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call GetWidth/Height() only once in Rotate() and not inside the loops (patch 1681544); some minor code cleanup

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git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44839 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Vadim Zeitlin
2007-03-16 00:19:16 +00:00
parent f2ccaa2279
commit e26d5213ec
1 changed files with 42 additions and 42 deletions
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84
src/common/image.cpp
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@@ -2804,31 +2804,38 @@ wxRotatePoint(double x, double y, double cos_angle, double sin_angle,
return wxRotatePoint (wxRealPoint(x,y), cos_angle, sin_angle, p0);
}
wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool interpolating, wxPoint * offset_after_rotation) const
wxImage wxImage::Rotate(double angle,
const wxPoint& centre_of_rotation,
bool interpolating,
wxPoint *offset_after_rotation) const
{
int i;
angle = -angle; // screen coordinates are a mirror image of "real" coordinates
// screen coordinates are a mirror image of "real" coordinates
angle = -angle;
bool has_alpha = HasAlpha();
const bool has_alpha = HasAlpha();
const int w = GetWidth();
const int h = GetHeight();
int i;
// 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
// (sine and cosine of the angle)
const double cos_angle = cos(angle);
const double sin_angle = sin(angle);
@@ -2839,9 +2846,9 @@ 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)));
@@ -2859,19 +2866,14 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
*offset_after_rotation = wxPoint (x1a, y1a);
}
// GRG: The rotated (destination) image is always accessed
// sequentially, so there is no need for a pointer-based
// array here (and in fact it would be slower).
//
unsigned char * dst = rotated.GetData();
// the rotated (destination) image is always accessed sequentially via this
// pointer, there is no need for pointer-based arrays here
unsigned char *dst = rotated.GetData();
unsigned char * alpha_dst = NULL;
if (has_alpha)
alpha_dst = rotated.GetAlpha();
unsigned char *alpha_dst = has_alpha ? rotated.GetAlpha() : NULL;
// GRG: if the original image has a mask, use its RGB values
// as the blank pixel, else, fall back to default (black).
//
// if the original image has a mask, use its RGB values as the blank pixel,
// else, fall back to default (black).
unsigned char blank_r = 0;
unsigned char blank_g = 0;
unsigned char blank_b = 0;
@@ -2888,27 +2890,28 @@ 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
// 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.
const int rH = rotated.GetHeight();
const int rW = rotated.GetWidth();
int x;
// do the (interpolating) test outside of the loops, so that it is done
// only once, instead of repeating it for each pixel.
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 +2921,7 @@ 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));
@@ -3039,19 +3042,18 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
}
}
}
else // not interpolating
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++);
@@ -3075,9 +3077,7 @@ wxImage wxImage::Rotate(double angle, const wxPoint & centre_of_rotation, bool i
}
delete [] data;
if (has_alpha)
delete [] alpha;
delete [] alpha;
return rotated;
}