PerspectiveTransform PerspectiveTransform::SquareToQuadrilateral(Point2i a, Point2i b,
Point2i c, Point2i d)
{
PerspectiveTransform pt;
long dy2 = d.y - c.y;
long dy3 = a.y - b.y + c.y - d.y;
if (dy2 == 0 && dy3 == 0)
{
pt = PerspectiveTransform(b.x - a.x, c.x - b.x, a.x,
b.y - a.y, c.y - b.y, a.y,
0, 0, 1);
}
else
{
long dx1 = b.x - c.x;
long dx2 = d.x - c.x;
long dx3 = a.x - b.x + c.x - d.x;
long dy1 = b.y - c.y;
long denominator = dx1 * dy2 - dx2 * dy1;
long a13 = (dx3 * dy2 - dx2 * dy3) / denominator;
long a23 = (dx1 * dy3 - dx3 * dy1) / denominator;
pt = PerspectiveTransform(b.x - a.x + a13 * b.x, d.x - a.x + a23 * d.x, a.x,
b.y - a.y + a13 * b.y, d.y - a.y + a23 * d.y, a.y,
a13, a23, 1);
}
return pt;
}
void Camera::Init(Math::Transform aCameraToWorld, double aFov, uint32_t xDim, uint32_t yDim)
{
mCameraToWorld = aCameraToWorld;
mScreenToCamera = PerspectiveTransform(aFov, CAMERA_CLOSE_PLANE, CAMERA_FAR_PLANE, xDim, yDim);
mX = xDim;
mY = yDim;
}
Camera::Camera():
mCameraToWorld(Math::Transform::Identity()),
mScreenToCamera(PerspectiveTransform(CAMERA_DEFAULT_FOV, CAMERA_CLOSE_PLANE, CAMERA_FAR_PLANE, CAMERA_DEFAULT_X, CAMERA_DEFAULT_Y)),
mX(CAMERA_DEFAULT_X),
mY(CAMERA_DEFAULT_Y)
{
}
PerspectiveTransform operator*(const PerspectiveTransform& a, const PerspectiveTransform& b)
{
return PerspectiveTransform(a.m11 * b.m11 + a.m21 * b.m12 + a.m31 * b.m13,
a.m11 * b.m21 + a.m21 * b.m22 + a.m31 * b.m23,
a.m11 * b.m31 + a.m21 * b.m32 + a.m31 * b.m33,
a.m12 * b.m11 + a.m22 * b.m12 + a.m32 * b.m13,
a.m12 * b.m21 + a.m22 * b.m22 + a.m32 * b.m23,
a.m12 * b.m31 + a.m22 * b.m32 + a.m32 * b.m33,
a.m13 * b.m11 + a.m23 * b.m12 + a.m33 * b.m13,
a.m13 * b.m21 + a.m23 * b.m22 + a.m33 * b.m23,
a.m13 * b.m31 + a.m23 * b.m32 + a.m33 * b.m33);
}
PerspectiveTransform PerspectiveTransform::BuildAdjoint()
{
return PerspectiveTransform(m22 * m33 - m23 * m32,
m23 * m31 - m21 * m33,
m21 * m32 - m22 * m31,
m13 * m32 - m12 * m33,
m11 * m33 - m13 * m31,
m12 * m31 - m11 * m32,
m12 * m23 - m13 * m22,
m13 * m21 - m11 * m23,
m11 * m22 - m12 * m21);
}