Skip to content

digitbox: more concise wraparound using unsigned overflow #206

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
prayerie wants to merge 1 commit into
base: new
Choose a base branch
from
Open

digitbox: more concise wraparound using unsigned overflow #206

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 4 additions & 6 deletions tobkit/source/digitbox.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -88,18 +88,16 @@ void DigitBox::penDown(u8 px, u8 py) {

if((px>x)&&(px<x+width/4)&&(py>y)&&(py<y+9)&&digits==2) { // top left arrow
btnstate = 1;
if (value > max-0x10) value = value + 0x10 - max - 1; // wrap around if (value + 0x10) > 0xff. so 0xf0 wraps to 0x00
else value+=0x10;
value+=0x10;
} else if((px>x)&&(px<x+width/4)&&(py>y+9)&&(py<y+18)&&digits==2) { // bottom left arrow
btnstate = 2;
if (value < 0x10) value = max - 0x10 + value + 1; // likewise wrap around downwards
else value-=0x10;
value-=0x10;
} else if((px>x)&&(px>x+(width/4)*3)&&(py>y)&&(py<y+9)) { // top right arrow
btnstate = 3;
if(value<max) value++; else value = min;
value++;
} else if((px>x)&&(px>x+(width/4)*3)&&(py>y+9)&&(py<y+18)) { // bottom right arrow
btnstate = 4;
if(value>min) value--; else value = max;
value--;
}

if(value!=oldvalue) {
Expand Down