Description

Shared base classes and context for Scene layers [v26.08.00].

Overview

This module defines the common SceneLayer contract and SceneLayerContext used by every Scene layer. Scene owns the frame order; each concrete layer supplies its own update and rendering behavior.

Class Hierarchy

SceneLayer (Base): Abstract base class providing common properties and virtual hooks for custom logic:
- Position, Velocity, and Parallax factors.
- Visibility and Alpha modulation.
- Feature flags (Render, Update, Loop, SmoothScroll).
- Event callbacks.
- Unified SceneLayerContext for synchronized update and render logic.
SceneLayerTile: Manages a 2D array of tile indices.
- Handles tileset mapping and cell rendering.
- Optimized for large static grids.
SceneLayerObject: Implements the HEGA system.
- SpatialGrid: A sparse hash-map for O(1) average spatial lookups.
- SceneObject: Represents game entities with position, bounds (AABB), and optional visual representation (Tile/Shape).
- Supports efficient region queries and dynamic object management.
SceneLayerImage: Manages a single large image.
- Efficiently handles repeating textures for infinite backgrounds.
- Supports internal optimization for display hardware.

Topics
	Scene Layer Tile
	SceneLayerTile class for grid-based tile map layers.
	Scene Layer Object
	Object layer containing game objects with spatial partitioning.
	Scene Layer Image
	Image layer containing a single image for background/foreground display.

Classes
struct	CRM64Pro::SceneLayerContext
	Layer Context structure. More...
struct	CRM64Pro::SceneLayerContext::[struct].data.Tile
	Data for SLT_TILE. More...
struct	CRM64Pro::SceneLayerContext::[struct].data.Object
	Data for SLT_OBJECT. More...
struct	CRM64Pro::SceneLayerContext::[struct].data.Image
	Data for SLT_IMAGE. More...
class	CRM64Pro::SceneLayer
	Base class for all Scene layer types. More...

Typedefs
using	CRM64Pro::SceneLayerCallback = function<void(const SceneLayerContext& rContext)>
	Scene layer callback type.
using	CRM64Pro::SceneCameraOffsetCallback = function<bool(Scene& rScene, Sint32 iLayer, SDL_FPoint& ptOffset)>
	Scene camera offset callback type.

Typedef Documentation

◆ SceneLayerCallback

using CRM64Pro::SceneLayerCallback = function<void(const SceneLayerContext& rContext)>

Scene layer callback type.

Parameters

rContext Read-only context for the current layer update or render callback.

◆ SceneCameraOffsetCallback

using CRM64Pro::SceneCameraOffsetCallback = function<bool(Scene& rScene, Sint32 iLayer, SDL_FPoint& ptOffset)>

Scene camera offset callback type.

Used by ::SCM_OFFSET mode. Callback should return true and write a pixel offset in ptOffset. Returning false disables additional offset for that tick (equivalent to {0,0}).