Add div by zero check back into WMath::map (espressif#4853)

lbernstone · me-no-dev · web-flow · commit 3fe7c2e8cdcc · 2021-02-24T19:04:36.000+02:00
* Add div by zero check back into WMath::map
* include esp32-hal-log.h

Co-authored-by: Me No Dev &lt;me-no-dev@users.noreply.github.com&gt;
diff --git a/cores/esp32/WMath.cpp b/cores/esp32/WMath.cpp
@@ -27,6 +27,7 @@ extern "C" {
 #include <stdlib.h>
 #include "esp_system.h"
 }
+#include "esp32-hal-log.h"
 
 void randomSeed(unsigned long seed)
 {
@@ -69,7 +70,10 @@ long map(long x, long in_min, long in_max, long out_min, long out_max) {
     const long dividend = out_max - out_min;
     const long divisor = in_max - in_min;
     const long delta = x - in_min;
-
+    if(divisor == 0){
+        log_e("Invalid map input range, min == max");
+        return -1; //AVR returns -1, SAM returns 0
+    }
     return (delta * dividend + (divisor / 2)) / divisor + out_min;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -27,6 +27,7 @@ extern "C" {`
`27`	`27`	`#include <stdlib.h>`
`28`	`28`	`#include "esp_system.h"`
`29`	`29`	`}`
	`30`	`+#include "esp32-hal-log.h"`
`30`	`31`
`31`	`32`	`void randomSeed(unsigned long seed)`
`32`	`33`	`{`
`@@ -69,7 +70,10 @@ long map(long x, long in_min, long in_max, long out_min, long out_max) {`
`69`	`70`	`const long dividend = out_max - out_min;`
`70`	`71`	`const long divisor = in_max - in_min;`
`71`	`72`	`const long delta = x - in_min;`
`72`		`-`
	`73`	`+ if(divisor == 0){`
	`74`	`+ log_e("Invalid map input range, min == max");`
	`75`	`+ return -1; //AVR returns -1, SAM returns 0`
	`76`	`+ }`
`73`	`77`	`return (delta * dividend + (divisor / 2)) / divisor + out_min;`
`74`	`78`	`}`
`75`	`79`