[PATCH 0/1] MR1246: vbscript: Implement PRNG functions.
Used LCG algorithm and its parameters are documented in various places. Parts that were not obvious - negative argument handling in Rnd(), and Randomize() use of current state were taken from LGPL2 FreeBASIC rtlib. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/1246
From: Nikolay Sivov <nsivov(a)codeweavers.com> Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53676 Signed-off-by: Nikolay Sivov <nsivov(a)codeweavers.com> --- dlls/vbscript/global.c | 83 ++++++++++++++++++++++++++++++++++--- dlls/vbscript/tests/api.vbs | 32 ++++++++++++++ dlls/vbscript/vbdisp.c | 1 + dlls/vbscript/vbscript.h | 2 + 4 files changed, 112 insertions(+), 6 deletions(-) diff --git a/dlls/vbscript/global.c b/dlls/vbscript/global.c index f35c4ac2fc4..5d7e41a2ef2 100644 --- a/dlls/vbscript/global.c +++ b/dlls/vbscript/global.c @@ -439,6 +439,20 @@ static HRESULT to_double(VARIANT *v, double *ret) return S_OK; } +static HRESULT to_float(VARIANT *v, float *ret) +{ + VARIANT dst; + HRESULT hres; + + V_VT(&dst) = VT_EMPTY; + hres = VariantChangeType(&dst, v, 0, VT_R4); + if(FAILED(hres)) + return hres; + + *ret = V_R4(&dst); + return S_OK; +} + static HRESULT to_string(VARIANT *v, BSTR *ret) { VARIANT dst; @@ -1075,16 +1089,73 @@ static HRESULT Global_Sqr(BuiltinDisp *This, VARIANT *arg, unsigned args_cnt, VA return return_double(res, sqrt(d)); } +static unsigned int get_next_rnd(int value) +{ + return (value * 0x43fd43fd + 0xc39ec3) & 0xffffff; +} + static HRESULT Global_Randomize(BuiltinDisp *This, VARIANT *arg, unsigned args_cnt, VARIANT *res) { - FIXME("\n"); - return E_NOTIMPL; + union + { + double d; + unsigned int i[2]; + } dtoi; + unsigned int seed; + HRESULT hres; + + assert(args_cnt == 0 || args_cnt == 1); + if (args_cnt == 1) + { + hres = to_double(arg, &dtoi.d); + if (FAILED(hres)) + return hres; + } + else + { + dtoi.d = GetTickCount() * 0.001; + } + + seed = dtoi.i[1]; + seed ^= (seed >> 16); + seed = ((seed & 0xffff) << 8) | (This->ctx->script_obj->rnd & 0xff); + This->ctx->script_obj->rnd = seed; + + return S_OK; } static HRESULT Global_Rnd(BuiltinDisp *This, VARIANT *arg, unsigned args_cnt, VARIANT *res) { - FIXME("\n"); - return E_NOTIMPL; + static const float modulus = 16777216.0f; + unsigned int value; + HRESULT hres; + float f; + + assert(args_cnt == 0 || args_cnt == 1); + + value = This->ctx->script_obj->rnd; + if (args_cnt == 1) + { + hres = to_float(arg, &f); + if (FAILED(hres)) + return hres; + + if (f < 0.0f) + { + value = *(unsigned int *)&f; + This->ctx->script_obj->rnd = value = get_next_rnd(value + (value >> 24)); + } + else if (f == 0.0f) + value = This->ctx->script_obj->rnd; + else + This->ctx->script_obj->rnd = value = get_next_rnd(value); + } + else + { + This->ctx->script_obj->rnd = value = get_next_rnd(value); + } + + return return_float(res, (float)value / modulus); } static HRESULT Global_Timer(BuiltinDisp *This, VARIANT *arg, unsigned args_cnt, VARIANT *res) @@ -3092,12 +3163,12 @@ static const builtin_prop_t global_props[] = { {L"MsgBox", Global_MsgBox, 0, 1, 5}, {L"Now", Global_Now, 0, 0}, {L"Oct", Global_Oct, 0, 1}, - {L"Randomize", Global_Randomize, 0, 1}, + {L"Randomize", Global_Randomize, 0, 0, 1}, {L"Replace", Global_Replace, 0, 3, 6}, {L"RGB", Global_RGB, 0, 3}, {L"Right", Global_Right, 0, 2}, {L"RightB", Global_RightB, 0, 2}, - {L"Rnd", Global_Rnd, 0, 1}, + {L"Rnd", Global_Rnd, 0, 0, 1}, {L"Round", Global_Round, 0, 1, 2}, {L"RTrim", Global_RTrim, 0, 1}, {L"ScriptEngine", Global_ScriptEngine, 0, 0}, diff --git a/dlls/vbscript/tests/api.vbs b/dlls/vbscript/tests/api.vbs index 000ae1b5167..f2d3201c7b3 100644 --- a/dlls/vbscript/tests/api.vbs +++ b/dlls/vbscript/tests/api.vbs @@ -2221,4 +2221,36 @@ call testTimeSerial(10, 60, 2, 11, 0, 2, DateSerial(1899, 12, 30)) call testTimeSerial(10, 0, 60, 10, 1, 0, DateSerial(1899, 12, 30)) call testTimeSerialError() +sub testRnd(arg, expresult) + dim x + x = Rnd(arg) + call ok(x = expresult, "result = " & x & " expected " & expresult) + call ok(getVT(x) = "VT_R4*", "getVT = " & getVT(x)) +end sub + +' Initial seed value +call testRnd(0, 327680 / 16777216) +call testRnd(0, 327680 / 16777216) +' Negative argument is a seed, does not use current RNG state +call ok(Rnd(-2) = Rnd(-2), "Expected same result") +call ok(Rnd(-1) <> Rnd(-2), "Expected differing result") + +' Randomize uses current RNG value, so it's reset using Rnd(-1) +sub testRandomize() + dim x, y + + Rnd(-1) + Randomize(123) + x = Rnd() + Randomize(123) + y = Rnd() + call ok(x <> y, "Expected differing result") + Rnd(-1) + Randomize(123) + y = Rnd() + call ok(x = y, "Expected same result") +end sub + +call testRandomize() + Call reportSuccess() diff --git a/dlls/vbscript/vbdisp.c b/dlls/vbscript/vbdisp.c index 74da0a21fb0..21142d5dcaf 100644 --- a/dlls/vbscript/vbdisp.c +++ b/dlls/vbscript/vbdisp.c @@ -1516,6 +1516,7 @@ HRESULT create_script_disp(script_ctx_t *ctx, ScriptDisp **ret) script_disp->ref = 1; script_disp->ctx = ctx; heap_pool_init(&script_disp->heap); + script_disp->rnd = 0x50000; *ret = script_disp; return S_OK; diff --git a/dlls/vbscript/vbscript.h b/dlls/vbscript/vbscript.h index 11564345aa3..d68056788c9 100644 --- a/dlls/vbscript/vbscript.h +++ b/dlls/vbscript/vbscript.h @@ -136,6 +136,8 @@ typedef struct { script_ctx_t *ctx; heap_pool_t heap; + + unsigned int rnd; } ScriptDisp; typedef struct _builtin_prop_t builtin_prop_t; -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/1246
Jacek Caban (@jacek) commented about dlls/vbscript/global.c:
+ { + hres = to_double(arg, &dtoi.d); + if (FAILED(hres)) + return hres; + } + else + { + dtoi.d = GetTickCount() * 0.001; + } + + seed = dtoi.i[1]; + seed ^= (seed >> 16); + seed = ((seed & 0xffff) << 8) | (This->ctx->script_obj->rnd & 0xff); + This->ctx->script_obj->rnd = seed; + + return S_OK; This may leave res uninitialized. It should probably be set to VT_EMPTY, a test for returned value would be nice.
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/1246#note_13016
participants (3)
-
Jacek Caban (＠jacek) -
Nikolay Sivov
-
Nikolay Sivov (＠nsivov)