pixel-examples/community/game_of_life/life/grid.go

75 lines
1.6 KiB
Go

package life
import (
"github.com/faiface/pixel"
"github.com/faiface/pixel/imdraw"
"golang.org/x/image/colornames"
)
// Shamelessly taken/inspired by https://golang.org/doc/play/life.go
// Grid is the structure in which the cellular automota live
type Grid struct {
h int
cellSize int
Cells [][]bool
}
// NewGrid constructs a new Grid
func NewGrid(h, size int) *Grid {
cells := make([][]bool, h)
for i := 0; i < h; i++ {
cells[i] = make([]bool, h)
}
return &Grid{h: h, cellSize: size, Cells: cells}
}
// Alive returns whether the specified position is alive
func (g *Grid) Alive(x, y int) bool {
x += g.h
x %= g.h
y += g.h
y %= g.h
return g.Cells[y][x]
}
// Set sets the state of a specific location
func (g *Grid) Set(x, y int, state bool) {
g.Cells[y][x] = state
}
// Draw draws the grid
func (g *Grid) Draw(imd *imdraw.IMDraw) {
for i := 0; i < g.h; i++ {
for j := 0; j < g.h; j++ {
if g.Alive(i, j) {
imd.Color = colornames.Black
} else {
imd.Color = colornames.White
}
imd.Push(
pixel.V(float64(i*g.cellSize), float64(j*g.cellSize)),
pixel.V(float64(i*g.cellSize+g.cellSize), float64(j*g.cellSize+g.cellSize)),
)
imd.Rectangle(0)
}
}
}
// Next returns the next state
func (g *Grid) Next(x, y int) bool {
// Count the adjacent cells that are alive.
alive := 0
for i := -1; i <= 1; i++ {
for j := -1; j <= 1; j++ {
if (j != 0 || i != 0) && g.Alive(x+i, y+j) {
alive++
}
}
}
// Return next state according to the game rules:
// exactly 3 neighbors: on,
// exactly 2 neighbors: maintain current state,
// otherwise: off.
return alive == 3 || alive == 2 && g.Alive(x, y)
}