Started resource loading (requires testing), need to add default loaders for ply and png (from gogeline).

res.go

@@ -0,0 +1,212 @@
+package goga
+
+import (
+	"errors"
+	"io/ioutil"
+	"path/filepath"
+	"strings"
+)
+
+// A generic resource.
+// Must be cast to appropriate type.
+// The name is the file name and must be unique.
+type Res struct {
+	name string
+	path string
+	ext  string
+}
+
+// Returns the file name of actual resource.
+func (r *Res) GetName() string {
+	return r.name
+}
+
+// Returns the file path (as passed in) of actual resource.
+func (r *Res) GetPath() string {
+	return r.path
+}
+
+// Returns the file extension of actual resource.
+func (r *Res) GetExt() string {
+	return r.ext
+}
+
+// Resource loader interface.
+// The loader accepts files by file extension.
+// and loads them if accepted.
+type ResLoader interface {
+	Load(string) (*Res, error)
+	Ext() string
+}
+
+var (
+	resloader []ResLoader
+	resources []*Res
+)
+
+// Adds a loader.
+// If a loader with the same file extension exists already, false will be returned.
+func AddLoader(loader ResLoader) bool {
+	ext := strings.ToLower(loader.Ext())
+
+	for _, l := range resloader {
+		if strings.ToLower(l.Ext()) == ext {
+			return false
+		}
+	}
+
+	resloader = append(resloader, loader)
+
+	return true
+}
+
+// Removes a loader.
+// Returns false if loader could not be found.
+func RemoveLoader(loader ResLoader) bool {
+	for i, l := range resloader {
+		if l == loader {
+			resloader = append(resloader[:i], resloader[i+1:]...)
+			return true
+		}
+	}
+
+	return false
+}
+
+// Removes a loader by file extension.
+// Returns false if loader could not be found.
+func RemoveLoaderByExt(ext string) bool {
+	ext = strings.ToLower(ext)
+
+	for i, l := range resloader {
+		if strings.ToLower(l.Ext()) == ext {
+			resloader = append(resloader[:i], resloader[i+1:]...)
+			return true
+		}
+	}
+
+	return false
+}
+
+// Removes all loaders.
+func RemoveAllLoaders() {
+	resloader = make([]ResLoader, 0)
+}
+
+// Returns a loader by file extension.
+// If not found, nil will be returned.
+func GetLoaderByExt(ext string) ResLoader {
+	ext = strings.ToLower(ext)
+
+	for _, l := range resloader {
+		if strings.ToLower(l.Ext()) == ext {
+			return l
+		}
+	}
+
+	return nil
+}
+
+// Loads a resource by file path.
+// If no loader is present for given file, an error will be returned.
+// If the loader fails to load the resource, an error will be returned.
+func LoadRes(path string) (*Res, error) {
+	ext := filepath.Ext(path)
+	loader := GetLoaderByExt(ext)
+
+	if loader == nil {
+		return nil, errors.New("No loader available for file extension " + ext)
+	}
+
+	res, err := loader.Load(path)
+
+	if err != nil {
+		return nil, err
+	}
+
+	for _, r := range resources {
+		if r.name == res.name {
+			return nil, errors.New("Resource with file name " + res.name + " exists already")
+		}
+	}
+
+	resources = append(resources, res)
+
+	return res, nil
+}
+
+// Loads all files from given folder path.
+// If a loader is missing or fails to load the resource, an error will be returned.
+// All resources will be kept until an error occures.
+func LoadResFromFolder(path string) error {
+	dir, err := ioutil.ReadDir(path)
+
+	if err != nil {
+		return err
+	}
+
+	for _, file := range dir {
+		if file.IsDir() {
+			continue
+		}
+
+		if _, err := LoadRes(filepath.Join(path, file.Name())); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// Returns a resource by name or nil, if not found.
+func GetResByName(name string) *Res {
+	for _, r := range resources {
+		if r.name == name {
+			return r
+		}
+	}
+
+	return nil
+}
+
+// Returns a resource by path or nil, if not found.
+func GetResByPath(path string) *Res {
+	for _, r := range resources {
+		if r.path == path {
+			return r
+		}
+	}
+
+	return nil
+}
+
+// Removes a resource by name.
+// Returns false if resource could not be found.
+func RemoveResByName(name string) bool {
+	for i, r := range resources {
+		if r.name == name {
+			resources = append(resources[:i], resources[i+1:]...)
+			return true
+		}
+	}
+
+	return false
+}
+
+// Removes a resource by path.
+// Returns false if resource could not be found.
+func RemoveResByPath(path string) bool {
+	for i, r := range resources {
+		if r.path == path {
+			resources = append(resources[:i], resources[i+1:]...)
+			return true
+		}
+	}
+
+	return false
+}
+
+// Removes all resources.
+func RemoveAllRes() {
+	resources = make([]*Res, 0)
+}