Lua: Create shot from code #4121

PieterVdc · 2025-07-16T14:30:22Z

implements #4120

Introduces a new Lua API function `lua_Add_shot_to_level` for spawning shots at a specified location and owner. Adds `script_process_new_shot` to handle shot creation, including position validation and wall collision checks. Also adds initial camera Lua API scaffolding in a new file.

Loobinex · 2025-08-22T00:26:21Z

Copilot

Pull request overview

This PR implements the ability to create shots from Lua code (addresses issue #4120), enabling Word of Power-like effects and directed shots. The implementation adds three main features: a new AddShotToLevel Lua function for creating shots, camera access through Player.camera to get camera direction for directed shots, and a Thing:set_velocity method to apply velocity to things.

Changes:

Adds script_process_new_shot C function and AddShotToLevel Lua API for creating shots from code
Exposes player camera to Lua with access to position, yaw, pitch, roll, zoom, and view mode
Adds Thing:set_velocity method to set velocity using angle and distance parameters

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/thing_shots.c	Implements `script_process_new_shot` to create shots with hit type and target, handles wall collision
src/thing_shots.h	Adds function declaration for `script_process_new_shot`
src/lua_params.c	Adds `luaL_checkHitType` and `luaL_optCheckThing`, changes Thing return values from NULL to INVALID_THING
src/lua_params.h	Declares new parameter checking functions
src/lua_api_things.c	Implements `lua_set_velocity` method using `angles_to_vector`
src/lua_api_player.c	Adds camera field to Player API
src/lua_api_camera.c	New file implementing Camera Lua object with getter/setter for camera properties
src/lua_api.c	Implements `lua_Add_shot_to_level` and registers Camera type
keeperfx_vs2010.vcxproj	Adds lua_api_camera.c to Visual Studio project
keeperfx_vs2010.vcxproj.filters	Adds lua_api_camera.c to source files filter
Makefile	Adds obj/lua_api_camera.o to build
config/fxdata/lua/config-api/native_types.lua	Adds shot_type and hit_type aliases
config/fxdata/lua/classes/Thing.lua	Documents set_velocity method
config/fxdata/lua/bindings/things.lua	Documents AddShotToLevel function

Comments suppressed due to low confidence (1)

src/lua_params.c:25

The header file thing_navigate.h is included twice, on lines 16 and 25. One of these duplicate includes should be removed.

#include "thing_navigate.h"
#include "thing_effects.h"
#include "keeperfx.hpp"
#include "lua_base.h"
#include "lvl_script_lib.h"
#include "map_data.h"
#include "player_utils.h"
#include "room_library.h"
#include "thing_data.h"
#include "thing_navigate.h"

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2026-02-12T20:52:24Z

config/fxdata/lua/bindings/things.lua

+---@param shot_type shot_type The shot name from fxdata\magic.cfg
+---@param location location
+---@param player playersingle When used it sets the owner of the object.
+---@param hit_type hittypes What the shot can hit


The type annotation uses 'hittypes' but this type alias is not defined in native_types.lua. It should be 'hit_type' instead (which is defined on line 20 of native_types.lua).

Suggested change

---@param hit_type hittypes What the shot can hit

---@param hit_type hit_type What the shot can hit

Copilot · 2026-02-12T20:52:25Z

src/lua_api_player.c

+    if (strcmp(key, "camera") == 0) {
+        lua_pushCamera(L, plyr_idx);
+    } else if (strcmp(key, "heart") == 0) {


The new 'camera' field added to Player is not documented in Player.lua. Following the pattern of other Player fields (like CONTROLS, MONEY, etc. in Player.lua lines 25-55), a documentation entry should be added for the camera field. Additionally, a Camera.lua class file should be created in config/fxdata/lua/classes/ to document Camera's fields (pos, yaw, pitch, roll, horizontal_fov, zoom, view_mode) similar to how other classes like Thing.lua and Player.lua document their fields.

Copilot · 2026-02-12T20:52:25Z

src/lua_params.c

+    if ((index < THit_None) || (index >= THit_TypesCount))
+    {
+        luaL_argerror(L, index, "Invalid hittype");
+        return THit_None;
+    }
+    return index;


The luaL_checkHitType function is checking if the parameter index (stack position) is within the enum range instead of retrieving and checking the actual value from the Lua stack. This will always fail since index will be 4 (the stack position) which is greater than or equal to THit_TypesCount.

This function should:

Retrieve the value from the Lua stack at position 'index' using lua_tointeger or use luaL_checkNamedCommand with a hit_type_desc descriptor

Check if that retrieved value is within the valid range (THit_None to THit_TypesCount-1)

Return the retrieved value

Based on the Lua type definition (hit_type as string like "THit_None"), this should probably use luaL_checkNamedCommand with a NamedCommand descriptor for hit types, similar to how shot_desc is used.

Suggested change

if ((index < THit_None) || (index >= THit_TypesCount))

{

luaL_argerror(L, index, "Invalid hittype");

return THit_None;

}

return index;

int hit_type;

if (lua_isnumber(L, index))

{

hit_type = (int)lua_tointeger(L, index);

}

else if (lua_isstring(L, index))

{

hit_type = luaL_checkNamedCommand(L, index, hit_type_desc);

}

else

{

luaL_argerror(L, index, "Invalid hittype");

return THit_None;

}

if ((hit_type < THit_None) || (hit_type >= THit_TypesCount))

{

luaL_argerror(L, index, "Invalid hittype");

return THit_None;

}

return hit_type;

Copilot · 2026-02-12T20:52:25Z

src/lua_api_camera.c

+    return playerId;
+}
+
+static const struct luaL_Reg slab_methods[] = {


Copy-paste error: this should be 'camera_methods' not 'slab_methods' since this is in the camera API file.

Suggested change

static const struct luaL_Reg slab_methods[] = {

static const struct luaL_Reg camera_methods[] = {

Copilot · 2026-02-12T20:52:25Z

src/lua_api_camera.c

+    } else if (try_get_from_methods(L, 1, key)) {
+        return 1;
+    } else {
+        return luaL_error(L, "Unknown field or method '%s' for Player", key);


Error message refers to "Player" but should refer to "Camera" since this is the camera_get_field function.

Suggested change

return luaL_error(L, "Unknown field or method '%s' for Player", key);

return luaL_error(L, "Unknown field or method '%s' for Camera", key);

Copilot · 2026-02-12T20:52:26Z

src/lua_api_camera.c

+int luaL_checkCamera(lua_State *L, int idx)
+{
+    if (!lua_istable(L, idx)) {
+        return luaL_argerror(L, idx, "Expected a table");
+    }
+
+    lua_getfield(L, idx, "playerId");
+    if (!lua_isnumber(L, -1)) {
+        return luaL_argerror(L, idx, "Table must have a numeric 'playerId' field");
+    }
+    PlayerNumber playerId = lua_tointeger(L, -1);
+    lua_pop(L, 1);
+
+    return playerId;
+}


The luaL_checkCamera function extracts the playerId from the Camera table but doesn't validate that it's a valid player ID. It should validate that playerId is within the valid range (0 to PLAYERS_COUNT-1 or similar) before returning it, similar to how luaL_checkPlayerSingle validates the player ID in lua_params.c lines 274-277.

PieterVdc and others added 5 commits July 16, 2025 16:04

Add new file to vs project

21c59db

.

978a3fd

.

50224c3

.

56a981e

PieterVdc marked this pull request as ready for review July 16, 2025 17:56

PieterVdc marked this pull request as draft July 16, 2025 19:49

PieterVdc linked an issue Jul 17, 2025 that may be closed by this pull request

Lua: Create shot from code #4120

Open

Loobinex added 2 commits August 22, 2025 15:40

Merge branch 'master' into pr/4121

41e589e

Added target and hittype to shot

10679dd

Loobinex marked this pull request as ready for review August 22, 2025 15:40

Loobinex marked this pull request as draft August 22, 2025 15:40

Loobinex and others added 6 commits August 22, 2025 18:35

Added Stuff to lua api

2b3c9b6

target is optional

5589ce9

Merge remote-tracking branch 'upstream/master' into shot_lua

368ca8d

Update lua_api_camera.c

ab0174b

Merge remote-tracking branch 'upstream/master' into shot_lua

cd7a3dd

put the optional one last

9920d70

rainlizard mentioned this pull request Dec 26, 2025

Multiplayer: Refactor to combine local and authoritative camera #4432

Closed

Merge branch 'master' into shot_lua

401df02

PieterVdc marked this pull request as ready for review February 12, 2026 20:45

Copilot AI review requested due to automatic review settings February 12, 2026 20:45

Copilot started reviewing on behalf of PieterVdc February 12, 2026 20:45 View session

Copilot AI reviewed Feb 12, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Lua: Create shot from code #4121

Lua: Create shot from code #4121

PieterVdc commented Jul 16, 2025

Uh oh!

Loobinex commented Aug 22, 2025

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Feb 12, 2026

Uh oh!

Copilot AI Feb 12, 2026

Uh oh!

Copilot AI Feb 12, 2026

Uh oh!

Copilot AI Feb 12, 2026

Uh oh!

Copilot AI Feb 12, 2026

Uh oh!

Copilot AI Feb 12, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

	---@param hit_type hittypes What the shot can hit
	---@param hit_type hit_type What the shot can hit

	static const struct luaL_Reg slab_methods[] = {
	static const struct luaL_Reg camera_methods[] = {

	return luaL_error(L, "Unknown field or method '%s' for Player", key);
	return luaL_error(L, "Unknown field or method '%s' for Camera", key);

Lua: Create shot from code #4121

Are you sure you want to change the base?

Lua: Create shot from code #4121

Conversation

PieterVdc commented Jul 16, 2025

Uh oh!

Loobinex commented Aug 22, 2025

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI Feb 12, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Feb 12, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Feb 12, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Feb 12, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Feb 12, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Feb 12, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants