[main/2026-10-08-1819] get_shader_colour_from_arrays:364

Your game just encountered an error!

System Details:

Date-Time: 8-10-2026 17:04:08
Game Version: main
Build Date: 2026-10-08-1819
Commit Hash: 0f17fbd

Save Details:

Chapter Name: None
Current Turn: ???
Game Seed: 0

Error Details:

{ line : 0, stacktrace : [ "gml_Script_get_shader_colour_from_arrays (line 357)","gml_Script_set_complex_shader_area (line 378)","gml_Script_setup_complex_livery_shader (line 298)","gml_Script_draw@anon@58984@ComplexSet@scr_ComplexSet (line 1541)","gml_Script_scr_draw_unit_image (line 408)","gml_Script_anon@19276@draw_base@anon@19228@ColourItem@ColourItem (line 746)","gml_Script_draw@anon@2143@DataSlate@scr_DataSlate (line 129)","gml_Script_draw_base@anon@19228@ColourItem@ColourItem (line 778)","gml_Script_scr_livery_setup (line 24)","gml_Object_obj_creation_Draw_0 (line 131)" ], script : "gml_Script_get_shader_colour_from_arrays", message : "I32 argument is undefined", longMessage : "ERROR in action number 1
of Draw Event for object obj_creation:
I32 argument is undefined" }

Stacktrace:

get_shader_colour_from_arrays:364
set_complex_shader_area:379
setup_complex_livery_shader:299
scr_ComplexSet:draw:1542
scr_draw_unit_image:409
ColourItem:anonymous:747
scr_DataSlate:draw:130
ColourItem:draw_base:779
scr_livery_setup:25
obj_creation_Draw_0:132

Reporter:

M60Wa

User Message:

hovering mouse over sapce marine armor customization

Investigation Report - Issue #1631: `get_shader_colour_from_arrays` - "I32 argument is undefined"

1. Summary

Crash report from build main/2026-10-08-1819 (commit 0f17fbd34), reporter M60Wa:

hovering mouse over space marine armor customization

Error:

gml_Script_get_shader_colour_from_arrays: "I32 argument is undefined"

Stack (build line numbers, each is current main + 1):

- get_shader_colour_from_arrays:364
- set_complex_shader_area:379
- setup_complex_livery_shader:299
- scr_ComplexSet:draw:1542
- scr_draw_unit_image:409
- ColourItem:anonymous:747
- scr_DataSlate:draw:130
- ColourItem:draw_base:779
- scr_livery_setup:25
- obj_creation_Draw_0:132

Root cause: setup_complex_livery_shader() iterates over every key in the livery struct and passes the raw value straight to set_complex_shader_area() -> get_shader_colour_from_arrays(), which indexes col_r[colour] / col_g[colour] / col_b[colour] with no validation. Any undefined, -1 sentinel, bool metadata flag, non-shader key (is_changed, block_company_colours, company_marks_loc), out-of-range int, or icon entry with missing .colour triggers arr[undefined] / arr[-1] / arr[out_of_range] inside the try block. The try/catch then calls ERROR_HANDLER.assert_popup(_exception), which is what generated this exact issue (callstack captured via debug_get_callstack, not an uncaught crash).

Files:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L349-L367 (get_shader_colour_from_arrays)
https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L369-L381 (set_complex_shader_area)
https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L47-L102 (setup_complex_livery_shader data-set selection)
https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L290-L344 (main per-area loop, crash site #L298)

2. Full call-chain walkthrough

2.1 `obj_creation_Draw_0` -> `scr_livery_setup`

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/objects/obj_creation/Draw_0.gml#L129-L132

} else if (slide == eCREATION_SLIDES.CHAPTERLIVERY) {
    /* Livery, Roles */
    scr_livery_setup();
}

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_livery_setup/scr_livery_setup.gml#L24

livery_picker.draw_base();

2.2 `ColourItem.draw_base` -> `DataSlate.draw` -> `inside_method` -> `dummy_marine.draw_unit_image()`

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L650-L779

draw_base sets data_slate.inside_method then calls:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L778

data_slate.draw(0, 5, 0.45, 1);

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_DataSlate/scr_DataSlate.gml#L128-L130

if (is_callable(inside_method)) {
    inside_method();
}

Inside inside_method, the preview marine is (re)drawn:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L742-L748

if (dummy_marine ?? true) {
    dummy_marine = new DummyMarine();
}
if (!is_struct(dummy_image)) {
    dummy_image = dummy_marine.draw_unit_image();
}

DummyMarine is defined here:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_culture_visuals/scr_culture_visuals.gml#L2180-L2196

function DummyMarine() constructor {
    // ...
    personal_livery = {};
    // ...
    static draw_unit_image = scr_draw_unit_image;

2.3 `scr_draw_unit_image` -> `ComplexSet.draw`

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_draw_unit_image/scr_draw_unit_image.gml#L404-L408

if (complex_livery) {
    if (struct_exists(complex_set, "armour")) {
        complex_set.x_surface_offset = x_surface_offset;
        complex_set.y_surface_offset = y_surface_offset;
        complex_set.draw();

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_ComplexSet/scr_ComplexSet.gml#L1535-L1542

static draw = function() {
    // ...
    var _texture_draws = setup_complex_livery_shader(draw_unit.role(), draw_unit);

draw_unit here is the DummyMarine instance, so unit != "none" is true.

2.4 `setup_complex_livery_shader` - crash site

Creation-screen branch:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L51-L68

if (_in_creation) {
    _data_set = variable_clone(obj_creation.livery_picker.map_colour);
    if (obj_creation.livery_selection_options.current_selection == 2) {
        var _base = obj_creation.full_liveries[0];
        // fill missing / -1 entries from base
    }
}

Personal-livery overlay (empty {} for DummyMarine unless Deathwatch, but real marines can inject anything):

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L96-L102

if (_is_unit) {
    var _names = struct_get_names(unit.personal_livery);
    for (var i = 0; i < array_length(_names); i++) {
        var _area = _names[i];
        _data_set[$ _area] = unit.personal_livery[$ _area];
    }
}

Main loop - no filtering, no -1 guard:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L292-L298

for (var i = 0; i < _position_count; i++) {
    var _colour_position = spot_names[i];
    var _colour = variable_clone(_data_set[$ _colour_position]);
    if (!is_array(_colour)) {
        set_complex_shader_area(_colour_position, _colour);

Icon branch - no .colour existence check:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L313-L342

} else if (_colour[0] == "icon") {
    var _data = _colour[1];
    // ...
    set_complex_shader_area(_colour_position, _data.colour);
}

2.5 `set_complex_shader_area` -> `get_shader_colour_from_arrays`

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L369-L381

function set_complex_shader_area(area, colour) {
    var _colour_set = [];
    if (is_array(area)) {
        for (var i = 0; i < array_length(area); i++) {
            var small_area = area[i];
            _colour_set = get_shader_colour_from_arrays(colour);
            shader_set_uniform_f_array(shader_get_uniform(full_livery_shader, small_area), _colour_set);
        }
    } else {
        _colour_set = get_shader_colour_from_arrays(colour);
        shader_set_uniform_f_array(shader_get_uniform(full_livery_shader, area), _colour_set);
    }
}

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L349-L367

function get_shader_colour_from_arrays(colour) {
    var _colours_instance = active_game_controller();
    var _colour_set = [0, 0, 0];
    try {
        _colour_set = [
            _colours_instance.col_r[colour] / 255,
            _colours_instance.col_g[colour] / 255,
            _colours_instance.col_b[colour] / 255,
        ];
    } catch (_exception) {
        ERROR_HANDLER.assert_popup(_exception);
    }
    return _colour_set;
}

active_game_controller() is:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_controller_helpers/scr_controller_helpers.gml#L3-L5

function active_game_controller() {
    return instance_exists(obj_creation) ? obj_creation : obj_controller;
}

col_r/col_g/col_b are built here (40 entries, indices 0..39):

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_colors_initialize/scr_colors_initialize.gml#L44-L294

Enum:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_colors_initialize/scr_colors_initialize.gml#L1-L42

obj_creation arrays are initialised here:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/objects/obj_creation/Create_0.gml#L568-L573

col = [];
col_r = [];
col_g = [];
col_b = [];
scr_colors_initialize();

ERROR_HANDLER.assert_popup captures debug_get_callstack() and files the report, which is why the issue stack starts inside get_shader_colour_from_arrays:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ErrorHandler/ErrorHandler.gml#L169-L178

3. Root cause - unvalidated `colour` reaches `col_r[colour]`

col_r[colour] throws I32 argument is undefined exactly when colour itself is undefined. The code has at least four reachable ways to produce that (plus the -1/out-of-range near-miss that the same guard must fix):

3.1 Primary: no `-1` / metadata / unknown-key filtering in main loop

map_colour (aka scr_unit_draw_data) contains non-colour entries:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L186-L222

map_colour = {
    is_changed: false,
    block_company_colours: false,
    left_leg_lower: default_val,
    // ... all areas ...
    company_marks: default_val,
    company_marks_loc: default_val,
};

The shader only defines these uniforms (no is_changed, block_company_colours, company_marks_loc, no main_colour setter either):

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/shaders/full_livery_shader/full_livery_shader.fsh#L1-L31

The cloth-variation collector explicitly skips -1 and arrays:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L115-L126

var _colour = _data_set[$ spot_names[i]];
if (_colour == -1 || is_array(_colour)) {
    continue;
}

...but the main shader loop does not. It also does not skip is_changed / block_company_colours / company_marks_loc. Consequences:

company_liveries are deliberately initialised with -1 = "no override":

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/objects/obj_creation/Step_0.gml#L275-L278
```
if (company_liveries == "") {
    livery_picker.scr_unit_draw_data(-1);
    company_liveries = array_create(11, variable_clone(livery_picker.map_colour));
}
```
The -1 -> base repair only runs when current_selection == 2:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L56-L68

Any other path that leaves a -1 in _data_set (stale map_colour after the Step init quirk above, company-livery clone, save/JSON with -1, hover-restore race) calls col_r[-1]. In GML an out-of-bounds read yields undefined, then undefined / 255 throws inside the same try, producing the same popup.
false (bool metadata) coerces to 0 today so it silently sets a non-existent uniform to white. It works by accident and still issues shader_get_uniform(..., "is_changed") == -1 calls every frame. Any future change that stores undefined instead of false crashes outright.

3.2 Icon entries with missing `.colour`

Valid icon payload (only example in repo):

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/datafiles/main/chapters/7.JSON#L233

"left_pauldron" : [ "icon",{ "icon" : "ultramarines", "colour" : 34, "type" : 2 } ],

Writer:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourPicker/ColourPicker.gml#L203-L211

chosen = ["icon", {icon: tex_data[1], colour: base_colour, type: markings_options.current_selection}];

Reader does not verify _data is a struct or that .colour exists before dereferencing. An old save, hand-edited JSON, or truncated ["icon"] array makes _data.colour == undefined, and set_complex_shader_area(pos, undefined) -> col_r[undefined] -> exact reported error.

3.3 Hover preview mutates the live `map_colour`

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L651-L671

colour_return = [hover_pos, map_colour[$ hover_pos]];
map_colour[$ hover_pos] = 0;

and restore:

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L770-L776

if (colour_return != false) {
    if (hover_pos != colour_return[0]) {
        map_colour[$ colour_return[0]] = colour_return[1];

If hover_pos ever names a key absent from map_colour (new image_location_maps entry, renamed area, company_marks_loc confusion), map_colour[$ hover_pos] reads undefined, the struct gains an undefined value, variable_clone preserves it, spot_names includes it, and the next ComplexSet.draw in the same frame crashes. This matches "hovering mouse over armor customization" perfectly: every hover forces reset_image() -> immediate draw_unit_image() -> setup_complex_livery_shader() on the mutated struct.

Hover areas vs livery keys drift independently:

Hover map: https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L225-L380
Livery keys: https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L186-L222
Runtime coordinate rewrites: https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L716-L740

3.4 `personal_livery` overlay can inject `undefined`

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L96-L102

blindly copies every personal_livery value over the base. A modded/legacy personal_livery entry with undefined overwrites a valid colour. DummyMarine uses {} (safe), real marines use e.g. irandom(30) (safe today):

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_culture_visuals/scr_culture_visuals.gml#L2187-L2190

but there is no contract enforcement.

Why the game shows a popup instead of hard-crashing

The try/catch in get_shader_colour_from_arrays catches the indexing error and forwards the exception object to assert_popup, which builds the GitHub issue from debug_get_callstack(). So the report is the catch handler firing. The returned colour stays black [0,0,0], and shader_set_uniform_f_array(-1_or_valid, black) continues. Repeated hovers = repeated popups.

4. Proposed fixes (in priority order)

All line refs below are current main.

Fix 1 (required): validate in `get_shader_colour_from_arrays` + `set_complex_shader_area`

Never index col_r/col_g/col_b with undefined, -1, non-numeric, or out-of-range. Fail loud in debug, fall back to a safe colour at runtime.

Location: https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L349-L381

Suggested shape (idiomatic GML, ASCII only):

function get_shader_colour_from_arrays(colour) {
    var _colours_instance = active_game_controller();
    var _fallback = [0, 0, 0];
    if (!is_numeric(colour)) {
        return _fallback;
    }
    var _idx = floor(colour);
    if (_idx < 0 || _idx >= array_length(_colours_instance.col_r)) {
        return _fallback;
    }
    try {
        return [
            _colours_instance.col_r[_idx] / 255,
            _colours_instance.col_g[_idx] / 255,
            _colours_instance.col_b[_idx] / 255,
        ];
    } catch (_exception) {
        ERROR_HANDLER.assert_popup(_exception);
    }
    return _fallback;
}

And in set_complex_shader_area, early-exit when the uniform does not exist (shader_get_uniform returns -1) so is_changed / block_company_colours / company_marks_loc stop issuing invalid uniform writes every frame:

function set_complex_shader_area(area, colour) {
    if (is_array(area)) {
        for (var i = 0; i < array_length(area); i++) {
            var _handle = shader_get_uniform(full_livery_shader, area[i]);
            if (_handle == -1) {
                continue;
            }
            shader_set_uniform_f_array(_handle, get_shader_colour_from_arrays(colour));
        }
    } else {
        var _handle = shader_get_uniform(full_livery_shader, area);
        if (_handle == -1) {
            return;
        }
        shader_set_uniform_f_array(_handle, get_shader_colour_from_arrays(colour));
    }
}

Fix 2 (required): iterate only real shader areas, skip sentinels

In setup_complex_livery_shader, replace the blind struct_get_names(_data_set) loop with an allowlist derived from complex_colour_swaps (already static in the same function):

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L142-L288

if (!struct_exists(complex_colour_swaps, _colour_position)) {
    continue; // skips is_changed, block_company_colours, company_marks_loc, stale keys
}
var _colour = variable_clone(_data_set[$ _colour_position]);
if (_colour == -1) {
    continue; // unpainted company slot; keep current uniform / default
}
if (is_undefined(_colour)) {
    continue;
}

Apply the same -1/undefined guard already used by the cloth collector at #L120 to the main loop. Optionally share one is_valid_livery_colour() helper.

Fix 3 (required): guard the `icon` branch

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_complex_colour_kit/scr_complex_colour_kit.gml#L313-L342

} else if (_colour[0] == "icon") {
    if (array_length(_colour) < 2 || !is_struct(_colour[1]) || !struct_exists(_colour[1], "colour")) {
        continue;
    }
    var _data = _colour[1];
    // ... existing texture lookup ...
    set_complex_shader_area(_colour_position, _data.colour);
}

Also validate _colour[0] access itself: check array_length(_colour) > 0 before _colour[0] == "texture" / "icon" so a truncated [] entry cannot throw a different indexing error.

Fix 4 (recommended): stop mutating live `map_colour` on hover

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L650-L776

Hover preview writes map_colour[$ hover_pos] = 0 then relies on a later-frame restore. Any missed restore (rapid mouse move, popup open, point_and_click creating colour_pick mid-hover) leaves 0 or undefined in the struct that the very next setup_complex_livery_shader clones.

Safer: keep map_colour immutable during hover and pass a preview override into the draw (e.g. clone once, apply highlight in the clone), or at minimum guard the save/restore:

if (!struct_exists(map_colour, hover_pos)) {
    hover_pos = false;
} else {
    // existing save/set logic, plus is_undefined(colour_return[1]) check
}

Fix 5 (cleanup): document `array_create(n, struct)` aliasing

https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/objects/obj_creation/Step_0.gml#L275-L278 and https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/ColourItem/ColourItem.gml#L516

array_create(11, variable_clone(map_colour)) fills all slots with the same struct reference. Current code happens to break sharing via later variable_clone on write, but one direct mutation (e.g. _comp_livs[i].foo = x without clone) would corrupt all 11 companies. Either loop-clone or add a comment explaining why every write path must clone. Same for array_create(eROLE.MARINEEND, ...).

5. How to verify

Open Chapter Creation -> Livery slide (covers obj_creation_Draw_0 #L131 path).
Hover every armour hitbox (image_location_maps keys at ColourItem #L225-L380, including R Trim / L Trim / Lenses / Weapon Primary/Secondary / Company Marks buttons rewritten at #L716-L740). Before fix: I32 argument is undefined popup via assert_popup; after Fix 1+2: no popup, preview highlights normally.
Set a company livery slot to -1 (fresh scr_unit_draw_data(-1) state) and switch livery_selection_options between 0/1/2. Before fix: popup on next ComplexSet.draw; after: skipped cleanly.
Craft a livery with ["icon"] (no payload) and ["icon", {}] (no .colour) in full_liveries[0]. Before fix: same popup; after Fix 3: skipped, base colour kept.
Regression: standard, bulk, and advanced livery modes in https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_livery_setup/scr_livery_setup.gml#L38-L98 still recolour all complex_colour_swaps areas; complex_helms paths at https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_ComplexSet/scr_ComplexSet.gml#L2176-L2227 still tint eye_lense / head / muzzle.

6. Secondary observations (not the crash, worth a ticket)

full_livery_shader.fsh declares uniform vec3 main_colour but setup_complex_livery_shader never sets it. Either dead uniform or missing feature. See https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/shaders/full_livery_shader/full_livery_shader.fsh#L11
is_changed / block_company_colours are iterated as colours every frame today; Fix 2 removes the wasted shader_get_uniform(-1) calls.
scr_creation re-init path at https://github.com/Adeptus-Dominus/ChapterMaster/blob/main/scripts/scr_creation/scr_creation.gml#L332-L342 duplicates Step_0 init logic; consider one shared ensure_liveries_exist() helper.

7. Confidence

High that the mechanism (unvalidated colour -> col_r[undefined]) is correct: it is the only expression in the reported frame that takes an I32 (array index), and the try/catch -> assert_popup explains the exact issue format. Medium on which of the four producers fired for this specific user (no save attached, Chapter Name: None, creation screen), with hover-mutated / -1-sentinel / stray-metadata keys as most likely given "hovering mouse over armor customization". Fixes 1-3 cover all of them regardless of which one fired.

Navigation Menu

Repository navigation

[main/2026-10-08-1819] get_shader_colour_from_arrays:364 #1631

System Details:

Save Details:

Error Details:

Stacktrace:

Reporter:

User Message:

Investigation Report - Issue #1631: `get_shader_colour_from_arrays` - "I32 argument is undefined"

1. Summary

2. Full call-chain walkthrough

2.1 `obj_creation_Draw_0` -> `scr_livery_setup`

2.2 `ColourItem.draw_base` -> `DataSlate.draw` -> `inside_method` -> `dummy_marine.draw_unit_image()`

2.3 `scr_draw_unit_image` -> `ComplexSet.draw`

2.4 `setup_complex_livery_shader` - crash site

2.5 `set_complex_shader_area` -> `get_shader_colour_from_arrays`

3. Root cause - unvalidated `colour` reaches `col_r[colour]`

3.1 Primary: no `-1` / metadata / unknown-key filtering in main loop

3.2 Icon entries with missing `.colour`

3.3 Hover preview mutates the live `map_colour`

3.4 `personal_livery` overlay can inject `undefined`

Why the game shows a popup instead of hard-crashing

4. Proposed fixes (in priority order)

Fix 1 (required): validate in `get_shader_colour_from_arrays` + `set_complex_shader_area`

Fix 2 (required): iterate only real shader areas, skip sentinels

Fix 3 (required): guard the `icon` branch

Fix 4 (recommended): stop mutating live `map_colour` on hover

Fix 5 (cleanup): document `array_create(n, struct)` aliasing

5. How to verify

6. Secondary observations (not the crash, worth a ticket)

7. Confidence

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

[main/2026-10-08-1819] get_shader_colour_from_arrays:364 #1631

Description

System Details:

Save Details:

Error Details:

Stacktrace:

Reporter:

User Message:

Activity

lyra-cactus commented on Oct 8, 2026

Investigation Report - Issue #1631: get_shader_colour_from_arrays - "I32 argument is undefined"

1. Summary

2. Full call-chain walkthrough

2.1 obj_creation_Draw_0 -> scr_livery_setup

2.2 ColourItem.draw_base -> DataSlate.draw -> inside_method -> dummy_marine.draw_unit_image()

2.3 scr_draw_unit_image -> ComplexSet.draw

2.4 setup_complex_livery_shader - crash site

2.5 set_complex_shader_area -> get_shader_colour_from_arrays

3. Root cause - unvalidated colour reaches col_r[colour]

3.1 Primary: no -1 / metadata / unknown-key filtering in main loop

3.2 Icon entries with missing .colour

3.3 Hover preview mutates the live map_colour

3.4 personal_livery overlay can inject undefined

Why the game shows a popup instead of hard-crashing

4. Proposed fixes (in priority order)

Fix 1 (required): validate in get_shader_colour_from_arrays + set_complex_shader_area

Fix 2 (required): iterate only real shader areas, skip sentinels

Fix 3 (required): guard the icon branch

Fix 4 (recommended): stop mutating live map_colour on hover

Fix 5 (cleanup): document array_create(n, struct) aliasing

5. How to verify

6. Secondary observations (not the crash, worth a ticket)

7. Confidence

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions

Investigation Report - Issue #1631: `get_shader_colour_from_arrays` - "I32 argument is undefined"

2.1 `obj_creation_Draw_0` -> `scr_livery_setup`

2.2 `ColourItem.draw_base` -> `DataSlate.draw` -> `inside_method` -> `dummy_marine.draw_unit_image()`

2.3 `scr_draw_unit_image` -> `ComplexSet.draw`

2.4 `setup_complex_livery_shader` - crash site

2.5 `set_complex_shader_area` -> `get_shader_colour_from_arrays`

3. Root cause - unvalidated `colour` reaches `col_r[colour]`

3.1 Primary: no `-1` / metadata / unknown-key filtering in main loop

3.2 Icon entries with missing `.colour`

3.3 Hover preview mutates the live `map_colour`

3.4 `personal_livery` overlay can inject `undefined`

Fix 1 (required): validate in `get_shader_colour_from_arrays` + `set_complex_shader_area`

Fix 3 (required): guard the `icon` branch

Fix 4 (recommended): stop mutating live `map_colour` on hover

Fix 5 (cleanup): document `array_create(n, struct)` aliasing