Initial commit

backends/pixel/pixel.go

@@ -0,0 +1,146 @@
+package pixel
+
+import "time"
+import "golang.org/x/image/font"
+import "github.com/faiface/pixel"
+import "github.com/faiface/pixel/pixelgl"
+import "golang.org/x/image/font/basicfont"
+import "git.tebibyte.media/sashakoshka/stone"
+
+type Backend struct {
+	window         *pixelgl.Window
+	boundsDirty    bool
+	previousBounds pixel.Vec
+	fontFace       font.Face
+	application    *stone.Application
+	config         *stone.Config
+
+	metrics struct {
+		cellWidth  int
+		cellHeight int
+	}
+}
+
+func (backend *Backend) Run (callback func (application *stone.Application)) {
+	if backend.fontFace == nil {
+		backend.fontFace = basicfont.Face7x13
+	}
+
+	faceMetrics := backend.fontFace.Metrics()
+	backend.metrics.cellHeight = faceMetrics.Height.Round()
+	// FIXME?: this might not be the best way to get the cell width
+	faceAdvance, ok := backend.fontFace.GlyphAdvance('M')
+	if ok {
+		backend.metrics.cellWidth = faceAdvance.Round()
+	} else {
+		backend.metrics.cellWidth = backend.metrics.cellHeight / 2
+	}
+	
+	pixelgl.Run (func () {
+		var err error
+		backend.window, err = pixelgl.NewWindow (pixelgl.WindowConfig {
+			Resizable:   true,
+			Undecorated: true,
+			VSync:       true,
+			NoIconify:   true,
+			Title:       backend.application.Title(),
+			Bounds:      backend.calculateWindowSize(),
+		})
+		backend.Poll()
+		
+		if err != nil { panic(err.Error()) }
+		callback(backend.application)
+	})
+}
+
+func (backend *Backend) Await (timeout time.Duration) (keepRunning bool) {
+	if backend.window == nil {
+		panic("call to Backend.Await before window exists")
+	}
+
+	backend.draw()
+	backend.window.UpdateInputWait(timeout)
+	backend.processEvents()
+	keepRunning = !backend.window.Closed()
+	return
+}
+
+func (backend *Backend) Poll () (keepRunning bool) {
+	if backend.window == nil {
+		panic("call to Backend.Poll before window exists")
+	}
+
+	backend.draw()
+	backend.window.UpdateInput()
+	backend.processEvents()
+	keepRunning = !backend.window.Closed()
+	return
+}
+
+func (backend *Backend) SetTitle (title string) {
+	if backend.window != nil {
+		backend.window.SetTitle(title)
+	}
+}
+
+func (backend *Backend) draw () {
+	didDrawing := false
+
+	if backend.boundsDirty {
+		backend.window.Clear (
+			backend.config.Color(stone.ColorApplication))
+		backend.boundsDirty = false
+		didDrawing = true
+	} else {
+		// TODO: clear out dirty cells before drawing them (we don't
+		// want to clear them out if we have already just cleared
+		// everything out)
+
+		
+	}
+
+	// TODO: draw dirty cells.
+	width, height := backend.application.Size()
+	for x := 0; x < width; x ++ {
+		for y := 0; y < height; y ++ {
+			clean := backend.application.Clean(x, y)
+			// cell  := application.content[index]
+			if clean { continue }
+
+			// draw cell
+			
+			didDrawing = true // TODO: set didDrawing up there ^
+			backend.application.MarkClean(x, y)
+		}
+	}
+
+	if didDrawing {
+		backend.window.SwapBuffers()
+	}
+}
+
+func (backend *Backend) processEvents () {
+	
+}
+
+func (backend *Backend) calculateWindowSize () (bounds pixel.Rect) {
+	width, height := backend.application.Size()
+	bounds = pixel.R (
+		0, 0,
+		float64(width  * backend.metrics.cellWidth),
+		float64(height * backend.metrics.cellHeight))
+	return
+}
+
+func factory (application *stone.Application) (output stone.Backend, err error) {
+	backend := &Backend {
+		application: application,
+		config:      application.Config(),
+	}
+	output = backend
+	return
+}
+
+func init () {
+	stone.RegisterBackend(factory)
+}