[PATCH 0/1] MR3545: gdiplus: reduce number of calculations for matrix rotation

[Bartosz Kosiorek (＠gang65)]

Instead of making many multiplication, we could directly assign exact values of rotated matrix.

[PATCH 1/1] gdiplus: reduce number of calculations for matrix rotation

[Bartosz Kosiorek]

From: Bartosz Kosiorek

---
 dlls/gdiplus/graphics.c | 32 ++++++++++++++++++++++++--------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/dlls/gdiplus/graphics.c b/dlls/gdiplus/graphics.c
index e3b5661fd67..260ae3719b1 100644
--- a/dlls/gdiplus/graphics.c
+++ b/dlls/gdiplus/graphics.c
@@ -1617,6 +1617,26 @@ static GpStatus brush_fill_pixels(GpGraphics *graphics, GpBrush *brush,
     }
 }

+/* Creates rotated and translated identity matrix.
+ * Equvalent (but much faster) of the:
+ *    GdipSetMatrixElements(&matrix, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0);
+ *    GdipRotateMatrix(&matrix, angle, MatrixOrderAppend);
+ *    GdipTranslateMatrix(&matrix, dx, dy, MatrixOrderAppend); */
+inline void create_rotated_translated_identity_matrix(GpMatrix *matrix, REAL angle, REAL dx, REAL dy)
+{
+    REAL cos_theta, sin_theta;
+
+    cos_theta = cos(angle);
+    sin_theta = sin(angle);
+
+    matrix->matrix[0] = cos_theta;
+    matrix->matrix[1] = sin_theta;
+    matrix->matrix[2] = -sin_theta;
+    matrix->matrix[3] = cos_theta;
+    matrix->matrix[4] = dx;
+    matrix->matrix[5] = dy;
+}
+
 /* Draws the linecap the specified color and size on the hdc.  The linecap is in
  * direction of the line from x1, y1 to x2, y2 and is anchored on x2, y2. Probably
  * should not be called on an hdc that has a path you care about. */
@@ -1795,12 +1815,8 @@ static void draw_cap(GpGraphics *graphics, COLORREF color, GpLineCap cap, REAL s
                 goto custend;

memcpy(custptf, custom->pathdata.Points, count * sizeof(PointF));
-
-            GdipSetMatrixElements(&matrix, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0);
+            create_rotated_translated_identity_matrix(&matrix, (theta - M_PI_2), x2, y2);
             GdipScaleMatrix(&matrix, size, size, MatrixOrderAppend);
-            GdipRotateMatrix(&matrix, (180.0 / M_PI) * (theta - M_PI_2),
-                             MatrixOrderAppend);
-            GdipTranslateMatrix(&matrix, x2, y2, MatrixOrderAppend);
             GdipTransformMatrixPoints(&matrix, custptf, count);

gdip_transform_points(graphics, WineCoordinateSpaceGdiDevice, CoordinateSpaceWorld, custptf, count);
@@ -7226,9 +7242,9 @@ static GpStatus GDI32_GdipDrawDriverString(GpGraphics *graphics, GDIPCONST UINT1
         memcpy(real_positions, positions, sizeof(PointF) * length);

gdip_transform_points(graphics, WineCoordinateSpaceGdiDevice, CoordinateSpaceWorld, real_positions, length);
-
-        GdipSetMatrixElements(&rotation, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0);
-        GdipRotateMatrix(&rotation, lfw.lfEscapement / 10.0, MatrixOrderAppend);
+        create_rotated_translated_identity_matrix(&rotation,
+                                                  (0.1 * lfw.lfEscapement) * M_PI / 180.0,
+                                                  0.0, 0.0);
         GdipTransformMatrixPoints(&rotation, real_positions, length);

for (i = 0; i < (length - 1); i++)

[PATCH 0/1] MR3545: gdiplus: reduce number of calculations for matrix rotation - closed

[Bartosz Kosiorek (＠gang65)]

This merge request was closed by Bartosz Kosiorek.