reference the
  Drawing.Doodad: now you had to refer to it as `a.Drawing.Doodad` which
  was ugly. Added convenience method .Doodad() for a shortcut.
* Moved functions like GetBoundingRect() from doodads package to
  collision, where it uses its own slimmer Actor interface for just the
  relevant methods it needs.
2020-04-04 21:00:32 -07:00
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
cb02feff1d Add Switches, Fire/Water Collision and Play Menu
* New doodads: Switches.
  * They come in four varieties: wall switch (background element, with
    "ON/OFF" text) and three side-profile switches for the floor, left
    or right walls.
  * On collision with the player, they flip their state from "OFF" to
    "ON" or vice versa. If the player walks away and then collides
    again, the switch flips again.
  * Can be used to open/close Electric Doors when turned on/off. Their
    default state is "off"
  * If a switch receives a power signal from another linked switch, it
    sets its own state to match. So, two "on/off" switches that are
    connected to a door AND to each other will both flip on/off when one
    of them flips.
* Update the Level Collision logic to support Decoration, Fire and Water
  pixel collisions.
  * Previously, ALL pixels in the level were acting as though solid.
  * Non-solid pixels don't count for collision detection, but their
    attributes (fire and water) are collected and returned.
* Updated the MenuScene to support loading a map file in Play Mode
  instead of Edit Mode. Updated the title screen menu to add a button
  for playing levels instead of editing them.
* Wrote some documentation.
2019-07-06 18:30:03 -07:00