Add new TileProvider implementation SizeReferenceTileProvider and add to lodMars

data/scene/lodmars/lodmars.mod

@@ -86,6 +86,11 @@ return {
                         Type = "ChunkIndex",
                         Name = "Indices",
                     },
+                    {
+                        Type = "SizeReference",
+                        Name = "Size Reference",
+                        Radii = marsEllipsoid,
+                    },
                 },
                 HeightMaps = {
                     {

modules/globebrowsing/globebrowsingmodule.cpp

@@ -63,6 +63,7 @@ void GlobeBrowsingModule::internalInitialize() {
     fTileProvider->registerClass<SingleImageProvider>("SingleImage");
     fTileProvider->registerClass<TemporalTileProvider>("Temporal");
     fTileProvider->registerClass<ChunkIndexTileProvider>("ChunkIndex");
+    fTileProvider->registerClass<SizeReferenceTileProvider>("SizeReference");
     
 }
 

modules/globebrowsing/tile/tileprovider/texttileprovider.cpp

@@ -53,6 +53,7 @@ namespace openspace {
     {
 
         _font = OsEng.fontManager().font("Mono", _fontSize);
+        
         _fontRenderer = std::unique_ptr<FontRenderer>(FontRenderer::createDefault());
         _fontRenderer->setFramebufferSize(textureSize);
 
@@ -142,7 +143,9 @@ namespace openspace {
     }
 
 
-
+    //////////////////////////////////////////////////////////////////////////////////////
+    //                             Chunk Index Tile Provider                            //
+    //////////////////////////////////////////////////////////////////////////////////////
 
     void ChunkIndexTileProvider::renderText(const FontRenderer& fontRenderer, const ChunkIndex& chunkIndex) const {
         fontRenderer.render(
@@ -156,8 +159,52 @@ namespace openspace {
             );
     }
 
+    //////////////////////////////////////////////////////////////////////////////////////
+    //                         Tile Size Reference Tile Provider                        //
+    //////////////////////////////////////////////////////////////////////////////////////
+
+    namespace {
+        const std::string KeyRadii = "Radii";
+    }
+
+    SizeReferenceTileProvider::SizeReferenceTileProvider(const ghoul::Dictionary& dictionary) {
+        _fontSize = 64;
+        _font = OsEng.fontManager().font("Mono", _fontSize);
+        glm::dvec3 radii(1,1,1);
+        if (!dictionary.getValue(KeyRadii, radii)) {
+            throw std::runtime_error("Must define key '" + KeyRadii + "'");
+        }
+        _ellipsoid = Ellipsoid(radii);
+    }
+
+    void SizeReferenceTileProvider::renderText(const FontRenderer& fontRenderer, const ChunkIndex& chunkIndex) const {
+        GeodeticPatch patch(chunkIndex);
+        bool aboveEquator = patch.isNorthern();
+        double lat = aboveEquator ? patch.minLat() : patch.maxLat();
+        double lon1 = patch.minLon();
+        double lon2 = patch.maxLon();
+        double tileLongitudalLength = _ellipsoid.longitudalDistance(lat, lon1, lon2);
 
 
+        std::string unit = "m";
+        if (tileLongitudalLength > 10000) {
+            tileLongitudalLength *= 0.001;
+            unit = "km";
+        }
+
+        glm::vec2 textPosition;
+        textPosition.x = 0;
+        textPosition.y = aboveEquator ? _fontSize / 2 : _textureSize.y - 3 * _fontSize / 2;
+        glm::vec4 color(1.0, 1.0, 1.0, 1.0);
+
+        fontRenderer.render(
+            *_font,
+            textPosition,
+            color,
+            " %.0f %s",
+            tileLongitudalLength, unit.c_str()
+            );
+    }
 
 
 }  // namespace openspace

modules/globebrowsing/tile/tileprovider/texttileprovider.h

@@ -25,6 +25,8 @@
 #ifndef __TEXT_TILE_PROVIDER_H__
 #define __TEXT_TILE_PROVIDER_H__
 
+#include <memory>
+
 #include <ghoul/logging/logmanager.h>
 #include <ghoul/filesystem/filesystem.h> // absPath
 #include <ghoul/opengl/texture.h>
@@ -37,6 +39,7 @@
 #include <modules/globebrowsing/tile/asynctilereader.h>
 #include <modules/globebrowsing/tile/tileprovider/tileprovider.h>
 #include <modules/globebrowsing/other/lrucache.h>
+#include <modules/globebrowsing/geometry/ellipsoid.h>
 
 
 //////////////////////////////////////////////////////////////////////////////////////////
@@ -60,7 +63,7 @@ namespace openspace {
         TextTileProvider(const glm::uvec2& textureSize = {512, 512}, size_t fontSize = 48);
         virtual ~TextTileProvider();
 
-        // Methods below are implemented in this class
+        // The TileProvider interface below is implemented in this class
 
         virtual Tile getTile(const ChunkIndex& chunkIndex);
         virtual Tile getDefaultTile();
@@ -72,7 +75,6 @@ namespace openspace {
 
         
         // This method is pure and should be implemented by subclasses
-
         virtual void renderText(const FontRenderer& fontRenderer, const ChunkIndex& chunkIndex) const = 0;
 
     protected:
@@ -97,6 +99,15 @@ namespace openspace {
     };
 
 
+    class SizeReferenceTileProvider : public TextTileProvider {
+    public:
+        SizeReferenceTileProvider(const ghoul::Dictionary& dictionary);
+        virtual void renderText(const FontRenderer& fontRenderer, const ChunkIndex& chunkIndex) const;
+
+    private:
+        Ellipsoid _ellipsoid;
+    };
+
 }  // namespace openspace