Codechange: Use `GetVisibleRangeIterators()` in more places. (#12190)

This replaces more first/last index calculation, along with indexed array/vector access, with iterator access instead.

Codechange: Remove direct access to _colour_gradient.

Access is now through GetColourGradient, which ensures parameters are in range.

Change: Decouple and remove landscape-dependent cargo types. (#11719)

Cargo types of default engines, industries and houses are now specified in terms of label.

Codechange: allow certain enumeration to be added

Otherwise C++20 doesn't like it.

Codechange: Make all NWidgetPart arrays constexpr.

This ensures that the arrays are not created at runtime and prevents using non-constexpr values.

Codechange: Redefine some cargo-related values in terms of CargoID instead of CargoType.

Values used as special filter types are now defined as offsets from NUM_CARGO instead of confusingly reusing CARGO_NO_REFIT/CARGO_AUTO_REFIT types.

Codechange: Split CT_INVALID into CT_INVALID and INVALID_CARGO.

INVALID_CARGO is a CargoID and should be used for most purposes in game.
CT_INVALID is a CargoType used for defining default properties.

Codechange: Replace mishmash of types for widget index with WidgetID.

Indices were stored as int, but often passed around as uint/uint8_t and casts.

Now they should all use WidgetID.

Codechange: Cargo filters no longer take an index. (#11582)

Update naming of functions to reflect that parameter is now a cargoid.

Change: Hide unused cargos from vehicle cargo filter. (#11533)

The list of used cargo types is updated when the list is invalidated.

Feature: Place cargo icon on cargo filter dropdowns.

Reveal the pixel art.

Codechange: Use range-for to simplify getting first non-zero value.

This reduces indexed array access.

Codechange: Remove FONT_HEIGHT_... macros. (#11481)

These make it look like we're dealing with a constant, but actually each is a call to `GetCharacterHeight(...)`.

Codechange: Simplify cargo filter lists, building only when required.

Some cargo filter lists were built in advance, and used as lookups to test which cargo type to filter.

Instead, use the Cargo ID directly as the filter parameter, and build the lists only when the drop down list is used.

Codechange: Add __FILE__/__LINE__ of WindowDesc to WindowDesc.

This is to allow unit-tests to produce more useful output.

Codechange: Avoid emplace_back(new()) into a unique_ptr. (#11384)

This could theoretically leave an unmanaged pointer in certain circumstances, and directly using
make_unique shows intent.

Codechange: Use std::map instead of fixed array to store refit options.

This simplifies handling of available refit options.

Add: data parameter in Window::Close method.

This allows passing data when closing a window, e.g. to indicate how it was closed.

Fix: #11329: Don't assert vehicle list length is non-zero when only asked to set string parameter. (#11330)

Since #11321, the vehicle list is not yet initialized when SetStringParameters is called, so a test that the vehicle list size is zero is triggered. However, doing this check in the SetStringParameters function is a bit out of its remit, so just remove it.

Codechange: Don't access cargo filter before it is initialized. (#11321)

The cargo filter list is initialized during window OnInit, but the first
build of the filtered list occurred before this.

Codechange: Use begin/end of nwidget parts of begin/length.

This simplifies processing nwidget parts as, unlike the remaining length, the pointer to the end of the list never changes. This is the same principle as we use(d) for tracking end instead of length for C-style strings.

And this removes 160~ instances of the lengthof() macro.

Codechange: automatic adding of _t to (u)int types, and WChar to char32_t

for i in `find src -type f|grep -v 3rdparty/fmt|grep -v 3rdparty/catch2|grep -v 3rdparty/opengl|grep -v stdafx.h`; do sed 's/uint16& /uint16 \&/g;s/int8\([ >*),;[]\)/int8_t\1/g;s/int16\([ >*),;[]\)/int16_t\1/g;s/int32\([ >*),;[]\)/int32_t\1/g;s/int64\([ >*),;[]\)/int64_t\1/g;s/ uint32(/ uint32_t(/g;s/_uint8_t/_uint8/;s/Uint8_t/Uint8/;s/ft_int64_t/ft_int64/g;s/uint64$/uint64_t/;s/WChar/char32_t/g;s/char32_t char32_t/char32_t WChar/' -i $i; done

Codechange: Reorganise hotkey initialisation. (#10951)

Hotkeys are now initialized inline, and use std::vector instead of
separate static C-arrays and std::string instead of char *. The list end
marker is no longer required.

Codechange: Use window parent association for dropdowns.

This replaces the separate window class and number properties, and
allows the window system to close dropdowns automatically.

Codechange: Base CargoArray off std::array.

This avoids needing to define array accessors and allows use of
default value initialization.

Codechange: Add and use GetScrolledItemFromWidget to get a list item.

This function returns an iterator, either to the selected item or the
container's end.

This makes handling the result more robust as indices are not used.

Change: Units-system can convert from N to kN, don't preconvert.

This allows force to passed as is and avoid premature rounding.

The AI function "GetMaxTractiveEffort" still needs to return kN to avoid breaking the API.

Codechange: Scrollbar methods now accept size_t.

This clears up a lot of casts from size_t to int.

Fix: Don't double-pad existing size when adding widget padding.

UpdateWidgetSize's size parameter already includes padding.

Feature: Separate rail/road and sea/air velocity units, and add knots. (#10594)

This is achieved by packing vehicle type along with the velocity so that
the string system can decode and pick the appropriate unit.

Codechange: introduce GetMainWindow() to properly account for nullptr checks

Some nullptr checks have been removed as they were not triggered with nullptr
with the null video driver and in dedicated server mode.

Fix #10032: Capacities of articulated vehicles in build window

See also: #9954

Change: Support flipping shorter engines without NewGRF support. (#10262)

* Change: Support flipping shorter engines without NewGRF support.
* Cleanup: Remove write-only prop27_set temporary flag.

Change: Use lowered not disabled widget for current tab. (#10252)

While tab-buttons are not often used, all other similar occurences use
lowered rather than disabled widgets, so use them for train detail
window too.

Fix #10191: Incorrect refit highlight position. (#10195)

Refit highlight was not correct for non-power-of-2 interface scale.

Fix #10114: Wonky depot layout. (#10191)

Depot lists internal layout was not handled well. This is improved by
throwing more Rects at it:
- Vehicle images are now be vertically centred in the rect.
- Image clipping is relaxed to cover the rect, improving larger sprites.
- Outline highlight is now aware of bevel thickness.

Fix #8770: Centre vehicle status bar icon.

The icon is now centred within its scaled bounding box, which intentionally
leaves a little space around the icon when not at 1/2/4x scale.

Change: Use power-of-2 scaling for some dimensions in GUI.

These are related to drawing sprites that are normally drawn on the
landscape, and should therefore still follow power-of-2 scaling to fit
correctly.

Change: Use Rect helpers for widget drawing.

This replaces repetitive and sometimes unwieldy use of constants.

Change: Use CenterBounds function in more places.

CenterBounds may have a 1 pixel difference so the result is not exactly
the same.

Fix #9995: Adjust viewport zoom level for HiDPI displays

On HiDPI screens the zoom level is increased for detailed rendering. This causes hard-coded zoom levels to be off by this adjustment. To fix these default zoom levels, we scale the zoom level based on `_gui_zoom` to get the scaled zoom level.

Fix #9811, 9156d7b: Use the NewGRF-defined vehicle center when dragging ships and aircraft. (#9812)

The alignment using the total-width of the vehicle-chain was meant for articulated trains and road vehicles only.

Codechange: Template DoCommandP to automagically reflect the parameters of the command proc.

When finished, this will allow each command handler to take individually
different parameters, obliviating the need for bit-packing.

Codechange: Template DoCommand to automagically reflect the parameters of the command proc.

When finished, this will allow each command handler to take individually
different parameters, obliviating the need for bit-packing.