Characters are now rendered with their proper descent

backends/pixel/pixel.go

@@ -20,6 +20,7 @@ type Backend struct {
 	fontAtlas         *text.Atlas
 	textDrawer        *text.Text
 	showBounds        bool
+	showCellBounds    bool
 
 	metrics struct {
 		cellWidth  int
@@ -27,16 +28,24 @@ type Backend struct {
 		padding    int
 		paddingX   int
 		paddingY   int
+		descent    int
 	}
 }
 
 func (backend *Backend) Run (callback func (application *stone.Application)) {
+	// backend.showBounds     = true
+	backend.showCellBounds = true
+	
 	if backend.fontFace == nil {
 		backend.fontFace = basicfont.Face7x13
 	}
 
-	faceMetrics := backend.fontFace.Metrics()
+	backend.backgroundStamper = imdraw.New(nil)
-	backend.metrics.cellHeight = faceMetrics.Height.Round()
+	backend.fontAtlas = text.NewAtlas(backend.fontFace, text.ASCII)
+	backend.textDrawer = text.New(pixel.V(0, 0), backend.fontAtlas)
+
+	backend.metrics.descent    = int(backend.fontAtlas.Descent())
+	backend.metrics.cellHeight = int(backend.fontAtlas.LineHeight())
 	// FIXME?: this might not be the best way to get the cell width
 	faceAdvance, ok := backend.fontFace.GlyphAdvance('M')
 	if ok {
@@ -56,9 +65,6 @@ func (backend *Backend) Run (callback func (application *stone.Application)) {
 			Title:       backend.application.Title(),
 			Bounds:      backend.calculateWindowSize(),
 		})
-		backend.backgroundStamper = imdraw.New(nil)
-		backend.fontAtlas = text.NewAtlas(backend.fontFace, text.ASCII)
-		backend.textDrawer = text.New(pixel.V(0, 0), backend.fontAtlas)
 		backend.Poll()
 		
 		if err != nil { panic(err.Error()) }
@@ -166,6 +172,17 @@ func (backend *Backend) draw () {
 					backend.vectorAtPosition(x + 1, y + 1))
 				backend.backgroundStamper.Rectangle(0)
 				// didDrawing = true
+
+				if backend.showCellBounds {
+					backend.backgroundStamper.Color =
+					backend.config.Color(stone.ColorForeground)
+					backend.backgroundStamper.Push (
+						backend.vectorAtPosition(x, y),
+						backend.vectorAtPosition(x + 1, y + 1))
+					backend.backgroundStamper.Rectangle(1)
+					backend.backgroundStamper.Color =
+						backend.config.Color(stone.ColorApplication)
+				}
 			}
 		}
 		backend.backgroundStamper.Draw(backend.window)
@@ -185,7 +202,15 @@ func (backend *Backend) draw () {
 			if content < 32 { continue }
 			
 			// draw cell
-			backend.textDrawer.Dot = backend.vectorAtPosition(x, y + 1)
+			backend.textDrawer.Dot = pixel.V (
+				float64 (
+					x * backend.metrics.cellWidth +
+					backend.metrics.paddingX),
+				backend.windowBounds.Y - float64 (
+					(y + 1) * backend.metrics.cellHeight +
+					backend.metrics.paddingY -
+					backend.metrics.descent))
+			
 			backend.textDrawer.WriteRune(content)
 			backend.textDrawer.Draw(backend.window, pixel.IM)
 		}