Refactor texmod:calc_dims to use a dispatch table

This commit is contained in:
Lars Mueller 2023-05-24 21:09:24 +02:00
parent 9fc4aaf3b8
commit b169077a40
4 changed files with 79 additions and 56 deletions

@ -8,7 +8,7 @@ end
local texmod, metatable = component"dsl"
texmod.write = component"write"
texmod.read = component("read", texmod)
texmod.calc_dims = component"calc_dims"
texmod.calc_dims = component("calc_dims", texmod)
function metatable:__tostring()
local rope = {}

@ -1,54 +1,77 @@
-- TODO ensure completeness, use table of dim calculation functions
local base_dims = modlib.table.set({
"opacity",
"invert",
"brighten",
"noalpha",
"makealpha",
"lowpart",
"mask",
"colorize",
})
local floor, max, clamp = math.floor, math.max, modlib.math.clamp
local texmod = ...
local cd = {}
local function calc_dims(self, get_file_dims)
return assert(cd[self.type])(self, get_file_dims)
end
function cd:file(d)
return d(self.filename)
end
do
local function base_dim(self, get_dims) return calc_dims(self.base, get_dims) end
cd.opacity = base_dim
cd.invert = base_dim
cd.brighten = base_dim
cd.noalpha = base_dim
cd.makealpha = base_dim
cd.lowpart = base_dim
cd.mask = base_dim
cd.colorize = base_dim
end
do
local function wh(self) return self.w, self.h end
cd.resize = wh
cd.combine = wh
end
function cd:overlay(get_dims)
local base_w, base_h = calc_dims(self.base, get_dims)
local over_w, over_h = calc_dims(self.over, get_dims)
return math.max(base_w, over_w), math.max(base_h, over_h)
end
function cd:transform(get_dims)
if self.rotation_deg % 180 ~= 0 then
local base_w, base_h = calc_dims(self.base, get_dims)
return base_h, base_w
end
return calc_dims(self.base, get_dims)
end
do
local math_clamp = modlib.math.clamp
local function next_pow_of_2(x)
-- I don't want to use a naive 2^ceil(log(x)/log(2)) due to possible float precision issues.
local m, e = math.frexp(x) -- x = _*2^e, _ in [0.5, 1)
if m == 0.5 then e = e - 1 end -- x = 2^(e-1)
return math.ldexp(1, e) -- 2^e, premature optimization here we go
end
return function(self, get_file_dims)
local function calc_dims(self)
local type = self.type
if type == "filename" then
return get_file_dims(self.filename)
end if base_dims[type] then
return calc_dims(self.base)
end if type == "resize" or type == "combine" then
return self.w, self.h
end if type == "overlay" then
local base_w, base_h = calc_dims(self.base)
local overlay_w, overlay_h = calc_dims(self.over)
return max(base_w, overlay_w), max(base_h, overlay_h)
end if type == "transform" then
if self.rotation_deg % 180 ~= 0 then
local base_w, base_h = calc_dims(self.base)
return base_h, base_w
end
return calc_dims(self.base)
end if type == "inventorycube" then
local top_w, top_h = calc_dims(self.top)
local left_w, left_h = calc_dims(self.left)
local right_w, right_h = calc_dims(self.right)
local d = clamp(next_pow_of_2(max(top_w, top_h, left_w, left_h, right_w, right_h)), 2, 64)
function cd:inventorycube(get_dims)
local top_w, top_h = calc_dims(self.top, get_dims)
local left_w, left_h = calc_dims(self.left, get_dims)
local right_w, right_h = calc_dims(self.right, get_dims)
local d = math_clamp(next_pow_of_2(math.max(top_w, top_h, left_w, left_h, right_w, right_h)), 2, 64)
return d, d
end if type == "verticalframe" or type == "crack" or type == "cracko" then
local base_w, base_h = calc_dims(self.base)
return base_w, floor(base_h / self.framecount)
end if type == "sheet" then
local base_w, base_h = calc_dims(self.base)
return floor(base_w / self.w), floor(base_h / self.h)
end
error("unsupported texture modifier: " .. type)
end
return calc_dims(self)
do
local function frame_dims(self, get_dims)
local base_w, base_h = calc_dims(self.base, get_dims)
return base_w, math.floor(base_h / self.framecount)
end
cd.verticalframe = frame_dims
cd.crack = frame_dims
cd.cracko = frame_dims
end
function cd:sheet(get_dims)
local base_w, base_h = calc_dims(self.base, get_dims)
return math.floor(base_w / self.w), math.floor(base_h / self.h)
end
return calc_dims

@ -12,7 +12,7 @@ setmetatable(texmod, {__call = new})
function texmod.file(filename)
return new{
type = "filename",
type = "file",
filename = filename
}
end

@ -143,7 +143,7 @@ return function(self, write_str)
w.str(("%d"):format(int))
end
function w.tex(tex)
if tex.type == "filename" then
if tex.type == "file" then
assert(not tex.filename:find"[:^\\&{[]", "invalid character in filename")
w.str(tex.filename)
return
@ -153,7 +153,7 @@ return function(self, write_str)
w.hat()
end
if tex.type == "overlay" then
if tex.over.type ~= "filename" then -- TODO also exclude [png, [combine and [inventorycube (generators)
if tex.over.type ~= "file" then -- TODO also exclude [png, [combine and [inventorycube (generators)
w.str"("; w.tex(tex.over); w.str")"
else
w.tex(tex.over)