How to pass array values to and from Android RenderScript using Allocations

Question

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.

Answer 1

I had the same problem with you. I think rsSendtoClient function is not useful and creates many bugs. Instead, using a pointer and allocate it a memory to bring result back to you is much easier.

I recommend the solution of your problem like this:

In rsintadd.rs use this snippet:

int32_t *a;
int32_t *b;
int32_t *c;

void intAdd() {
    for(int i = 0; i<10;i++){
    c[i] = a[i] + b[i];
}

In your JAVA code use this snippet:

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

    for (int i = 0; i < 10; i++) {
        A[i] = 2;
        B[i] = 1;
    }

    // provide memory for b using data in B
    Allocation b = Allocation.createSized(rs, Element.I32(rs), B.length);
    b.copyFrom(B);
    inv.bind_b(b);

    // provide memory for a using data in A
    Allocation a = Allocation.createSized(rs, Element.I32(rs), A.length);
    a.copyFrom(A);
    inv.bind_a(a);

    // create blank memory for c
    inv.bind_c(Allocation.createSized(rs, Element.I32(rs), 10));

    // call intAdd function
    inv.invoke_intAdd();

    // get result
    int[] C = new int[10];
    inv.get_c().copyTo(C);
    for (int i = 0; i < C.length; i++) {
        System.out.println(C[i]);
    }

And this is your result on Logcat:

Your first question is about Asynchronous, you can use thread to wait result. In this example, the function is fast enough and instantly gives the output to C array so result can show on logcat.

Your second question is about implement intAdd() function without recalling it. The code above is the answer. You can access any part of int array in Java until the method is done ( different from root() function ).

Hope this can help someone :)