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#include "Halide.h"
#include <algorithm>
#include <stdio.h>
using namespace Halide;
int main(int argc, char **argv) {
Var x, y;
const int size = 32;
Buffer<float> noise(size, size);
for (int i = 0; i < size; i++) {
for (int j = 0; j < size; j++) {
noise(j, i) = (float)rand() / (float)RAND_MAX;
}
}
// Define a seam carving-esque energy. The meaning of this
// depends on the interleaving of the x and y dimensions during
// the reduction update. This is why we have RDoms instead of just
// using multiple RVars in an update.
Func energy;
RDom r(0, noise.width(), 1, noise.height() - 1);
Expr xm = max(r.x - 1, 0), xp = min(r.x + 1, noise.width() - 1);
energy(x, y) = 0.0f;
energy(x, 0) = noise(x, 0); // The first row is just the first row of the input.
energy(r.x, r.y) = noise(r.x, r.y) + min(energy(xm, r.y - 1),
energy(r.x, r.y - 1),
energy(xp, r.y - 1));
Buffer<float> im_energy = energy.realize({size, size});
Buffer<float> ref_energy(size, size);
for (int y = 0; y < size; y++) {
for (int x = 0; x < size; x++) {
int xm = std::max(x - 1, 0);
int xp = std::min(x + 1, size - 1);
float incr = 0.0f;
if (y > 0) {
incr = std::min(ref_energy(xm, y - 1), std::min(ref_energy(x, y - 1), ref_energy(xp, y - 1)));
}
ref_energy(x, y) = noise(x, y) + incr;
float delta = ref_energy(x, y) - im_energy(x, y);
if (fabs(delta) > 1e-5) {
printf("energy(%d,%d) was %f instead of %f\n", x, y, im_energy(x, y), ref_energy(x, y));
return 1;
}
}
}
printf("Success!\n");
return 0;
}
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