Add an alternative solver to lp_solve. The solver based on Ingo's active set solver but is able to handle arbitrary hard and soft constraints. The advantage to lp_solve is that the active set solver can optimize variable in respect to a quadratic objective function. This makes it possible to minimise the quadratic derivation to a desired value e.g. \Sum_i(x_i - x_{i,pref})^2 -> min.

The solver part has been refactored in this way that both solver can be used with the same layout specifications. The active set solver is default now; the performance is not as good as lp_solve, though.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40285 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/libs/alm/ALMLayout.h

@@ -124,8 +124,6 @@ private:
 			/*! Add a view without initialize the Area. */
 			BLayoutItem*		_CreateLayoutItem(BView* view);
 
-			void				_SolveLayout();
-
 			void				_UpdateAreaConstraints();
 
 			BSize				_CalculateMinSize();
@@ -152,8 +150,10 @@ private:
 
 			Area*				fCurrentArea;
 
+#if USE_SCALE_VARIABLE
 			Variable*			fScaleWidth;
 			Variable*			fScaleHeight;
+#endif
 };
 
 }	// namespace BALM

headers/libs/alm/Area.h

@@ -20,6 +20,9 @@
 #include "Tab.h"
 
 
+#define USE_SCALE_VARIABLE 1
+
+
 class Constraint;
 
 
@@ -106,6 +109,7 @@ public:
 private:
 								Area(BLayoutItem* item);
 
+#if USE_SCALE_VARIABLE
 			void				_Init(LinearSpec* ls, XTab* left, YTab* top,
 									XTab* right, YTab* bottom,
 									Variable* scaleWidth,
@@ -113,6 +117,11 @@ private:
 			void				_Init(LinearSpec* ls, Row* row, Column* column,
 									Variable* scaleWidth,
 									Variable* scaleHeight);
+#else
+			void				_Init(LinearSpec* ls, XTab* left, YTab* top,
+									XTab* right, YTab* bottom);
+			void				_Init(LinearSpec* ls, Row* row, Column* column);
+#endif
 
 			void				_DoLayout();
 
@@ -152,9 +161,10 @@ private:
 			double				fContentAspectRatio;
 			Constraint*			fContentAspectRatioC;
 
+#if USE_SCALE_VARIABLE
 			Variable*			fScaleWidth;
 			Variable*			fScaleHeight;
-
+#endif
 public:
 	friend class		BALMLayout;