Stop mapping all Unicode through CJK fonts and cut D2D working-set growth

Custom font fallback no longer covers the whole BMP/SIP, so Segoe UI Emoji
can paint color glyphs again; CJK still prefers Noto Sans SC then YaHei.
Drop GaussianBlur compatible targets during BeginDraw (they retained GPU
memory as the candidate window grew), grow the composition swapchain in
64px steps without shrinking, and reuse Card chrome plus cached text
formats instead of reallocating them every layout.

ui/src/DeviceResources.cpp

@@ -7,6 +7,16 @@
 
 namespace msimeui
 {
+namespace
+{
+UINT AlignSwapExtent(UINT value)
+{
+    constexpr UINT kBucket = 64;
+    value = (std::max)(value, 1U);
+    return ((value + kBucket - 1U) / kBucket) * kBucket;
+}
+} // namespace
+
 bool DeviceResources::IsSameColor(const D2D1_COLOR_F &lhs, const D2D1_COLOR_F &rhs)
 {
     return lhs.r == rhs.r && lhs.g == rhs.g && lhs.b == rhs.b && lhs.a == rhs.a;
@@ -128,10 +138,10 @@ bool DeviceResources::EnsureForComposition(HWND hwnd)
 
     RECT rc = {};
     GetClientRect(hwnd, &rc);
-    const UINT width = static_cast<UINT>((std::max)(rc.right, 1L));
-    const UINT height = static_cast<UINT>((std::max)(rc.bottom, 1L));
+    const UINT width = AlignSwapExtent(static_cast<UINT>((std::max)(rc.right, 1L)));
+    const UINT height = AlignSwapExtent(static_cast<UINT>((std::max)(rc.bottom, 1L)));
 
-    if (composition_ && deviceContext_ && swapChain_ && pixelWidth_ == width && pixelHeight_ == height)
+    if (composition_ && deviceContext_ && swapChain_ && pixelWidth_ >= width && pixelHeight_ >= height)
     {
         return true;
     }
@@ -210,11 +220,13 @@ bool DeviceResources::EnsureForComposition(HWND hwnd)
         return true;
     }
 
-    pixelWidth_ = width;
-    pixelHeight_ = height;
+    const UINT newWidth = (std::max)(pixelWidth_, width);
+    const UINT newHeight = (std::max)(pixelHeight_, height);
+    pixelWidth_ = newWidth;
+    pixelHeight_ = newHeight;
     deviceContext_->SetTarget(nullptr);
     dxgiBitmap_.Reset();
-    if (FAILED(swapChain_->ResizeBuffers(0, width, height, DXGI_FORMAT_B8G8R8A8_UNORM, 0)))
+    if (FAILED(swapChain_->ResizeBuffers(0, newWidth, newHeight, DXGI_FORMAT_B8G8R8A8_UNORM, 0)))
     {
         return false;
     }
@@ -232,13 +244,19 @@ void DeviceResources::Resize(UINT width, UINT height)
         pixelHeight_ = height;
         return;
     }
-    if (composition_ && swapChain_ && deviceContext_ && (pixelWidth_ != width || pixelHeight_ != height))
+    if (composition_ && swapChain_ && deviceContext_)
     {
-        pixelWidth_ = width;
-        pixelHeight_ = height;
+        const UINT neededW = AlignSwapExtent(width);
+        const UINT neededH = AlignSwapExtent(height);
+        if (pixelWidth_ >= neededW && pixelHeight_ >= neededH)
+        {
+            return;
+        }
+        pixelWidth_ = (std::max)(pixelWidth_, neededW);
+        pixelHeight_ = (std::max)(pixelHeight_, neededH);
         deviceContext_->SetTarget(nullptr);
         dxgiBitmap_.Reset();
-        if (SUCCEEDED(swapChain_->ResizeBuffers(0, width, height, DXGI_FORMAT_B8G8R8A8_UNORM, 0)))
+        if (SUCCEEDED(swapChain_->ResizeBuffers(0, pixelWidth_, pixelHeight_, DXGI_FORMAT_B8G8R8A8_UNORM, 0)))
         {
             BindCompositionSurface();
         }