Added DivisionOperatorFix option for signed integer division (#278)

* it changes the behavior of vanilla division operator to use signed
integer division. Before it used signed division for floats but
unsigned for integers.

Added a new "div" operator for unsigned integer division.
Moved mathematical script functions from ScriptUtils.hpp to new MathOps.
Added include guard to sfall.h and main.h in modders pack.

artifacts/ddraw.ini

@@ -568,6 +568,9 @@ StartGDialogFix=0
 ;attacker_results - unused, must be 0 or not equal to the target_results argument when specifying result flags for the target
 AttackComplexFix=0
 
+;Set to 1 to fix the issue with the division operator treating negative integers as unsigned
+DivisionOperatorFix=1
+
 ;Set to 1 to enable the balanced bullet distribution formula for burst attacks
 ComputeSprayMod=0
 

artifacts/example_mods/ItemHighlight_Lite/main.h

@@ -1,3 +1,5 @@
+#ifndef MAIN_H
+#define MAIN_H
 
 #include "..\scripting\headers\sfall.h"
 #include "..\scripting\headers\define_lite.h"
@@ -71,3 +73,5 @@ end
 procedure InitConfigs begin
    translationIni := GetIniConfigStr("Main", "TranslationsINI", "Translations.ini", "ddraw.ini");
 end
+
+#endif

artifacts/scripting/compiler/sslc_readme.txt

@@ -344,6 +344,7 @@ There are several changes in this version of sslc which may result in problems f
 - fixed compiler giving "assignment operator expected" error when a variable-like macro is not being defined properly
 - added new logical operators "AndAlso", "OrElse" for short-circuit evaluation of logical expressions
 - added an alternative (C/Java-style) assignment operator "="
+- added support for new "div" operator (unsigned integer division)
 
 > sfall 4.2.2
 - added support for new opcode "reg_anim_callback"

artifacts/scripting/headers/lib.math.h

@@ -10,10 +10,10 @@
 #define below(a, b)        (unsigned_comp(a, b) < 0)
 #define below_equal(a, b)  (unsigned_comp(a, b) <= 0)
 
-procedure unsigned_comp(variable a, variable b) begin
+// for sfall 4.2.3/3.8.23
+pure procedure unsigned_comp(variable a, variable b) begin
    if ((a bwxor b) == 0) then return 0; // a == b
-   if (b == 0) then return 1;
-   return 1 if (a / b) else -1;
+   return 1 if ((b == 0) orElse a div b) else -1;
 end
 
 #define MAX(x, y)    ((x > y) * x + (x <= y) * y)

artifacts/scripting/headers/sfall.h

@@ -1,3 +1,6 @@
+#ifndef SFALL_H
+#define SFALL_H
+
 //Recognised modes for set_shader_mode and get_game_mode
 #define WORLDMAP    (0x1)
 #define DIALOG      (0x4)
@@ -305,3 +308,5 @@
 #define unjam_lock(obj)                                 sfall_func1("unjam_lock", obj)
 #define unset_unique_id(obj)                            sfall_func2("set_unique_id", obj, -1)
 #define unwield_slot(critter, slot)                     sfall_func2("unwield_slot", critter, slot)
+
+#endif

artifacts/scripting/sfall opcode list.txt

@@ -360,6 +360,8 @@
 0x827d - void register_hook_proc_spec(int hook, procedure proc)
 0x827e - void reg_anim_callback(procedure proc)
 
+0x827f - div operator (unsigned integer division)
+
 
 * These functions require AllowUnsafeScripting to be enabled in ddraw.ini