Inconsistent state about kiwi HOT 6 CLOSED

Can you please provide a reproducible test case. As small as possible preferably :)

Also, Kiwi should never return bad values, if it can't find a solution it should throw an unsatisfiable constraint exception. Are you perhaps eating an exception somewhere?

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Yes, I am trying to get a small example that triggers it. Will get back to you.

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@sccolbert Hi, I have found a inconsistent test, with the code below:

#include "kiwi.h"

#include <stdio.h>

using namespace kiwi;

int main(void)
{
    Variable xl("xl"), xm("xm"), xr("xr");
    Solver solver;

    solver.addConstraint(xm*2 == xl + xr);
    solver.addConstraint(xl + 10 <= xr);
    solver.addConstraint(xr <= 100);
    solver.addConstraint(xl >= 0);

    solver.updateVariables();
    printf("%g, %g, %g\n", xl.value(), xm.value(), xr.value());

    solver.addEditVariable(xm, strength::strong);
    solver.updateVariables();
    printf("%g, %g, %g\n", xl.value(), xm.value(), xr.value());

    solver.suggestValue(xm, 70);
    solver.updateVariables();
    printf("%g, %g, %g\n", xl.value(), xm.value(), xr.value());

    return 0;
}

this is my result:

test
90, 95, 100
0, 5, 10
40, 70, 100
Hit any key to close this window...

it should be 65, 70, 75, but not 40, 70, 100, the second constraint missing.

I have found this here, this is the examples in the Cassowary algorithm paper.

could give some help about this? I'm trying implement this algorithm in pure Lua language and meet this issue.

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@starwing

(40, 70, 100) is a solution to the problem, and so is (65, 70, 75). There may also be more valid solutions.

The problem as-written is underconstrained, so kiwi is just going to pick one of the solutions. Which one is picked is more or less random.

If your second constraint was == instead of <=, or if you added another constraint to pin one of the values, you would get your desired solution.

Kiwi appears to be behaving as designed here.

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@sccolbert okay, my fault :( I just realize this fact, sorry for noise

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Closing as it appears to be normal

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