如何在小游戏上读取texture的rgb数据

Creator 3.x
#1

之前用device.copyTextureToBuffers方法读的数据，web上基于这个功能做了很多功能，在微信小游戏上实测时，提示“使用 OpenDataContext 后，“受限Canvas” 的 gl 上下文不能调用 readPixels”，有没有什么方法避开这个

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image954×538 80 KB

#2

试试这个。

#3

public readPixels(tex: Texture2D, x: number = 0, y: number = 0): Uint8Array {
const gfxTexture = tex.getGFXTexture();
if (!gfxTexture) {
return null;
}
const { width, height } = gfxTexture;
const needSize = 4 * width * height;
const buffer = new Uint8Array(needSize);
const bufferViews: ArrayBufferView[] = [];
const regions: gfx.BufferTextureCopy[] = [];

    const region0 = new gfx.BufferTextureCopy();
    region0.texOffset.x = x;
    region0.texOffset.y = y;
    region0.texExtent.width = width;
    region0.texExtent.height = height;
    regions.push(region0);
    bufferViews.push(buffer);
    director.root.device.copyTextureToBuffers(gfxTexture, bufferViews, regions);
    return buffer;
}

public getPixelColor(buffer: Uint8Array, width: number, x: number, y: number): Color {
    if (buffer.length <= 0) {
        return null;
    }
    const index: number = (y * width + x) * 4;
    const r: number = buffer[index];
    const g: number = buffer[index + 1];
    const b: number = buffer[index + 2];
    const a: number = buffer[index + 3];
    // console.log(`第${x}行，第${y}列的像素颜色为：${r},${g},${b},${a}`)
    return new Color(r, g, b, a);
}