ichigo/engine/misc.go

package engine

import "image"

// ID implements Identifier directly (as a string value).
type ID string

// Ident returns id as a string.
func (id ID) Ident() string { return string(id) }

// Bounds implements Bounder directly (as an image.Rectangle value).
type Bounds image.Rectangle

// BoundingRect returns b as an image.Rectangle.
func (b Bounds) BoundingRect() image.Rectangle { return image.Rectangle(b) }

// Disabled implements Disabler directly (as a bool).
type Disabled bool

// IsHidden returns h as a bool.
func (d Disabled) IsDisabled() bool { return bool(d) }

// Hide sets h to true.
func (d *Disabled) Disable() { *d = true }

// Show sets h to false.
func (d *Disabled) Enable() { *d = false }

// Hidden implements Hider directly (as a bool).
type Hidden bool

// IsHidden returns h as a bool.
func (h Hidden) IsHidden() bool { return bool(h) }

// Hide sets h to true.
func (h *Hidden) Hide() { *h = true }

// Show sets h to false.
func (h *Hidden) Show() { *h = false }

// ZOrder implements DrawOrder (in Drawer) directly (as an int value).
type ZOrder int

// DrawOrder returns z as a int with 0 bias.
func (z ZOrder) DrawOrder() (int, int) { return int(z), 0 }

// ---------- Some helpers for image.Point ----------

// cmul performs componentwise multiplication of two image.Points.
func cmul(p, q image.Point) image.Point {
	return image.Point{p.X * q.X, p.Y * q.Y}
}

// cdiv performs componentwise division of two image.Points.
func cdiv(p, q image.Point) image.Point {
	return image.Point{p.X / q.X, p.Y / q.Y}
}

// cfloat returns the components of an image.Point as two floats.
func cfloat(p image.Point) (x, y float64) {
	return float64(p.X), float64(p.Y)
}

// dot returns the dot product of two image.Points.
func dot(p, q image.Point) int {
	return p.X*q.X + p.Y*q.Y
}