Bartosz Kosiorek : gdiplus: Use iterator instead calculate pointer position every time.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 9705fbd493c502a4ca32113ebeacaaf7d729f36a
URL:    https://gitlab.winehq.org/wine/wine/-/commit/9705fbd493c502a4ca32113ebeacaaf...

Author: Bartosz Kosiorek 
Date:   Sun May 21 20:35:28 2023 +0200

gdiplus: Use iterator instead calculate pointer position every time.

With previous implementation, every iteration pointer value was
calculated by taking row and column of the image.
It needs multiply calculation. With current implementation,
pointer value calculation, is replaced with iterator, which takes
next pixel data.

It improves efficiency by using addition instead of multiplication
for iterating through points data.

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

---

dlls/gdiplus/graphics.c | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/dlls/gdiplus/graphics.c b/dlls/gdiplus/graphics.c
index 11dc06e6c9e..04ac89ec128 100644
--- a/dlls/gdiplus/graphics.c
+++ b/dlls/gdiplus/graphics.c
@@ -3236,6 +3236,7 @@ GpStatus WINGDIPAPI GdipDrawImagePointsRect(GpGraphics *graphics, GpImage *image
                 REAL m11, m12, m21, m22, mdx, mdy;
                 GpPointF dst_to_src_points[3] = {{0.0, 0.0}, {1.0, 0.0}, {0.0, 1.0}};
                 REAL x_dx, x_dy, y_dx, y_dy;
+                ARGB *dst_color;

m11 = (ptf[1].X - ptf[0].X) / srcwidth;
                 m21 = (ptf[2].X - ptf[0].X) / srcheight;
@@ -3249,14 +3250,6 @@ GpStatus WINGDIPAPI GdipDrawImagePointsRect(GpGraphics *graphics, GpImage *image
                 stat = GdipInvertMatrix(&dst_to_src);
                 if (stat != Ok) return stat;

-                /* Transform the bits as needed to the destination. */
-                dst_data = dst_dyn_data = heap_alloc_zero(sizeof(ARGB) * (dst_area.right - dst_area.left) * (dst_area.bottom - dst_area.top));
-                if (!dst_data)
-                {
-                    heap_free(src_data);
-                    return OutOfMemory;
-                }
-
                 dst_stride = sizeof(ARGB) * (dst_area.right - dst_area.left);

GdipTransformMatrixPoints(&dst_to_src, dst_to_src_points, 3);
@@ -3266,23 +3259,28 @@ GpStatus WINGDIPAPI GdipDrawImagePointsRect(GpGraphics *graphics, GpImage *image
                 y_dx = dst_to_src_points[2].X - dst_to_src_points[0].X;
                 y_dy = dst_to_src_points[2].Y - dst_to_src_points[0].Y;

-                for (x=dst_area.left; x<dst_area.right; x++)
+                /* Transform the bits as needed to the destination. */
+                dst_data = dst_dyn_data = heap_alloc_zero(sizeof(ARGB) * (dst_area.right - dst_area.left) * (dst_area.bottom - dst_area.top));
+                if (!dst_data)
                 {
-                    for (y=dst_area.top; y<dst_area.bottom; y++)
+                    heap_free(src_data);
+                    return OutOfMemory;
+                }
+
+                dst_color = (ARGB*)(dst_data);
+                for (y = dst_area.top; y < dst_area.bottom; y++)
+                {
+                    for (x = dst_area.left; x < dst_area.right; x++)
                     {
                         GpPointF src_pointf;
-                        ARGB *dst_color;
-
                         src_pointf.X = dst_to_src_points[0].X + x * x_dx + y * y_dx;
                         src_pointf.Y = dst_to_src_points[0].Y + x * x_dy + y * y_dy;

-                        dst_color = (ARGB*)(dst_data + dst_stride * (y - dst_area.top) + sizeof(ARGB) * (x - dst_area.left));
-
-                        if (src_pointf.X >= srcx && src_pointf.X < srcx + srcwidth && src_pointf.Y >= srcy && src_pointf.Y < srcy+srcheight)
+                        if (src_pointf.X >= srcx && src_pointf.X < srcx + srcwidth &&
+                            src_pointf.Y >= srcy && src_pointf.Y < srcy + srcheight)
                             *dst_color = resample_bitmap_pixel(&src_area, src_data, bitmap->width, bitmap->height, &src_pointf,
                                                                imageAttributes, interpolation, offset_mode);
-                        else
-                            *dst_color = 0;
+                        dst_color++;
                     }
                 }
             }