ordoor/internal/assetstore/map.go

package assetstore

import (
	"github.com/hajimehoshi/ebiten"
	"image"

	"code.ur.gs/lupine/ordoor/internal/maps"
)

type Map struct {
	assets *AssetStore
	set    *Set
	Rect   image.Rectangle

	raw *maps.GameMap
}

// Map loads a game map with the given name (e.g. "Chapter01")
func (a *AssetStore) Map(name string) (*Map, error) {
	name = canonical(name)

	if m, ok := a.maps[name]; ok {
		return m, nil
	}

	mapFile, err := a.lookup(name, "map", "Maps", "MultiMaps")
	if err != nil {
		return nil, err
	}

	txtFile, err := a.lookup(name, "txt", "Maps", "MultiMaps")
	if err != nil {
		return nil, err
	}

	raw, err := maps.LoadGameMapByFiles(mapFile, txtFile)
	if err != nil {
		return nil, err
	}

	// The set for a map is small and frequently referenced, so load it here
	set, err := a.Set(raw.MapSetName())
	if err != nil {
		return nil, err
	}

	m := &Map{
		Rect: image.Rect(
			int(raw.MinWidth),
			int(raw.MinLength),
			int(raw.MaxWidth),
			int(raw.MaxLength),
		),
		assets: a,
		raw:    raw,
		set:    set,
	}

	a.maps[canonical(name)] = m

	return m, nil
}

// ImagesForCell returns the sprites needed to correctly render this cell.
// They should be rendered from first to last to get the correct ordering
func (m *Map) ImagesForCell(x, y, z int) ([]*ebiten.Image, error) {
	cell := m.raw.At(x, y, z)
	images := make([]*ebiten.Image, 0, 4)

	for _, ref := range []maps.ObjRef{cell.Surface, cell.Center, cell.Left, cell.Right} {
		if !ref.IsActive() {
			continue
		}

		obj, err := m.set.Object(ref.Index())
		if err != nil {
			return nil, err
		}

		img, err := obj.Image(ref.Sprite())
		if err != nil {
			return nil, err
		}

		images = append(images, img)
	}

	return images, nil
}