从另一个脚本全局设置一个渲染脚本

Question

Is there a possibility to set a field in the Android renderscript A out of another renderscript B? I know that you can call a kernel of another Script, using rsForEach() , but how to set globals or bind allocations?

Example:

I have a (of course there will be multiple) slave script slave.rs :

// just two example allocations
rs_allocation gImg1;
rs_allocation gImg2;

/** merge the two images element wise - just an example */
float2 __attribute__((kernel)) root(uint32_t x, uint32_t y) {
    float2 merged = 0;
    merged.x = rsGetElementAt_float(gImg1, x, y);
    merged.y = rsGetElementAt_float(gImg2, x, y);
    return merged;
}

which i would like to call from my master.rs script:

// my globals (which will be set from java)
rs_allocation gI0;
rs_allocation gI1;
rs_allocation gMerged;

rs_script mSlave; 

/**
 * This function is called from Java and should delegate some of its work
 * to the kernel function of the slave - script
 */
void myFunction(){
    // do some stuff

    // now bind the allocations to the slave sript
    rsBind(mSlave, "gImg1", gI0); // ??? does there exists something like that?
    rsBind(mSlave, "gImg2", gI1); // ???

    // and invoke the kernel
    rsForEach(mSlave, 0 , gMerged );
}

Of course this is just a toy example, but I was hoping to realize some more complex renderscript constructs with avoiding too many context switches from Java to renderscript.

Some information about multiple Scripts are also provided in a comment to another question: https://stackoverflow.com/a/18926003/4118132

Also an overview on the renderscript functions are provided here: https://stuff.mit.edu/afs/sipb/project/android/docs/guide/topics/renderscript/reference.html

I'm aware that, starting in Android 4.4, the renderscript - engine can be used directly from the ndk.

Answer 1

No, there's no way to directly call functions of other scripts or bind allocations from one script to another. However, you can use a ScriptGroup to create a chain of scripts to be run together with output of one feeding the input of another, or even a field of another.