2016-01-12 16:26:00

1 files changed, 107 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/supp-ran.lua b/tex/context/base/mkiv/supp-ran.lua
new file mode 100644
index 000000000..4968e8cfc
--- /dev/null
+++ b/tex/context/base/mkiv/supp-ran.lua
@@ -0,0 +1,107 @@
+if not modules then modules = { } end modules ['supp-ran'] = {
+    version   = 1.001,
+    comment   = "companion to supp-ran.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+-- We cannot ask for the current seed, so we need some messy hack here.
+
+local report_system = logs.reporter("system","randomizer")
+
+local trace_random    = false  trackers.register("system.randomizer",   function(v) trace_random    = v end)
+local trace_random_mp = false  trackers.register("system.randomizer.mp",function(v) trace_random_mp = v end)
+
+local insert, remove = table.insert, table.remove
+
+local math       = math
+local context    = context
+local implement  = interfaces.implement
+
+local random     = math.random
+local randomseed = math.randomseed
+local round      = math.round
+local stack      = { }
+local last       = 1
+local maxcount   = 2^30-1 -- 1073741823
+
+local function setrandomseedi(n)
+    if n <= 1 then
+        n = n * maxcount
+    elseif n < 1000 then
+        n = n * 1000
+    end
+    n = round(n)
+    if trace_random then
+        report_system("setting seed to %s",n)
+    end
+    randomseed(n)
+    last = random(0,maxcount) -- we need an initial value
+end
+
+math.setrandomseedi = setrandomseedi
+
+local function getrandomnumber(min,max)
+    last = random(min,max)
+    return last
+end
+
+local function setrandomseed(n)
+    last = n
+    setrandomseedi(n)
+end
+
+local function getrandomseed()
+    return last
+end
+
+local function getmprandomnumber()
+    last = random(0,4095)
+    if trace_random_mp then
+        report_system("using mp seed %s",last)
+    end
+    return last
+end
+
+-- maybe stack
+
+local function pushrandomseed()
+    insert(stack,last)
+    if trace_random then
+        report_system("pushing seed %s",last)
+    end
+end
+
+local function reuserandomseed(n)
+    local seed = stack[#stack]
+    if seed then
+        if trace_random then
+            report_system("reusing seed %s",last)
+        end
+        randomseed(seed)
+    end
+end
+
+local function poprandomseed()
+    local seed = remove(stack)
+    if seed then
+        if trace_random then
+            report_system("popping seed %s",seed)
+        end
+        randomseed(seed)
+    end
+end
+
+-- todo: also open up in utilities.randomizer.*
+
+implement { name = "getrandomnumber",   actions = { getrandomnumber, context }, arguments = { "integer", "integer" } }
+implement { name = "getrandomdimen",    actions = { getrandomnumber, context }, arguments = { "dimen", "dimen" } }
+implement { name = "getrandomfloat",    actions = { getrandomnumber, context }, arguments = { "number", "number" } }
+implement { name = "getmprandomnumber", actions = { getmprandomnumber, context } }
+implement { name = "setrandomseed",     actions = { setrandomseed },            arguments = { "integer" } }
+implement { name = "getrandomseed",     actions = { getrandomseed, context } }
+implement { name = "pushrandomseed",    actions = { pushrandomseed  } }
+implement { name = "poprandomseed",     actions = { poprandomseed } }
+implement { name = "reuserandomseed",   actions = { reuserandomseed } }
+