add phys.apply

asteroids/inspect.lua

@@ -0,0 +1,371 @@
+local _tl_compat; if (tonumber((_VERSION or ''):match('[%d.]*$')) or 0) < 5.3 then local p, m = pcall(require, 'compat53.module'); if p then _tl_compat = m end end; local math = _tl_compat and _tl_compat.math or math; local string = _tl_compat and _tl_compat.string or string; local table = _tl_compat and _tl_compat.table or table; local type = type
+local inspect = { Options = {} }
+
+
+
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+
+
+
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+
+
+
+
+
+inspect._VERSION = 'inspect.lua 3.1.0'
+inspect._URL = 'http://github.com/kikito/inspect.lua'
+inspect._DESCRIPTION = 'human-readable representations of tables'
+inspect._LICENSE = [[
+  MIT LICENSE
+
+  Copyright (c) 2022 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.
+]]
+inspect.KEY = setmetatable({}, { __tostring = function() return 'inspect.KEY' end })
+inspect.METATABLE = setmetatable({}, { __tostring = function() return 'inspect.METATABLE' end })
+
+local tostring = tostring
+local rep = string.rep
+local match = string.match
+local char = string.char
+local gsub = string.gsub
+local fmt = string.format
+
+local _rawget
+if rawget then
+   _rawget = rawget
+else
+   _rawget = function(t, k) return t[k] end
+end
+
+local function rawpairs(t)
+   return next, t, nil
+end
+
+
+
+local function smartQuote(str)
+   if match(str, '"') and not match(str, "'") then
+      return "'" .. str .. "'"
+   end
+   return '"' .. gsub(str, '"', '\\"') .. '"'
+end
+
+
+local shortControlCharEscapes = {
+   ["\a"] = "\\a", ["\b"] = "\\b", ["\f"] = "\\f", ["\n"] = "\\n",
+   ["\r"] = "\\r", ["\t"] = "\\t", ["\v"] = "\\v", ["\127"] = "\\127",
+}
+local longControlCharEscapes = { ["\127"] = "\127" }
+for i = 0, 31 do
+   local ch = char(i)
+   if not shortControlCharEscapes[ch] then
+      shortControlCharEscapes[ch] = "\\" .. i
+      longControlCharEscapes[ch] = fmt("\\%03d", i)
+   end
+end
+
+local function escape(str)
+   return (gsub(gsub(gsub(str, "\\", "\\\\"),
+   "(%c)%f[0-9]", longControlCharEscapes),
+   "%c", shortControlCharEscapes))
+end
+
+local luaKeywords = {
+   ['and'] = true,
+   ['break'] = true,
+   ['do'] = true,
+   ['else'] = true,
+   ['elseif'] = true,
+   ['end'] = true,
+   ['false'] = true,
+   ['for'] = true,
+   ['function'] = true,
+   ['goto'] = true,
+   ['if'] = true,
+   ['in'] = true,
+   ['local'] = true,
+   ['nil'] = true,
+   ['not'] = true,
+   ['or'] = true,
+   ['repeat'] = true,
+   ['return'] = true,
+   ['then'] = true,
+   ['true'] = true,
+   ['until'] = true,
+   ['while'] = true,
+}
+
+local function isIdentifier(str)
+   return type(str) == "string" and
+   not not str:match("^[_%a][_%a%d]*$") and
+   not luaKeywords[str]
+end
+
+local flr = math.floor
+local function isSequenceKey(k, sequenceLength)
+   return type(k) == "number" and
+   flr(k) == k and
+   1 <= (k) and
+   k <= sequenceLength
+end
+
+local defaultTypeOrders = {
+   ['number'] = 1, ['boolean'] = 2, ['string'] = 3, ['table'] = 4,
+   ['function'] = 5, ['userdata'] = 6, ['thread'] = 7,
+}
+
+local function sortKeys(a, b)
+   local ta, tb = type(a), type(b)
+
+
+   if ta == tb and (ta == 'string' or ta == 'number') then
+      return (a) < (b)
+   end
+
+   local dta = defaultTypeOrders[ta] or 100
+   local dtb = defaultTypeOrders[tb] or 100
+
+
+   return dta == dtb and ta < tb or dta < dtb
+end
+
+local function getKeys(t)
+
+   local seqLen = 1
+   while _rawget(t, seqLen) ~= nil do
+      seqLen = seqLen + 1
+   end
+   seqLen = seqLen - 1
+
+   local keys, keysLen = {}, 0
+   for k in rawpairs(t) do
+      if not isSequenceKey(k, seqLen) then
+         keysLen = keysLen + 1
+         keys[keysLen] = k
+      end
+   end
+   table.sort(keys, sortKeys)
+   return keys, keysLen, seqLen
+end
+
+local function countCycles(x, cycles)
+   if type(x) == "table" then
+      if cycles[x] then
+         cycles[x] = cycles[x] + 1
+      else
+         cycles[x] = 1
+         for k, v in rawpairs(x) do
+            countCycles(k, cycles)
+            countCycles(v, cycles)
+         end
+         countCycles(getmetatable(x), cycles)
+      end
+   end
+end
+
+local function makePath(path, a, b)
+   local newPath = {}
+   local len = #path
+   for i = 1, len do newPath[i] = path[i] end
+
+   newPath[len + 1] = a
+   newPath[len + 2] = b
+
+   return newPath
+end
+
+
+local function processRecursive(process,
+   item,
+   path,
+   visited)
+   if item == nil then return nil end
+   if visited[item] then return visited[item] end
+
+   local processed = process(item, path)
+   if type(processed) == "table" then
+      local processedCopy = {}
+      visited[item] = processedCopy
+      local processedKey
+
+      for k, v in rawpairs(processed) do
+         processedKey = processRecursive(process, k, makePath(path, k, inspect.KEY), visited)
+         if processedKey ~= nil then
+            processedCopy[processedKey] = processRecursive(process, v, makePath(path, processedKey), visited)
+         end
+      end
+
+      local mt = processRecursive(process, getmetatable(processed), makePath(path, inspect.METATABLE), visited)
+      if type(mt) ~= 'table' then mt = nil end
+      setmetatable(processedCopy, mt)
+      processed = processedCopy
+   end
+   return processed
+end
+
+local function puts(buf, str)
+   buf.n = buf.n + 1
+   buf[buf.n] = str
+end
+
+
+
+local Inspector = {}
+
+
+
+
+
+
+
+
+
+
+local Inspector_mt = { __index = Inspector }
+
+local function tabify(inspector)
+   puts(inspector.buf, inspector.newline .. rep(inspector.indent, inspector.level))
+end
+
+function Inspector:getId(v)
+   local id = self.ids[v]
+   local ids = self.ids
+   if not id then
+      local tv = type(v)
+      id = (ids[tv] or 0) + 1
+      ids[v], ids[tv] = id, id
+   end
+   return tostring(id)
+end
+
+function Inspector:putValue(v)
+   local buf = self.buf
+   local tv = type(v)
+   if tv == 'string' then
+      puts(buf, smartQuote(escape(v)))
+   elseif tv == 'number' or tv == 'boolean' or tv == 'nil' or
+      tv == 'cdata' or tv == 'ctype' then
+      puts(buf, tostring(v))
+   elseif tv == 'table' and not self.ids[v] then
+      local t = v
+
+      if t == inspect.KEY or t == inspect.METATABLE then
+         puts(buf, tostring(t))
+      elseif self.level >= self.depth then
+         puts(buf, '{...}')
+      else
+         if self.cycles[t] > 1 then puts(buf, fmt('<%d>', self:getId(t))) end
+
+         local keys, keysLen, seqLen = getKeys(t)
+
+         puts(buf, '{')
+         self.level = self.level + 1
+
+         for i = 1, seqLen + keysLen do
+            if i > 1 then puts(buf, ',') end
+            if i <= seqLen then
+               puts(buf, ' ')
+               self:putValue(t[i])
+            else
+               local k = keys[i - seqLen]
+               tabify(self)
+               if isIdentifier(k) then
+                  puts(buf, k)
+               else
+                  puts(buf, "[")
+                  self:putValue(k)
+                  puts(buf, "]")
+               end
+               puts(buf, ' = ')
+               self:putValue(t[k])
+            end
+         end
+
+         local mt = getmetatable(t)
+         if type(mt) == 'table' then
+            if seqLen + keysLen > 0 then puts(buf, ',') end
+            tabify(self)
+            puts(buf, '<metatable> = ')
+            self:putValue(mt)
+         end
+
+         self.level = self.level - 1
+
+         if keysLen > 0 or type(mt) == 'table' then
+            tabify(self)
+         elseif seqLen > 0 then
+            puts(buf, ' ')
+         end
+
+         puts(buf, '}')
+      end
+
+   else
+      puts(buf, fmt('<%s %d>', tv, self:getId(v)))
+   end
+end
+
+
+
+
+function inspect.inspect(root, options)
+   options = options or {}
+
+   local depth = options.depth or (math.huge)
+   local newline = options.newline or '\n'
+   local indent = options.indent or '  '
+   local process = options.process
+
+   if process then
+      root = processRecursive(process, root, {}, {})
+   end
+
+   local cycles = {}
+   countCycles(root, cycles)
+
+   local inspector = setmetatable({
+      buf = { n = 0 },
+      ids = {},
+      cycles = cycles,
+      depth = depth,
+      level = 0,
+      newline = newline,
+      indent = indent,
+   }, Inspector_mt)
+
+   inspector:putValue(root)
+
+   return table.concat(inspector.buf)
+end
+
+setmetatable(inspect, {
+   __call = function(_, root, options)
+      return inspect.inspect(root, options)
+   end,
+})
+
+return inspect

asteroids/phys.lua

@@ -1,3 +1,5 @@
+local inspect = require('inspect')
+
 local phys = {
     tau = 2 * math.pi
 }
@@ -10,9 +12,30 @@ end
 -- updates the actor's location by applying the passage of time
 -- TODO spin
 function phys.update(actor, dt)
+    assert(actor.speed >= 0)
     local dv = actor.speed * dt
     actor.x = actor.x + math.cos(actor.angle) * dv
     actor.y = actor.y + math.sin(actor.angle) * dv
 end
 
+function phys.rotate(actor, angle)
+    actor.angle = (actor.angle + angle) % phys.tau
+end
+
+function phys.apply(actor, force)
+    assert(actor.speed >= 0)
+    assert(force.speed >= 0)
+    local ax = math.cos(actor.angle) * actor.speed
+    local ay = math.sin(actor.angle) * actor.speed
+    local fx = math.cos(force.angle) * force.speed
+    local fy = math.sin(force.angle) * force.speed
+    local x = ax + fx
+    local y = ay + fy
+
+    local speed = math.sqrt(x ^ 2 + y ^ 2)
+    local angle = math.atan(y, x) % phys.tau
+    actor.speed = speed
+    actor.angle = angle
+end
+
 return phys

asteroids/test_phys.lua

@@ -0,0 +1,33 @@
+t = require('luaunit')
+local phys = require('phys')
+
+function TestUpdate()
+    local actor = { x = 0, y = 0, speed = 1, angle = math.pi }
+    phys.update(actor, 0.1)
+    t.assertAlmostEquals(
+        actor,
+        { x = -0.1, y = 0, speed = 1, angle = math.pi })
+end
+
+function TestApply()
+    local actor = { x = 0, y = 0, speed = 1, angle = math.pi }
+
+    phys.apply(actor, { speed = 1, angle = 0 })
+    t.assertAlmostEquals(
+        { x = actor.x, y = actor.y, speed = actor.speed },
+        { x = 0, y = 0, speed = 0 })
+
+    phys.apply(actor, { speed = 1, angle = math.pi })
+    t.assertAlmostEquals(
+        actor,
+        { x = 0, y = 0, speed = 1, angle = math.pi }
+    )
+
+    phys.apply(actor, { speed = 1, angle = math.pi / 2 })
+    t.assertAlmostEquals(
+        actor,
+        { x = 0, y = 0, speed = math.sqrt(2), angle = math.pi * 3 / 4 }
+    )
+end
+
+os.exit(t.LuaUnit.run())