Added keyboard support for zooming.

Added information but to show intro.

gamecontrols.go

@@ -127,6 +127,7 @@ func (c *GameControls) Init(ctx *Context) error {
 			c.game.New()
 			c.updateFlowerControls(ctx)
 		}),
+		NewIconButton("control-information", func(*Context) { c.dialogs.ShowIntro() }),
 	}
 
 	c.shovel = NewIconButtonConfig("control-shovel", func(*Context) { c.game.SelectShovel() }, func(b *IconButton) { b.IconHeight = 32 })

projection.go

@@ -100,3 +100,26 @@ func (p *projection) visibleTiles(action func(int32, int32, Point)) {
 		}
 	}
 }
+
+func (p *projection) ZoomOut(ctx *Context, center PointF) {
+	if p.zoom <= .25 {
+		return
+	}
+	p.SetZoom(ctx, center, .5*p.zoom)
+}
+
+func (p *projection) ZoomIn(ctx *Context, center PointF) {
+	if p.zoom >= 2 {
+		return
+	}
+	p.SetZoom(ctx, center, 2*p.zoom)
+}
+
+func (p *projection) SetZoom(ctx *Context, center PointF, zoom float32) {
+	if p.zoom == zoom {
+		return
+	}
+	p.center = center.Sub(center.Sub(p.center).Mul(p.zoom / zoom))
+	p.zoom = zoom
+	p.update(ctx.Renderer)
+}

terrainrenderer.go

@@ -78,17 +78,10 @@ func (r *terrainRenderer) Handle(ctx *Context, event sdl.Event) bool {
 		}
 	case *sdl.MouseWheelEvent:
 		if r.hover != nil {
-			zoom := r.project.zoom
+			if e.Y < 0 {
-			if e.Y < 0 && r.project.zoom > .25 {
+				r.project.ZoomOut(ctx, r.hover.ToPtF())
-				zoom *= .5
+			} else {
-			} else if e.Y > 0 && r.project.zoom < 2 {
+				r.project.ZoomIn(ctx, r.hover.ToPtF())
-				zoom *= 2
-			}
-			if zoom != r.project.zoom {
-				hover := r.hover.ToPtF()
-				r.project.center = hover.Sub(hover.Sub(r.project.center).Mul(r.project.zoom / zoom))
-				r.project.zoom = zoom
-				r.project.update(ctx.Renderer)
 			}
 		}
 	case *sdl.WindowEvent:
@@ -96,6 +89,19 @@ func (r *terrainRenderer) Handle(ctx *Context, event sdl.Event) bool {
 			r.hover = nil
 			r.project.update(ctx.Renderer)
 		}
+	case *sdl.KeyboardEvent:
+		if e.Type == sdl.KEYDOWN {
+			switch e.Keysym.Sym {
+			case sdl.K_PLUS:
+				r.project.ZoomIn(ctx, r.project.center)
+			case sdl.K_KP_PLUS:
+				r.project.ZoomIn(ctx, r.project.center)
+			case sdl.K_MINUS:
+				r.project.ZoomOut(ctx, r.project.center)
+			case sdl.K_KP_MINUS:
+				r.project.ZoomOut(ctx, r.project.center)
+			}
+		}
 	}
 	return false
 }