问是否可以反转GPUImageMaskFilter的掩码？

EN

uniform sampler2D tex0 ;
uniform sampler2D tex1; // mask
void main()
{
vec4 nowcolor = texture2D(texture1, uv);
vec4 newmask = vec4(1.0,1.0,1.0,1.0) - nowcolor;

// and use the new mask here instead the old mask texture

}