shifting values in array

to update graph, need shift values in whole array 1 position left before adding new value end of array. following code me:

for(int i=1; i<width; i++) {
xvals[i-1] = xvals;
}

but array quite long, seems quite inefficient way of doing this, since requires lot of clock cycles complete. there way shift values in array more efficiently?

try:

code: [select]

void memcpy(void* target, const void* source, size_t length);
// ...
memcpy(&xvals[0], &xvals[1], (width-1)*sizeof(*xvals));

the memcpy() function implement best possible under limitations of platform, it's doing same thing.

on fancier microprocessors, there special memory moving instructions , dedicated buses take care of these things @ speed of memory hardware.  not microcontrollers.

note if you're "scrolling" array right, need count-down loop instead of count-up loop.  otherwise, each copy overwriting next copy done.  the memcpy() routine should internally check 1 necessary.

code: [select]

memcpy(&xvals[1], &xvals[0], (width-1)*sizeof(*xvals));

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