"use strict";
const common_vendor = require("../../common/vendor.js");
const _sfc_main = {
  props: {
    width: Number,
    // 画布实际宽度(像素)
    height: Number,
    // 画布实际高度(像素)
    imgUrl: String,
    // 图片URL
    matrix: {
      // 变换矩阵
      type: Object,
      default: () => ({
        a: 1,
        b: 0,
        c: 0,
        d: 1,
        tx: 0,
        ty: 0
      })
    }
  },
  data() {
    return {
      canvasContext: null,
      image: null,
      dpr: 1,
      canvasDisplayWidth: 300,
      // 默认显示尺寸
      canvasDisplayHeight: 300,
      canvasActualWidth: 300,
      // 实际像素尺寸
      canvasActualHeight: 300
    };
  },
  watch: {
    imgUrl: {
      handler(newUrl) {
        if (newUrl)
          this.loadImage(newUrl);
      },
      immediate: true
    },
    width: {
      handler() {
        this.updateCanvasSize();
      },
      immediate: true
    },
    height: {
      handler() {
        this.updateCanvasSize();
      },
      immediate: true
    },
    matrix: {
      deep: true,
      handler() {
        this.$nextTick(() => {
          if (this.canvasContext) {
            this.redraw();
          }
        });
      }
    }
  },
  mounted() {
    this.initCanvas();
  },
  methods: {
    initCanvas() {
      const query = common_vendor.index.createSelectorQuery().in(this);
      query.select("#myCanvas").fields({ node: true, size: true }).exec(async (res) => {
        if (!res[0])
          return;
        this.canvas = res[0].node;
        this.ctx = res[0].node.getContext("2d");
        this.dpr = common_vendor.index.getSystemInfoSync().pixelRatio;
        this.updateCanvasSize();
        if (this.imgUrl) {
          await this.loadImage(this.imgUrl);
        }
      });
    },
    updateCanvasSize() {
      this.canvasDisplayWidth = this.width;
      this.canvasDisplayHeight = this.height;
      this.canvasActualWidth = this.width * this.dpr;
      this.canvasActualHeight = this.height * this.dpr;
      if (this.canvas) {
        this.canvas.width = this.canvasActualWidth;
        this.canvas.height = this.canvasActualHeight;
        this.ctx.scale(this.dpr, this.dpr);
        this.redraw();
      }
    },
    async loadImage(src) {
      try {
        this.image = await new Promise((resolve, reject) => {
          const image = this.canvas.createImage();
          image.src = src;
          image.onload = () => resolve(image);
          image.onerror = reject;
        });
        this.redraw();
      } catch (e) {
        common_vendor.index.__f__("error", "at pages/index/transform-canvas.vue:125", "图片加载失败:", e);
        this.image = null;
        this.redraw();
      }
    },
    redraw() {
      if (!this.ctx)
        return;
      this.ctx.save();
      this.ctx.resetTransform();
      this.ctx.clearRect(0, 0, this.canvasActualWidth, this.canvasActualHeight);
      this.ctx.scale(this.dpr, this.dpr);
      const { a, b, c, d, tx, ty } = this.matrix;
      this.ctx.setTransform(a, b, c, d, tx, ty);
      if (this.image) {
        this.ctx.drawImage(
          this.image,
          0,
          0,
          this.canvasDisplayWidth,
          this.canvasDisplayHeight
        );
      } else {
        this.ctx.fillStyle = "#f0f0f0";
        this.ctx.fillRect(0, 0, this.width, this.height);
        this.ctx.fillStyle = "#999";
        this.ctx.textAlign = "center";
        this.ctx.textBaseline = "middle";
        this.ctx.fillText("图片加载失败", this.width / 2, this.height / 2);
      }
      this.ctx.restore();
    }
  }
};
function _sfc_render(_ctx, _cache, $props, $setup, $data, $options) {
  return {
    a: `${$data.canvasDisplayWidth}px`,
    b: `${$data.canvasDisplayHeight}px`
  };
}
const Component = /* @__PURE__ */ common_vendor._export_sfc(_sfc_main, [["render", _sfc_render]]);
wx.createComponent(Component);
//# sourceMappingURL=../../../.sourcemap/mp-weixin/pages/index/transform-canvas.js.map