From 29435411cbf4e747f86d2b4280a75cdf7c80c4b1 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Fri, 16 Mar 2007 00:23:07 +0000
Subject: [PATCH] call GetWidth/Height() only once in Rotate() and not inside
 the loops (patch 1681544) [backport from HEAD]

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@44840 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 src/common/image.cpp | 44 ++++++++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/src/common/image.cpp b/src/common/image.cpp
index 3aae548ccc..6cb0dd0ad2 100644
--- a/src/common/image.cpp
+++ b/src/common/image.cpp
@@ -2811,20 +2811,23 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
 
     bool has_alpha = HasAlpha();
 
+    const int w = GetWidth(),
+              h = GetHeight();
+
     // Create pointer-based array to accelerate access to wxImage's data
-    unsigned char ** data = new unsigned char * [GetHeight()];
+    unsigned char ** data = new unsigned char * [h];
     data[0] = GetData();
-    for (i = 1; i < GetHeight(); i++)
-        data[i] = data[i - 1] + (3 * GetWidth());
+    for (i = 1; i < h; i++)
+        data[i] = data[i - 1] + (3 * w);
 
     // Same for alpha channel
     unsigned char ** alpha = NULL;
     if (has_alpha)
     {
-        alpha = new unsigned char * [GetHeight()];
+        alpha = new unsigned char * [h];
         alpha[0] = GetAlpha();
-        for (i = 1; i < GetHeight(); i++)
-            alpha[i] = alpha[i - 1] + GetWidth();
+        for (i = 1; i < h; i++)
+            alpha[i] = alpha[i - 1] + w;
     }
 
     // precompute coefficients for rotation formula
@@ -2839,9 +2842,9 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
     const wxRealPoint p0(centre_of_rotation.x, centre_of_rotation.y);
 
     wxRealPoint p1 = wxRotatePoint (0, 0, cos_angle, sin_angle, p0);
-    wxRealPoint p2 = wxRotatePoint (0, GetHeight(), cos_angle, sin_angle, p0);
-    wxRealPoint p3 = wxRotatePoint (GetWidth(), 0, cos_angle, sin_angle, p0);
-    wxRealPoint p4 = wxRotatePoint (GetWidth(), GetHeight(), cos_angle, sin_angle, p0);
+    wxRealPoint p2 = wxRotatePoint (0, h, cos_angle, sin_angle, p0);
+    wxRealPoint p3 = wxRotatePoint (w, 0, cos_angle, sin_angle, p0);
+    wxRealPoint p4 = wxRotatePoint (w, h, cos_angle, sin_angle, p0);
 
     int x1a = (int) floor (wxMin (wxMin(p1.x, p2.x), wxMin(p3.x, p4.x)));
     int y1a = (int) floor (wxMin (wxMin(p1.y, p2.y), wxMin(p3.y, p4.y)));
@@ -2888,27 +2891,29 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
     // performing an inverse rotation (a rotation of -angle) and getting the
     // pixel at those coordinates
 
+    const int rH = rotated.GetHeight();
+    const int rW = rotated.GetWidth();
+
     // GRG: I've taken the (interpolating) test out of the loops, so that
     //      it is done only once, instead of repeating it for each pixel.
 
-    int x;
     if (interpolating)
     {
-        for (int y = 0; y < rotated.GetHeight(); y++)
+        for (int y = 0; y < rH; y++)
         {
-            for (x = 0; x < rotated.GetWidth(); x++)
+            for (int x = 0; x < rW; x++)
             {
                 wxRealPoint src = wxRotatePoint (x + x1a, y + y1a, cos_angle, -sin_angle, p0);
 
-                if (-0.25 < src.x && src.x < GetWidth() - 0.75 &&
-                    -0.25 < src.y && src.y < GetHeight() - 0.75)
+                if (-0.25 < src.x && src.x < w - 0.75 &&
+                    -0.25 < src.y && src.y < h - 0.75)
                 {
                     // interpolate using the 4 enclosing grid-points.  Those
                     // points can be obtained using floor and ceiling of the
                     // exact coordinates of the point
                     int x1, y1, x2, y2;
 
-                    if (0 < src.x && src.x < GetWidth() - 1)
+                    if (0 < src.x && src.x < w - 1)
                     {
                         x1 = wxRound(floor(src.x));
                         x2 = wxRound(ceil(src.x));
@@ -2918,7 +2923,7 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
                         x1 = x2 = wxRound (src.x);
                     }
 
-                    if (0 < src.y && src.y < GetHeight() - 1)
+                    if (0 < src.y && src.y < h - 1)
                     {
                         y1 = wxRound(floor(src.y));
                         y2 = wxRound(ceil(src.y));
@@ -3041,17 +3046,16 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
     }
     else    // not interpolating
     {
-        for (int y = 0; y < rotated.GetHeight(); y++)
+        for (int y = 0; y < rH; y++)
         {
-            for (x = 0; x < rotated.GetWidth(); x++)
+            for (int x = 0; x < rW; x++)
             {
                 wxRealPoint src = wxRotatePoint (x + x1a, y + y1a, cos_angle, -sin_angle, p0);
 
                 const int xs = wxRound (src.x);      // wxRound rounds to the
                 const int ys = wxRound (src.y);      // closest integer
 
-                if (0 <= xs && xs < GetWidth() &&
-                    0 <= ys && ys < GetHeight())
+                if (0 <= xs && xs < w && 0 <= ys && ys < h)
                 {
                     unsigned char *p = data[ys] + (3 * xs);
                     *(dst++) = *(p++);