AI-Video/frontend/src/components/inpainting/tools/lasso-tool.ts

/**
 * Lasso Tool - Free polygon selection for mask
 */

import { Point } from './brush-tool'

export interface LassoToolOptions {
  color: string
}

export class LassoTool {
  private ctx: CanvasRenderingContext2D
  private isDrawing: boolean = false
  private points: Point[] = []
  private options: LassoToolOptions
  private previewCanvas: HTMLCanvasElement | null = null

  constructor(ctx: CanvasRenderingContext2D, options: LassoToolOptions) {
    this.ctx = ctx
    this.options = options
  }

  setColor(color: string) {
    this.options.color = color
  }

  setPreviewCanvas(canvas: HTMLCanvasElement) {
    this.previewCanvas = canvas
  }

  // Add point on click
  addPoint(point: Point) {
    if (!this.isDrawing) {
      this.isDrawing = true
      this.points = []
    }
    this.points.push(point)
    this.drawPreview()
  }

  // Draw preview polygon
  private drawPreview() {
    if (!this.previewCanvas || this.points.length === 0) return

    const previewCtx = this.previewCanvas.getContext('2d')
    if (!previewCtx) return

    previewCtx.clearRect(0, 0, this.previewCanvas.width, this.previewCanvas.height)

    // Draw polygon outline
    previewCtx.strokeStyle = this.options.color
    previewCtx.lineWidth = 2
    previewCtx.setLineDash([5, 5])

    previewCtx.beginPath()
    previewCtx.moveTo(this.points[0].x, this.points[0].y)
    for (let i = 1; i < this.points.length; i++) {
      previewCtx.lineTo(this.points[i].x, this.points[i].y)
    }
    previewCtx.stroke()

    // Draw points
    this.points.forEach((p, i) => {
      previewCtx.fillStyle = i === 0 ? '#00ff00' : this.options.color
      previewCtx.beginPath()
      previewCtx.arc(p.x, p.y, 4, 0, Math.PI * 2)
      previewCtx.fill()
    })
  }

  // Close and fill polygon on double-click
  closePath() {
    if (!this.isDrawing || this.points.length < 3) {
      this.cancel()
      return
    }

    // Fill polygon on mask
    this.ctx.fillStyle = this.options.color
    this.ctx.beginPath()
    this.ctx.moveTo(this.points[0].x, this.points[0].y)
    for (let i = 1; i < this.points.length; i++) {
      this.ctx.lineTo(this.points[i].x, this.points[i].y)
    }
    this.ctx.closePath()
    this.ctx.fill()

    this.cancel()
  }

  cancel() {
    this.isDrawing = false
    this.points = []
    if (this.previewCanvas) {
      const ctx = this.previewCanvas.getContext('2d')
      ctx?.clearRect(0, 0, this.previewCanvas.width, this.previewCanvas.height)
    }
  }

  isActive(): boolean {
    return this.isDrawing
  }

  getPointCount(): number {
    return this.points.length
  }
}