mirror of
https://github.com/EsotericSoftware/spine-runtimes.git
synced 2025-12-20 01:06:00 +08:00
337 lines
9.9 KiB
Lua
337 lines
9.9 KiB
Lua
-------------------------------------------------------------------------------
|
|
-- Spine Runtimes Software License v2.5
|
|
--
|
|
-- Copyright (c) 2013-2016, Esoteric Software
|
|
-- All rights reserved.
|
|
--
|
|
-- You are granted a perpetual, non-exclusive, non-sublicensable, and
|
|
-- non-transferable license to use, install, execute, and perform the Spine
|
|
-- Runtimes software and derivative works solely for personal or internal
|
|
-- use. Without the written permission of Esoteric Software (see Section 2 of
|
|
-- the Spine Software License Agreement), you may not (a) modify, translate,
|
|
-- adapt, or develop new applications using the Spine Runtimes or otherwise
|
|
-- create derivative works or improvements of the Spine Runtimes or (b) remove,
|
|
-- delete, alter, or obscure any trademarks or any copyright, trademark, patent,
|
|
-- or other intellectual property or proprietary rights notices on or in the
|
|
-- Software, including any copy thereof. Redistributions in binary or source
|
|
-- form must include this license and terms.
|
|
--
|
|
-- THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE "AS IS" AND ANY EXPRESS OR
|
|
-- IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
|
-- MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
|
|
-- EVENT SHALL ESOTERIC SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
-- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
-- PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, BUSINESS INTERRUPTION, OR LOSS OF
|
|
-- USE, DATA, OR PROFITS) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
|
|
-- IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
-- POSSIBILITY OF SUCH DAMAGE.
|
|
-------------------------------------------------------------------------------
|
|
|
|
local utils = require "spine-lua.utils"
|
|
|
|
local setmetatable = setmetatable
|
|
local math_min = math.min
|
|
local math_max = math.max
|
|
local ipairs = ipairs
|
|
local table_insert = table.insert
|
|
local table_remove = table.remove
|
|
|
|
local Triangulator = {}
|
|
Triangulator.__index = Triangulator
|
|
|
|
function Triangulator.new ()
|
|
local self = {
|
|
convexPolygons = {},
|
|
convexPolygonsIndices = {},
|
|
indicesArray = {},
|
|
isConcaveArray = {},
|
|
triangles = {}
|
|
}
|
|
setmetatable(self, Triangulator)
|
|
|
|
return self
|
|
end
|
|
|
|
function Triangulator:triangulate (verticesArray)
|
|
local vertices = verticesArray
|
|
local vertexCount = #verticesArray / 2
|
|
|
|
self.indicesArray = {}
|
|
local indicesArray = self.indicesArray
|
|
local indices = utils.setArraySize(indicesArray, vertexCount)
|
|
local i = 0
|
|
while i < vertexCount do
|
|
indices[i] = i
|
|
i = i + 1
|
|
end
|
|
|
|
local isConcaveArray = self.isConcaveArray
|
|
local isConcave = isConcaveArray
|
|
i = 0
|
|
while i < vertexCount do
|
|
isConcave[i] = self:isConcave(i, vertexCount, vertices, indices)
|
|
i = i + 1
|
|
end
|
|
|
|
self.triangles = {}
|
|
local triangles = self.triangles;
|
|
|
|
while vertexCount > 3 do
|
|
-- Find ear tip.
|
|
local previous = vertexCount - 1
|
|
local i = 0
|
|
local _next = 1
|
|
while true do
|
|
local goToHead = false
|
|
local breakLoop = false
|
|
if not isConcave[i] then
|
|
local p1 = indices[previous] * 2 + 1
|
|
local p2 = indices[i] * 2 + 1
|
|
local p3 = indices[_next] * 2 + 1
|
|
local p1x = vertices[p1]
|
|
local p1y = vertices[p1 + 1]
|
|
local p2x = vertices[p2]
|
|
local p2y = vertices[p2 + 1]
|
|
local p3x = vertices[p3]
|
|
local p3y = vertices[p3 + 1]
|
|
local ii = ((_next + 1) % vertexCount)
|
|
while ii ~= previous do
|
|
if isConcave[ii] then
|
|
local v = indices[ii] * 2 + 1
|
|
local vx = vertices[v]
|
|
local vy = vertices[v + 1]
|
|
if self:positiveArea(p3x, p3y, p1x, p1y, vx, vy) then
|
|
if self:positiveArea(p1x, p1y, p2x, p2y, vx, vy) then
|
|
if self:positiveArea(p2x, p2y, p3x, p3y, vx, vy) then
|
|
goToHead = true
|
|
break
|
|
end
|
|
end
|
|
end
|
|
end
|
|
ii = (ii + 1) % vertexCount
|
|
end
|
|
if (not goToHead) then
|
|
breakLoop = true
|
|
break
|
|
end
|
|
end
|
|
|
|
if breakLoop then break end
|
|
|
|
if _next == 0 then
|
|
repeat
|
|
if not isConcave[i] then
|
|
break;
|
|
end
|
|
i = i - 1
|
|
until i == 0
|
|
break
|
|
end
|
|
|
|
previous = i
|
|
i = _next
|
|
_next = (_next + 1) % vertexCount
|
|
end
|
|
|
|
-- Cut ear tip.
|
|
table_insert(triangles, indices[(vertexCount + i - 1) % vertexCount] + 1)
|
|
table_insert(triangles, indices[i] + 1)
|
|
table_insert(triangles, indices[(i + 1) % vertexCount] + 1)
|
|
if i == 0 then
|
|
local ii = 1
|
|
while ii <= #indicesArray do
|
|
indicesArray[ii-1] = indicesArray[ii]
|
|
isConcaveArray[ii-1] = isConcaveArray[ii]
|
|
ii = ii + 1
|
|
end
|
|
else
|
|
table_remove(indicesArray, i)
|
|
table_remove(isConcaveArray, i)
|
|
end
|
|
vertexCount = vertexCount - 1
|
|
|
|
local previousIndex = (vertexCount + i - 1) % vertexCount
|
|
local nextIndex = i
|
|
if i == vertexCount then nextIndex = 0 end
|
|
isConcave[previousIndex] = self:isConcave(previousIndex, vertexCount, vertices, indices)
|
|
isConcave[nextIndex] = self:isConcave(nextIndex, vertexCount, vertices, indices)
|
|
end
|
|
|
|
if vertexCount == 3 then
|
|
table_insert(triangles, indices[2] + 1)
|
|
table_insert(triangles, indices[0] + 1)
|
|
table_insert(triangles, indices[1] + 1)
|
|
end
|
|
|
|
return triangles
|
|
end
|
|
|
|
function Triangulator:decompose(verticesArray, triangles)
|
|
local vertices = verticesArray
|
|
|
|
self.convexPolygons = {}
|
|
local convexPolygons = self.convexPolygons;
|
|
|
|
self.convexPolygonsIndices = {}
|
|
local convexPolygonsIndices = self.convexPolygonsIndices;
|
|
|
|
local polygonIndices = {}
|
|
local polygon = {}
|
|
|
|
-- Merge subsequent triangles if they form a triangle fan.
|
|
local fanBaseIndex = -1
|
|
local lastWinding = 0
|
|
local trianglesItems = triangles
|
|
local i = 1
|
|
local n = #triangles
|
|
while i <= n do
|
|
local t1 = (trianglesItems[i] - 1) * 2 + 1
|
|
local t2 = (trianglesItems[i + 1] - 1) * 2 + 1
|
|
local t3 = (trianglesItems[i + 2] - 1) * 2 + 1
|
|
local x1 = vertices[t1]
|
|
local y1 = vertices[t1 + 1]
|
|
local x2 = vertices[t2]
|
|
local y2 = vertices[t2 + 1]
|
|
local x3 = vertices[t3]
|
|
local y3 = vertices[t3 + 1]
|
|
|
|
-- If the base of the last triangle is the same as this triangle, check if they form a convex polygon (triangle fan).
|
|
local merged = false;
|
|
if fanBaseIndex == t1 then
|
|
local o = #polygon - 4 + 1;
|
|
local p = polygon;
|
|
local winding1 = self:winding(p[o], p[o + 1], p[o + 2], p[o + 3], x3, y3);
|
|
local winding2 = self:winding(x3, y3, p[1], p[2], p[3], p[4]);
|
|
if winding1 == lastWinding and winding2 == lastWinding then
|
|
table_insert(polygon, x3)
|
|
table_insert(polygon, y3)
|
|
table_insert(polygonIndices, t3)
|
|
merged = true
|
|
end
|
|
end
|
|
|
|
-- Otherwise make this triangle the new base.
|
|
if not merged then
|
|
if #polygon > 0 then
|
|
table_insert(convexPolygons, polygon)
|
|
table_insert(convexPolygonsIndices, polygonIndices)
|
|
end
|
|
polygon = {}
|
|
table_insert(polygon, x1)
|
|
table_insert(polygon, y1)
|
|
table_insert(polygon, x2)
|
|
table_insert(polygon, y2)
|
|
table_insert(polygon, x3)
|
|
table_insert(polygon, y3)
|
|
polygonIndices = {}
|
|
table_insert(polygonIndices, t1)
|
|
table_insert(polygonIndices, t2);
|
|
table_insert(polygonIndices, t3);
|
|
lastWinding = self:winding(x1, y1, x2, y2, x3, y3)
|
|
fanBaseIndex = t1
|
|
end
|
|
i = i + 3
|
|
end
|
|
|
|
if #polygon > 0 then
|
|
table_insert(convexPolygons, polygon)
|
|
table_insert(convexPolygonsIndices, polygonIndices)
|
|
end
|
|
|
|
-- Go through the list of polygons and try to merge the remaining triangles with the found triangle fans.
|
|
i = 1
|
|
n = #convexPolygons
|
|
while i <= n do
|
|
polygonIndices = convexPolygonsIndices[i]
|
|
if (#polygonIndices > 0) then
|
|
local firstIndex = polygonIndices[1]
|
|
local lastIndex = polygonIndices[#polygonIndices]
|
|
|
|
polygon = convexPolygons[i]
|
|
local o = #polygon - 4 + 1
|
|
local p = polygon
|
|
local prevPrevX = p[o]
|
|
local prevPrevY = p[o + 1]
|
|
local prevX = p[o + 2]
|
|
local prevY = p[o + 3]
|
|
local firstX = p[1]
|
|
local firstY = p[2]
|
|
local secondX = p[3]
|
|
local secondY = p[4]
|
|
local winding = self:winding(prevPrevX, prevPrevY, prevX, prevY, firstX, firstY)
|
|
|
|
local ii = 1
|
|
while ii <= n do
|
|
if ii ~= i then
|
|
local otherIndices = convexPolygonsIndices[ii]
|
|
if (#otherIndices == 3) then
|
|
local otherFirstIndex = otherIndices[1];
|
|
local otherSecondIndex = otherIndices[2];
|
|
local otherLastIndex = otherIndices[3];
|
|
|
|
local otherPoly = convexPolygons[ii];
|
|
local x3 = otherPoly[#otherPoly - 2 + 1]
|
|
local y3 = otherPoly[#otherPoly - 1 + 1]
|
|
|
|
if not (otherFirstIndex ~= firstIndex or otherSecondIndex ~= lastIndex) then
|
|
local winding1 = self:winding(prevPrevX, prevPrevY, prevX, prevY, x3, y3)
|
|
local winding2 = self:winding(x3, y3, firstX, firstY, secondX, secondY)
|
|
if winding1 == winding and winding2 == winding then
|
|
convexPolygons[ii] = {}
|
|
convexPolygonsIndices[ii] = {}
|
|
table_insert(polygon, x3)
|
|
table_insert(polygon, y3)
|
|
table_insert(polygonIndices, otherLastIndex)
|
|
prevPrevX = prevX
|
|
prevPrevY = prevY
|
|
prevX = x3
|
|
prevY = y3
|
|
ii = 1
|
|
end
|
|
end
|
|
end
|
|
end
|
|
ii = ii + 1
|
|
end
|
|
end
|
|
i = i + 1
|
|
end
|
|
|
|
-- Remove empty polygons that resulted from the merge step above.
|
|
i = #convexPolygons
|
|
while i >= 1 do
|
|
polygon = convexPolygons[i]
|
|
if #polygon == 0 then
|
|
table_remove(convexPolygons, i)
|
|
end
|
|
i = i - 1
|
|
end
|
|
|
|
return convexPolygons;
|
|
end
|
|
|
|
function Triangulator:isConcave(index, vertexCount, vertices, indices)
|
|
local previous = indices[(vertexCount + index - 1) % vertexCount] * 2 + 1;
|
|
local current = indices[index] * 2 + 1;
|
|
local _next = indices[(index + 1) % vertexCount] * 2 + 1;
|
|
return not self:positiveArea(vertices[previous], vertices[previous + 1], vertices[current], vertices[current + 1], vertices[_next],vertices[_next + 1]);
|
|
end
|
|
|
|
function Triangulator:positiveArea(p1x, p1y, p2x, p2y, p3x, p3y)
|
|
return p1x * (p3y - p2y) + p2x * (p1y - p3y) + p3x * (p2y - p1y) >= 0
|
|
end
|
|
|
|
function Triangulator:winding(p1x, p1y, p2x, p2y, p3x, p3y)
|
|
local px = p2x - p1x
|
|
local py = p2y - p1y
|
|
if p3x * py - p3y * px + px * p1y - p1x * py >= 0 then
|
|
return 1
|
|
else
|
|
return -1;
|
|
end
|
|
end
|
|
|
|
return Triangulator
|