Placement Lifecycle

This guide describes the normal lifecycle for placing a single object.

Step 1: Create or update request

PlacementRequestComponent captures placement intent:

• target position
• rotation
• scale
• request activity and timing metadata

Step 2: Validate request

PlacementValidationSystem processes active requests and writes result into request.validation_result.

Validation combines:

• physics collision checks
• optional rule callbacks (PlacementRuleComponent)
• basic request sanity checks

Step 3: Update preview visuals

PlacementPreviewSystem updates preview state using validation output:

• valid → preview in VALID state
• invalid → preview in INVALID state
• no result yet → NEUTRAL

Step 4: Execute successful request

PlacementExecutionSystem converts successful requests to PlacementCommandComponent, executes action, and updates placement relationships.

Step 5: Emit events

PlacementSignalBus events are the primary integration point for gameplay/UI responses.

Failure path

When validation fails repeatedly, placement attempts can lock via PlacementComponent lock fields and failure events are emitted with issue details.