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doc: geometry module
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@ -309,7 +309,7 @@ function ReaderFooter:addToMainMenu(tab_item_table)
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y = DTAP_ZONE_MINIBAR.y,
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w = DTAP_ZONE_MINIBAR.w,
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h = DTAP_ZONE_MINIBAR.h
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}:sizeof() == 0 then
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}:area() == 0 then
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table.insert(sub_items, {
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text = _("Toggle mode"),
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enabled_func = function()
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@ -1,22 +1,34 @@
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local Math = require("optmath")
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local DEBUG = require("dbg")
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--[[
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--[[--
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2D Geometry utilities
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all of these apply to full rectangles { x = ..., y = ..., w = ..., h = ... }
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All of these apply to full rectangles:
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some behaviour is defined for points { x = ..., y = ... }
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some behaviour is defined for dimensions { w = ..., h = ... }
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local Geom = require("ui/geometry")
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Geom:new{ x = 1, y = 0, w = 100, h = 200, }
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just use it on simple tables that have x, y and/or w, h
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Some behaviour is defined for points:
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Geom:new{ x = 0, y = 0, }
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Some behaviour is defined for dimensions:
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Geom:new{ w = 600, h = 800, }
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Just use it on simple tables that have x, y and/or w, h
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or define your own types using this as a metatable
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]]--
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]]
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local Math = require("optmath")
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--[[--
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@table Geom
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]]
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local Geom = {
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x = 0,
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y = 0,
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w = 0,
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h = 0
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h = 0,
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}
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function Geom:new(o)
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@ -26,6 +38,10 @@ function Geom:new(o)
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return o
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end
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--[[--
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Make a deep copy of itself.
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@treturn Geom
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]]
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function Geom:copy()
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local n = Geom:new()
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n.x = self.x
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@ -39,48 +55,60 @@ function Geom:__tostring()
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return self.w.."x"..self.h.."+"..self.x.."+"..self.y
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end
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--[[
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offset rectangle or point by relative values
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]]--
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--[[--
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Offset rectangle or point by relative values
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@int dx x delta
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@int dy y delta
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]]
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function Geom:offsetBy(dx, dy)
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self.x = self.x + dx
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self.y = self.y + dy
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return self
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end
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--[[
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offset rectangle or point to certain coordinates
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]]--
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--[[--
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Offsets rectangle or point to certain coordinates
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@int x new x
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@int y new y
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]]
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function Geom:offsetTo(x, y)
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self.x = x
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self.y = y
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return self
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end
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--[[
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scale rectangle (grow to bottom and to the right) or dimension
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--[[--
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Scales rectangle (grow to bottom and to the right) or dimension
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if a single factor is given, it is applied to both width and height
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]]--
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If a single factor is given, it is applied to both width and height
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@int zx scale for x axis
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@int zy scale for y axis
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]]
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function Geom:scaleBy(zx, zy)
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self.w = Math.round(self.w * zx)
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self.h = Math.round(self.h * (zy or zx))
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return self
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end
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--[[
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this method also takes care of x and y
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]]--
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--[[--
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This method also takes care of x and y on top of @{Geom:scaleBy}
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@int zx scale for x axis
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@int zy scale for y axis
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]]
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function Geom:transformByScale(zx, zy)
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self.x = Math.round(self.x * zx)
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self.y = Math.round(self.y * (zx or zy))
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self:scaleBy(zx, zy)
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end
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--[[
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return size of geom
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]]--
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function Geom:sizeof()
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--[[--
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Returns area of itself.
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@treturn int
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]]
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function Geom:area()
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if not self.w or not self.h then
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return 0
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else
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@ -88,25 +116,31 @@ function Geom:sizeof()
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end
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end
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--[[
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enlarges or shrinks dimensions or rectangles
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--[[--
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Enlarges or shrinks dimensions or rectangles
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note that for rectangles the offset stays the same
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]]--
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Note that for rectangles the offset stays the same
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@int dw width delta
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@int dh height delta
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]]
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function Geom:changeSizeBy(dw, dh)
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self.w = self.w + dw
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self.h = self.h + dh
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return self
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end
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--[[
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return the outer rectangle that contains both us and a given rectangle
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--[[--
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Returns a new outer rectangle that contains both us and a given rectangle
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works for rectangles, dimensions and points
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]]--
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Works for rectangles, dimensions and points
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@tparam Geom rect_b
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@treturn Geom
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]]
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function Geom:combine(rect_b)
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local combined = self:copy()
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if not rect_b or rect_b:sizeof() == 0 then return combined end
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if not rect_b or rect_b:area() == 0 then return combined end
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if combined.x > rect_b.x then
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combined.x = rect_b.x
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end
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@ -126,11 +160,13 @@ function Geom:combine(rect_b)
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return combined
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end
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--[[
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returns a rectangle for the part that we and a given rectangle share
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--[[--
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Returns a new rectangle for the part that we and a given rectangle share
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TODO: what happens if there is no rectangle shared? currently behaviour is undefined.
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@tparam Geom rect_b
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@treturn Geom
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]]--
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-- TODO: what happens if there is no rectangle shared? currently behaviour is undefined.
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function Geom:intersect(rect_b)
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-- make a copy of self
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local intersected = self:copy()
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@ -153,9 +189,11 @@ function Geom:intersect(rect_b)
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return intersected
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end
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--[[
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return true if self does not share any area with rect_b
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]]--
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--[[--
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Return true if self does not share any area with rect_b
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@tparam Geom rect_b
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]]
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function Geom:notIntersectWith(rect_b)
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if (self.x >= (rect_b.x + rect_b.w))
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or (self.y >= (rect_b.y + rect_b.h))
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@ -166,28 +204,33 @@ function Geom:notIntersectWith(rect_b)
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return false
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end
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--[[
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return true if self geom shares area with rect_b
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]]--
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--[[--
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Return true if self geom shares area with rect_b
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@tparam Geom rect_b
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]]
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function Geom:intersectWith(rect_b)
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return not self:notIntersectWith(rect_b)
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end
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--[[
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set size of dimension or rectangle to size of given dimension/rectangle
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]]--
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--[[--
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Set size of dimension or rectangle to size of given dimension/rectangle
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@tparam Geom rect_b
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]]
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function Geom:setSizeTo(rect_b)
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self.w = rect_b.w
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self.h = rect_b.h
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return self
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end
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--[[
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check whether rect_b is within current rectangle
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--[[--
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Check whether rect_b is within current rectangle
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works for dimensions, too
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for points, it is basically an equality check
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]]--
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Works for dimensions, too. For points, it is basically an equality check
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@tparam Geom rect_b
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]]
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function Geom:contains(rect_b)
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if self.x <= rect_b.x
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and self.y <= rect_b.y
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@ -199,11 +242,13 @@ function Geom:contains(rect_b)
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return false
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end
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--[[
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check for equality
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--[[--
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Check for equality
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works for rectangles, points, dimensions
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]]--
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Works for rectangles, points, dimensions
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@tparam Geom rect_b
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]]
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function Geom:__eq(rect_b)
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if self.x == rect_b.x
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and self.y == rect_b.y
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@ -214,9 +259,11 @@ function Geom:__eq(rect_b)
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return false
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end
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--[[
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check size of dimension/rectangle for equality
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]]--
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--[[--
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Check size of dimension/rectangle for equality
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@tparam Geom rect_b
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]]
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function Geom:equalSize(rect_b)
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if self.w == rect_b.w
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and self.h == rect_b.h
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@ -226,9 +273,11 @@ function Geom:equalSize(rect_b)
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return false
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end
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--[[
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check if our size is smaller than the size of the given dimension/rectangle
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]]--
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--[[--
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Check if our size is smaller than the size of the given dimension/rectangle
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@tparam Geom rect_b
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]]
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function Geom:__lt(rect_b)
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DEBUG("lt:",self,rect_b)
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if self.w < rect_b.w and self.h < rect_b.h then
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@ -239,9 +288,10 @@ DEBUG("lt-")
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return false
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end
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--[[
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check if our size is smaller or equal the size of the given dimension/rectangle
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]]--
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--[[--
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Check if our size is smaller or equal the size of the given dimension/rectangle
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@tparam Geom rect_b
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]]
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function Geom:__le(rect_b)
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if self.w <= rect_b.w and self.h <= rect_b.h then
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return true
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@ -249,13 +299,17 @@ function Geom:__le(rect_b)
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return false
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end
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--[[
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offset the current rectangle by dx, dy while fitting it into the space
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--[[--
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Offset the current rectangle by dx, dy while fitting it into the space
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of a given rectangle
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this can also be called with dx=0 and dy=0, which will fit the current
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This can also be called with dx=0 and dy=0, which will fit the current
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rectangle into the given rectangle
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]]--
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@tparam Geom rect_b
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@int dx
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@int dy
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]]
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function Geom:offsetWithin(rect_b, dx, dy)
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-- check size constraints and shrink us when we're too big
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if self.w > rect_b.w then
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@ -282,9 +336,13 @@ function Geom:offsetWithin(rect_b, dx, dy)
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end
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end
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--[[
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center the current rectangle at position x and y of a given rectangle
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]]--
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--[[--
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Center the current rectangle at position x and y of a given rectangle
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@tparam Geom rect_b
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@int dx
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@int dy
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]]
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function Geom:centerWithin(rect_b, x, y)
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-- check size constraints and shrink us when we're too big
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if self.w > rect_b.w then
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@ -316,16 +374,21 @@ function Geom:shrinkInside(rect_b, dx, dy)
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return self:intersect(rect_b)
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end
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--[[
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return the Euclidean distance between two geoms
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]]--
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--[[--
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Return the Euclidean distance between two geoms
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@tparam Geom rect_b
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]]
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function Geom:distance(geom)
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return math.sqrt(math.pow(self.x - geom.x, 2) + math.pow(self.y - geom.y, 2))
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end
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--[[
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return the midpoint of two geoms
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]]--
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--[[--
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Return the midpoint of two geoms
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@tparam Geom geom
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@treturn Geom
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]]
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function Geom:midpoint(geom)
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return Geom:new{
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x = Math.round((self.x + geom.x) / 2),
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@ -334,9 +397,10 @@ function Geom:midpoint(geom)
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}
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end
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--[[
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return center point in this geom
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]]--
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--[[--
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Return center point in this geom
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@treturn Geom
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]]
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function Geom:center()
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return Geom:new{
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x = self.x + Math.round(self.w / 2),
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