doodle/pkg/doodads/actor.go

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package doodads
import (
"git.kirsle.net/go/render"
)
// Actor is a reusable run-time drawing component used in Doodle. Actors are an
// active instance of a Doodad which have a position, velocity, etc.
type Actor interface {
ID() string
// Position and velocity, not saved to disk.
Position() render.Point
Velocity() render.Point
Size() render.Rect
Grounded() bool
SetGrounded(bool)
// Actor's elected hitbox set by their script.
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// SetHitbox(x, y, w, h int)
// Hitbox() render.Rect
// Movement commands.
MoveBy(render.Point) // Add {X,Y} to current Position.
MoveTo(render.Point) // Set current Position to {X,Y}.
}
// GetBoundingRect computes the full pairs of points for the bounding box of
// the actor.
//
// The X,Y coordinates are the position in the level of the actor,
// The W,H are the size of the actor's drawn box.
func GetBoundingRect(d Actor) render.Rect {
var (
P = d.Position()
S = d.Size()
)
return render.Rect{
X: P.X,
Y: P.Y,
W: S.W,
H: S.H,
}
}
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// GetBoundingRectHitbox returns the bounding rect of the Actor taking into
// account their self-declared collision hitbox.
//
// The rect returned has the X,Y coordinate set to the actor's position, plus
// the X,Y of their hitbox, if any.
//
// The W,H of the rect is the W,H of their declared hitbox.
//
// If the actor has NOT declared its hitbox, this function returns exactly the
// same way as GetBoundingRect() does.
func GetBoundingRectHitbox(d Actor, hitbox render.Rect) render.Rect {
rect := GetBoundingRect(d)
if !hitbox.IsZero() {
rect.X += hitbox.X
rect.Y += hitbox.Y
rect.W = hitbox.W
rect.H = hitbox.H
}
return rect
}
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// GetBoundingRectWithHitbox is like GetBoundingRect but adjusts it for the
// relative hitbox of the actor.
// func GetBoundingRectWithHitbox(d Actor, hitbox render.Rect) render.Rect {
// rect := GetBoundingRect(d)
// rect.W = hitbox.W
// rect.H = hitbox.H
// return rect
// }