carotidartillery/ss_environment.go

package main

import (
	"image"
	_ "image/png"

	"github.com/hajimehoshi/ebiten/v2"
)

var sandstoneSS *EnvironmentSpriteSheet

// EnvironmentSpriteSheet represents a collection of sprite images.
type EnvironmentSpriteSheet struct {
	FloorA          *ebiten.Image
	FloorB          *ebiten.Image
	FloorC          *ebiten.Image
	WallTop         *ebiten.Image
	WallBottom      *ebiten.Image
	WallBottomLeft  *ebiten.Image
	WallBottomRight *ebiten.Image
	WallLeft        *ebiten.Image
	WallRight       *ebiten.Image
	WallTopLeft     *ebiten.Image
	WallTopRight    *ebiten.Image
	WallPillar      *ebiten.Image
	TorchTop1       *ebiten.Image
	TorchTop2       *ebiten.Image
	TorchTop3       *ebiten.Image
	TorchTop4       *ebiten.Image
	TorchTop5       *ebiten.Image
	TorchTop6       *ebiten.Image
	TorchTop7       *ebiten.Image
	TorchTop8       *ebiten.Image
	TorchTop9       *ebiten.Image
	TorchMulti      *ebiten.Image
}

// LoadEnvironmentSpriteSheet loads the embedded EnvironmentSpriteSheet.
func LoadEnvironmentSpriteSheet() (*EnvironmentSpriteSheet, error) {
	tileSize := 32

	// Populate EnvironmentSpriteSheet.
	s := &EnvironmentSpriteSheet{}

	// Dungeon sprites
	dungeonFile, err := assetsFS.Open("assets/sandstone-dungeon/Tiles-SandstoneDungeons.png")
	if err != nil {
		return nil, err
	}
	defer dungeonFile.Close()
	dungeonImg, _, err := image.Decode(dungeonFile)
	if err != nil {
		return nil, err
	}
	dungeonSheet := ebiten.NewImageFromImage(dungeonImg)
	// dungeonSpriteAt returns a sprite at the provided coordinates.
	dungeonSpriteAt := func(x, y int) *ebiten.Image {
		return dungeonSheet.SubImage(image.Rect(x*tileSize, (y+1)*tileSize, (x+1)*tileSize, y*tileSize)).(*ebiten.Image)
	}
	s.FloorA = dungeonSpriteAt(3, 1)
	s.FloorB = dungeonSpriteAt(2, 0)
	s.FloorC = dungeonSpriteAt(2, 1)
	s.WallTop = dungeonSpriteAt(1, 2)
	s.WallBottom = dungeonSpriteAt(1, 6)
	s.WallBottomLeft = dungeonSpriteAt(2, 6)
	s.WallBottomRight = dungeonSpriteAt(0, 6)
	s.WallLeft = dungeonSpriteAt(2, 2)
	s.WallRight = dungeonSpriteAt(0, 2)
	s.WallTopLeft = dungeonSpriteAt(2, 3)
	s.WallTopRight = dungeonSpriteAt(0, 3)
	s.WallPillar = dungeonSpriteAt(8, 4)

	// Prop sprites
	propFile, err := assetsFS.Open("assets/sandstone-dungeon/Tiles-Props-pack.png")
	if err != nil {
		return nil, err
	}
	defer propFile.Close()
	propImg, _, err := image.Decode(propFile)
	if err != nil {
		return nil, err
	}
	propSheet := ebiten.NewImageFromImage(propImg)
	// dungeonSpriteAt returns a sprite at the provided coordinates.
	propSpriteAt := func(x, y int) *ebiten.Image {
		return propSheet.SubImage(image.Rect(x*tileSize, (y+1)*tileSize, (x+1)*tileSize, y*tileSize)).(*ebiten.Image)
	}
	s.TorchTop1 = propSpriteAt(0, 2)
	s.TorchTop2 = propSpriteAt(1, 2)
	s.TorchTop3 = propSpriteAt(2, 2)
	s.TorchTop4 = propSpriteAt(3, 2)
	s.TorchTop5 = propSpriteAt(4, 2)
	s.TorchTop6 = propSpriteAt(5, 2)
	s.TorchTop7 = propSpriteAt(6, 2)
	s.TorchTop8 = propSpriteAt(7, 2)
	s.TorchTop9 = propSpriteAt(8, 2)
	s.TorchMulti = propSpriteAt(2, 4)

	return s, nil
}