toBase64 自适应裁剪图像并缩放到指定大小

toBase64

类型: MethodDeclaration

所属类: Texture

定义位置: webgl.ts

描述

自适应裁剪图像并缩放到指定大小

再转换为BASE64编码

参数 width: 目标图像宽度

参数 height: 目标图像高度

返回值:BASE64

参数

参数名	类型	描述	默认值
width	number	-	-
height	number	-	-

返回值

类型: string

BASE64

源代码

位置: 第 2085 行

public toBase64(width: number, height: number): string {
    const texture = new Texture()
    texture.resize(width, height)
    const tx = this.x
    const ty = this.y
    const tw = this.width
    const th = this.height
    const bw = this.base.width
    const bh = this.base.height
    let sx, sy, sw, sh
    if (width / height >= bw / bh) {
      sw = bw
      sh = Math.round(bw * height / width)
      sx = 0
      sy = bh - sh >> 1
    } else {
      sw = Math.round(bh * width / height)
      sh = bh
      sx = bw - sw >> 1
      sy = 0
    }
    const gl = this.gl
    this.clip(sx, sy, sw, sh)
    gl.reset()
    gl.bindFBO(gl.frameBuffer)
    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture.base.glTexture, 0)
    gl.drawImage(this, 0, 0, width, height)
    gl.unbindFBO()
    this.clip(tx, ty, tw, th)
    const imageData = texture.getImageData(0, 0, width, height)!
    const canvas = document.createElement('canvas')
    canvas.width = width
    canvas.height = height
    const context = canvas.getContext('2d')!
    context.putImageData(imageData, 0, 0)
    texture.destroy()
    return canvas.toDataURL()
  }

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文档生成时间：2025/7/21 20:53:39