From d9cb0782997c7b11eda542627ab29640afb0f904 Mon Sep 17 00:00:00 2001
From: maiphi <39464783+maiphi@users.noreply.github.com>
Date: Sun, 31 Aug 2025 11:34:05 +0200
Subject: [PATCH] FindNearestConnectorMode: prefer mode with smallest number of
 unused pixels (#5158)

Co-authored-by: Philipp Maierhoefer <particle@maierhoefer.net>
---
 src/platforms/rcore_drm.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/src/platforms/rcore_drm.c b/src/platforms/rcore_drm.c
index 2354bb3d2..a2151ea38 100644
--- a/src/platforms/rcore_drm.c
+++ b/src/platforms/rcore_drm.c
@@ -53,6 +53,7 @@
 #include <termios.h>        // POSIX terminal control definitions - tcgetattr(), tcsetattr()
 #include <pthread.h>        // POSIX threads management (inputs reading)
 #include <dirent.h>         // POSIX directory browsing
+#include <limits.h>         // INT_MAX
 
 #include <sys/ioctl.h>      // Required for: ioctl() - UNIX System call for device-specific input/output operations
 #include <linux/kd.h>       // Linux: KDSKBMODE, K_MEDIUMRAM constants definition
@@ -2150,6 +2151,8 @@ static int FindNearestConnectorMode(const drmModeConnector *connector, uint widt
     if (NULL == connector) return -1;
 
     int nearestIndex = -1;
+    int minUnusedPixels = INT_MAX;
+    int minFpsDiff = INT_MAX;
     for (int i = 0; i < platform.connector->count_modes; i++)
     {
         const drmModeModeInfo *const mode = &platform.connector->modes[i];
@@ -2169,21 +2172,17 @@ static int FindNearestConnectorMode(const drmModeConnector *connector, uint widt
             continue;
         }
 
-        if (nearestIndex < 0)
+        const int unusedPixels = (mode->hdisplay - width) * (mode->vdisplay - height);
+        const int fpsDiff = mode->vrefresh - fps;
+
+        if ((unusedPixels < minUnusedPixels) ||
+            ((unusedPixels == minUnusedPixels) && (abs(fpsDiff) < abs(minFpsDiff))) ||
+            ((unusedPixels == minUnusedPixels) && (abs(fpsDiff) == abs(minFpsDiff)) && (fpsDiff > 0)))
         {
             nearestIndex = i;
-            continue;
+            minUnusedPixels = unusedPixels;
+            minFpsDiff = fpsDiff;
         }
-
-        const int widthDiff = abs(mode->hdisplay - width);
-        const int heightDiff = abs(mode->vdisplay - height);
-        const int fpsDiff = abs(mode->vrefresh - fps);
-
-        const int nearestWidthDiff = abs(platform.connector->modes[nearestIndex].hdisplay - width);
-        const int nearestHeightDiff = abs(platform.connector->modes[nearestIndex].vdisplay - height);
-        const int nearestFpsDiff = abs(platform.connector->modes[nearestIndex].vrefresh - fps);
-
-        if ((widthDiff < nearestWidthDiff) || (heightDiff < nearestHeightDiff) || (fpsDiff < nearestFpsDiff)) nearestIndex = i;
     }
 
     return nearestIndex;