[PATCH 0/1] MR4393: gdiplus: Boost performance of GdipDrawImagePointsRect.

[Bartosz Kosiorek (＠gang65)]

By not using floorf from external library ucrtbase.dll
the performance of GdipDrawImagePointsRect was improved.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53947

[PATCH 1/1] gdiplus: Boost performance of GdipDrawImagePointsRect.

[Bartosz Kosiorek]

From: Bartosz Kosiorek

By not using floorf from external library ucrtbase.dll
the performance of GdipDrawImagePointsRect was improved.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53947
---
 dlls/gdiplus/graphics.c | 38 +++++++++++++++++++++++++++-----------
 1 file changed, 27 insertions(+), 11 deletions(-)

diff --git a/dlls/gdiplus/graphics.c b/dlls/gdiplus/graphics.c
index 371629a5bef..b75a46c57eb 100644
--- a/dlls/gdiplus/graphics.c
+++ b/dlls/gdiplus/graphics.c
@@ -1055,22 +1055,38 @@ static ARGB resample_bitmap_pixel(GDIPCONST GpRect *src_rect, LPBYTE bits, UINT
     }
     case InterpolationModeNearestNeighbor:
     {
-        FLOAT pixel_offset;
+        /* Using floorf from ucrtbase.dll is extremaly slow compared to own implementation (casting to INT) */
+        INT pixel_with_offset_x, pixel_with_offset_y;
         switch (offset_mode)
         {
-        default:
-        case PixelOffsetModeNone:
-        case PixelOffsetModeHighSpeed:
-            pixel_offset = 0.5;
-            break;
+            default:
+            case PixelOffsetModeNone:
+            case PixelOffsetModeHighSpeed:
+                if (point->X >= 0.0f)
+                    pixel_with_offset_x = (INT)(point->X + 0.5f);
+                else
+                    pixel_with_offset_x = (INT)(point->X - 0.5f);

-        case PixelOffsetModeHalf:
-        case PixelOffsetModeHighQuality:
-            pixel_offset = 0.0;
-            break;
+                if (point->Y >= 0.0f)
+                    pixel_with_offset_y = (INT)(point->Y + 0.5f);
+                else
+                    pixel_with_offset_y = (INT)(point->Y - 0.5f);
+                break;
+            case PixelOffsetModeHalf:
+            case PixelOffsetModeHighQuality:
+                if (point->X >= 0.0f)
+                    pixel_with_offset_x = (INT)(point->X);
+                else
+                    pixel_with_offset_x = (INT)(point->X - 1.0f);
+
+                if (point->Y >= 0.0f)
+                    pixel_with_offset_y = (INT)(point->Y);
+                else
+                    pixel_with_offset_y = (INT)(point->Y - 1.0f);
+                break;
         }
         return sample_bitmap_pixel(src_rect, bits, width, height,
-            floorf(point->X + pixel_offset), floorf(point->Y + pixel_offset), attributes);
+            pixel_with_offset_x, pixel_with_offset_y, attributes);
     }

}

[Fabian Maurer (＠DarkShadow44)]

It looks like floor does a lot more, for example handling all the corner cases. Are you sure this isn't a problem here?

FWIW, just having the function inlined already helps a lot.

Btw, is there a reason you changed the switch/case identation? IMHO it makes reading the patch harder.

[Nikolay Sivov (＠nsivov)]

I think a bigger question is why we need float coordinates here to begin with.