surface/wayland: conform to small surface requirements

do not stretch small surfaces, instead center them if they fit.

src/Window.cpp

@@ -424,6 +424,7 @@ void CWindow::onUnmap() {
 void CWindow::onMap() {
 
     m_pWLSurface.assign(g_pXWaylandManager->getWindowSurface(this));
+    m_pWLSurface.m_pOwner = this;
 
     // JIC, reset the callbacks. If any are set, we'll make sure they are cleared so we don't accidentally unset them. (In case a window got remapped)
     m_vRealPosition.resetAllCallbacks();
@@ -453,6 +454,8 @@ void CWindow::onMap() {
 
     hyprListener_unmapWindow.initCallback(m_bIsX11 ? &m_uSurface.xwayland->surface->events.unmap : &m_uSurface.xdg->surface->events.unmap, &Events::listener_unmapWindow, this,
                                           "CWindow");
+
+    m_vReportedSize = m_vPendingReportedSize;
 }
 
 void CWindow::onBorderAngleAnimEnd(void* ptr) {
@@ -882,6 +885,9 @@ bool CWindow::opaque() {
 
     const auto PWORKSPACE = g_pCompositor->getWorkspaceByID(m_iWorkspaceID);
 
+    if (m_pWLSurface.small() && !m_pWLSurface.m_bFillIgnoreSmall)
+        return false;
+
     if (PWORKSPACE->m_fAlpha.fl() != 1.f)
         return false;
 

src/Window.hpp

@@ -203,6 +203,7 @@ class CWindow {
     // for not spamming the protocols
     Vector2D m_vReportedPosition;
     Vector2D m_vReportedSize;
+    Vector2D m_vPendingReportedSize;
 
     // for restoring floating statuses
     Vector2D m_vLastFloatingSize;

src/events/Windows.cpp

@@ -789,6 +789,8 @@ void Events::listener_commitWindow(void* owner, void* data) {
     if (!PWINDOW->m_bMappedX11 || PWINDOW->isHidden() || (PWINDOW->m_bIsX11 && !PWINDOW->m_bMappedX11))
         return;
 
+    PWINDOW->m_vReportedSize = PWINDOW->m_vPendingReportedSize; // apply pending size. We pinged, the window ponged.
+
     PWINDOW->updateSurfaceOutputs();
 
     g_pHyprRenderer->damageSurface(PWINDOW->m_pWLSurface.wlr(), PWINDOW->m_vRealPosition.goalv().x, PWINDOW->m_vRealPosition.goalv().y,

src/helpers/WLSurface.cpp

@@ -27,12 +27,29 @@ wlr_surface* CWLSurface::wlr() const {
     return m_pWLRSurface;
 }
 
+bool CWLSurface::small() const {
+    if (!m_pOwner || !exists())
+        return false;
+
+    return m_pOwner->m_vReportedSize.x > m_pWLRSurface->current.buffer_width || m_pOwner->m_vReportedSize.y > m_pWLRSurface->current.buffer_height;
+}
+
+Vector2D CWLSurface::correctSmallVec() const {
+    if (!m_pOwner || !exists() || !small() || m_bFillIgnoreSmall)
+        return {};
+
+    return Vector2D{(m_pOwner->m_vReportedSize.x - m_pWLRSurface->current.buffer_width) / 2, (m_pOwner->m_vReportedSize.y - m_pWLRSurface->current.buffer_height) / 2}.clamp(
+               {}, {INFINITY, INFINITY}) *
+        (m_pOwner->m_vRealSize.vec() / m_pOwner->m_vReportedSize);
+}
+
 void CWLSurface::destroy() {
     if (!m_pWLRSurface)
         return;
 
     hyprListener_destroy.removeCallback();
     m_pWLRSurface->data = nullptr;
+    m_pOwner            = nullptr;
 
     if (g_pCompositor->m_pLastFocus == m_pWLRSurface)
         g_pCompositor->m_pLastFocus = nullptr;

src/helpers/WLSurface.hpp

@@ -1,6 +1,9 @@
 #pragma once
 
 #include "../defines.hpp"
+
+class CWindow;
+
 class CWLSurface {
   public:
     CWLSurface() = default;
@@ -17,6 +20,14 @@ class CWLSurface {
 
     wlr_surface* wlr() const;
     bool         exists() const;
+    bool         small() const;           // means surface is smaller than the requested size
+    Vector2D     correctSmallVec() const; // returns a corrective vector for small() surfaces
+
+    // allow stretching. Useful for plugins.
+    bool m_bFillIgnoreSmall = false;
+
+    // if present, means this is a base surface of a window. Cleaned on unassign()
+    CWindow*    m_pOwner = nullptr;
 
     CWLSurface& operator=(wlr_surface* pSurface) {
         destroy();
@@ -38,6 +49,10 @@ class CWLSurface {
         return exists();
     }
 
+    static CWLSurface* surfaceFromWlr(wlr_surface* pSurface) {
+        return (CWLSurface*)pSurface->data;
+    }
+
   private:
     wlr_surface* m_pWLRSurface = nullptr;
 

src/managers/XWaylandManager.cpp

@@ -164,7 +164,7 @@ void CHyprXWaylandManager::setWindowSize(CWindow* pWindow, Vector2D size, bool f
         return;
 
     pWindow->m_vReportedPosition    = windowPos;
-    pWindow->m_vReportedSize     = size;
+    pWindow->m_vPendingReportedSize = size;
 
     pWindow->m_fX11SurfaceScaledBy = 1.f;
 

src/render/Renderer.cpp

@@ -23,9 +23,23 @@ void renderSurface(struct wlr_surface* surface, int x, int y, void* data) {
     wlr_output_layout_output_coords(g_pCompositor->m_sWLROutputLayout, RDATA->pMonitor->output, &outputX, &outputY);
 
     wlr_box windowBox;
-    if (RDATA->surface && surface == RDATA->surface)
+    if (RDATA->surface && surface == RDATA->surface) {
         windowBox = {(int)outputX + RDATA->x + x, (int)outputY + RDATA->y + y, RDATA->w, RDATA->h};
-    else { //  here we clamp to 2, these might be some tiny specks
+
+        // however, if surface buffer w / h < box, we need to adjust them
+        auto* const PSURFACE = CWLSurface::surfaceFromWlr(surface);
+
+        if (PSURFACE && !PSURFACE->m_bFillIgnoreSmall && PSURFACE->small() /* guarantees m_pOwner */) {
+            const auto CORRECT = PSURFACE->correctSmallVec();
+
+            windowBox.x += CORRECT.x;
+            windowBox.y += CORRECT.y;
+
+            windowBox.width  = (double)surface->current.buffer_width * (PSURFACE->m_pOwner->m_vRealSize.vec().x / PSURFACE->m_pOwner->m_vReportedSize.x);
+            windowBox.height = (double)surface->current.buffer_height * (PSURFACE->m_pOwner->m_vRealSize.vec().y / PSURFACE->m_pOwner->m_vReportedSize.y);
+        }
+
+    } else { //  here we clamp to 2, these might be some tiny specks
         windowBox = {(int)outputX + RDATA->x + x, (int)outputY + RDATA->y + y, std::max(surface->current.width, 2), std::max(surface->current.height, 2)};
         if (RDATA->pWindow && RDATA->pWindow->m_vRealSize.isBeingAnimated() && RDATA->surface && RDATA->surface != surface && RDATA->squishOversized /* subsurface */) {
             // adjust subsurfaces to the window
@@ -1392,6 +1406,13 @@ void CHyprRenderer::damageSurface(wlr_surface* pSurface, double x, double y, dou
     if (g_pCompositor->m_bUnsafeState)
         return;
 
+    auto* const PSURFACE = CWLSurface::surfaceFromWlr(pSurface);
+    if (PSURFACE && PSURFACE->m_pOwner && PSURFACE->small()) {
+        const auto CORRECTION = PSURFACE->correctSmallVec();
+        x += CORRECTION.x;
+        y += CORRECTION.y;
+    }
+
     CRegion damageBox;
     wlr_surface_get_effective_damage(pSurface, damageBox.pixman());
     if (scale != 1.0)