krampus19/cmd/krampus19/level.go
2019-12-28 21:20:56 +01:00

143 lines
2.6 KiB
Go

package main
import (
"errors"
"fmt"
"io"
"opslag.de/schobers/geom"
)
type entityType byte
type tile byte
const (
entityTypeInvalid entityType = entityType(0)
entityTypeNone = '_'
entityTypeCharacter = '@'
entityTypeVillain = 'X'
entityTypeBrick = 'B'
)
func (e entityType) IsValid() bool {
switch e {
case entityTypeNone:
case entityTypeCharacter:
case entityTypeVillain:
case entityTypeBrick:
default:
return false
}
return true
}
const (
tileInvalid tile = tile(0)
tileNothing = '.'
tileBasic = '#'
tileMagma = '~'
)
func (t tile) IsValid() bool {
switch t {
case tileNothing:
case tileBasic:
case tileMagma:
default:
return false
}
return true
}
type level struct {
width int
height int
tiles []tile
entities []entityType
}
func (l level) idxToPos(i int) geom.Point { return geom.Pt(i%l.width, i/l.width) }
func (l level) posToIdx(p geom.Point) int {
if p.X < 0 || p.Y < 0 || p.X >= l.width || p.Y >= l.height {
return -1
}
return p.Y*l.width + p.X
}
func parseLevelAsset(r io.Reader) (level, error) {
var l level
ctx := levelContext{&l}
err := parseLines(r, ctx.parse)
if err != nil {
return level{}, err
}
return l, nil
}
type levelContext struct {
level *level
}
func (c *levelContext) parse(p *lineParser) parseLineFn {
if p.eof() {
return nil
}
switch p.peek() {
case "level:":
return c.parseContent
case "":
p.next() // skip
return c.parse
default:
return nil
}
}
func (c *levelContext) parseContent(p *lineParser) parseLineFn {
if p.next() != "level:" {
return p.emitErr(errors.New("expected level start"))
}
return c.parseRow
}
func (c *levelContext) parseRow(p *lineParser) parseLineFn {
if p.eof() {
return p.emitErr(errors.New("unexpected end of file"))
}
line := p.next()
if line == ":level" {
return c.parse
}
if c.level.height == 0 {
c.level.width = len(line) / 2
}
return c.addRow(p, line)
}
func (c *levelContext) addRow(p *lineParser, line string) parseLineFn {
var tiles []tile
var entities []entityType
for i := 0; i < len(line); i += 2 {
tiles = append(tiles, tile(line[i]))
entities = append(entities, entityType(line[i+1]))
}
for i, t := range tiles {
if !t.IsValid() {
return p.emitErr(fmt.Errorf("level contains invalid tile at (%d, %d)", i, c.level.height))
}
}
for i, e := range entities {
if !e.IsValid() {
return p.emitErr(fmt.Errorf("level contains invalid entity type at (%d, %d)", i, c.level.height))
}
}
c.level.height++
c.level.tiles = append(c.level.tiles, tiles...)
c.level.entities = append(c.level.entities, entities...)
return c.parseRow
}