1 files changed, 234 insertions, 0 deletions
diff --git a/src/object/sp-mesh-array.h b/src/object/sp-mesh-array.h
new file mode 100644
index 0000000..eb28a12
--- /dev/null
+++ b/src/object/sp-mesh-array.h
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_SP_MESH_ARRAY_H
+#define SEEN_SP_MESH_ARRAY_H
+/*
+ * Authors:
+ *   Tavmjong Bah <tavmjong@free.fr>
+ *
+ * Copyrigt  (C) 2012 Tavmjong Bah
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+/**
+   A group of classes and functions for manipulating mesh gradients.
+
+   A mesh is made up of an array of patches. Each patch has four sides and four corners. The sides can
+   be shared between two patches and the corners between up to four.
+
+   The order of the points for each side always goes from left to right or top to bottom.
+   For sides 2 and 3 the points must be reversed when used (as in calls to cairo functions). 
+
+   Two patches: (C=corner, S=side, H=handle, T=tensor)
+
+                         C0   H1  H2 C1 C0 H1  H2  C1
+                          + ---------- + ---------- +
+                          |     S0     |     S0     |
+                       H1 |  T0    T1  |H1 T0   T1  | H1
+                          |S3        S1|S3        S1|
+                       H2 |  T3    T2  |H2 T3   T2  | H2
+                          |     S2     |     S2     |
+                          + ---------- + ---------- +
+                         C3   H1  H2 C2 C3 H1  H2   C2
+
+   The mesh is stored internally as an array of nodes that includes the tensor nodes.
+
+   Note: This code uses tensor points which are not part of the SVG2 plan at the moment.
+   Including tensor points was motivated by a desire to experiment with their usefulness
+   in smoothing color transitions. There doesn't seem to be much advantage for that
+   purpose. However including them internally allows for storing all the points in
+   an array which simplifies things like inserting new rows or columns.
+*/
+
+#include <2geom/point.h>
+#include "color.h"
+
+// For color picking
+#include "sp-item.h"
+
+#include <memory>
+
+enum SPMeshType {
+  SP_MESH_TYPE_COONS,
+  SP_MESH_TYPE_BICUBIC
+};
+
+enum SPMeshGeometry {
+  SP_MESH_GEOMETRY_NORMAL,
+  SP_MESH_GEOMETRY_CONICAL
+};
+
+enum NodeType {
+  MG_NODE_TYPE_UNKNOWN,
+  MG_NODE_TYPE_CORNER,
+  MG_NODE_TYPE_HANDLE,
+  MG_NODE_TYPE_TENSOR
+};
+
+// Is a node along an edge?
+enum NodeEdge {
+  MG_NODE_EDGE_NONE,
+  MG_NODE_EDGE_TOP = 1,
+  MG_NODE_EDGE_LEFT = 2,
+  MG_NODE_EDGE_BOTTOM = 4,
+  MG_NODE_EDGE_RIGHT = 8
+};
+
+enum MeshCornerOperation {
+  MG_CORNER_SIDE_TOGGLE,
+  MG_CORNER_SIDE_ARC,
+  MG_CORNER_TENSOR_TOGGLE,
+  MG_CORNER_COLOR_SMOOTH,
+  MG_CORNER_COLOR_PICK,
+  MG_CORNER_INSERT
+};
+
+enum MeshNodeOperation {
+  MG_NODE_NO_SCALE,
+  MG_NODE_SCALE,
+  MG_NODE_SCALE_HANDLE
+};
+
+class SPStop;
+
+class SPMeshNode {
+public:
+  SPMeshNode() {
+    node_type = MG_NODE_TYPE_UNKNOWN;
+    node_edge = MG_NODE_EDGE_NONE;
+    set = false;
+    draggable = -1;
+    path_type = 'u';
+    opacity = 0.0;
+    stop = nullptr;
+  }
+  NodeType node_type;
+  unsigned int     node_edge;
+  bool set;
+  Geom::Point p;
+  unsigned int draggable;  // index of on-screen node
+  char path_type;
+  SPColor color;
+  double opacity;
+  SPStop *stop; // Stop corresponding to node.
+};
+
+
+// I for Internal to distinguish it from the Object class
+// This is a convenience class...
+class SPMeshPatchI {
+
+private:
+  std::vector<std::vector< SPMeshNode* > > *nodes;
+  int row;
+  int col;
+
+public:
+  SPMeshPatchI( std::vector<std::vector< SPMeshNode* > > *n, int r, int c );
+  Geom::Point getPoint( unsigned int side, unsigned int point );
+  std::vector< Geom::Point > getPointsForSide( unsigned int i );
+  void        setPoint( unsigned int side, unsigned int point, Geom::Point p, bool set = true );
+  char getPathType( unsigned int i );
+  void  setPathType( unsigned int, char t );
+  Geom::Point getTensorPoint( unsigned int i );
+  void        setTensorPoint( unsigned int i, Geom::Point p );
+  bool tensorIsSet();
+  bool tensorIsSet( unsigned int i );
+  Geom::Point coonsTensorPoint( unsigned int i );
+  void    updateNodes();
+  SPColor getColor( unsigned int i );
+  void    setColor( unsigned int i, SPColor c );
+  double  getOpacity( unsigned int i );
+  void    setOpacity( unsigned int i, double o );
+  SPStop* getStopPtr( unsigned int i );
+  void    setStopPtr( unsigned int i, SPStop* );
+};
+
+class SPMeshGradient;
+class SPCurve;
+
+// An array of mesh nodes.
+class SPMeshNodeArray {
+
+// Should be private
+public:
+  SPMeshGradient *mg;
+  std::vector< std::vector< SPMeshNode* > > nodes;
+
+public:
+  // Draggables to nodes
+  bool draggers_valid;
+  std::vector< SPMeshNode* > corners;
+  std::vector< SPMeshNode* > handles;
+  std::vector< SPMeshNode* > tensors;
+
+public:
+
+  friend class SPMeshPatchI;
+
+  SPMeshNodeArray() { built = false; mg = nullptr; draggers_valid = false; };
+  SPMeshNodeArray( SPMeshGradient *mg );
+  SPMeshNodeArray( const SPMeshNodeArray& rhs );
+  SPMeshNodeArray& operator=(const SPMeshNodeArray& rhs);
+
+  ~SPMeshNodeArray() { clear(); };
+  bool built;
+
+  bool read( SPMeshGradient *mg );
+  void write( SPMeshGradient *mg );
+  void create( SPMeshGradient *mg, SPItem *item, Geom::OptRect bbox );
+  void clear();
+  void print();
+
+  // Fill 'smooth' with a smoothed version by subdividing each patch.
+  void bicubic( SPMeshNodeArray* smooth, SPMeshType type);
+
+  // Get size of patch
+  unsigned int patch_rows();
+  unsigned int patch_columns();
+
+  SPMeshNode * node( unsigned int i, unsigned int j ) { return nodes[i][j]; }
+
+  // Operations on corners
+  bool adjacent_corners( unsigned int i, unsigned int j, SPMeshNode* n[4] );
+  unsigned int side_toggle( std::vector< unsigned int > );
+  unsigned int side_arc( std::vector< unsigned int > );
+  unsigned int tensor_toggle( std::vector< unsigned int > );
+  unsigned int color_smooth( std::vector< unsigned int > );
+  unsigned int color_pick( std::vector< unsigned int >, SPItem* );
+  unsigned int insert( std::vector< unsigned int > );
+
+  // Update other nodes in response to a node move.
+  void update_handles( unsigned int corner, std::vector< unsigned int > selected_corners, Geom::Point old_p, MeshNodeOperation op );
+
+  // Return outline path
+  std::unique_ptr<SPCurve> outline_path() const;
+
+  // Transform array
+  void transform(Geom::Affine const &m);
+
+  // Transform mesh to fill box. Return true if not identity transform.
+  bool fill_box(Geom::OptRect &box);
+
+  // Find bounding box
+  // Geom::OptRect findBoundingBox();
+
+  void split_row( unsigned int i, unsigned int n );
+  void split_column( unsigned int j, unsigned int n );
+  void split_row( unsigned int i, double coord );
+  void split_column( unsigned int j, double coord );
+};
+
+#endif /* !SEEN_SP_MESH_ARRAY_H */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  c-basic-offset:2
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :