/** @format */

// author: http://lamyoung.com/

const {ccclass, property, requireComponent} = cc._decorator
@ccclass
@requireComponent(cc.Graphics)
export default class GraphicsSpriteMesh extends cc.Component {
    @property(cc.Sprite)
    sprite: cc.Sprite = null

    graphics: cc.Graphics = null

    private _vertices: {x: number[]; y: number[]; nu: number[]; nv: number[]; triangles: number[]} = {
        x: [],
        y: [],
        nu: [],
        nv: [],
        triangles: [],
    }

    onLoad() {
        this.graphics = this.node.getComponent(cc.Graphics)
        this.sprite.type = cc.Sprite.Type.MESH
        this.sprite.node.anchorY = 1
        this.sprite.node.anchorX = 0
        this.sprite.node.scaleY = -1
        this.sprite.node.x = this.node.y = 0
        this.sprite.spriteFrame['vertices'] = this._vertices
    }

    stroke() {
        if (cc.game.renderType === cc.game.RENDER_TYPE_WEBGL) {
            const vertices = this._vertices
            vertices.x.length = vertices.y.length = vertices.nu.length = vertices.nv.length = vertices.triangles.length = 0
            const _impl = this.graphics['_impl']
            // const _assembler = this.graphics['_assembler'];
            // cc.log(_impl);
            const w = this.graphics.lineWidth
            const uv_mul = 1 / 50

            let trianglesCache: number[][] = []
            let offsetX = cc.v2() // 记录每节长度
            for (let index = 0; index < _impl._paths.length; index++) {
                const path = _impl._paths[index]
                const pathPoints = path.points
                // cc.log(index, path);
                if (pathPoints.length < 2) continue
                for (let index2 = pathPoints.length - 1; index2 > 0; index2--) {
                    let triangles: number[] = []
                    const p = cc.v2(pathPoints[index2].x, pathPoints[index2].y) // 当前点
                    const p_pre = cc.v2(pathPoints[index2 - 1].x, pathPoints[index2 - 1].y) //上一个点
                    const dir = p.sub(p_pre) //方向
                    const cross_dir = (dir.y == 0 ? cc.v2(0, 1) : cc.v2(1, -dir.x / dir.y).normalize()).mulSelf(w / 2) //垂直方向
                    const p_r_t = p.add(cross_dir) //右上
                    const p_r_b = p.sub(cross_dir) // 右下
                    const p_l_t = p_pre.add(cross_dir) // 左上
                    const p_l_b = p_pre.sub(cross_dir) // 左下

                    // 当前线段长度
                    const dirLen = dir.len()

                    // 画长方形
                    let i_offset = vertices.x.length
                    vertices.x.push(p_r_t.x, p_r_b.x, p_l_t.x, p_l_b.x)
                    vertices.y.push(p_r_t.y, p_r_b.y, p_l_t.y, p_l_b.y)
                    // 计算长方形的uv
                    vertices.nu.push(
                        offsetX.x * uv_mul,
                        offsetX.x * uv_mul,
                        (offsetX.x + dirLen) * uv_mul,
                        (offsetX.x + dirLen) * uv_mul,
                    )
                    vertices.nv.push(1, 0, 1, 0)

                    triangles.push(i_offset + 0)
                    triangles.push(i_offset + 1)
                    triangles.push(i_offset + 2)
                    triangles.push(i_offset + 1)
                    triangles.push(i_offset + 2)
                    triangles.push(i_offset + 3)

                    //画圆
                    const dir_angle = dir.signAngle(cc.v2(-1, 0)) //与x轴的负方向的夹角
                    const count = 12
                    i_offset = vertices.x.length
                    // 这里是圆心
                    vertices.x.push(p.x)
                    vertices.y.push(p.y)
                    vertices.nu.push(offsetX.x * uv_mul)
                    vertices.nv.push(0.5)
                    for (let index3 = 0; index3 < count; index3++) {
                        const r = (2 * Math.PI * index3) / count
                        // 圆心到各个边的向量
                        const pos_circle = cc.v2((w / 2) * Math.cos(r), (w / 2) * Math.sin(r))
                        vertices.x.push(pos_circle.add(p).x)
                        vertices.y.push(pos_circle.add(p).y)
                        // 对于圆的uv需要旋转
                        vertices.nu.push((pos_circle.rotate(dir_angle).x + offsetX.x) * uv_mul)
                        vertices.nv.push(pos_circle.rotate(dir_angle).y / w + 0.5)
                        if (index3 === 0) {
                            triangles.push(i_offset, i_offset + 1 + index3, i_offset + count)
                        } else {
                            triangles.push(i_offset, i_offset + 1 + index3, i_offset + index3)
                        }
                    }

                    trianglesCache.push(triangles)

                    offsetX.addSelf(cc.v2(dirLen, 0)) // 记录已经画的长度长度
                }
            }
            trianglesCache.reverse() // 顶点索引反转
            trianglesCache.forEach(v => {
                // 真正的顶点索引顺序
                vertices.triangles.push(...v)
            })
            // cc.log(vertices);
            this.sprite['setVertsDirty']()
            // this.graphics.stroke();
        } else {
            this.graphics.stroke()
        }
    }

    clear() {
        this.graphics.clear(true)
        if (cc.game.renderType === cc.game.RENDER_TYPE_WEBGL) {
            const vertices = this._vertices
            vertices.x.length = vertices.y.length = vertices.nu.length = vertices.nv.length = vertices.triangles.length = 0
            this.sprite['setVertsDirty']()
        }
    }
}

/**
 *
 *
 前置教程:
 [初探精灵中的网格渲染模式 ！](https://mp.weixin.qq.com/s/2FcixeoV-Fg-7OodILECeg)
 图文:
 part-1:  https://mp.weixin.qq.com/s/ozXjdpyid5f2Xwo7uo0MuQ
 part-2:  https://mp.weixin.qq.com/s/xniwz-a_FI0snWqqPd2NOg
 */

// 欢迎关注微信公众号[白玉无冰]

/**
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 */