doc: geometry module

frontend/apps/reader/modules/readerfooter.lua

@@ -309,7 +309,7 @@ function ReaderFooter:addToMainMenu(tab_item_table)
            y = DTAP_ZONE_MINIBAR.y,
            w = DTAP_ZONE_MINIBAR.w,
            h = DTAP_ZONE_MINIBAR.h
-       }:sizeof() == 0 then
+       }:area() == 0 then
         table.insert(sub_items, {
             text = _("Toggle mode"),
             enabled_func = function()

frontend/ui/geometry.lua

@@ -1,22 +1,34 @@
-local Math = require("optmath")
+--[[--
-local DEBUG = require("dbg")
-
---[[
 2D Geometry utilities
 
-all of these apply to full rectangles { x = ..., y = ..., w = ..., h = ... }
+All of these apply to full rectangles:
+
+    local Geom = require("ui/geometry")
+    Geom:new{ x = 1, y = 0, w = 100, h = 200, }
+
+Some behaviour is defined for points:
+
+    Geom:new{ x = 0, y = 0, }
+
+Some behaviour is defined for dimensions:
 
-some behaviour is defined for points { x = ..., y = ... }
+    Geom:new{ w = 600, h = 800, }
-some behaviour is defined for dimensions { w = ..., h = ... }
 
-just use it on simple tables that have x, y and/or w, h
+Just use it on simple tables that have x, y and/or w, h
 or define your own types using this as a metatable
-]]--
+
+]]
+
+local Math = require("optmath")
+
+--[[--
+@table Geom
+]]
 local Geom = {
     x = 0,
     y = 0,
     w = 0,
-    h = 0
+    h = 0,
 }
 
 function Geom:new(o)
@@ -26,6 +38,10 @@ function Geom:new(o)
     return o
 end
 
+--[[--
+Make a deep copy of itself.
+@treturn Geom
+]]
 function Geom:copy()
     local n = Geom:new()
     n.x = self.x
@@ -39,48 +55,60 @@ function Geom:__tostring()
     return self.w.."x"..self.h.."+"..self.x.."+"..self.y
 end
 
---[[
+--[[--
-offset rectangle or point by relative values
+Offset rectangle or point by relative values
-]]--
+@int dx x delta
+@int dy y delta
+]]
 function Geom:offsetBy(dx, dy)
     self.x = self.x + dx
     self.y = self.y + dy
     return self
 end
 
---[[
+--[[--
-offset rectangle or point to certain coordinates
+Offsets rectangle or point to certain coordinates
-]]--
+@int x new x
+@int y new y
+]]
 function Geom:offsetTo(x, y)
     self.x = x
     self.y = y
     return self
 end
 
---[[
+--[[--
-scale rectangle (grow to bottom and to the right) or dimension
+Scales rectangle (grow to bottom and to the right) or dimension
 
-if a single factor is given, it is applied to both width and height
+If a single factor is given, it is applied to both width and height
-]]--
+
+@int zx scale for x axis
+@int zy scale for y axis
+]]
 function Geom:scaleBy(zx, zy)
     self.w = Math.round(self.w * zx)
     self.h = Math.round(self.h * (zy or zx))
     return self
 end
 
---[[
+--[[--
-this method also takes care of x and y
+This method also takes care of x and y on top of @{Geom:scaleBy}
-]]--
+
+@int zx scale for x axis
+@int zy scale for y axis
+]]
 function Geom:transformByScale(zx, zy)
     self.x = Math.round(self.x * zx)
     self.y = Math.round(self.y * (zx or zy))
     self:scaleBy(zx, zy)
 end
 
---[[
+--[[--
-return size of geom
+Returns area of itself.
-]]--
+
-function Geom:sizeof()
+@treturn int
+]]
+function Geom:area()
     if not self.w or not self.h then
         return 0
     else
@@ -88,25 +116,31 @@ function Geom:sizeof()
     end
 end
 
---[[
+--[[--
-enlarges or shrinks dimensions or rectangles
+Enlarges or shrinks dimensions or rectangles
 
-note that for rectangles the offset stays the same
+Note that for rectangles the offset stays the same
-]]--
+
+@int dw width delta
+@int dh height delta
+]]
 function Geom:changeSizeBy(dw, dh)
     self.w = self.w + dw
     self.h = self.h + dh
     return self
 end
 
---[[
+--[[--
-return the outer rectangle that contains both us and a given rectangle
+Returns a new outer rectangle that contains both us and a given rectangle
 
-works for rectangles, dimensions and points
+Works for rectangles, dimensions and points
-]]--
+
+@tparam Geom rect_b
+@treturn Geom
+]]
 function Geom:combine(rect_b)
     local combined = self:copy()
-    if not rect_b or rect_b:sizeof() == 0 then return combined end
+    if not rect_b or rect_b:area() == 0 then return combined end
     if combined.x > rect_b.x then
         combined.x = rect_b.x
     end
@@ -126,11 +160,13 @@ function Geom:combine(rect_b)
     return combined
 end
 
---[[
+--[[--
-returns a rectangle for the part that we and a given rectangle share
+Returns a new rectangle for the part that we and a given rectangle share
 
-TODO: what happens if there is no rectangle shared? currently behaviour is undefined.
+@tparam Geom rect_b
+@treturn Geom
 ]]--
+-- TODO: what happens if there is no rectangle shared? currently behaviour is undefined.
 function Geom:intersect(rect_b)
     -- make a copy of self
     local intersected = self:copy()
@@ -153,9 +189,11 @@ function Geom:intersect(rect_b)
     return intersected
 end
 
---[[
+--[[--
-return true if self does not share any area with rect_b
+Return true if self does not share any area with rect_b
-]]--
+
+@tparam Geom rect_b
+]]
 function Geom:notIntersectWith(rect_b)
     if (self.x >= (rect_b.x + rect_b.w))
     or (self.y >= (rect_b.y + rect_b.h))
@@ -166,28 +204,33 @@ function Geom:notIntersectWith(rect_b)
     return false
 end
 
---[[
+--[[--
-return true if self geom shares area with rect_b
+Return true if self geom shares area with rect_b
-]]--
+
+@tparam Geom rect_b
+]]
 function Geom:intersectWith(rect_b)
     return not self:notIntersectWith(rect_b)
 end
 
---[[
+--[[--
-set size of dimension or rectangle to size of given dimension/rectangle
+Set size of dimension or rectangle to size of given dimension/rectangle
-]]--
+
+@tparam Geom rect_b
+]]
 function Geom:setSizeTo(rect_b)
     self.w = rect_b.w
     self.h = rect_b.h
     return self
 end
 
---[[
+--[[--
-check whether rect_b is within current rectangle
+Check whether rect_b is within current rectangle
 
-works for dimensions, too
+Works for dimensions, too. For points, it is basically an equality check
-for points, it is basically an equality check
+
-]]--
+@tparam Geom rect_b
+]]
 function Geom:contains(rect_b)
     if self.x <= rect_b.x
     and self.y <= rect_b.y
@@ -199,11 +242,13 @@ function Geom:contains(rect_b)
     return false
 end
 
---[[
+--[[--
-check for equality
+Check for equality
 
-works for rectangles, points, dimensions
+Works for rectangles, points, dimensions
-]]--
+
+@tparam Geom rect_b
+]]
 function Geom:__eq(rect_b)
     if self.x == rect_b.x
     and self.y == rect_b.y
@@ -214,9 +259,11 @@ function Geom:__eq(rect_b)
     return false
 end
 
---[[
+--[[--
-check size of dimension/rectangle for equality
+Check size of dimension/rectangle for equality
-]]--
+
+@tparam Geom rect_b
+]]
 function Geom:equalSize(rect_b)
     if self.w == rect_b.w
     and self.h == rect_b.h
@@ -226,9 +273,11 @@ function Geom:equalSize(rect_b)
     return false
 end
 
---[[
+--[[--
-check if our size is smaller than the size of the given dimension/rectangle
+Check if our size is smaller than the size of the given dimension/rectangle
-]]--
+
+@tparam Geom rect_b
+]]
 function Geom:__lt(rect_b)
     DEBUG("lt:",self,rect_b)
     if self.w < rect_b.w and self.h < rect_b.h then
@@ -239,9 +288,10 @@ DEBUG("lt-")
     return false
 end
 
---[[
+--[[--
-check if our size is smaller or equal the size of the given dimension/rectangle
+Check if our size is smaller or equal the size of the given dimension/rectangle
-]]--
+@tparam Geom rect_b
+]]
 function Geom:__le(rect_b)
     if self.w <= rect_b.w and self.h <= rect_b.h then
         return true
@@ -249,13 +299,17 @@ function Geom:__le(rect_b)
     return false
 end
 
---[[
+--[[--
-offset the current rectangle by dx, dy while fitting it into the space
+Offset the current rectangle by dx, dy while fitting it into the space
 of a given rectangle
 
-this can also be called with dx=0 and dy=0, which will fit the current
+This can also be called with dx=0 and dy=0, which will fit the current
 rectangle into the given rectangle
-]]--
+
+@tparam Geom rect_b
+@int dx
+@int dy
+]]
 function Geom:offsetWithin(rect_b, dx, dy)
     -- check size constraints and shrink us when we're too big
     if self.w > rect_b.w then
@@ -282,9 +336,13 @@ function Geom:offsetWithin(rect_b, dx, dy)
     end
 end
 
---[[
+--[[--
-center the current rectangle at position x and y of a given rectangle
+Center the current rectangle at position x and y of a given rectangle
-]]--
+
+@tparam Geom rect_b
+@int dx
+@int dy
+]]
 function Geom:centerWithin(rect_b, x, y)
     -- check size constraints and shrink us when we're too big
     if self.w > rect_b.w then
@@ -316,16 +374,21 @@ function Geom:shrinkInside(rect_b, dx, dy)
     return self:intersect(rect_b)
 end
 
---[[
+--[[--
-return the Euclidean distance between two geoms
+Return the Euclidean distance between two geoms
-]]--
+
+@tparam Geom rect_b
+]]
 function Geom:distance(geom)
     return math.sqrt(math.pow(self.x - geom.x, 2) + math.pow(self.y - geom.y, 2))
 end
 
---[[
+--[[--
-return the midpoint of two geoms
+Return the midpoint of two geoms
-]]--
+
+@tparam Geom geom
+@treturn Geom
+]]
 function Geom:midpoint(geom)
     return Geom:new{
         x = Math.round((self.x + geom.x) / 2),
@@ -334,9 +397,10 @@ function Geom:midpoint(geom)
     }
 end
 
---[[
+--[[--
-return center point in this geom
+Return center point in this geom
-]]--
+@treturn Geom
+]]
 function Geom:center()
     return Geom:new{
         x = self.x + Math.round(self.w / 2),