wxRotationPoint p3 = rotated_point (img.GetWidth(), 0, cos_angle, sin_angle, p0);
wxRotationPoint p4 = rotated_point (img.GetWidth(), img.GetHeight(), cos_angle, sin_angle, p0);
wxRotationPoint p3 = rotated_point (img.GetWidth(), 0, cos_angle, sin_angle, p0);
wxRotationPoint p4 = rotated_point (img.GetWidth(), img.GetHeight(), cos_angle, sin_angle, p0);