added loadedspritesheet and loadedfont functions (#786)

* added loadedspritesheet and loadedfont functions to access preloaded spritesheets and fonts

common/font.go

@@ -1,6 +1,7 @@
 package common
 
 import (
+	"errors"
 	"fmt"
 	"image"
 	"image/color"
@@ -20,6 +21,8 @@ var (
 	dpi = float64(72)
 )
 
+var fontCache []*Font
+
 // Font keeps track of a specific Font. Fonts are explicit instances of a font file,
 // including the Size and Color. A separate font will have to be generated to get
 // different sizes and colors of the same font file.
@@ -32,6 +35,24 @@ type Font struct {
 	face font.Face
 }
 
+// LoadedFont returns a Font that was previously loaded via CreatePreloaded
+func LoadedFont(url string, size float64, bg, fg color.Color) (*Font, error) {
+	idx := -1
+	for i, fnt := range fontCache {
+		r, g, b, a := bg.RGBA()
+		r2, g2, b2, a2 := fnt.BG.RGBA()
+		r3, g3, b3, a3 := fg.RGBA()
+		r4, g4, b4, a4 := fnt.FG.RGBA()
+		if fnt.URL == url && fnt.Size == size && r == r2 && g == g2 && b == b2 && a == a2 && r3 == r4 && g3 == g4 && b3 == b4 && a3 == a4 {
+			idx = i
+		}
+	}
+	if idx < 0 {
+		return nil, errors.New("No font matching that description was found.")
+	}
+	return fontCache[idx], nil
+}
+
 // Create is for loading fonts from the disk, given a location
 func (f *Font) Create() error {
 	// Read and parse the font
@@ -72,6 +93,7 @@ func (f *Font) CreatePreloaded() error {
 		DPI:     dpi,
 		Hinting: font.HintingFull,
 	})
+	fontCache = append(fontCache, f)
 	return nil
 }
 

common/spritesheet.go

@@ -1,13 +1,16 @@
 package common
 
 import (
+	"errors"
 	"log"
 
 	"github.com/EngoEngine/engo"
 	"github.com/EngoEngine/engo/math"
 	"github.com/EngoEngine/gl"
 )
 
+var spritesheetCache = make(map[string]*Spritesheet)
+
 // Spritesheet is a class that stores a set of tiles from a file, used by tilemaps and animations
 type Spritesheet struct {
 	texture       *gl.Texture     // The original texture
@@ -22,16 +25,27 @@ type SpriteRegion struct {
 	Width, Height int
 }
 
+// LoadedSpritesheet returns a Spritesheet that has already been created by New*
+func LoadedSpritesheet(url string) (*Spritesheet, error) {
+	sheet, ok := spritesheetCache[url]
+	if !ok {
+		return nil, errors.New("Unable to find Spritesheet at URL " + url)
+	}
+	return sheet, nil
+}
+
 // NewAsymmetricSpritesheetFromTexture creates a new AsymmetricSpriteSheet from a
 // TextureResource. The data provided is the location and size of the sprites
 func NewAsymmetricSpritesheetFromTexture(tr *TextureResource, spriteRegions []SpriteRegion) *Spritesheet {
-	return &Spritesheet{
+	sheet := &Spritesheet{
 		texture: tr.Texture,
 		width:   tr.Width,
 		height:  tr.Height,
 		cells:   spriteRegions,
 		cache:   make(map[int]Texture),
 	}
+	spritesheetCache[tr.URL()] = sheet
+	return sheet
 }
 
 // NewAsymmetricSpritesheetFromFile creates a new AsymmetricSpriteSheet from a