Add input state queries

backends/pixel/pixel.go

@@ -83,6 +83,36 @@ func (backend *Backend) SetTitle (title string) {
 	}
 }
 
+func (backend *Backend) JustPressed (button stone.Button) (pressed bool) {
+	pressed = backend.window.JustPressed(pixelgl.Button(button))
+	return
+}
+
+func (backend *Backend) JustReleased (button stone.Button) (released bool) {
+	released = backend.window.JustReleased(pixelgl.Button(button))
+	return
+}
+
+func (backend *Backend) Pressed (button stone.Button) (pressed bool) {
+	pressed = backend.window.Pressed(pixelgl.Button(button))
+	return
+}
+
+func (backend *Backend) Repeated (button stone.Button) (repeated bool) {
+	repeated = backend.window.Repeated(pixelgl.Button(button))
+	return
+}
+
+func (backend *Backend) Typed () (text string) {
+	text = backend.window.Typed()
+	return
+}
+
+func (backend *Backend) Resized () (resized bool) {
+	resized = backend.boundsDirty
+	return
+}
+
 func (backend *Backend) draw () {
 	didDrawing := false