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PObool function taking array as argument
 

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    <p>I have a bool function used in a test to see whether or not two objects are neighbours. If they are, a previous function InitFaceCheck() will write either 0 or 1 into a global array N[16] (16 cases to check for).</p> <pre><code>for (n = 0; n &lt; count; n++ ) { int l = 0; for (m = 0; m &lt; count; m++ ) { InitFaceCheck(tet[n], tet_copy[m]); // if( (tet[n].ID != tet_copy[m].ID) &amp;&amp; (isNeighbour(N) == 1) ) // if T's { for(j = 0; j &lt; 16; j++){ printf("N[%i] = %i ",j, N[j]); } printf("\n"); tet[n].next[l] = tet_copy[m].ID; // mark them as neighbours l++; // neighbour counter }; } } </code></pre> <p>The InitFaceCheck() function evaluates if any the two tetrahedra share any of their faces (i.e. they share a face if the share the x,y,z coords of the three vertices that constitute that face) in total there are 16 tests, only 2 are included here:</p> <pre><code>void InitFaceCheck (TETRA a, TETRA b) { /*... Setup of bool variables to be used in CheckFace () .... a bit tedious due to having .x .y .z components but it is solid for our purposes ... */ bool f11 = ( (a.vert[0].x == b.vert[0].x) &amp;&amp; (a.vert[0].y == b.vert[0].y) &amp;&amp; (a.vert[0].z == b.vert[0].z) &amp;&amp; (a.vert[1].x == b.vert[1].x) &amp;&amp; (a.vert[1].y == b.vert[1].y) &amp;&amp; (a.vert[1].z == b.vert[1].z) &amp;&amp; (a.vert[2].x == b.vert[2].x) &amp;&amp; (a.vert[2].y == b.vert[2].y) &amp;&amp; (a.vert[2].z == b.vert[2].z) ); bool f12 = ( (a.vert[0].x == b.vert[0].x) &amp;&amp; (a.vert[0].y == b.vert[0].y) &amp;&amp; (a.vert[0].z == b.vert[0].z) &amp;&amp; (a.vert[1].x == b.vert[3].x) &amp;&amp; (a.vert[1].y == b.vert[3].y) &amp;&amp; (a.vert[1].z == b.vert[3].z) &amp;&amp; (a.vert[2].x == b.vert[2].x) &amp;&amp; (a.vert[2].y == b.vert[2].y) &amp;&amp; (a.vert[2].z == b.vert[2].z) ); ....... // write output of tests to global array N, so as to make them accessible to all functions N[0] = f11; N[1] = f12; N[2] = f13; N[3] = f14; N[4] = f21; N[5] = f22; N[6] = f23; N[7] = f24; N[8] = f31; N[9] = f32; N[10] = f33; N[11] = f34; N[12] = f41; N[13] = f42; N[14] = f43; N[15] = f44; </code></pre> <p>The isNeighbour function looks like this:</p> <pre><code>bool isNeighbour (int a[16]) { return (a[0] || a[1] || a[2] || a[3] || a[4] || a[5] || a[6] || a[7] || a[8] || a[9] || a[10] || a[11] || a[12] || a[13] || a[14] || a[15]); // int i = 0; //for (i = 0; i &lt; 16; i++) // { // if ( a[i] == 1 ) return true; // // } } </code></pre> <p>The output looks something like this:</p> <pre><code>T4092 T4100 N[0] = 0 N[1] = 0 N[2] = 0 N[3] = 0 N[4] = 0 N[5] = 0 N[6] = 0 N[7] = 0 N[8] = 1 N[9] = 0 N[10] = 0 N[11] = 0 N[12] = 0 N[13] = 0 N[14] = 0 N[15] = 0 T4101 T4120 N[0] = 0 N[1] = 0 N[2] = 1 N[3] = 0 N[4] = 0 N[5] = 0 N[6] = 0 N[7] = 0 N[8] = 0 N[9] = 0 N[10] = 0 N[11] = 0 N[12] = 0 N[13] = 0 N[14] = 0 N[15] = 0 T4169 N[0] = 0 N[1] = 0 N[2] = 0 N[3] = 0 N[4] = 0 N[5] = 0 N[6] = 0 N[7] = 0 N[8] = 0 N[9] = 0 N[10] = 0 N[11] = 0 N[12] = 1 N[13] = 0 N[14] = 0 N[15] = 0 N[0] = 0 N[1] = 1 N[2] = 0 N[3] = 0 N[4] = 0 N[5] = 0 N[6] = 0 N[7] = 0 N[8] = 0 N[9] = 0 N[10] = 0 N[11] = 0 N[12] = 0 N[13] = 0 N[14] = 0 N[15] = 0 </code></pre> <p>My questions are the following: </p> <ol> <li><p>why won't the commented out part of isNeighbour() work (it crashes) ? is the condition in the if loop correct ? (is it doing what I think it is doing?)</p> <p>why is N[] being rewritten as 0 when a tetrahedron has more than 1 neighbour (see T4169 with two lines of N[], in the second line, N[12] was previously evaluated to be true (=1), </p> <p>why is it when evaluating for the second time and it finds N[1]=1; N[12] is reset to 0.</p> <p>-and for the love of god is there anyway I could achieve a similar result but in a more elegant manner ? Also I am aware that I might be violating basic rules of coding so please do not hesitate to point them out!</p></li> </ol> <p>Thank you EDIT: this indeed C. I asked around and was told to include and bool should work just fine.</p>
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    1. CO"why won't the commented out part of `isNeighbour()` work (it crashes)?" That would probably be because you're not returning anything if none of the entries is 1. Add a `return false;` after the loop.
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    2. COYou could look into improving your indentation style, I personally prefer the Allman style - http://en.wikipedia.org/wiki/Indent_style#Allman_style choose something established and stick to it, it will make it easier for other programmers who need to maintain your code.
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    3. COThere's no `bool` datatype in C, not sure what you mean by being told to include it and it 'should work just fine'. How are you compiling it?
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