epervier-old/birb/modules/world/maps/libs/sti/utils.lua

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2019-04-07 13:15:55 +02:00
-- Some utility functions that shouldn't be exposed.
local utils = {}
-- https://github.com/stevedonovan/Penlight/blob/master/lua/pl/path.lua#L286
function utils.format_path(path)
local np_gen1,np_gen2 = '[^SEP]+SEP%.%.SEP?','SEP+%.?SEP'
local np_pat1, np_pat2 = np_gen1:gsub('SEP','/'), np_gen2:gsub('SEP','/')
local k
repeat -- /./ -> /
path,k = path:gsub(np_pat2,'/')
until k == 0
repeat -- A/../ -> (empty)
path,k = path:gsub(np_pat1,'')
until k == 0
if path == '' then path = '.' end
return path
end
-- Compensation for scale/rotation shift
function utils.compensate(tile, tileX, tileY, tileW, tileH)
local compx = 0
local compy = 0
if tile.sx < 0 then compx = tileW end
if tile.sy < 0 then compy = tileH end
if tile.r > 0 then
tileX = tileX + tileH - compy
tileY = tileY + tileH + compx - tileW
elseif tile.r < 0 then
tileX = tileX + compy
tileY = tileY - compx + tileH
else
tileX = tileX + compx
tileY = tileY + compy
end
return tileX, tileY
end
-- Cache images in main STI module
function utils.cache_image(sti, path, image)
image = image or love.graphics.newImage(path)
image:setFilter("nearest", "nearest")
sti.cache[path] = image
end
-- We just don't know.
function utils.get_tiles(imageW, tileW, margin, spacing)
imageW = imageW - margin
local n = 0
while imageW >= tileW do
imageW = imageW - tileW
if n ~= 0 then imageW = imageW - spacing end
if imageW >= 0 then n = n + 1 end
end
return n
end
-- Decompress tile layer data
function utils.get_decompressed_data(data)
local ffi = require "ffi"
local d = {}
local decoded = ffi.cast("uint32_t*", data)
for i = 0, data:len() / ffi.sizeof("uint32_t") do
table.insert(d, tonumber(decoded[i]))
end
return d
end
-- Convert a Tiled ellipse object to a LOVE polygon
function utils.convert_ellipse_to_polygon(x, y, w, h, max_segments)
local ceil = math.ceil
local cos = math.cos
local sin = math.sin
local function calc_segments(segments)
local function vdist(a, b)
local c = {
x = a.x - b.x,
y = a.y - b.y,
}
return c.x * c.x + c.y * c.y
end
segments = segments or 64
local vertices = {}
local v = { 1, 2, ceil(segments/4-1), ceil(segments/4) }
local m
if love and love.physics then
m = love.physics.getMeter()
else
m = 32
end
for _, i in ipairs(v) do
local angle = (i / segments) * math.pi * 2
local px = x + w / 2 + cos(angle) * w / 2
local py = y + h / 2 + sin(angle) * h / 2
table.insert(vertices, { x = px / m, y = py / m })
end
local dist1 = vdist(vertices[1], vertices[2])
local dist2 = vdist(vertices[3], vertices[4])
-- Box2D threshold
if dist1 < 0.0025 or dist2 < 0.0025 then
return calc_segments(segments-2)
end
return segments
end
local segments = calc_segments(max_segments)
local vertices = {}
table.insert(vertices, { x = x + w / 2, y = y + h / 2 })
for i = 0, segments do
local angle = (i / segments) * math.pi * 2
local px = x + w / 2 + cos(angle) * w / 2
local py = y + h / 2 + sin(angle) * h / 2
table.insert(vertices, { x = px, y = py })
end
return vertices
end
function utils.rotate_vertex(map, vertex, x, y, cos, sin)
if map.orientation == "isometric" then
x, y = utils.convert_isometric_to_screen(map, x, y)
vertex.x, vertex.y = utils.convert_isometric_to_screen(map, vertex.x, vertex.y)
end
vertex.x = vertex.x - x
vertex.y = vertex.y - y
return
x + cos * vertex.x - sin * vertex.y,
y + sin * vertex.x + cos * vertex.y
end
--- Project isometric position to cartesian position
function utils.convert_isometric_to_screen(map, x, y)
local mapH = map.height
local tileW = map.tilewidth
local tileH = map.tileheight
local tileX = x / tileH
local tileY = y / tileH
local offsetX = mapH * tileW / 2
return
(tileX - tileY) * tileW / 2 + offsetX,
(tileX + tileY) * tileH / 2
end
function utils.hex_to_color(hex)
if hex:sub(1, 1) == "#" then
hex = hex:sub(2)
end
return {
r = tonumber(hex:sub(1, 2), 16) / 255,
g = tonumber(hex:sub(3, 4), 16) / 255,
b = tonumber(hex:sub(5, 6), 16) / 255
}
end
function utils.pixel_function(_, _, r, g, b, a)
local mask = utils._TC
if r == mask.r and
g == mask.g and
b == mask.b then
return r, g, b, 0
end
return r, g, b, a
end
function utils.fix_transparent_color(tileset, path)
local image_data = love.image.newImageData(path)
tileset.image = love.graphics.newImage(image_data)
if tileset.transparentcolor then
utils._TC = utils.hex_to_color(tileset.transparentcolor)
image_data:mapPixel(utils.pixel_function)
tileset.image = love.graphics.newImage(image_data)
end
end
return utils