Introduce min_scale config

README.md

@@ -68,6 +68,7 @@ Supported parameters:
 
 | Name           | Description                                        |
 |----------------|----------------------------------------------------|
+| min_scale      | The smallest it can get when zooming out           |
 | scroll_speed   | How quickly you can zoom in/out by scrolling       |
 | drag_friction  | How quickly the movement slows down after dragging |
 | scale_friction | How quickly the zoom slows down after scrolling    |

src/config.nim

@@ -1,11 +1,13 @@
 import macros, strutils
 
 type Config* = object
+  min_scale*: float
   scroll_speed*: float
   drag_friction*: float
   scale_friction*: float
 
 const defaultConfig* = Config(
+  min_scale: 1,
   scroll_speed: 1.5,
   drag_friction: 6.0,
   scale_friction: 4.0,
@@ -21,6 +23,8 @@ proc loadConfig*(filePath: string): Config =
     let key = pair[0].strip
     let value = pair[1].strip
     case key
+    of "min_scale":
+      result.min_scale = parseFloat(value)
     of "scroll_speed":
       result.scroll_speed = parseFloat(value)
     of "drag_friction":
@@ -33,6 +37,7 @@ proc loadConfig*(filePath: string): Config =
 proc generateDefaultConfig*(filePath: string) =
   var f = open(filePath, fmWrite)
   defer: f.close
+  f.write("min_scale = ", defaultConfig.min_scale, "\n")
   f.write("scroll_speed = ", defaultConfig.scroll_speed, "\n")
   f.write("drag_friction = ", defaultConfig.drag_friction, "\n")
   f.write("scale_friction = ", defaultConfig.scale_friction, "\n")

src/navigation.nim

@@ -23,7 +23,7 @@ proc world*(camera: Camera, v: Vec2f): Vec2f =
 proc update*(camera: var Camera, config: Config, dt: float, mouse: Mouse, image: PXImage, windowSize: Vec2f) =
   if abs(camera.deltaScale) > 0.5:
     let p0 = (camera.scalePivot - (windowSize * 0.5)) / camera.scale
-    camera.scale = max(camera.scale + camera.delta_scale * dt, 0.01)
+    camera.scale = max(camera.scale + camera.delta_scale * dt, config.min_scale)
     let p1 = (camera.scalePivot - (windowSize * 0.5)) / camera.scale
     camera.position += p0 - p1