Added renderer factory.

- Removes dependency on the specific backend from an application point-of-view.

allg5ui/renderer.go

@@ -202,8 +202,8 @@ func (r *Renderer) Rectangle(rect geom.RectangleF32, c color.Color, thickness fl
 	allg5.DrawRectangle(minX, minY, maxX, maxY, newColor(c), thickness)
 }
 
-func (r *Renderer) RegisterFont(path, name string, size int) error {
+func (r *Renderer) RegisterFont(name, path string, size int) error {
-	var f, err = allg5.LoadTTFFont(path, int(size))
+	var f, err = allg5.LoadTTFFont(path, size)
 	if err != nil {
 		return err
 	}

allg5ui/rendererfactory.go

@@ -0,0 +1,27 @@
+package allg5ui
+
+import (
+	"opslag.de/schobers/allg5"
+	"opslag.de/schobers/zntg/ui"
+)
+
+func init() {
+	ui.SetRendererFactory(&rendererFactory{})
+}
+
+type rendererFactory struct{}
+
+func (f rendererFactory) New(title string, width, height int) (ui.Renderer, error) {
+	return f.NewOptions(title, width, height, ui.NewRendererOptions{Resizable: true})
+}
+
+func (f rendererFactory) NewOptions(title string, width, height int, opts ui.NewRendererOptions) (ui.Renderer, error) {
+	renderer, err := NewRenderer(width, height, allg5.NewDisplayOptions{
+		Resizable: opts.Resizable,
+	})
+	if err != nil {
+		return nil, err
+	}
+	renderer.SetWindowTitle(title)
+	return renderer, nil
+}

ui/examples/01_basic/basic.go

@@ -4,9 +4,9 @@ import (
 	"image/color"
 	"log"
 
-	"opslag.de/schobers/allg5"
+	_ "opslag.de/schobers/zntg/allg5ui" // import the renderer for the UI
+
 	"opslag.de/schobers/geom"
-	"opslag.de/schobers/zntg/allg5ui"
 	"opslag.de/schobers/zntg/ui"
 )
 
@@ -63,13 +63,13 @@ func (b *basic) Init(ctx ui.Context) error {
 }
 
 func run() error {
-	var render, err = allg5ui.NewRenderer(800, 600, allg5.NewDisplayOptions{})
+	var render, err = ui.NewRenderer("Basic Example", 800, 600)
 	if err != nil {
 		return err
 	}
 	defer render.Destroy()
 
-	err = render.RegisterFont("../resources/font/OpenSans-Regular.ttf", "default", 14)
+	err = render.RegisterFont("default", "../resources/font/OpenSans-Regular.ttf", 14)
 	if err != nil {
 		return err
 	}

ui/renderer.go

@@ -24,8 +24,9 @@ type Renderer interface {
 	DrawImage(im Image, p geom.PointF32)
 	DrawImageOptions(im Image, p geom.PointF32, opts DrawOptions)
 	FillRectangle(r geom.RectangleF32, c color.Color)
-	Font(font string) Font
+	Font(name string) Font
 	Rectangle(r geom.RectangleF32, c color.Color, thickness float32)
+	RegisterFont(name, path string, size int) error
 	RenderTo(Image)
 	RenderToDisplay()
 	SetMouseCursor(c MouseCursor)

ui/rendererfactory.go

@@ -0,0 +1,31 @@
+package ui
+
+import (
+	"errors"
+
+	"opslag.de/schobers/geom"
+)
+
+type RendererFactory interface {
+	New(title string, width, height int) (Renderer, error)
+	NewOptions(title string, width, height int, opts NewRendererOptions) (Renderer, error)
+}
+
+var rendererFactory RendererFactory
+
+func NewRenderer(title string, width, height int) (Renderer, error) {
+	if rendererFactory == nil {
+		return nil, errors.New("no renderer factory registered")
+	}
+	return rendererFactory.New(title, width, height)
+}
+
+// SetRendererFactory sets the new factory that is used to create a new renderer.
+func SetRendererFactory(factory RendererFactory) {
+	rendererFactory = factory
+}
+
+type NewRendererOptions struct {
+	Location  *geom.PointF32
+	Resizable bool
+}