Added opcode_exists script function from CE

Updated scripting documents.

artifacts/scripting/functions.yml

@@ -1238,7 +1238,7 @@
     opcode: 0x823c
   - name: get_sfall_arg_at
     detail: mixed get_sfall_arg_at(int argNum)
-    doc: Returns the value of hook argument with the specified argument number (first argument of hook starts from 0)
+    doc: Returns the value of hook argument with the specified argument number (first argument of hook starts at 0)
     macro: sfall.h
   - name: set_sfall_return
     detail: void set_sfall_return(any value)
@@ -1495,6 +1495,13 @@
     doc: Returns True if the specified name of metarule (sfall_funcX) function exists in the current version of sfall.
     macro: sfall.h
 
+  - name: opcode_exists
+    detail: bool opcode_exists(int opcodeNum)
+    doc: |
+      Returns True if an opcode with the specified number exists in the current version of sfall.
+      - `opcodeNum` starts at `0x8000`.
+    macro: sfall.h
+
   - name: add_extra_msg_file
     detail: int add_extra_msg_file(string fileName)
     doc: |
@@ -1723,7 +1730,7 @@
         - returns the dimensions of a given PCX or FRM frame as a temp array in the form **[width, height]**
         - `artFile/artId`: path to the PCX/FRM file (e.g. `art\\inven\\5mmap.frm`), or its FRM ID number (e.g. `0x7000026`, see specification of the FID format)
         optional arguments:
-        - `frame`: frame number, the first frame starts from zero
+        - `frame`: frame number, the first frame starts at zero
         - `rotation`: rotation to get the frame for, useful when reading FRM files by path
       macro: sfall.h
 
@@ -1742,7 +1749,7 @@
         - `x/y`: offset relative to the top-left corner of the window
 
         optional arguments:
-        - `frame`: frame number, the first frame starts from zero
+        - `frame`: frame number, the first frame starts at zero
         - `param`: an array which specifies additional parameters, where:
           index 0 - sprite direction for multi-directional FRM
           index 1/index 2 - the new width/height to scale the image to. Pass -1 to use the original width/height
@@ -1772,7 +1779,7 @@
         - displays the specified PCX or FRM image in the active window created by vanilla `CreateWin` or sfall's `create_win` script function
         - artFile/artId: path to the PCX/FRM file (e.g. `art\\inven\\5mmap.frm`), or its FRM ID number (e.g. `0x7000026`, see specification of the FID format)
         optional arguments:
-        - `frame`: frame number, the first frame starts from zero
+        - `frame`: frame number, the first frame starts at zero
         - `x/y`: offset relative to the top-left corner of the window
         - `noTransparent`: pass True to display an image without transparent background
         - NOTE: to omit optional arguments starting from the right, call the functions with different `sfall_funcX` (e.g. `sfall_func4("draw_image", pathFile, frame, x, y))`

artifacts/scripting/headers/sfall.h

@@ -368,6 +368,7 @@
 #define obj_is_openable(obj)                                    sfall_func1("obj_is_openable", obj)
 #define obj_under_cursor(onlyCritter, includeDude)              sfall_func2("obj_under_cursor", onlyCritter, includeDude)
 #define objects_in_radius(tile, radius, elev, type)             sfall_func4("objects_in_radius", tile, radius, elev, type)
+#define opcode_exists(opcodeNum)                                sfall_func1("opcode_exists", opcodeNum)
 #define outlined_object                                         sfall_func0("outlined_object")
 #define overlay_create(winType)                                 sfall_func2("interface_overlay", winType, 1)
 #define overlay_clear(winType)                                  sfall_func2("interface_overlay", winType, 2)

artifacts/scripting/sfall function notes.md

@@ -504,6 +504,12 @@ sfall_funcX metarule functions
 `bool sfall_func1("metarule_exist", string metaruleName)`
 - Returns True if the specified name of `sfall_funcX` metarule function exists in the current version of sfall
 
+----
+#### opcode_exists
+`bool sfall_func1("opcode_exists", int opcodeNum)`
+- Returns True if an opcode with the specified number exists in the current version of sfall
+- `opcodeNum` starts at `0x8000`
+
 ----
 #### spatial_radius
 `int sfall_func1("spatial_radius", object obj)`
@@ -842,7 +848,7 @@ sfall_funcX metarule functions
 - `artFile/artId`: path to the PCX/FRM file (e.g. `art\\inven\\5mmap.frm`), or its FRM ID number (e.g. `0x7000026`, see specification of the FID format)
 
 **Optional arguments:**
-- `frame`: frame number, the first frame starts from zero
+- `frame`: frame number, the first frame starts at zero
 - `x/y`: offset relative to the top-left corner of the window
 - `width/height`: the new width/height to scale the image to. Pass -1 to either width or height to keep the aspect ratio when scaling
 - `noTransparent`: pass True to display an image without transparent background
@@ -901,7 +907,7 @@ sfall_funcX metarule functions
 ----
 #### get_sfall_arg_at
 `mixed sfall_func1("get_sfall_arg_at", int argNum)`
-- Returns the value of hook argument with the specified argument number (*first argument of hook starts from 0*)
+- Returns the value of hook argument with the specified argument number (*first argument of hook starts at 0*)
 
 ----
 #### hide_window
@@ -1028,7 +1034,7 @@ sfall_funcX metarule functions
 - `x/y`: offset relative to the top-left corner of the window
 
 **Optional arguments:**
-- `frame`: frame number, the first frame starts from zero
+- `frame`: frame number, the first frame starts at zero
 - `param`: an array which specifies additional parameters, where:\
     index 0 - sprite direction for multi-directional FRM\
     index 1/index 2 - the new width/height to scale the image to. Pass -1 to use the original width/height
@@ -1156,7 +1162,7 @@ sfall_funcX metarule functions
 - `artFile/artId`: path to the PCX/FRM file (e.g. `art\\inven\\5mmap.frm`), or its FRM ID number (e.g. `0x7000026`, see specification of the FID format)
 
 **Optional arguments:**
-- `frame`: frame number, the first frame starts from zero
+- `frame`: frame number, the first frame starts at zero
 - `rotation`: rotation to get the frame for, useful when reading FRM files by path
 
 ----

sfall/Modules/Scripting/Handlers/Core.cpp

@@ -23,6 +23,7 @@
 #include "..\..\HookScripts\Common.h"
 #include "..\..\ScriptExtender.h"
 #include "..\Arrays.h"
+#include "..\Opcodes.h"
 
 #include "Core.h"
 
@@ -198,6 +199,10 @@ void mf_remove_timer_event(OpcodeContext& ctx) {
 	}
 }
 
+void mf_opcode_exists(OpcodeContext& ctx) {
+	ctx.setReturn(Opcodes::OpcodeExists(ctx.arg(0).intValue()));
+}
+
 __declspec(naked) void op_sfall_ver_major() {
 	__asm {
 		mov  edx, VERSION_MAJOR;

sfall/Modules/Scripting/Handlers/Core.h

@@ -64,6 +64,8 @@ void mf_add_g_timer_event(OpcodeContext&);
 
 void mf_remove_timer_event(OpcodeContext&);
 
+void mf_opcode_exists(OpcodeContext&);
+
 void op_sfall_ver_major();
 
 void op_sfall_ver_minor();

sfall/Modules/Scripting/Handlers/Metarule.cpp

@@ -130,6 +130,7 @@ static const SfallMetarule metarules[] = {
 	{"obj_is_openable",           mf_obj_is_openable,           1, 1,  0, {ARG_OBJECT}},
 	{"obj_under_cursor",          mf_obj_under_cursor,          2, 2,  0, {ARG_INT, ARG_INT}},
 	{"objects_in_radius",         mf_objects_in_radius,         3, 4,  0, {ARG_INT, ARG_INT, ARG_INT, ARG_INT}},
+	{"opcode_exists",             mf_opcode_exists,             1, 1,  0, {ARG_INT}},
 	{"outlined_object",           mf_outlined_object,           0, 0},
 	{"real_dude_obj",             mf_real_dude_obj,             0, 0},
 	{"reg_anim_animate_and_move", mf_reg_anim_animate_and_move, 4, 4, -1, {ARG_OBJECT, ARG_INT, ARG_INT, ARG_INT}},

sfall/Modules/Scripting/Opcodes.cpp

@@ -434,5 +434,15 @@ void Opcodes::InitNew() {
 	}
 }
 
+bool Opcodes::OpcodeExists(int opcode) {
+	constexpr int opcodeStart = 0x8000;
+
+	if (opcode < opcodeStart || opcode >= opcodeStart + opcodeCount) return false;
+	opcode -= opcodeStart;
+
+	if (opcodes[opcode] != defaultOpcodeHandler) return true; // raw handlers
+	return (opcodeInfoTable[opcode - sfallOpcodeStart] != nullptr);
+}
+
 }
 }

sfall/Modules/Scripting/Opcodes.h

@@ -28,6 +28,8 @@ namespace script
 class Opcodes {
 public:
 	static void InitNew();
+
+	static bool OpcodeExists(int opcode);
 };
 
 }