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[rcore] GetCurrentMonitor(), fix for integer overflow in distance calculation #5842

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Merged
raysan5 merged 4 commits into from
May 29, 2026
+9 −2
Merged

[rcore] GetCurrentMonitor(), fix for integer overflow in distance calculation #5842

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e0083bc
Fix signed integer overflow in GetCurrentMonitor distance calc
Vasilis-Narain May 7, 2026
be9d2e2
Revert "Fix signed integer overflow in GetCurrentMonitor distance calc"
Vasilis-Narain May 15, 2026
fe6be21
fix GetCurrentMonitor() distance calc overflow
Vasilis-Narain May 15, 2026
727271f
fix GetCurrentMonitor() distance calc
Vasilis-Narain May 15, 2026
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11 changes: 9 additions & 2 deletions src/platforms/rcore_desktop_glfw.c
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Original file line number Diff line number Diff line change
Expand Up @@ -839,7 +839,7 @@ int GetCurrentMonitor(void)
// this is probably an overengineered solution for a side case
// trying to match SDL behaviour

int closestDist = 0x7FFFFFFF;
unsigned int closestDist = 0xFFFFFFFFu;

// Window center position
int wcx = 0;
Expand Down Expand Up @@ -883,7 +883,14 @@ int GetCurrentMonitor(void)

int dx = wcx - xclosest;
int dy = wcy - yclosest;
int dist = (dx*dx) + (dy*dy);

// Unsigned to dodge signed overflow UB; (-x)^2 == x^2 mod 2^32 so sign drops out.
// If |dx| or |dy| >= 65536, dist wraps and the wrong monitor may win.
// Not a concern for realistic monitor layouts.
unsigned int ux = (unsigned int)dx;
unsigned int uy = (unsigned int)dy;
unsigned int dist = ux*ux + uy*uy;

if (dist < closestDist)
{
index = i;
Expand Down