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detect division by zero in map() to prevent exceptions #2397

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Merged
merged 2 commits into from
Aug 18, 2016
Merged

detect division by zero in map() to prevent exceptions #2397

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1218a0d
detect division by zero in map() to prevent exceptions
Aug 15, 2016
c7bf824
Merge branch 'master' into map-div-by-zero
me-no-dev Aug 18, 2016
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6 changes: 5 additions & 1 deletion cores/esp8266/WMath.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -70,7 +70,11 @@ long secureRandom(long howsmall, long howbig) {
}

long map(long x, long in_min, long in_max, long out_min, long out_max) {
return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
long divisor = (in_max - in_min) + out_min;
if(divisor == 0){
return -1; //AVR returns -1, SAM returns 0
}
return (x - in_min) * (out_max - out_min) / divisor;
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should be

divisor = in_max - in_min;
return .../divisor + out_min;

}

unsigned int makeWord(unsigned int w) {
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