commit 5edb54e3c2096d09a33ea158d07b0259990ea21f
parent 9c4dbc1e22ffa1f6b3a3bc3b74a5b22eb7106a76
Author: Brian C. Lane <bcl@brianlane.com>
Date: Sun, 27 Nov 2022 15:32:17 -0800
Add support for RLE patterns
Diffstat:
| M | main.go | | | 131 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
1 file changed, 131 insertions(+), 0 deletions(-)
diff --git a/main.go b/main.go
@@ -10,6 +10,7 @@ import (
"math/rand"
"net/http"
"os"
+ "regexp"
"strconv"
"strings"
"time"
@@ -22,6 +23,10 @@ const (
threshold = 0.15
)
+// RLE header with variable spacing and optional rules
+// Matches it with or without rule at the end, and with 0 or more spaces between elements.
+var rleHeaderRegex = regexp.MustCompile(`x\s*=\s*(\d+)\s*,\s*y\s*=\s*(\d+)(?:\s*,\s*rule\s*=\s*(.*))*`)
+
/* commandline flags */
type cmdlineArgs struct {
Width int // Width of window in pixels
@@ -172,6 +177,8 @@ func (g *LifeGame) InitializeCells() {
err = g.ParseLife105(lines)
} else if strings.HasPrefix(lines[0], "#Life 1.06") {
log.Fatal("Life 1.06 file format is not supported")
+ } else if isRLE(lines) {
+ err = g.ParseRLE(lines, 0, 0)
} else {
err = g.ParsePlaintext(lines)
}
@@ -316,6 +323,128 @@ func (g *LifeGame) ParsePlaintext(lines []string) error {
return nil
}
+// isRLEPattern checks the lines to determine if it is a RLE pattern
+func isRLE(lines []string) bool {
+ for _, line := range lines {
+ if rleHeaderRegex.MatchString(line) {
+ return true
+ }
+ }
+ return false
+}
+
+// ParseRLE pattern file
+// Parses files matching the RLE specification - https://conwaylife.com/wiki/Run_Length_Encoded
+// Optional x, y starting position for later use
+func (g *LifeGame) ParseRLE(lines []string, x, y int) error {
+ // Move x, y to center of field and wrap at the edges
+ // NOTE: % in go preserves sign of a, unlike Python :)
+ x = cfg.Columns/2 + x
+ x = (x%cfg.Columns + cfg.Columns) % cfg.Columns
+ y = cfg.Rows/2 + y
+ y = (y%cfg.Rows + cfg.Rows) % cfg.Rows
+
+ var header []string
+ var first int
+ for i, line := range lines {
+ header = rleHeaderRegex.FindStringSubmatch(line)
+ if len(header) > 0 {
+ first = i + 1
+ break
+ }
+ // All lines before the header must be a # line
+ if line[0] != '#' {
+ return fmt.Errorf("Incorrect or missing RLE header")
+ }
+ }
+ if len(header) < 3 {
+ return fmt.Errorf("Incorrect or missing RLE header")
+ }
+ if first > len(lines)-1 {
+ return fmt.Errorf("Missing lines after RLE header")
+ }
+ width, err := strconv.Atoi(header[1])
+ if err != nil {
+ return fmt.Errorf("Error parsing width: %s", err)
+ }
+ height, err := strconv.Atoi(header[2])
+ if err != nil {
+ return fmt.Errorf("Error parsing height: %s", err)
+ }
+
+ // TODO Parse rules from header[3] and alter the game
+
+ count := 0
+ xLine := x
+ yStart := y
+ for _, line := range lines[first:] {
+ for _, c := range line {
+ if c == '$' {
+ // End of this line (which can have a count)
+ eols := 0
+ if count == 0 {
+ eols = 1
+ } else {
+ eols = count
+ }
+
+ // Blank cells to the edge of the pattern, and full empty lines
+ for i := 0; i < eols; i++ {
+ for j := xLine; j < x+width; j++ {
+ g.cells[y][j].alive = false
+ g.cells[y][j].aliveNext = false
+ }
+ // 2nd line and more fill the full line
+ xLine = x
+ y = y + 1
+ }
+
+ count = 0
+ xLine = x
+ continue
+ }
+ if c == '!' {
+ // Finished
+
+ // Fill in any remaining space with dead cells
+ eols := height - (y - yStart)
+ // Blank cells to the edge of the pattern, and full empty lines
+ for i := 0; i < eols; i++ {
+ for j := xLine; j < x+width; j++ {
+ g.cells[y][j].alive = false
+ g.cells[y][j].aliveNext = false
+ }
+ // 2nd line and more fill the full line
+ xLine = x
+ y = y + 1
+ }
+
+ return nil
+ }
+
+ // Is it a digit?
+ digit, err := strconv.Atoi(string(c))
+ if err == nil {
+ count = (count * 10) + digit
+ continue
+ }
+
+ if count == 0 {
+ count = 1
+ }
+
+ // TODO wrap at edges
+ for i := 0; i < count; i++ {
+ g.cells[y][xLine].alive = bool(c != 'b')
+ g.cells[y][xLine].aliveNext = bool(c != 'b')
+ xLine++
+ }
+ count = 0
+ }
+ }
+ return nil
+}
+
// checkState determines the state of the cell for the next tick of the game.
func (g *LifeGame) checkState(c *Cell) {
liveCount := g.liveNeighbors(c)
@@ -526,6 +655,8 @@ func (g *LifeGame) Run() {
var err error
if strings.HasPrefix(pattern[0], "#Life 1.05") {
err = g.ParseLife105(pattern)
+ } else if isRLE(pattern) {
+ err = g.ParseRLE(pattern, 0, 0)
} else {
err = g.ParsePlaintext(pattern)
}
