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Diffstat (limited to 'vendor/bump.lua')
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diff --git a/vendor/bump.lua b/vendor/bump.lua new file mode 100644 index 0000000..6dabca7 --- /dev/null +++ b/vendor/bump.lua @@ -0,0 +1,773 @@ +local bump = { + _VERSION = 'bump v3.1.7', + _URL = 'https://github.com/kikito/bump.lua', + _DESCRIPTION = 'A collision detection library for Lua', + _LICENSE = [[ + MIT LICENSE + + Copyright (c) 2014 Enrique García Cota + + Permission is hereby granted, free of charge, to any person obtaining a + copy of this software and associated documentation files (the + "Software"), to deal in the Software without restriction, including + without limitation the rights to use, copy, modify, merge, publish, + distribute, sublicense, and/or sell copies of the Software, and to + permit persons to whom the Software is furnished to do so, subject to + the following conditions: + + The above copyright notice and this permission notice shall be included + in all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY + CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, + TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE + SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + ]] +} + +------------------------------------------ +-- Auxiliary functions +------------------------------------------ +local DELTA = 1e-10 -- floating-point margin of error + +local abs, floor, ceil, min, max = math.abs, math.floor, math.ceil, math.min, math.max + +local function sign(x) + if x > 0 then return 1 end + if x == 0 then return 0 end + return -1 +end + +local function nearest(x, a, b) + if abs(a - x) < abs(b - x) then return a else return b end +end + +local function assertType(desiredType, value, name) + if type(value) ~= desiredType then + error(name .. ' must be a ' .. desiredType .. ', but was ' .. tostring(value) .. '(a ' .. type(value) .. ')') + end +end + +local function assertIsPositiveNumber(value, name) + if type(value) ~= 'number' or value <= 0 then + error(name .. ' must be a positive integer, but was ' .. tostring(value) .. '(' .. type(value) .. ')') + end +end + +local function assertIsRect(x,y,w,h) + assertType('number', x, 'x') + assertType('number', y, 'y') + assertIsPositiveNumber(w, 'w') + assertIsPositiveNumber(h, 'h') +end + +local defaultFilter = function() + return 'slide' +end + +------------------------------------------ +-- Rectangle functions +------------------------------------------ + +local function rect_getNearestCorner(x,y,w,h, px, py) + return nearest(px, x, x+w), nearest(py, y, y+h) +end + +-- This is a generalized implementation of the liang-barsky algorithm, which also returns +-- the normals of the sides where the segment intersects. +-- Returns nil if the segment never touches the rect +-- Notice that normals are only guaranteed to be accurate when initially ti1, ti2 == -math.huge, math.huge +local function rect_getSegmentIntersectionIndices(x,y,w,h, x1,y1,x2,y2, ti1,ti2) + ti1, ti2 = ti1 or 0, ti2 or 1 + local dx, dy = x2-x1, y2-y1 + local nx, ny + local nx1, ny1, nx2, ny2 = 0,0,0,0 + local p, q, r + + for side = 1,4 do + if side == 1 then nx,ny,p,q = -1, 0, -dx, x1 - x -- left + elseif side == 2 then nx,ny,p,q = 1, 0, dx, x + w - x1 -- right + elseif side == 3 then nx,ny,p,q = 0, -1, -dy, y1 - y -- top + else nx,ny,p,q = 0, 1, dy, y + h - y1 -- bottom + end + + if p == 0 then + if q <= 0 then return nil end + else + r = q / p + if p < 0 then + if r > ti2 then return nil + elseif r > ti1 then ti1,nx1,ny1 = r,nx,ny + end + else -- p > 0 + if r < ti1 then return nil + elseif r < ti2 then ti2,nx2,ny2 = r,nx,ny + end + end + end + end + + return ti1,ti2, nx1,ny1, nx2,ny2 +end + +-- Calculates the minkowsky difference between 2 rects, which is another rect +local function rect_getDiff(x1,y1,w1,h1, x2,y2,w2,h2) + return x2 - x1 - w1, + y2 - y1 - h1, + w1 + w2, + h1 + h2 +end + +local function rect_containsPoint(x,y,w,h, px,py) + return px - x > DELTA and py - y > DELTA and + x + w - px > DELTA and y + h - py > DELTA +end + +local function rect_isIntersecting(x1,y1,w1,h1, x2,y2,w2,h2) + return x1 < x2+w2 and x2 < x1+w1 and + y1 < y2+h2 and y2 < y1+h1 +end + +local function rect_getSquareDistance(x1,y1,w1,h1, x2,y2,w2,h2) + local dx = x1 - x2 + (w1 - w2)/2 + local dy = y1 - y2 + (h1 - h2)/2 + return dx*dx + dy*dy +end + +local function rect_detectCollision(x1,y1,w1,h1, x2,y2,w2,h2, goalX, goalY) + goalX = goalX or x1 + goalY = goalY or y1 + + local dx, dy = goalX - x1, goalY - y1 + local x,y,w,h = rect_getDiff(x1,y1,w1,h1, x2,y2,w2,h2) + + local overlaps, ti, nx, ny + + if rect_containsPoint(x,y,w,h, 0,0) then -- item was intersecting other + local px, py = rect_getNearestCorner(x,y,w,h, 0, 0) + local wi, hi = min(w1, abs(px)), min(h1, abs(py)) -- area of intersection + ti = -wi * hi -- ti is the negative area of intersection + overlaps = true + else + local ti1,ti2,nx1,ny1 = rect_getSegmentIntersectionIndices(x,y,w,h, 0,0,dx,dy, -math.huge, math.huge) + + -- item tunnels into other + if ti1 + and ti1 < 1 + and (abs(ti1 - ti2) >= DELTA) -- special case for rect going through another rect's corner + and (0 < ti1 + DELTA + or 0 == ti1 and ti2 > 0) + then + ti, nx, ny = ti1, nx1, ny1 + overlaps = false + end + end + + if not ti then return end + + local tx, ty + + if overlaps then + if dx == 0 and dy == 0 then + -- intersecting and not moving - use minimum displacement vector + local px, py = rect_getNearestCorner(x,y,w,h, 0,0) + if abs(px) < abs(py) then py = 0 else px = 0 end + nx, ny = sign(px), sign(py) + tx, ty = x1 + px, y1 + py + else + -- intersecting and moving - move in the opposite direction + local ti1, _ + ti1,_,nx,ny = rect_getSegmentIntersectionIndices(x,y,w,h, 0,0,dx,dy, -math.huge, 1) + if not ti1 then return end + tx, ty = x1 + dx * ti1, y1 + dy * ti1 + end + else -- tunnel + tx, ty = x1 + dx * ti, y1 + dy * ti + end + + return { + overlaps = overlaps, + ti = ti, + move = {x = dx, y = dy}, + normal = {x = nx, y = ny}, + touch = {x = tx, y = ty}, + itemRect = {x = x1, y = y1, w = w1, h = h1}, + otherRect = {x = x2, y = y2, w = w2, h = h2} + } +end + +------------------------------------------ +-- Grid functions +------------------------------------------ + +local function grid_toWorld(cellSize, cx, cy) + return (cx - 1)*cellSize, (cy-1)*cellSize +end + +local function grid_toCell(cellSize, x, y) + return floor(x / cellSize) + 1, floor(y / cellSize) + 1 +end + +-- grid_traverse* functions are based on "A Fast Voxel Traversal Algorithm for Ray Tracing", +-- by John Amanides and Andrew Woo - http://www.cse.yorku.ca/~amana/research/grid.pdf +-- It has been modified to include both cells when the ray "touches a grid corner", +-- and with a different exit condition + +local function grid_traverse_initStep(cellSize, ct, t1, t2) + local v = t2 - t1 + if v > 0 then + return 1, cellSize / v, ((ct + v) * cellSize - t1) / v + elseif v < 0 then + return -1, -cellSize / v, ((ct + v - 1) * cellSize - t1) / v + else + return 0, math.huge, math.huge + end +end + +local function grid_traverse(cellSize, x1,y1,x2,y2, f) + local cx1,cy1 = grid_toCell(cellSize, x1,y1) + local cx2,cy2 = grid_toCell(cellSize, x2,y2) + local stepX, dx, tx = grid_traverse_initStep(cellSize, cx1, x1, x2) + local stepY, dy, ty = grid_traverse_initStep(cellSize, cy1, y1, y2) + local cx,cy = cx1,cy1 + + f(cx, cy) + + -- The default implementation had an infinite loop problem when + -- approaching the last cell in some occassions. We finish iterating + -- when we are *next* to the last cell + while abs(cx - cx2) + abs(cy - cy2) > 1 do + if tx < ty then + tx, cx = tx + dx, cx + stepX + f(cx, cy) + else + -- Addition: include both cells when going through corners + if tx == ty then f(cx + stepX, cy) end + ty, cy = ty + dy, cy + stepY + f(cx, cy) + end + end + + -- If we have not arrived to the last cell, use it + if cx ~= cx2 or cy ~= cy2 then f(cx2, cy2) end + +end + +local function grid_toCellRect(cellSize, x,y,w,h) + local cx,cy = grid_toCell(cellSize, x, y) + local cr,cb = ceil((x+w) / cellSize), ceil((y+h) / cellSize) + return cx, cy, cr - cx + 1, cb - cy + 1 +end + +------------------------------------------ +-- Responses +------------------------------------------ + +local touch = function(world, col, x,y,w,h, goalX, goalY, filter) + return col.touch.x, col.touch.y, {}, 0 +end + +local cross = function(world, col, x,y,w,h, goalX, goalY, filter) + local cols, len = world:project(col.item, x,y,w,h, goalX, goalY, filter) + return goalX, goalY, cols, len +end + +local slide = function(world, col, x,y,w,h, goalX, goalY, filter) + goalX = goalX or x + goalY = goalY or y + + local tch, move = col.touch, col.move + if move.x ~= 0 or move.y ~= 0 then + if col.normal.x ~= 0 then + goalX = tch.x + else + goalY = tch.y + end + end + + col.slide = {x = goalX, y = goalY} + + x,y = tch.x, tch.y + local cols, len = world:project(col.item, x,y,w,h, goalX, goalY, filter) + return goalX, goalY, cols, len +end + +local bounce = function(world, col, x,y,w,h, goalX, goalY, filter) + goalX = goalX or x + goalY = goalY or y + + local tch, move = col.touch, col.move + local tx, ty = tch.x, tch.y + + local bx, by = tx, ty + + if move.x ~= 0 or move.y ~= 0 then + local bnx, bny = goalX - tx, goalY - ty + if col.normal.x == 0 then bny = -bny else bnx = -bnx end + bx, by = tx + bnx, ty + bny + end + + col.bounce = {x = bx, y = by} + x,y = tch.x, tch.y + goalX, goalY = bx, by + + local cols, len = world:project(col.item, x,y,w,h, goalX, goalY, filter) + return goalX, goalY, cols, len +end + +------------------------------------------ +-- World +------------------------------------------ + +local World = {} +local World_mt = {__index = World} + +-- Private functions and methods + +local function sortByWeight(a,b) return a.weight < b.weight end + +local function sortByTiAndDistance(a,b) + if a.ti == b.ti then + local ir, ar, br = a.itemRect, a.otherRect, b.otherRect + local ad = rect_getSquareDistance(ir.x,ir.y,ir.w,ir.h, ar.x,ar.y,ar.w,ar.h) + local bd = rect_getSquareDistance(ir.x,ir.y,ir.w,ir.h, br.x,br.y,br.w,br.h) + return ad < bd + end + return a.ti < b.ti +end + +local function addItemToCell(self, item, cx, cy) + self.rows[cy] = self.rows[cy] or setmetatable({}, {__mode = 'v'}) + local row = self.rows[cy] + row[cx] = row[cx] or {itemCount = 0, x = cx, y = cy, items = setmetatable({}, {__mode = 'k'})} + local cell = row[cx] + self.nonEmptyCells[cell] = true + if not cell.items[item] then + cell.items[item] = true + cell.itemCount = cell.itemCount + 1 + end +end + +local function removeItemFromCell(self, item, cx, cy) + local row = self.rows[cy] + if not row or not row[cx] or not row[cx].items[item] then return false end + + local cell = row[cx] + cell.items[item] = nil + cell.itemCount = cell.itemCount - 1 + if cell.itemCount == 0 then + self.nonEmptyCells[cell] = nil + end + return true +end + +local function getDictItemsInCellRect(self, cl,ct,cw,ch) + local items_dict = {} + for cy=ct,ct+ch-1 do + local row = self.rows[cy] + if row then + for cx=cl,cl+cw-1 do + local cell = row[cx] + if cell and cell.itemCount > 0 then -- no cell.itemCount > 1 because tunneling + for item,_ in pairs(cell.items) do + items_dict[item] = true + end + end + end + end + end + + return items_dict +end + +local function getCellsTouchedBySegment(self, x1,y1,x2,y2) + + local cells, cellsLen, visited = {}, 0, {} + + grid_traverse(self.cellSize, x1,y1,x2,y2, function(cx, cy) + local row = self.rows[cy] + if not row then return end + local cell = row[cx] + if not cell or visited[cell] then return end + + visited[cell] = true + cellsLen = cellsLen + 1 + cells[cellsLen] = cell + end) + + return cells, cellsLen +end + +local function getInfoAboutItemsTouchedBySegment(self, x1,y1, x2,y2, filter) + local cells, len = getCellsTouchedBySegment(self, x1,y1,x2,y2) + local cell, rect, l,t,w,h, ti1,ti2, tii0,tii1 + local visited, itemInfo, itemInfoLen = {},{},0 + for i=1,len do + cell = cells[i] + for item in pairs(cell.items) do + if not visited[item] then + visited[item] = true + if (not filter or filter(item)) then + rect = self.rects[item] + l,t,w,h = rect.x,rect.y,rect.w,rect.h + + ti1,ti2 = rect_getSegmentIntersectionIndices(l,t,w,h, x1,y1, x2,y2, 0, 1) + if ti1 and ((0 < ti1 and ti1 < 1) or (0 < ti2 and ti2 < 1)) then + -- the sorting is according to the t of an infinite line, not the segment + tii0,tii1 = rect_getSegmentIntersectionIndices(l,t,w,h, x1,y1, x2,y2, -math.huge, math.huge) + itemInfoLen = itemInfoLen + 1 + itemInfo[itemInfoLen] = {item = item, ti1 = ti1, ti2 = ti2, weight = min(tii0,tii1)} + end + end + end + end + end + table.sort(itemInfo, sortByWeight) + return itemInfo, itemInfoLen +end + +local function getResponseByName(self, name) + local response = self.responses[name] + if not response then + error(('Unknown collision type: %s (%s)'):format(name, type(name))) + end + return response +end + + +-- Misc Public Methods + +function World:addResponse(name, response) + self.responses[name] = response +end + +function World:project(item, x,y,w,h, goalX, goalY, filter) + assertIsRect(x,y,w,h) + + goalX = goalX or x + goalY = goalY or y + filter = filter or defaultFilter + + local collisions, len = {}, 0 + + local visited = {} + if item ~= nil then visited[item] = true end + + -- This could probably be done with less cells using a polygon raster over the cells instead of a + -- bounding rect of the whole movement. Conditional to building a queryPolygon method + local tl, tt = min(goalX, x), min(goalY, y) + local tr, tb = max(goalX + w, x+w), max(goalY + h, y+h) + local tw, th = tr-tl, tb-tt + + local cl,ct,cw,ch = grid_toCellRect(self.cellSize, tl,tt,tw,th) + + local dictItemsInCellRect = getDictItemsInCellRect(self, cl,ct,cw,ch) + + for other,_ in pairs(dictItemsInCellRect) do + if not visited[other] then + visited[other] = true + + local responseName = filter(item, other) + if responseName then + local ox,oy,ow,oh = self:getRect(other) + local col = rect_detectCollision(x,y,w,h, ox,oy,ow,oh, goalX, goalY) + + if col then + col.other = other + col.item = item + col.type = responseName + + len = len + 1 + collisions[len] = col + end + end + end + end + + table.sort(collisions, sortByTiAndDistance) + + return collisions, len +end + +function World:countCells() + local count = 0 + for _,row in pairs(self.rows) do + for _,_ in pairs(row) do + count = count + 1 + end + end + return count +end + +function World:hasItem(item) + return not not self.rects[item] +end + +function World:getItems() + local items, len = {}, 0 + for item,_ in pairs(self.rects) do + len = len + 1 + items[len] = item + end + return items, len +end + +function World:countItems() + local len = 0 + for _ in pairs(self.rects) do len = len + 1 end + return len +end + +function World:getRect(item) + local rect = self.rects[item] + if not rect then + error('Item ' .. tostring(item) .. ' must be added to the world before getting its rect. Use world:add(item, x,y,w,h) to add it first.') + end + return rect.x, rect.y, rect.w, rect.h +end + +function World:toWorld(cx, cy) + return grid_toWorld(self.cellSize, cx, cy) +end + +function World:toCell(x,y) + return grid_toCell(self.cellSize, x, y) +end + + +--- Query methods + +function World:queryRect(x,y,w,h, filter) + + assertIsRect(x,y,w,h) + + local cl,ct,cw,ch = grid_toCellRect(self.cellSize, x,y,w,h) + local dictItemsInCellRect = getDictItemsInCellRect(self, cl,ct,cw,ch) + + local items, len = {}, 0 + + local rect + for item,_ in pairs(dictItemsInCellRect) do + rect = self.rects[item] + if (not filter or filter(item)) + and rect_isIntersecting(x,y,w,h, rect.x, rect.y, rect.w, rect.h) + then + len = len + 1 + items[len] = item + end + end + + return items, len +end + +function World:queryPoint(x,y, filter) + local cx,cy = self:toCell(x,y) + local dictItemsInCellRect = getDictItemsInCellRect(self, cx,cy,1,1) + + local items, len = {}, 0 + + local rect + for item,_ in pairs(dictItemsInCellRect) do + rect = self.rects[item] + if (not filter or filter(item)) + and rect_containsPoint(rect.x, rect.y, rect.w, rect.h, x, y) + then + len = len + 1 + items[len] = item + end + end + + return items, len +end + +function World:querySegment(x1, y1, x2, y2, filter) + local itemInfo, len = getInfoAboutItemsTouchedBySegment(self, x1, y1, x2, y2, filter) + local items = {} + for i=1, len do + items[i] = itemInfo[i].item + end + return items, len +end + +function World:querySegmentWithCoords(x1, y1, x2, y2, filter) + local itemInfo, len = getInfoAboutItemsTouchedBySegment(self, x1, y1, x2, y2, filter) + local dx, dy = x2-x1, y2-y1 + local info, ti1, ti2 + for i=1, len do + info = itemInfo[i] + ti1 = info.ti1 + ti2 = info.ti2 + + info.weight = nil + info.x1 = x1 + dx * ti1 + info.y1 = y1 + dy * ti1 + info.x2 = x1 + dx * ti2 + info.y2 = y1 + dy * ti2 + end + return itemInfo, len +end + + +--- Main methods + +function World:add(item, x,y,w,h) + local rect = self.rects[item] + if rect then + error('Item ' .. tostring(item) .. ' added to the world twice.') + end + assertIsRect(x,y,w,h) + + self.rects[item] = {x=x,y=y,w=w,h=h} + + local cl,ct,cw,ch = grid_toCellRect(self.cellSize, x,y,w,h) + for cy = ct, ct+ch-1 do + for cx = cl, cl+cw-1 do + addItemToCell(self, item, cx, cy) + end + end + + return item +end + +function World:remove(item) + local x,y,w,h = self:getRect(item) + + self.rects[item] = nil + local cl,ct,cw,ch = grid_toCellRect(self.cellSize, x,y,w,h) + for cy = ct, ct+ch-1 do + for cx = cl, cl+cw-1 do + removeItemFromCell(self, item, cx, cy) + end + end +end + +function World:update(item, x2,y2,w2,h2) + local x1,y1,w1,h1 = self:getRect(item) + w2,h2 = w2 or w1, h2 or h1 + assertIsRect(x2,y2,w2,h2) + + if x1 ~= x2 or y1 ~= y2 or w1 ~= w2 or h1 ~= h2 then + + local cellSize = self.cellSize + local cl1,ct1,cw1,ch1 = grid_toCellRect(cellSize, x1,y1,w1,h1) + local cl2,ct2,cw2,ch2 = grid_toCellRect(cellSize, x2,y2,w2,h2) + + if cl1 ~= cl2 or ct1 ~= ct2 or cw1 ~= cw2 or ch1 ~= ch2 then + + local cr1, cb1 = cl1+cw1-1, ct1+ch1-1 + local cr2, cb2 = cl2+cw2-1, ct2+ch2-1 + local cyOut + + for cy = ct1, cb1 do + cyOut = cy < ct2 or cy > cb2 + for cx = cl1, cr1 do + if cyOut or cx < cl2 or cx > cr2 then + removeItemFromCell(self, item, cx, cy) + end + end + end + + for cy = ct2, cb2 do + cyOut = cy < ct1 or cy > cb1 + for cx = cl2, cr2 do + if cyOut or cx < cl1 or cx > cr1 then + addItemToCell(self, item, cx, cy) + end + end + end + + end + + local rect = self.rects[item] + rect.x, rect.y, rect.w, rect.h = x2,y2,w2,h2 + + end +end + +function World:move(item, goalX, goalY, filter) + local actualX, actualY, cols, len = self:check(item, goalX, goalY, filter) + + self:update(item, actualX, actualY) + + return actualX, actualY, cols, len +end + +function World:check(item, goalX, goalY, filter) + filter = filter or defaultFilter + + local visited = {[item] = true} + local visitedFilter = function(itm, other) + if visited[other] then return false end + return filter(itm, other) + end + + local cols, len = {}, 0 + + local x,y,w,h = self:getRect(item) + + local projected_cols, projected_len = self:project(item, x,y,w,h, goalX,goalY, visitedFilter) + + while projected_len > 0 do + local col = projected_cols[1] + len = len + 1 + cols[len] = col + + visited[col.other] = true + + local response = getResponseByName(self, col.type) + + goalX, goalY, projected_cols, projected_len = response( + self, + col, + x, y, w, h, + goalX, goalY, + visitedFilter + ) + end + + return goalX, goalY, cols, len +end + + +-- Public library functions + +bump.newWorld = function(cellSize) + cellSize = cellSize or 64 + assertIsPositiveNumber(cellSize, 'cellSize') + local world = setmetatable({ + cellSize = cellSize, + rects = {}, + rows = {}, + nonEmptyCells = {}, + responses = {} + }, World_mt) + + world:addResponse('touch', touch) + world:addResponse('cross', cross) + world:addResponse('slide', slide) + world:addResponse('bounce', bounce) + + return world +end + +bump.rect = { + getNearestCorner = rect_getNearestCorner, + getSegmentIntersectionIndices = rect_getSegmentIntersectionIndices, + getDiff = rect_getDiff, + containsPoint = rect_containsPoint, + isIntersecting = rect_isIntersecting, + getSquareDistance = rect_getSquareDistance, + detectCollision = rect_detectCollision +} + +bump.responses = { + touch = touch, + cross = cross, + slide = slide, + bounce = bounce +} + +return bump |