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POMemcpy unexpected behavior
 

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  1. POMemcpy unexpected behavior
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    <p>I'm coding my own version of Tetris. While creating blockRotation method I encountered weird problem with memcpy. During second call for blockRotate, my bool[4*4] array is not saved corectly, despite that is generated properly. What's wrong?</p> <p>This is my error log:</p> <pre><code>arr_shift[0]: true arr_shift[1]: false arr_shift[2]: false arr_shift[3]: false arr_shift[4]: true arr_shift[5]: true arr_shift[6]: false arr_shift[7]: false arr_shift[8]: true arr_shift[9]: false arr_shift[10]: false arr_shift[11]: false arr_shift[12]: false arr_shift[13]: false arr_shift[14]: false arr_shift[15]: false arr_rot[0]: false arr_rot[1]: false arr_rot[2]: true arr_rot[3]: false arr_rot[4]: false arr_rot[5]: false arr_rot[6]: true arr_rot[7]: true arr_rot[8]: false arr_rot[9]: false arr_rot[10]: true arr_rot[11]: false arr_rot[12]: false arr_rot[13]: false arr_rot[14]: false arr_rot[15]: false shape[0]: true shape[1]: false shape[2]: false shape[3]: false shape[4]: true shape[5]: true shape[6]: false shape[7]: false shape[8]: true shape[9]: false shape[10]: false shape[11]: false shape[12]: false shape[13]: false shape[14]: false shape[15]: false arr_shift[0]: false arr_shift[1]: false arr_shift[2]: false arr_shift[3]: false arr_shift[4]: false arr_shift[5]: false arr_shift[6]: false arr_shift[7]: false arr_shift[8]: false arr_shift[9]: false arr_shift[10]: false arr_shift[11]: false arr_shift[12]: false arr_shift[13]: false arr_shift[14]: false arr_shift[15]: false arr_rot[0]: false arr_rot[1]: true &lt;--- arr_rot[2]: true &lt;--- arr_rot[3]: true &lt;--- arr_rot[4]: false arr_rot[5]: false arr_rot[6]: true &lt;--- arr_rot[7]: false arr_rot[8]: false arr_rot[9]: false arr_rot[10]: false arr_rot[11]: false arr_rot[12]: false arr_rot[13]: false arr_rot[14]: false arr_rot[15]: false shape[0]: false shape[1]: false &lt;--- shape[2]: false &lt;--- shape[3]: false &lt;--- shape[4]: false shape[5]: false shape[6]: false &lt;--- shape[7]: false shape[8]: false shape[9]: false shape[10]: false shape[11]: false shape[12]: false shape[13]: false shape[14]: false shape[15]: false </code></pre> <p>And this is my code:</p> <pre><code>memset(shape, 0, 16*sizeof(bool)); if(toShift == true) { memcpy(shape, arr_shift, 16*sizeof(bool)); } else { memcpy(shape, arr_rot, 16*sizeof(bool)); } for(int i = 0; i &lt; 4; i++) { for(int j = 0; j &lt; 4; j++) { fprintf(stderr, "shape[%i]: %s\n", i*4+j, shape[i*4+j]? "true":"false" ); } } fprintf(stderr, "\n\n"); </code></pre> <p>Declararation of shape is in Block class header, and is as follows:</p> <pre><code> bool shape[16]; </code></pre>
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    1. This table or related slice is empty.
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    1. USicepopo
    1. USicepopo
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    1. This table or related slice is empty.
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    1. This table or related slice is empty.
    1. COIf this is a `memcpy` problem, please could you construct a simpler code example that avoids all the (apparently) irrelevant stuff (shifting, rotating, etc.). Ideally, no more than 10 lines!
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      1. POMemcpy unexpected behavior
      1. USOliver Charlesworth
    2. CO'memcpy' unexpected behaviour ! News at 11...
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      1. POMemcpy unexpected behavior
      1. USMalkocoglu
    3. COWhat's the point of the totally irrelevant `memset` *right before* you overwrite the very same memory with other values? Also, how did you manage to print so much noise but **miss** the declaration of `shape`, which is apparently central to your problem?
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      1. POMemcpy unexpected behavior
      1. USKerrek SB
 

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