I've been working with RenderScript recently with the intent of creating an API that a programmer can use with ease, similar to the way that Microsoft Accelerator works.

The trouble I'm stuck with at the moment as that I want to pass values to and from the RenderScript layer and have everything run in the most efficient way possible, this is an extract of my source code so far:

```
    int[] A = new int[10];
    int[] B = new int[10];

    for (int i = 0; i < 10; i++) {
        A[i] = 2;
        B[i] = i;
    }
    intAdd(A, B);

```

This just creates two basic arrays and fills them with values and calls the functions that will send them to RenderScript.

```
 private void intAdd(int[] A, int[] B) {
    RenderScript rs = RenderScript.create(this);
    ScriptC_rsintadd intaddscript = new ScriptC_rsintadd(rs, getResources(), R.raw.rsintadd);
    mScript = intaddscript;

    for(int i = 0; i < A.length; i++) {
    setNewValues(mScript, A[i], B[i]);
    intaddscript.invoke_intAdd();
    int C = getResult(mScript);
    notifyUser.append(" " + C);
    }
}

    public void setNewValues(Script script, int A, int B) {
    mScript.set_numberA(A);
    mScript.set_numberB(B);
}

public int getResult(Script script) {
    int C = mScript.get_numberC();
    return C;
}

```

This will send a pair of values to the following RenderScript code:

```
int numberA;
int numberB;
int numberC;

void intAdd() {
/*Add the two together*/
numberC = numberA + numberB;
/*Send their values to the logcat*/
rsDebug("Current Value", numberC);
 }

```

But there are two problems with this, the first one is the Asynchronous nature of RenderScript means that when the Java layer requests the value, the script either hasn't done the operation yet, or it's already done it, destroyed the value of the output and started on the next one. And thanks to the low debugging visibility of RenderScript there's no way of telling.

The other problem is that it's not very efficient, the code is constantly calling the RenderScript function to add two numbers together. Ideally I'd want to pass the array to RenderScript and store it in a struct and have the entire operation done in one script call rather than many. But in order to get it back I reckon I'll need to user the rsSendtoClient function, but I've not found any material on how to use it. And preferably I'd like to use the rsForEach strategy, but again information is scare.

If anyone has any ideas I'd be very grateful. Thanks.

Will Scott-Jackson