Reduced diameter of star as thickness increases to remain within bounding box

Author: 83N170

changelog.txt

@@ -16,10 +16,16 @@ Template for new versions:
 
 ## New Features
 
-- `gui/design`: add option to draw N-point stars, hollow or filled or inverted, and change the main axis to orient in any direction
+- `gui/design`: add new option to draw N-point stars.
+  - The default has 5 points, use 'B'/'b' to increase/decrease points.
+  - They can be hollow or filled, and inverted.
+  - The next-point offset can be increased/decreased using 'N'/'n' which particularly affects 7 point stars and above to make them spikier or smoother, but can also be used to decrease to 1 to make symmetrical polygons or increase to N which only paints the vertexes.
+  - The orientation can be changed by adding a main axis point using 'v' and moving this to point in the desired direction.
 
 ## Fixes
 
+- `gui/design`: reduced diameter of star as thickness increases to remain within bounding box
+ 
 ## Misc Improvements
 
 ## Removed

internal/design/shapes.lua

@@ -411,12 +411,11 @@ function LineDrawer:plot_bresenham(x0, y0, x1, y1, thickness)
     local sy = y0 < y1 and 1 or -1
     local e2, x, y
 
-    for i = 0, thickness - 1 do
+    for i = -math.floor(thickness / 2), math.ceil(thickness / 2) - 1 do
         x = x0
         y = y0 + i
         local err = dx - dy
-        local p = math.max(dx, dy)
-        while p >= 0 do
+        while true do
             for j = -math.floor(thickness / 2), math.ceil(thickness / 2) - 1 do
                 if not self.arr[x + j] then self.arr[x + j] = {} end
                 if not self.arr[x + j][y] then
@@ -440,7 +439,6 @@ function LineDrawer:plot_bresenham(x0, y0, x1, y1, thickness)
                 err = err + dx
                 y = y + sy
             end
-            p = p - 1
         end
     end
 end
@@ -770,11 +768,17 @@ function Star:update(points, extra_points)
     self.arr = {}
     if #points < self.min_points then return end
     self.threshold = self.options.total_points.value - 2 * self.options.next_point_offset.value
+
+    local thickness = 1
+    if self.options.hollow.value then
+        thickness = self.options.thickness.value
+    end
+
     local top_left, bot_right = self:get_point_dims()
-    self.height = bot_right.y - top_left.y
-    self.width = bot_right.x - top_left.x
-    if self.height == 1 or self.width == 1 then return end
-    self.center = { x = self.width * 0.5, y = self.height * 0.5 }
+    self.height = bot_right.y - top_left.y - thickness + 1
+    self.width = bot_right.x - top_left.x - thickness + 1
+    if self.height < 2 or self.width < 2 then return end
+    self.center = { x = (bot_right.x - top_left.x + ((thickness - 1) % 2)) * 0.5, y = (bot_right.y - top_left.y + ((thickness - 1) % 2)) * 0.5 }
     local axes = {}
 
     axes[1] = (#extra_points > 0) and { x = extra_points[1].x - self.center.x - top_left.x, y = extra_points[1].y - self.center.y - top_left.y } or { x = 0, y = -self.center.y }
@@ -786,10 +790,6 @@ function Star:update(points, extra_points)
         axes[a] = { x = math.cos(angle) * axes[1].x - math.sin(angle) * axes[1].y, y = math.sin(angle) * axes[1].x + math.cos(angle) * axes[1].y }
     end
 
-    local thickness = 1
-    if self.options.hollow.value then
-        thickness = self.options.thickness.value
-    end
 
     self.lines = {}
     for l = 1, self.options.total_points.value do