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mirror of https://github.com/koreader/koreader synced 2024-10-31 21:20:20 +00:00

doc: geometry module

This commit is contained in:
Qingping Hou 2016-12-04 15:13:49 -08:00
parent 93e075feb6
commit 8799b4b6b1
2 changed files with 147 additions and 83 deletions

View File

@ -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()

View File

@ -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:
some behaviour is defined for points { x = ..., y = ... }
some behaviour is defined for dimensions { w = ..., h = ... }
local Geom = require("ui/geometry")
Geom:new{ x = 1, y = 0, w = 100, h = 200, }
just use it on simple tables that have x, y and/or w, h
Some behaviour is defined for points:
Geom:new{ x = 0, y = 0, }
Some behaviour is defined for dimensions:
Geom:new{ w = 600, h = 800, }
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
]]--
function Geom:sizeof()
--[[--
Returns area of itself.
@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
for points, it is basically an equality check
]]--
Works for dimensions, too. 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),