sprites.go

package zelduh

import (
	"fmt"
	"image"
	"math"
	"os"

	"github.com/faiface/pixel"
)

func loadPicture(path string) pixel.Picture {
	file, err := os.Open(path)
	if err != nil {
		fmt.Println("Could not open the picture:")
		fmt.Println(err)
		os.Exit(1)
	}
	defer file.Close()
	img, _, err := image.Decode(file)
	if err != nil {
		fmt.Println("Could not decode the picture:")
		fmt.Println(err)
		os.Exit(1)
	}
	return pixel.PictureDataFromImage(img)
}

// LoadAndBuildSpritesheet this is a map of pixel engine sprites
func LoadAndBuildSpritesheet(path string, tileSize float64) map[int]*pixel.Sprite {
	pic := loadPicture(path)

	cols := pic.Bounds().W() / tileSize
	rows := pic.Bounds().H() / tileSize

	maxIndex := (rows * cols) - 1.0

	index := maxIndex
	id := maxIndex + 1
	spritesheet := map[int]*pixel.Sprite{}
	for row := (rows - 1); row >= 0; row-- {
		for col := (cols - 1); col >= 0; col-- {
			x := col
			y := math.Abs(rows-row) - 1
			spritesheet[int(id)] = pixel.NewSprite(pic, pixel.R(
				x*tileSize,
				y*tileSize,
				x*tileSize+tileSize,
				y*tileSize+tileSize,
			))
			index--
			id--
		}
	}
	return spritesheet
}

// GetSpriteSet returns a sprite set by key
func GetSpriteSet(key string) []int {
	return spriteSets[key]
}

var spriteSets = map[string][]int{
	"eyeburrower": []int{50, 50, 50, 91, 91, 91, 92, 92, 92, 93, 93, 93, 92, 92, 92},
	"explosion": []int{
		122, 122, 122,
		123, 123, 123,
		124, 124, 124,
		125, 125, 125,
	},
	"uiCoin":           []int{20},
	"skeleton":         []int{31, 32},
	"skull":            []int{36, 37, 38, 39},
	"spinner":          []int{51, 52},
	"puzzleBox":        []int{63},
	"warpStone":        []int{61},
	"playerUp":         []int{4, 195},
	"playerRight":      []int{3, 194},
	"playerDown":       []int{1, 192},
	"playerLeft":       []int{2, 193},
	"playerSwordUp":    []int{165},
	"playerSwordRight": []int{164},
	"playerSwordLeft":  []int{179},
	"playerSwordDown":  []int{180},
	"floorSwitch":      []int{112, 127},
	"toggleObstacle":   []int{144, 114},
	"swordUp":          []int{70},
	"swordRight":       []int{67},
	"swordDown":        []int{68},
	"swordLeft":        []int{69},
	"arrowUp":          []int{101},
	"arrowRight":       []int{100},
	"arrowDown":        []int{103},
	"arrowLeft":        []int{102},
	"bomb":             []int{138, 139, 140, 141},
	"coin":             []int{5, 5, 6, 6, 21, 21},
	"heart":            []int{106},
}