Class CanvasRenderer

lib/renderer.ts:94–979

// ============================================================================

export class CanvasRenderer {
  private canvas: HTMLCanvasElement;
  private ctx: CanvasRenderingContext2D;
  private fontSize: number;
  private fontFamily: string;
  private cursorStyle: 'block' | 'underline' | 'bar';
  private cursorBlink: boolean;
  private theme: Required<ITheme>;
  private devicePixelRatio: number;
  private metrics: FontMetrics;
  private palette: string[];

  // Cursor blinking state
  private cursorVisible: boolean = true;
  private cursorBlinkInterval?: number;
  private lastCursorPosition: { x: number; y: number } = { x: 0, y: 0 };

  // Viewport tracking (for scrolling)
  private lastViewportY: number = 0;

  // Current buffer being rendered (for grapheme lookups)
  private currentBuffer: IRenderable | null = null;

  // Selection manager (for rendering selection)
  private selectionManager?: SelectionManager;
  // Cached selection coordinates for current render pass (viewport-relative)
  private currentSelectionCoords: {
    startCol: number;
    startRow: number;
    endCol: number;
    endRow: number;
  } | null = null;

  // Link rendering state
  private hoveredHyperlinkId: number = 0;
  private previousHoveredHyperlinkId: number = 0;

  // Regex link hover tracking (for links without hyperlink_id)
  private hoveredLinkRange: { startX: number; startY: number; endX: number; endY: number } | null =
    null;
  private previousHoveredLinkRange: {
    startX: number;
    startY: number;
    endX: number;
    endY: number;
  } | null = null;

  constructor(canvas: HTMLCanvasElement, options: RendererOptions = {}) {
    this.canvas = canvas;
    const ctx = canvas.getContext('2d', { alpha: true });
    if (!ctx) {
      throw new Error('Failed to get 2D rendering context');
    }
    this.ctx = ctx;

    // Apply options
    this.fontSize = options.fontSize ?? 15;
    this.fontFamily = options.fontFamily ?? 'monospace';