// Function provided by Joe Dowsett, 2014 double DrawProjGroup::calculateAutomaticScale() const { TechDraw::DrawPage *page = getPage(); if (page == NULL) throw Base::Exception("No page is assigned to this feature"); if(!page->hasValidTemplate()) throw Base::Exception("Page template isn't valid"); DrawProjGroupItem *viewPtrs[10]; arrangeViewPointers(viewPtrs); double width, height; minimumBbViews(viewPtrs, width, height); // C++ Standard says casting bool to int gives 0 or 1 int numVertSpaces = (viewPtrs[0] || viewPtrs[3] || viewPtrs[7]) + (viewPtrs[2] || viewPtrs[5] || viewPtrs[9]) + (viewPtrs[6] != NULL); int numHorizSpaces = (viewPtrs[0] || viewPtrs[1] || viewPtrs[2]) + (viewPtrs[7] || viewPtrs[8] || viewPtrs[9]); double availableX = page->getPageWidth() - spacingX.getValue() * (numVertSpaces + 1); double availableY = page->getPageHeight() - spacingY.getValue() * (numHorizSpaces + 1); double scale_x = availableX / width; double scale_y = availableY / height; float working_scale = std::min(scale_x, scale_y); //which gives the largest scale for which the min_space requirements can be met, but we want a 'sensible' scale, rather than 0.28457239... //eg if working_scale = 0.115, then we want to use 0.1, similarly 7.65 -> 5, and 76.5 -> 50 float exponent = std::floor(std::log10(working_scale)); //if working_scale = a * 10^b, what is b? working_scale *= std::pow(10, -exponent); //now find what 'a' is. float valid_scales[2][8] = {{1.0, 1.25, 2.0, 2.5, 3.75, 5.0, 7.5, 10.0}, //equate to 1:10, 1:8, 1:5, 1:4, 3:8, 1:2, 3:4, 1:1 {1.0, 1.5 , 2.0, 3.0, 4.0 , 5.0, 8.0, 10.0}}; //equate to 1:1, 3:2, 2:1, 3:1, 4:1, 5:1, 8:1, 10:1 int i = 7; while (valid_scales[(exponent >= 0)][i] > working_scale) //choose closest value smaller than 'a' from list. i -= 1; //choosing top list if exponent -ve, bottom list for +ve exponent //now have the appropriate scale, reapply the *10^b return valid_scales[(exponent >= 0)][i] * pow(10, exponent); }
App::DocumentObjectExecReturn *DrawView::execute(void) { TechDraw::DrawPage *page = findParentPage(); if(page) { if (ScaleType.isValue("Document")) { if(std::abs(page->Scale.getValue() - Scale.getValue()) > FLT_EPSILON) { Scale.setValue(page->Scale.getValue()); } } else if (ScaleType.isValue("Automatic")) { //check fit. if too big, rescale if (!checkFit(page)) { double newScale = autoScale(page->getPageWidth(),page->getPageHeight()); if(std::abs(newScale - Scale.getValue()) > FLT_EPSILON) { //stops onChanged/execute loop Scale.setValue(newScale); } } } } return App::DocumentObject::execute(); }