void
ImageTransformation::setPostRotation(double const degrees)
{
m_postRotateXform = calcPostRotateXform(degrees);
m_postRotation = degrees;
update();
}
void
ImageTransformation::preScaleToDpi(Dpi const& dpi)
{
if (m_origDpi.isNull() || dpi.isNull()) {
return;
}
m_preScaledDpi = dpi;
double const xscale = (double)dpi.horizontal() / m_origDpi.horizontal();
double const yscale = (double)dpi.vertical() / m_origDpi.vertical();
QSizeF const new_pre_scaled_image_size(
m_origRect.width() * xscale, m_origRect.height() * yscale
);
// Undo's for the specified steps.
QTransform const undo21(m_preRotateXform.inverted() * m_preScaleXform.inverted());
QTransform const undo4321(m_postRotateXform.inverted() * m_preCropXform.inverted() * undo21);
// Update transform #1: pre-scale.
m_preScaleXform.reset();
m_preScaleXform.scale(xscale, yscale);
// Update transform #2: pre-rotate.
m_preRotateXform = m_preRotation.transform(new_pre_scaled_image_size);
// Update transform #3: pre-crop.
QTransform const redo12(m_preScaleXform * m_preRotateXform);
m_preCropArea = (undo21 * redo12).map(m_preCropArea);
m_preCropXform = calcCropXform(m_preCropArea);
// Update transform #4: post-rotate.
m_postRotateXform = calcPostRotateXform(m_postRotation);
// Update transform #5: post-crop.
QTransform const redo1234(redo12 * m_preCropXform * m_postRotateXform);
m_postCropArea = (undo4321 * redo1234).map(m_postCropArea);
m_postCropXform = calcCropXform(m_postCropArea);
// Update transform #6: post-scale.
m_postScaleXform = calcPostScaleXform(m_postScaledDpi);
update();
}
void
ImageTransformation::preScaleToDpi(Dpi const& dpi)
{
if (m_origDpi.isNull() || dpi.isNull()) {
return;
}
m_preScaledDpi = dpi;
double const xscale = (double)dpi.horizontal() / m_origDpi.horizontal();
double const yscale = (double)dpi.vertical() / m_origDpi.vertical();
QSizeF const new_pre_scaled_image_size(
m_origRect.width() * xscale, m_origRect.height() * yscale
);
// Reverse pre-rotation.
QPolygonF tmp_crop_area(m_preRotateXform.inverted().map(m_cropArea));
// Reverse pre-scaling.
tmp_crop_area = m_preScaleXform.inverted().map(tmp_crop_area);
// Update m_preScaleXform and m_preRotateXform.
m_preScaleXform.reset();
m_preScaleXform.scale(xscale, yscale);
m_preRotateXform = m_preRotation.transform(new_pre_scaled_image_size);
// Apply new pre-scaling.
tmp_crop_area = m_preScaleXform.map(tmp_crop_area);
// Re-apply pre-rotation.
m_cropArea = m_preRotateXform.map(tmp_crop_area);
m_cropXform = calcCropXform(m_cropArea);
m_postRotateXform = calcPostRotateXform(m_postRotation);
update();
}