Created
June 8, 2012 16:03
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ShapeHexagon
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ShapeHexagon = Attribute('ShapeHexagon') | |
local _sin60 = math.sin( math.rad( 60 ) ) | |
local _sin30 = math.sin( math.rad( 30 ) ) | |
local _cos30 = math.cos( math.rad( 30 ) ) | |
function ShapeHexagon:onInit( sideLength ) | |
self:build( sideLength or 1 ) | |
end | |
function ShapeHexagon:setSideLength( sideLength ) | |
self.sideLength = sideLength | |
self:build( sideLength ) | |
end | |
function ShapeHexagon:getSideLength() | |
return self.sideLength | |
end | |
function ShapeHexagon:build( sideLength ) | |
local h, r, width, height, horizontalOffset, verticalOffset | |
h = _sin30 * sideLength | |
r = _cos30 * sideLength | |
height = 2 * r | |
width = sideLength * height | |
horizontalOffset = sideLength + h | |
verticalOffset = r | |
self.sideLength = sideLength | |
self.h = h | |
self.r = r | |
self.height = height | |
self.width = width | |
self.horizontalOffset = horizontalOffset | |
self.verticalOffset = verticalOffset | |
-- Bounds. | |
self.x1 = -h | |
self.y1 = 0 | |
self.x2 = horizontalOffset | |
self.y2 = height | |
-- Vertices. | |
self.vertices = { | |
0, 0, | |
sideLength, 0, | |
sideLength + h, r, | |
sideLength, r + r, | |
0, r + r, | |
-h, r | |
} | |
end | |
function ShapeHexagon:getEdgeBySide( side, inset ) | |
local edge = {} | |
local start = side * 2 | |
for i = start, start + 3 do | |
local i1 = (i % 12) + 1 | |
edge[#edge + 1] = self.vertices[ i1 ] | |
end | |
if inset then | |
local normalize = vector.normalize | |
local cx, cy = self:getCenter() | |
local vec1 = vector( cx, cy ) | |
local vec2 = vector( edge[1], edge[2] ) | |
local vec3 = vector( edge[3], edge[4] ) | |
local vec1_2 = normalize( vec1 - vec2 ) | |
local vec1_3 = normalize( vec1 - vec3 ) | |
vec2 = vec2 + vec1_2 * inset | |
vec3 = vec3 + vec1_3 * inset | |
edge[1] = vec2.x | |
edge[2] = vec2.y | |
edge[3] = vec3.x | |
edge[4] = vec3.y | |
end | |
return edge | |
end | |
function ShapeHexagon:getCenter() | |
return (self.sideLength / 2), self.r | |
end | |
function ShapeHexagon:centerAroundPoint( px, py ) | |
local cx, cy = self:getCenter() | |
for i = 1, #self.vertices, 2 do | |
local x, y = self.vertices[i], self.vertices[i+1] | |
self.vertices[i] = (cx-x) - px | |
self.vertices[i+1] = (cy-y) - py | |
end | |
end | |
function ShapeHexagon:isPointInside( px, py ) | |
-- transform point to always be in bottom right quadrant. | |
local cx, cy = self:getCenter() | |
local qx = math.abs( px - cx ) + cx | |
local qy = math.abs( py - cy ) + cy | |
-- check bounds. | |
if qx > cx+self.sideLength or qy > self.height then return false end | |
-- check corner. | |
local p = vector(self.vertices[7], self.vertices[8]) | |
local d = -p.y * (qx - p.x) - p.x * (qy - p.y) | |
return d >= 0 | |
end | |
function ShapeHexagon:getVertices() | |
return self.vertices | |
end |
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