examples/life: Refactoring

This commit is contained in:
Hajime Hoshi 2018-05-13 00:33:11 +09:00
parent f7c19ef517
commit b69d564d89

View File

@ -35,21 +35,17 @@ import (
// World represents the game state. // World represents the game state.
type World struct { type World struct {
area [][]bool area []bool
} width int
height int
func newArea(width, height int) [][]bool {
a := make([][]bool, height)
for i := 0; i < height; i++ {
a[i] = make([]bool, width)
}
return a
} }
// NewWorld creates a new world. // NewWorld creates a new world.
func NewWorld(width, height int, maxInitLiveCells int) *World { func NewWorld(width, height int, maxInitLiveCells int) *World {
w := &World{ w := &World{
area: newArea(width, height), area: make([]bool, width*height),
width: width,
height: height,
} }
w.init(maxInitLiveCells) w.init(maxInitLiveCells)
return w return w
@ -61,43 +57,41 @@ func init() {
// init inits world with a random state. // init inits world with a random state.
func (w *World) init(maxLiveCells int) { func (w *World) init(maxLiveCells int) {
height := len(w.area)
width := len(w.area[0])
for i := 0; i < maxLiveCells; i++ { for i := 0; i < maxLiveCells; i++ {
x := rand.Intn(width) x := rand.Intn(w.width)
y := rand.Intn(height) y := rand.Intn(w.height)
w.area[y][x] = true w.area[y*w.width+x] = true
} }
} }
// Update game state by one tick. // Update game state by one tick.
func (w *World) Update() { func (w *World) Update() {
height := len(w.area) width := w.width
width := len(w.area[0]) height := w.height
next := newArea(width, height) next := make([]bool, width*height)
for y := 0; y < height; y++ { for y := 0; y < height; y++ {
for x := 0; x < width; x++ { for x := 0; x < width; x++ {
pop := neighbourCount(w.area, x, y) pop := neighbourCount(w.area, width, height, x, y)
switch { switch {
case pop < 2: case pop < 2:
// rule 1. Any live cell with fewer than two live neighbours // rule 1. Any live cell with fewer than two live neighbours
// dies, as if caused by under-population. // dies, as if caused by under-population.
next[y][x] = false next[y*width+x] = false
case (pop == 2 || pop == 3) && w.area[y][x]: case (pop == 2 || pop == 3) && w.area[y*width+x]:
// rule 2. Any live cell with two or three live neighbours // rule 2. Any live cell with two or three live neighbours
// lives on to the next generation. // lives on to the next generation.
next[y][x] = true next[y*width+x] = true
case pop > 3: case pop > 3:
// rule 3. Any live cell with more than three live neighbours // rule 3. Any live cell with more than three live neighbours
// dies, as if by over-population. // dies, as if by over-population.
next[y][x] = false next[y*width+x] = false
case pop == 3: case pop == 3:
// rule 4. Any dead cell with exactly three live neighbours // rule 4. Any dead cell with exactly three live neighbours
// becomes a live cell, as if by reproduction. // becomes a live cell, as if by reproduction.
next[y][x] = true next[y*width+x] = true
} }
} }
} }
@ -106,22 +100,17 @@ func (w *World) Update() {
// Draw paints current game state. // Draw paints current game state.
func (w *World) Draw(pix []byte) { func (w *World) Draw(pix []byte) {
height := len(w.area) for i, v := range w.area {
width := len(w.area[0]) if v {
for y := 0; y < height; y++ { pix[4*i] = 0xff
for x := 0; x < width; x++ { pix[4*i+1] = 0xff
idx := 4*y*width + 4*x pix[4*i+2] = 0xff
if w.area[y][x] { pix[4*i+3] = 0xff
pix[idx] = 0xff } else {
pix[idx+1] = 0xff pix[4*i] = 0
pix[idx+2] = 0xff pix[4*i+1] = 0
pix[idx+3] = 0xff pix[4*i+2] = 0
} else { pix[4*i+3] = 0
pix[idx] = 0
pix[idx+1] = 0
pix[idx+2] = 0
pix[idx+3] = 0
}
} }
} }
} }
@ -141,21 +130,19 @@ func min(a, b int) int {
} }
// neighbourCount calculates the Moore neighborhood of (x, y). // neighbourCount calculates the Moore neighborhood of (x, y).
func neighbourCount(a [][]bool, x, y int) int { func neighbourCount(a []bool, width, height, x, y int) int {
w := len(a[0])
h := len(a)
minI := max(x-1, 0)
minJ := max(y-1, 0)
maxI := min(x+1, w-1)
maxJ := min(y+1, h-1)
c := 0 c := 0
for j := minJ; j <= maxJ; j++ { for j := -1; j <= 1; j++ {
for i := minI; i <= maxI; i++ { for i := -1; i <= 1; i++ {
if i == x && j == y { if i == 0 && j == 0 {
continue continue
} }
if a[j][i] { x2 := x + i
y2 := y + j
if x2 < 0 || y2 < 0 || width <= x2 || height <= y2 {
continue
}
if a[y2*width+x2] {
c++ c++
} }
} }