d2d1: Derive shared bitmap format from the source bitmap.

dlls/d2d1/bitmap.c

@@ -544,15 +544,23 @@ HRESULT d2d_bitmap_create_shared(struct d2d_device_context *context, REFIID iid,
             goto failed;
         }
 
-        if (!desc)
+        if (desc)
+        {
+            d = *desc;
+            if (d.pixelFormat.format == DXGI_FORMAT_UNKNOWN)
+                d.pixelFormat.format = src_impl->format.format;
+            if (d.pixelFormat.alphaMode == D2D1_ALPHA_MODE_UNKNOWN)
+                d.pixelFormat.alphaMode = src_impl->format.alphaMode;
+        }
+        else
         {
             d.pixelFormat = src_impl->format;
             d.dpiX = src_impl->dpi_x;
             d.dpiY = src_impl->dpi_y;
             d.bitmapOptions = src_impl->options;
             d.colorContext = NULL;
-            desc = &d;
         }
+        desc = &d;
 
         if (!format_supported(&desc->pixelFormat))
         {

dlls/d2d1/tests/d2d1.c

@@ -5254,6 +5254,68 @@ static void test_shared_bitmap(BOOL d3d11)
         }
     }
 
+    ID2D1Bitmap_Release(bitmap1);
+
+    /* Create from another bitmap, with a different description. */
+    set_size_u(&size, 4, 4);
+    bitmap_desc.pixelFormat.format = DXGI_FORMAT_B8G8R8A8_UNORM;
+    bitmap_desc.pixelFormat.alphaMode = D2D1_ALPHA_MODE_PREMULTIPLIED;
+    bitmap_desc.dpiX = 96.0f;
+    bitmap_desc.dpiY = 96.0f;
+    hr = ID2D1RenderTarget_CreateBitmap(rt2, size, NULL, 0, &bitmap_desc, &bitmap1);
+    ok(hr == S_OK, "Got unexpected hr %#lx.\n", hr);
+
+    if (SUCCEEDED(hr))
+    {
+        static const struct bitmap_format_test
+        {
+            D2D1_PIXEL_FORMAT original;
+            D2D1_PIXEL_FORMAT result;
+            HRESULT hr;
+        }
+        bitmap_format_tests[] =
+        {
+            { { DXGI_FORMAT_UNKNOWN, D2D1_ALPHA_MODE_PREMULTIPLIED },
+              { DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_PREMULTIPLIED } },
+
+            { { DXGI_FORMAT_UNKNOWN, D2D1_ALPHA_MODE_IGNORE },
+              { DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_IGNORE } },
+
+            { { DXGI_FORMAT_UNKNOWN, D2D1_ALPHA_MODE_UNKNOWN },
+              { DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_PREMULTIPLIED } },
+
+            { { DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_UNKNOWN },
+              { DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_PREMULTIPLIED } },
+
+            { { DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_IGNORE },
+              { DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_IGNORE } },
+
+            { { DXGI_FORMAT_UNKNOWN, D2D1_ALPHA_MODE_STRAIGHT }, { 0 }, D2DERR_UNSUPPORTED_PIXEL_FORMAT },
+            { { DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_STRAIGHT }, { 0 }, D2DERR_UNSUPPORTED_PIXEL_FORMAT },
+        };
+        unsigned int i;
+
+        for (i = 0; i < ARRAY_SIZE(bitmap_format_tests); ++i)
+        {
+            bitmap_desc.pixelFormat = bitmap_format_tests[i].original;
+
+            hr = ID2D1RenderTarget_CreateSharedBitmap(rt2, &IID_ID2D1Bitmap, bitmap1, &bitmap_desc, &bitmap2);
+            ok(hr == bitmap_format_tests[i].hr, "%u: Got unexpected hr %#lx.\n", i, hr);
+
+            if (SUCCEEDED(hr) && hr == bitmap_format_tests[i].hr)
+            {
+                pixel_format = ID2D1Bitmap_GetPixelFormat(bitmap2);
+                ok(pixel_format.format == bitmap_format_tests[i].result.format, "%u: unexpected pixel format %#x.\n",
+                        i, pixel_format.format);
+                ok(pixel_format.alphaMode == bitmap_format_tests[i].result.alphaMode, "%u: unexpected alpha mode %d.\n",
+                        i, pixel_format.alphaMode);
+            }
+
+            if (SUCCEEDED(hr))
+                ID2D1Bitmap_Release(bitmap2);
+        }
+    }
+
     ID2D1RenderTarget_Release(rt2);
 
     ID2D1Bitmap_Release(bitmap1);