Add a Grid base class for HorizontalShiftGrid and VerticalShiftGrid

3 files changed, 65 insertions, 71 deletions

diff --git a/src/4D_api.cpp b/src/4D_api.cpp
index 3300a6bb..efb4a86a 100644
--- a/src/4D_api.cpp
+++ b/src/4D_api.cpp
@@ -1556,39 +1556,44 @@ PJ_GRID_INFO proj_grid_info(const char *gridname) {
     PJ_CONTEXT *ctx = pj_get_default_ctx();
     memset(&grinfo, 0, sizeof(PJ_GRID_INFO));
 
+    const auto fillGridInfo = [&grinfo, ctx, gridname]
+                        (const NS_PROJ::Grid& grid, const std::string& format)
     {
-        const auto gridSet = NS_PROJ::VerticalShiftGridSet::open(ctx, gridname);
-        if( gridSet )
-        {
-            const auto& grids = gridSet->grids();
-            if( !grids.empty() )
-            {
-                const auto& grid = grids.front();
-                const auto& extent = grid->extentAndRes();
+        const auto& extent = grid.extentAndRes();
 
-                /* name of grid */
-                strncpy (grinfo.gridname, gridname, sizeof(grinfo.gridname) - 1);
+        /* name of grid */
+        strncpy (grinfo.gridname, gridname, sizeof(grinfo.gridname) - 1);
 
-                /* full path of grid */
-                pj_find_file(ctx, gridname, grinfo.filename, sizeof(grinfo.filename) - 1);
+        /* full path of grid */
+        pj_find_file(ctx, gridname, grinfo.filename, sizeof(grinfo.filename) - 1);
 
-                /* grid format */
-                strncpy (grinfo.format, gridSet->format().c_str(), sizeof(grinfo.format) - 1);
+        /* grid format */
+        strncpy (grinfo.format, format.c_str(), sizeof(grinfo.format) - 1);
 
-                /* grid size */
-                grinfo.n_lon = grid->width();
-                grinfo.n_lat = grid->height();
+        /* grid size */
+        grinfo.n_lon = grid.width();
+        grinfo.n_lat = grid.height();
 
-                /* cell size */
-                grinfo.cs_lon = extent.resLon;
-                grinfo.cs_lat = extent.resLat;
+        /* cell size */
+        grinfo.cs_lon = extent.resLon;
+        grinfo.cs_lat = extent.resLat;
 
-                /* bounds of grid */
-                grinfo.lowerleft.lam  = extent.westLon;
-                grinfo.lowerleft.phi  = extent.southLat;
-                grinfo.upperright.lam = extent.eastLon;
-                grinfo.upperright.phi = extent.northLat;
+        /* bounds of grid */
+        grinfo.lowerleft.lam  = extent.westLon;
+        grinfo.lowerleft.phi  = extent.southLat;
+        grinfo.upperright.lam = extent.eastLon;
+        grinfo.upperright.phi = extent.northLat;
+    };
 
+    {
+        const auto gridSet = NS_PROJ::VerticalShiftGridSet::open(ctx, gridname);
+        if( gridSet )
+        {
+            const auto& grids = gridSet->grids();
+            if( !grids.empty() )
+            {
+                const auto& grid = grids.front();
+                fillGridInfo(*grid, gridSet->format());
                 return grinfo;
             }
         }
@@ -1602,31 +1607,7 @@ PJ_GRID_INFO proj_grid_info(const char *gridname) {
             if( !grids.empty() )
             {
                 const auto& grid = grids.front();
-                const auto& extent = grid->extentAndRes();
-
-                /* name of grid */
-                strncpy (grinfo.gridname, gridname, sizeof(grinfo.gridname) - 1);
-
-                /* full path of grid */
-                pj_find_file(ctx, gridname, grinfo.filename, sizeof(grinfo.filename) - 1);
-
-                /* grid format */
-                strncpy (grinfo.format, gridSet->format().c_str(), sizeof(grinfo.format) - 1);
-
-                /* grid size */
-                grinfo.n_lon = grid->width();
-                grinfo.n_lat = grid->height();
-
-                /* cell size */
-                grinfo.cs_lon = extent.resLon;
-                grinfo.cs_lat = extent.resLat;
-
-                /* bounds of grid */
-                grinfo.lowerleft.lam  = extent.westLon;
-                grinfo.lowerleft.phi  = extent.southLat;
-                grinfo.upperright.lam = extent.eastLon;
-                grinfo.upperright.phi = extent.northLat;
-
+                fillGridInfo(*grid, gridSet->format());
                 return grinfo;
             }
         }
diff --git a/src/grids.cpp b/src/grids.cpp
index 54dae555..7d19b1f7 100644
--- a/src/grids.cpp
+++ b/src/grids.cpp
@@ -70,13 +70,24 @@ bool ExtentAndRes::fullWorldLongitude() const {
 
 // ---------------------------------------------------------------------------
 
+Grid::Grid(int widthIn, int heightIn, const ExtentAndRes &extentIn)
+    : m_width(widthIn), m_height(heightIn), m_extent(extentIn) {}
+
+// ---------------------------------------------------------------------------
+
+Grid::~Grid() = default;
+
+// ---------------------------------------------------------------------------
+
 VerticalShiftGrid::VerticalShiftGrid(int widthIn, int heightIn,
                                      const ExtentAndRes &extentIn)
-    : m_width(widthIn), m_height(heightIn), m_extent(extentIn) {}
+    : Grid(widthIn, heightIn, extentIn) {}
 
 // ---------------------------------------------------------------------------
 
-VerticalShiftGrid::~VerticalShiftGrid() = default;
+bool VerticalShiftGrid::isNodata(float /*val*/, double /* multiplier */) const {
+    return false;
+}
 
 // ---------------------------------------------------------------------------
 
@@ -98,6 +109,7 @@ class NullVerticalShiftGrid : public VerticalShiftGrid {
   public:
     NullVerticalShiftGrid() : VerticalShiftGrid(3, 3, globalExtent()) {}
 
+    bool isNullGrid() const override { return true; }
     bool valueAt(int, int, float &out) const override;
     bool isNodata(float, double) const override { return false; }
 };
@@ -306,7 +318,7 @@ const VerticalShiftGrid *VerticalShiftGridSet::gridAt(double lon,
 
 HorizontalShiftGrid::HorizontalShiftGrid(int widthIn, int heightIn,
                                          const ExtentAndRes &extentIn)
-    : m_width(widthIn), m_height(heightIn), m_extent(extentIn) {}
+    : Grid(widthIn, heightIn, extentIn) {}
 
 // ---------------------------------------------------------------------------
 
diff --git a/src/grids.hpp b/src/grids.hpp
index 975f7716..65bf502b 100644
--- a/src/grids.hpp
+++ b/src/grids.hpp
@@ -49,26 +49,36 @@ struct ExtentAndRes {
 
 // ---------------------------------------------------------------------------
 
-class VerticalShiftGrid {
+class Grid {
   protected:
     int m_width;
     int m_height;
     ExtentAndRes m_extent;
-    std::vector<std::unique_ptr<VerticalShiftGrid>> m_children{};
+
+    Grid(int widthIn, int heightIn, const ExtentAndRes &extentIn);
 
   public:
-    VerticalShiftGrid(int widthIn, int heightIn, const ExtentAndRes &extentIn);
-    virtual ~VerticalShiftGrid();
+    virtual ~Grid();
 
     int width() const { return m_width; }
     int height() const { return m_height; }
     const ExtentAndRes &extentAndRes() const { return m_extent; }
 
+    virtual bool isNullGrid() const { return false; }
+};
+
+// ---------------------------------------------------------------------------
+
+class VerticalShiftGrid : public Grid {
+  protected:
+    std::vector<std::unique_ptr<VerticalShiftGrid>> m_children{};
+
+  public:
+    VerticalShiftGrid(int widthIn, int heightIn, const ExtentAndRes &extentIn);
+
     const VerticalShiftGrid *gridAt(double lon, double lat) const;
 
-    virtual bool isNodata(float /*val*/, double /* multiplier */) const {
-        return false;
-    }
+    virtual bool isNodata(float /*val*/, double /* multiplier */) const;
 
     // x = 0 is western-most column, y = 0 is southern-most line
     virtual bool valueAt(int x, int y, float &out) const = 0;
@@ -99,26 +109,17 @@ class VerticalShiftGridSet {
 
 // ---------------------------------------------------------------------------
 
-class HorizontalShiftGrid {
+class HorizontalShiftGrid : public Grid {
   protected:
-    int m_width;
-    int m_height;
-    ExtentAndRes m_extent;
     std::vector<std::unique_ptr<HorizontalShiftGrid>> m_children{};
 
   public:
     HorizontalShiftGrid(int widthIn, int heightIn,
                         const ExtentAndRes &extentIn);
-    virtual ~HorizontalShiftGrid();
-
-    int width() const { return m_width; }
-    int height() const { return m_height; }
-    const ExtentAndRes &extentAndRes() const { return m_extent; }
+    ~HorizontalShiftGrid() override;
 
     const HorizontalShiftGrid *gridAt(double lon, double lat) const;
 
-    virtual bool isNullGrid() const { return false; }
-
     // x = 0 is western-most column, y = 0 is southern-most line
     virtual bool valueAt(int x, int y, float &lonShift,
                          float &latShift) const = 0;