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////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2015 Laurent Gomila (laurent@sfml-dev.org)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
// you must not claim that you wrote the original software.
// If you use this software in a product, an acknowledgment
// in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
// and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Graphics/Transform.hpp>
#include <cmath>
namespace sf
{
////////////////////////////////////////////////////////////
const Transform Transform::Identity;
////////////////////////////////////////////////////////////
Transform::Transform()
{
// Identity matrix
m_matrix[0] = 1.f; m_matrix[4] = 0.f; m_matrix[8] = 0.f; m_matrix[12] = 0.f;
m_matrix[1] = 0.f; m_matrix[5] = 1.f; m_matrix[9] = 0.f; m_matrix[13] = 0.f;
m_matrix[2] = 0.f; m_matrix[6] = 0.f; m_matrix[10] = 1.f; m_matrix[14] = 0.f;
m_matrix[3] = 0.f; m_matrix[7] = 0.f; m_matrix[11] = 0.f; m_matrix[15] = 1.f;
}
////////////////////////////////////////////////////////////
Transform::Transform(float a00, float a01, float a02,
float a10, float a11, float a12,
float a20, float a21, float a22)
{
m_matrix[0] = a00; m_matrix[4] = a01; m_matrix[8] = 0.f; m_matrix[12] = a02;
m_matrix[1] = a10; m_matrix[5] = a11; m_matrix[9] = 0.f; m_matrix[13] = a12;
m_matrix[2] = 0.f; m_matrix[6] = 0.f; m_matrix[10] = 1.f; m_matrix[14] = 0.f;
m_matrix[3] = a20; m_matrix[7] = a21; m_matrix[11] = 0.f; m_matrix[15] = a22;
}
////////////////////////////////////////////////////////////
const float* Transform::getMatrix() const
{
return m_matrix;
}
////////////////////////////////////////////////////////////
Transform Transform::getInverse() const
{
// Compute the determinant
float det = m_matrix[0] * (m_matrix[15] * m_matrix[5] - m_matrix[7] * m_matrix[13]) -
m_matrix[1] * (m_matrix[15] * m_matrix[4] - m_matrix[7] * m_matrix[12]) +
m_matrix[3] * (m_matrix[13] * m_matrix[4] - m_matrix[5] * m_matrix[12]);
// Compute the inverse if the determinant is not zero
// (don't use an epsilon because the determinant may *really* be tiny)
if (det != 0.f)
{
return Transform( (m_matrix[15] * m_matrix[5] - m_matrix[7] * m_matrix[13]) / det,
-(m_matrix[15] * m_matrix[4] - m_matrix[7] * m_matrix[12]) / det,
(m_matrix[13] * m_matrix[4] - m_matrix[5] * m_matrix[12]) / det,
-(m_matrix[15] * m_matrix[1] - m_matrix[3] * m_matrix[13]) / det,
(m_matrix[15] * m_matrix[0] - m_matrix[3] * m_matrix[12]) / det,
-(m_matrix[13] * m_matrix[0] - m_matrix[1] * m_matrix[12]) / det,
(m_matrix[7] * m_matrix[1] - m_matrix[3] * m_matrix[5]) / det,
-(m_matrix[7] * m_matrix[0] - m_matrix[3] * m_matrix[4]) / det,
(m_matrix[5] * m_matrix[0] - m_matrix[1] * m_matrix[4]) / det);
}
else
{
return Identity;
}
}
////////////////////////////////////////////////////////////
Vector2f Transform::transformPoint(float x, float y) const
{
return Vector2f(m_matrix[0] * x + m_matrix[4] * y + m_matrix[12],
m_matrix[1] * x + m_matrix[5] * y + m_matrix[13]);
}
////////////////////////////////////////////////////////////
Vector2f Transform::transformPoint(const Vector2f& point) const
{
return transformPoint(point.x, point.y);
}
////////////////////////////////////////////////////////////
FloatRect Transform::transformRect(const FloatRect& rectangle) const
{
// Transform the 4 corners of the rectangle
const Vector2f points[] =
{
transformPoint(rectangle.left, rectangle.top),
transformPoint(rectangle.left, rectangle.top + rectangle.height),
transformPoint(rectangle.left + rectangle.width, rectangle.top),
transformPoint(rectangle.left + rectangle.width, rectangle.top + rectangle.height)
};
// Compute the bounding rectangle of the transformed points
float left = points[0].x;
float top = points[0].y;
float right = points[0].x;
float bottom = points[0].y;
for (int i = 1; i < 4; ++i)
{
if (points[i].x < left) left = points[i].x;
else if (points[i].x > right) right = points[i].x;
if (points[i].y < top) top = points[i].y;
else if (points[i].y > bottom) bottom = points[i].y;
}
return FloatRect(left, top, right - left, bottom - top);
}
////////////////////////////////////////////////////////////
Transform& Transform::combine(const Transform& transform)
{
const float* a = m_matrix;
const float* b = transform.m_matrix;
*this = Transform(a[0] * b[0] + a[4] * b[1] + a[12] * b[3],
a[0] * b[4] + a[4] * b[5] + a[12] * b[7],
a[0] * b[12] + a[4] * b[13] + a[12] * b[15],
a[1] * b[0] + a[5] * b[1] + a[13] * b[3],
a[1] * b[4] + a[5] * b[5] + a[13] * b[7],
a[1] * b[12] + a[5] * b[13] + a[13] * b[15],
a[3] * b[0] + a[7] * b[1] + a[15] * b[3],
a[3] * b[4] + a[7] * b[5] + a[15] * b[7],
a[3] * b[12] + a[7] * b[13] + a[15] * b[15]);
return *this;
}
////////////////////////////////////////////////////////////
Transform& Transform::translate(float x, float y)
{
Transform translation(1, 0, x,
0, 1, y,
0, 0, 1);
return combine(translation);
}
////////////////////////////////////////////////////////////
Transform& Transform::translate(const Vector2f& offset)
{
return translate(offset.x, offset.y);
}
////////////////////////////////////////////////////////////
Transform& Transform::rotate(float angle)
{
float rad = angle * 3.141592654f / 180.f;
float cos = std::cos(rad);
float sin = std::sin(rad);
Transform rotation(cos, -sin, 0,
sin, cos, 0,
0, 0, 1);
return combine(rotation);
}
////////////////////////////////////////////////////////////
Transform& Transform::rotate(float angle, float centerX, float centerY)
{
float rad = angle * 3.141592654f / 180.f;
float cos = std::cos(rad);
float sin = std::sin(rad);
Transform rotation(cos, -sin, centerX * (1 - cos) + centerY * sin,
sin, cos, centerY * (1 - cos) - centerX * sin,
0, 0, 1);
return combine(rotation);
}
////////////////////////////////////////////////////////////
Transform& Transform::rotate(float angle, const Vector2f& center)
{
return rotate(angle, center.x, center.y);
}
////////////////////////////////////////////////////////////
Transform& Transform::scale(float scaleX, float scaleY)
{
Transform scaling(scaleX, 0, 0,
0, scaleY, 0,
0, 0, 1);
return combine(scaling);
}
////////////////////////////////////////////////////////////
Transform& Transform::scale(float scaleX, float scaleY, float centerX, float centerY)
{
Transform scaling(scaleX, 0, centerX * (1 - scaleX),
0, scaleY, centerY * (1 - scaleY),
0, 0, 1);
return combine(scaling);
}
////////////////////////////////////////////////////////////
Transform& Transform::scale(const Vector2f& factors)
{
return scale(factors.x, factors.y);
}
////////////////////////////////////////////////////////////
Transform& Transform::scale(const Vector2f& factors, const Vector2f& center)
{
return scale(factors.x, factors.y, center.x, center.y);
}
////////////////////////////////////////////////////////////
Transform operator *(const Transform& left, const Transform& right)
{
return Transform(left).combine(right);
}
////////////////////////////////////////////////////////////
Transform& operator *=(Transform& left, const Transform& right)
{
return left.combine(right);
}
////////////////////////////////////////////////////////////
Vector2f operator *(const Transform& left, const Vector2f& right)
{
return left.transformPoint(right);
}
} // namespace sf
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