DisplayServer: reports DPI instead of scaled resolution

CarterLi · CarterLi · commit 37b8bb4fc01d · 2026-03-13T20:44:21.000+08:00
Fixes #2224
diff --git a/src/detection/displayserver/displayserver.c b/src/detection/displayserver/displayserver.c
@@ -5,8 +5,7 @@ FFDisplayResult* ffdsAppendDisplay(
     uint32_t width,
     uint32_t height,
     double refreshRate,
-    uint32_t scaledWidth,
-    uint32_t scaledHeight,
+    uint32_t dpi,
     uint32_t preferredWidth,
     uint32_t preferredHeight,
     double preferredRefreshRate,
@@ -26,8 +25,7 @@ FFDisplayResult* ffdsAppendDisplay(
     display->width = width;
     display->height = height;
     display->refreshRate = refreshRate;
-    display->scaledWidth = scaledWidth;
-    display->scaledHeight = scaledHeight;
+    display->dpi = dpi ?: 96; // 0 means unknown
     display->preferredWidth = preferredWidth;
     display->preferredHeight = preferredHeight;
     display->preferredRefreshRate = preferredRefreshRate;
diff --git a/src/detection/displayserver/displayserver.h b/src/detection/displayserver/displayserver.h
@@ -72,8 +72,7 @@ typedef struct FFDisplayResult
     uint32_t width; // in px
     uint32_t height; // in px
     double refreshRate; // in Hz
-    uint32_t scaledWidth; // in px
-    uint32_t scaledHeight; // in px
+    uint32_t dpi; // Base 96
     uint32_t preferredWidth; // in px
     uint32_t preferredHeight; // in px
     double preferredRefreshRate; // in Hz
@@ -110,8 +109,7 @@ FFDisplayResult* ffdsAppendDisplay(
     uint32_t width,
     uint32_t height,
     double refreshRate,
-    uint32_t scaledWidth,
-    uint32_t scaledHeight,
+    uint32_t dpi,
     uint32_t preferredWidth,
     uint32_t preferredHeight,
     double preferredRefreshRate,
diff --git a/src/detection/displayserver/displayserver_android.c b/src/detection/displayserver/displayserver_android.c
@@ -85,7 +85,7 @@ static void detectWithDumpsys(FFDisplayServerResult* ds)
             FFDisplayResult* display = ffdsAppendDisplay(ds,
                 (uint32_t)width, (uint32_t)height,
                 refreshRate,
-                0, 0,
+                0,
                 0, 0,
                 0,
                 0,
@@ -117,11 +117,11 @@ static bool detectWithGetprop(FFDisplayServerResult* ds)
         ffStrbufSubstrAfterFirstC(&buffer, ',');
         uint32_t height = (uint32_t) ffStrbufToUInt(&buffer, 0);
         ffStrbufSubstrAfterFirstC(&buffer, ',');
-        double scaleFactor = (double) ffStrbufToUInt(&buffer, 0) / 160.;
+        uint32_t dpi = (uint32_t) ffStrbufToUInt(&buffer, 0) * 96 / 160;
         FFDisplayResult* display = ffdsAppendDisplay(ds,
             width, height,
             0,
-            (uint32_t) (width / scaleFactor + .5), (uint32_t) (height / scaleFactor + .5),
+            dpi,
             0, 0,
             0,
             0,
diff --git a/src/detection/displayserver/displayserver_apple.c b/src/detection/displayserver/displayserver_apple.c
@@ -116,12 +116,14 @@ static void detectDisplays(FFDisplayServerResult* ds)
                 physicalHeight = (uint32_t) (size.height + 0.5);
             }
 
+            uint32_t pixelWidth = (uint32_t) CGDisplayModeGetPixelWidth(mode);
+            uint32_t pixelHeight = (uint32_t) CGDisplayModeGetPixelHeight(mode);
+
             FFDisplayResult* display = ffdsAppendDisplay(ds,
-                (uint32_t)CGDisplayModeGetPixelWidth(mode),
-                (uint32_t)CGDisplayModeGetPixelHeight(mode),
+                pixelWidth,
+                pixelHeight,
                 refreshRate,
-                (uint32_t)CGDisplayModeGetWidth(mode),
-                (uint32_t)CGDisplayModeGetHeight(mode),
+                pixelHeight * 96 / (uint32_t)CGDisplayModeGetHeight(mode),
                 preferredWidth,
                 preferredHeight,
                 preferredRefreshRate,
diff --git a/src/detection/displayserver/displayserver_haiku.cpp b/src/detection/displayserver/displayserver_haiku.cpp
@@ -37,13 +37,11 @@ static void detectDisplays(FFDisplayServerResult* ds)
 
         uint32_t width = (uint32_t) s.Frame().Width() + 1;
         uint32_t height = (uint32_t) (uint32_t)s.Frame().Height() + 1;
-        double scaleFactor = (double) 1.0;
         FFDisplayResult* res = ffdsAppendDisplay(ds,
             width,
             height,
             (double)mode.timing.pixel_clock * 1000 / (mode.timing.v_total * mode.timing.h_total),
-            (uint32_t) (width / scaleFactor + .5),
-            (uint32_t) (height / scaleFactor + .5),
+            0,
             0,
             0,
             0,
diff --git a/src/detection/displayserver/displayserver_windows.c b/src/detection/displayserver/displayserver_windows.c
@@ -93,17 +93,6 @@ static void detectDisplays(FFDisplayServerResult* ds)
 
             uint32_t width = sourceMode->width;
             uint32_t height = sourceMode->height;
-            if (path->targetInfo.rotation == DISPLAYCONFIG_ROTATION_ROTATE90 ||
-                path->targetInfo.rotation == DISPLAYCONFIG_ROTATION_ROTATE270)
-            {
-                uint32_t temp = width;
-                width = height;
-                height = temp;
-                temp = physicalWidth;
-                physicalWidth = physicalHeight;
-                physicalHeight = temp;
-            }
-
             uint32_t rotation;
             switch (path->targetInfo.rotation)
             {
@@ -144,12 +133,19 @@ static void detectDisplays(FFDisplayServerResult* ds)
                 ReleaseDC(NULL, hdc);
             }
 
+            if (path->targetInfo.rotation == DISPLAYCONFIG_ROTATION_ROTATE90 ||
+                path->targetInfo.rotation == DISPLAYCONFIG_ROTATION_ROTATE270)
+            {
+                uint32_t temp = width;
+                width = height;
+                height = temp;
+            }
+
             FFDisplayResult* display = ffdsAppendDisplay(ds,
                 width,
                 height,
                 path->targetInfo.refreshRate.Numerator / (double) path->targetInfo.refreshRate.Denominator,
-                width * 96 / systemDpi,
-                height * 96 / systemDpi,
+                systemDpi,
                 preferredMode.width,
                 preferredMode.height,
                 preferredRefreshRate,
diff --git a/src/detection/displayserver/linux/displayserver_linux.c b/src/detection/displayserver/linux/displayserver_linux.c
@@ -79,7 +79,7 @@ void ffConnectDisplayServerImpl(FFDisplayServerResult* ds)
                 if (ffSettingsGetFreeBSDKenv("screen.height", &buf))
                 {
                     uint32_t height = (uint32_t) ffStrbufToUInt(&buf, 0);
-                    ffdsAppendDisplay(ds, width, height, 0, 0, 0, 0, 0, 0, 0, NULL, FF_DISPLAY_TYPE_UNKNOWN, false, 0, 0, 0, "kenv");
+                    ffdsAppendDisplay(ds, width, height, 0, 0, 0, 0, 0, 0, NULL, FF_DISPLAY_TYPE_UNKNOWN, false, 0, 0, 0, "kenv");
                 }
             }
         }
diff --git a/src/detection/displayserver/linux/drm.c b/src/detection/displayserver/linux/drm.c
@@ -83,7 +83,7 @@ static const char* drmParseSysfs(FFDisplayServerResult* result)
             result,
             width, height,
             refreshRate,
-            0, 0,
+            0,
             0, 0,
             0,
             0,
@@ -398,7 +398,7 @@ static const char* drmConnectLibdrm(FFDisplayServerResult* result)
                 FFDisplayResult* item = ffdsAppendDisplay(result,
                     width, height,
                     refreshRate,
-                    0, 0,
+                    0,
                     preferredWidth, preferredHeight,
                     preferredRefreshRate,
                     0,
diff --git a/src/detection/displayserver/linux/wayland/global-output.c b/src/detection/displayserver/linux/wayland/global-output.c
@@ -25,7 +25,7 @@ static void waylandOutputModeListener(void* data, FF_MAYBE_UNUSED struct wl_outp
 static void waylandOutputScaleListener(void* data, FF_MAYBE_UNUSED struct wl_output* output, int32_t scale)
 {
     WaylandDisplay* display = data;
-    display->scale = scale;
+    display->dpi = 96 * (uint32_t) scale;
 }
 
 static void waylandOutputGeometryListener(void *data,
@@ -51,7 +51,7 @@ static void handleXdgLogicalSize(void *data, FF_MAYBE_UNUSED struct zxdg_output_
     // Seems the values are only useful when ractional scale is enabled
     if (width < display->width)
     {
-        display->scale = (double) display->width / width;
+        display->dpi = (uint32_t) (display->width * 96 / width);
     }
 }
 
@@ -86,7 +86,6 @@ const char* ffWaylandHandleGlobalOutput(WaylandData* wldata, struct wl_registry*
 
     WaylandDisplay display = {
         .parent = wldata,
-        .scale = 1,
         .transform = WL_OUTPUT_TRANSFORM_NORMAL,
         .type = FF_DISPLAY_TYPE_UNKNOWN,
         .name = ffStrbufCreate(),
@@ -128,8 +127,7 @@ const char* ffWaylandHandleGlobalOutput(WaylandData* wldata, struct wl_registry*
         (uint32_t) display.width,
         (uint32_t) display.height,
         display.refreshRate / 1000.0,
-        (uint32_t) (display.width / display.scale + .5),
-        (uint32_t) (display.height / display.scale + .5),
+        display.dpi,
         (uint32_t) display.preferredWidth,
         (uint32_t) display.preferredHeight,
         display.preferredRefreshRate / 1000.0,
diff --git a/src/detection/displayserver/linux/wayland/kde-output.c b/src/detection/displayserver/linux/wayland/kde-output.c
@@ -83,7 +83,7 @@ static void waylandKdeCurrentModeListener(void* data, FF_MAYBE_UNUSED struct kde
 static void waylandKdeScaleListener(void* data, FF_MAYBE_UNUSED struct kde_output_device_v2* _, wl_fixed_t scale)
 {
     WaylandDisplay* wldata = (WaylandDisplay*) data;
-    wldata->scale = wl_fixed_to_double(scale);
+    wldata->dpi = (uint32_t) scale * 3 / 8; // wl_fixed_to_double(scale) * 96;
 }
 
 static void waylandKdeEdidListener(void* data, FF_MAYBE_UNUSED struct kde_output_device_v2* _, const char* raw)
@@ -193,7 +193,6 @@ const char* ffWaylandHandleKdeOutput(WaylandData* wldata, struct wl_registry* re
     FF_LIST_AUTO_DESTROY modes = ffListCreate(sizeof(WaylandKdeMode));
     WaylandDisplay display = {
         .parent = wldata,
-        .scale = 1,
         .transform = WL_OUTPUT_TRANSFORM_NORMAL,
         .type = FF_DISPLAY_TYPE_UNKNOWN,
         .name = ffStrbufCreate(),
@@ -224,8 +223,7 @@ const char* ffWaylandHandleKdeOutput(WaylandData* wldata, struct wl_registry* re
         (uint32_t) display.width,
         (uint32_t) display.height,
         display.refreshRate / 1000.0,
-        (uint32_t) (display.width / display.scale + .5),
-        (uint32_t) (display.height / display.scale + .5),
+        display.dpi,
         (uint32_t) display.preferredWidth,
         (uint32_t) display.preferredHeight,
         display.preferredRefreshRate / 1000.0,
diff --git a/src/detection/displayserver/linux/wayland/wayland.h b/src/detection/displayserver/linux/wayland/wayland.h
@@ -43,7 +43,7 @@ typedef struct WaylandDisplay
     int32_t preferredRefreshRate;
     int32_t physicalWidth;
     int32_t physicalHeight;
-    double scale;
+    uint32_t dpi;
     enum wl_output_transform transform;
     FFDisplayType type;
     FFstrbuf name;
diff --git a/src/detection/displayserver/linux/wayland/zwlr-output.c b/src/detection/displayserver/linux/wayland/zwlr-output.c
@@ -12,7 +12,7 @@ static void waylandZwlrTransformListener(void* data, FF_MAYBE_UNUSED struct zwlr
 static void waylandZwlrScaleListener(void* data, FF_MAYBE_UNUSED struct zwlr_output_head_v1 *zwlr_output_head_v1, wl_fixed_t scale)
 {
     WaylandDisplay* wldata = (WaylandDisplay*) data;
-    wldata->scale = wl_fixed_to_double(scale);
+    wldata->dpi = (uint32_t) scale * 3 / 8; // wl_fixed_to_double(scale) * 96;
 }
 
 typedef struct WaylandZwlrMode
@@ -125,7 +125,6 @@ static void waylandHandleZwlrHead(void *data, FF_MAYBE_UNUSED struct zwlr_output
     FF_LIST_AUTO_DESTROY modes = ffListCreate(sizeof(WaylandZwlrMode));
     WaylandDisplay display = {
         .parent = wldata,
-        .scale = 1,
         .transform = WL_OUTPUT_TRANSFORM_NORMAL,
         .type = FF_DISPLAY_TYPE_UNKNOWN,
         .name = ffStrbufCreate(),
@@ -146,8 +145,7 @@ static void waylandHandleZwlrHead(void *data, FF_MAYBE_UNUSED struct zwlr_output
         (uint32_t) display.width,
         (uint32_t) display.height,
         display.refreshRate / 1000.0,
-        (uint32_t) (display.width / display.scale + 0.5),
-        (uint32_t) (display.height / display.scale + 0.5),
+        (uint32_t) display.dpi,
         (uint32_t) display.preferredWidth,
         (uint32_t) display.preferredHeight,
         display.preferredRefreshRate / 1000.0,
diff --git a/src/detection/displayserver/linux/xcb.c b/src/detection/displayserver/linux/xcb.c
@@ -93,7 +93,7 @@ static xcb_randr_get_output_property_reply_t* xcbRandrGetProperty(XcbRandrData*
 
 static void xcbDetectWMfromEWMH(XcbRandrData* data, xcb_window_t rootWindow, FFDisplayServerResult* result)
 {
-    if(result->wmProcessName.length > 0 || ffStrbufCompS(&result->wmProtocolName, FF_WM_PROTOCOL_WAYLAND) == 0)
+    if(result->wmProcessName.length > 0 || ffStrbufEqualS(&result->wmProtocolName, FF_WM_PROTOCOL_WAYLAND))
         return;
 
     FF_AUTO_FREE xcb_window_t* wmWindow = (xcb_window_t*) xcbGetProperty(data, rootWindow, "_NET_SUPPORTING_WM_CHECK");
@@ -127,7 +127,7 @@ static void xcbFetchServerVendor(XcbRandrData* data, FFDisplayServerResult* resu
     }
 }
 
-static bool xcbRandrHandleOutput(XcbRandrData* data, xcb_randr_output_t output, FFstrbuf* name, bool primary, FFDisplayType displayType, struct xcb_randr_get_screen_resources_current_reply_t* screenResources, uint8_t bitDepth, double scaleFactor)
+static bool xcbRandrHandleOutput(XcbRandrData* data, xcb_randr_output_t output, FFstrbuf* name, bool primary, FFDisplayType displayType, struct xcb_randr_get_screen_resources_current_reply_t* screenResources, uint8_t bitDepth, uint32_t dpi)
 {
     xcb_randr_get_output_info_cookie_t outputInfoCookie = data->ffxcb_randr_get_output_info(data->connection, output, XCB_CURRENT_TIME);
     FF_AUTO_FREE xcb_randr_get_output_info_reply_t* outputInfoReply = data->ffxcb_randr_get_output_info_reply(data->connection, outputInfoCookie, NULL);
@@ -211,8 +211,7 @@ static bool xcbRandrHandleOutput(XcbRandrData* data, xcb_randr_output_t output,
         (uint32_t) (currentMode ? currentMode->width : crtcInfoReply->width),
         (uint32_t) (currentMode ? currentMode->height : crtcInfoReply->height),
         currentMode ? (double) currentMode->dot_clock / (double) ((uint32_t) currentMode->htotal * currentMode->vtotal) : 0,
-        (uint32_t) (crtcInfoReply->width / scaleFactor + .5),
-        (uint32_t) (crtcInfoReply->height / scaleFactor + .5),
+        dpi,
         preferredMode ? (uint32_t) preferredMode->width : 0,
         preferredMode ? (uint32_t) preferredMode->height : 0,
         preferredMode ? (double) preferredMode->dot_clock / (double) ((uint32_t) preferredMode->htotal * preferredMode->vtotal) : 0,
@@ -238,7 +237,7 @@ static bool xcbRandrHandleOutput(XcbRandrData* data, xcb_randr_output_t output,
     return !!item;
 }
 
-static bool xcbRandrHandleMonitor(XcbRandrData* data, xcb_randr_monitor_info_t* monitor, struct xcb_randr_get_screen_resources_current_reply_t* screenResources, uint8_t bitDepth, double scaleFactor)
+static bool xcbRandrHandleMonitor(XcbRandrData* data, xcb_randr_monitor_info_t* monitor, struct xcb_randr_get_screen_resources_current_reply_t* screenResources, uint8_t bitDepth, uint32_t dpi)
 {
     //for some reasons, we have to construct this our self
     xcb_randr_output_iterator_t outputIterator = {
@@ -262,7 +261,7 @@ static bool xcbRandrHandleMonitor(XcbRandrData* data, xcb_randr_monitor_info_t*
 
     while(outputIterator.rem > 0)
     {
-        if(xcbRandrHandleOutput(data, *outputIterator.data, &name, monitor->primary, displayType, screenResources, bitDepth, scaleFactor))
+        if(xcbRandrHandleOutput(data, *outputIterator.data, &name, monitor->primary, displayType, screenResources, bitDepth, dpi))
             foundOutput = true;
         data->ffxcb_randr_output_next(&outputIterator);
     }
@@ -274,8 +273,7 @@ static bool xcbRandrHandleMonitor(XcbRandrData* data, xcb_randr_monitor_info_t*
         (uint32_t) monitor->width,
         (uint32_t) monitor->height,
         0,
-        (uint32_t) (monitor->width / scaleFactor + .5),
-        (uint32_t) (monitor->height / scaleFactor + .5),
+        dpi,
         0, 0, 0,
         0,
         &name,
@@ -301,13 +299,13 @@ static bool xcbRandrHandleMonitors(XcbRandrData* data, xcb_screen_t* screen)
     xcb_randr_get_screen_resources_current_cookie_t screenResourcesCookie = data->ffxcb_randr_get_screen_resources_current(data->connection, screen->root);
     FF_AUTO_FREE struct xcb_randr_get_screen_resources_current_reply_t* screenResources = data->ffxcb_randr_get_screen_resources_current_reply(data->connection, screenResourcesCookie, NULL);
 
-    double scaleFactor = 1;
+    uint32_t dpi = 0;
     FF_AUTO_FREE const char* resourceManager = xcbGetProperty(data, screen->root, "RESOURCE_MANAGER");
     if (resourceManager)
     {
-        FF_STRBUF_AUTO_DESTROY dpi = ffStrbufCreate();
-        if (ffParsePropLines(resourceManager, "Xft.dpi:", &dpi))
-            scaleFactor = ffStrbufToDouble(&dpi, 96) / 96;
+        FF_STRBUF_AUTO_DESTROY dpiStr = ffStrbufCreate();
+        if (ffParsePropLines(resourceManager, "Xft.dpi:", &dpiStr))
+            dpi = (uint32_t) ffStrbufToUInt(&dpiStr, 96);
     }
     uint8_t bitDepth = (uint8_t) (screen->root_depth / 3);
 
@@ -317,7 +315,7 @@ static bool xcbRandrHandleMonitors(XcbRandrData* data, xcb_screen_t* screen)
 
     while(monitorInfoIterator.rem > 0)
     {
-        if(xcbRandrHandleMonitor(data, monitorInfoIterator.data, screenResources, bitDepth, scaleFactor))
+        if(xcbRandrHandleMonitor(data, monitorInfoIterator.data, screenResources, bitDepth, dpi))
             foundMonitor = true;
         data->ffxcb_randr_monitor_info_next(&monitorInfoIterator);
     }
@@ -337,8 +335,7 @@ static void xcbRandrHandleScreen(XcbRandrData* data, xcb_screen_t* screen)
         (uint32_t) screen->width_in_pixels,
         (uint32_t) screen->height_in_pixels,
         0,
-        (uint32_t) screen->width_in_pixels,
-        (uint32_t) screen->height_in_pixels,
+        0,
         0, 0, 0,
         0,
         NULL,
diff --git a/src/detection/displayserver/linux/xlib.c b/src/detection/displayserver/linux/xlib.c
diff --git a/src/modules/display/display.c b/src/modules/display/display.c

Original file line number	Diff line number	Diff line change
`@@ -79,7 +79,7 @@ void ffConnectDisplayServerImpl(FFDisplayServerResult* ds)`
`79`	`79`	`if (ffSettingsGetFreeBSDKenv("screen.height", &buf))`
`80`	`80`	`{`
`81`	`81`	`uint32_t height = (uint32_t) ffStrbufToUInt(&buf, 0);`
`82`		`- ffdsAppendDisplay(ds, width, height, 0, 0, 0, 0, 0, 0, 0, NULL, FF_DISPLAY_TYPE_UNKNOWN, false, 0, 0, 0, "kenv");`
	`82`	`+ ffdsAppendDisplay(ds, width, height, 0, 0, 0, 0, 0, 0, NULL, FF_DISPLAY_TYPE_UNKNOWN, false, 0, 0, 0, "kenv");`
`83`	`83`	`}`
`84`	`84`	`}`
`85`	`85`	`}`