doodle/pkg/uix/canvas_link_tool.go
Noah Petherbridge 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

37 lines
818 B
Go

package uix
import (
"errors"
"git.kirsle.net/apps/doodle/pkg/drawtool"
"git.kirsle.net/apps/doodle/pkg/shmem"
)
// LinkStart initializes the Link tool.
func (w *Canvas) LinkStart() {
w.Tool = drawtool.LinkTool
w.linkFirst = nil
}
// LinkAdd adds an actor to be linked in the Link tool.
func (w *Canvas) LinkAdd(a *Actor) error {
if w.linkFirst == nil {
// First click, hold onto this actor.
w.linkFirst = a
shmem.Flash("Doodad '%s' selected, click the next Doodad to link it to",
a.Doodad().Title,
)
} else {
// Second click, call the OnLinkActors handler with the two actors.
if w.OnLinkActors != nil {
w.OnLinkActors(w.linkFirst, a)
} else {
return errors.New("Canvas.LinkAdd: no OnLinkActors handler is ready")
}
// Reset the link state.
w.linkFirst = nil
}
return nil
}