cache atlasses on demand

src/Atlas.cpp

@@ -1,7 +1,9 @@
 #include "Atlas.h"
+#include "GlyphGeometry.h"
 #include "conversion.h"
 #include "edge-coloring.h"
 #include "import-font.h"
+#include "ofFileUtils.h"
 
 namespace ofxMsdfgen {
 
@@ -122,10 +124,20 @@ void Atlas::addVariations(vector <FontVariation> variations){
     }
 }
 
-bool Atlas::generate(){
+bool Atlas::generate(bool useCache,
+                     bool saveToCache){
     cout << "Atlas::generate()" << endl;
     bool success = false;
-    //{
+    bool foundAtlasCacheImage = false;
+    if(useCache){
+        ofFile atlasPathFile(getAtlasPath());
+        if(atlasPathFile.isFile()){
+            foundAtlasCacheImage = true;
+            if(atlasImage.load(getAtlasPath())){
+                foundAtlasCacheImage = true;
+            }
+        }
+    }
     if(ft){
         if(font){
             // Storage for glyph geometry and their coordinates in the atlas
@@ -208,6 +220,7 @@ bool Atlas::generate(){
             packer.setMiterLimit(settings.miterLimit);
             // Compute atlas layout - pack glyphs
             packer.pack(glyphs.data(), glyphs.size());
+            if(!useCache || !foundAtlasCacheImage){
                 // Get final atlas dimensions
                 int width = 0, height = 0;
                 packer.getDimensions(width, height);
@@ -230,12 +243,21 @@ bool Atlas::generate(){
                 msdfgen::Bitmap <float, 3> bitmap(generator.atlasStorage());
                 toOfImage(bitmap, atlasImage);
                 atlasImage.update();
+                if(saveToCache){
+                    ofDirectory dir(getAtlasPathDir());
+                    dir.create();
+                    atlasImage.save(getAtlasPath());
+                }
+            }
 
-            std::vector <msdf_atlas::GlyphBox> layout = generator.getLayout();
+            //std::vector <msdf_atlas::GlyphBox> layout = generator.getLayout();
-            int i = 0;
+            //int i = 0;
-            for(const msdf_atlas::GlyphBox & gb : layout){
+            //for(const msdf_atlas::GlyphBox & gb : layout){
-                msdf_atlas::GlyphGeometry gg = glyphs[i];
+            //msdf_atlas::GlyphGeometry gg = glyphs[i];
-                i++;
+            //i++;
+            //glyphGeometries.push_back(gg);
+            //}
+            for(const msdf_atlas::GlyphGeometry & gg : glyphs){
                 glyphGeometries.push_back(gg);
             }
             // Cleanup
@@ -345,4 +367,23 @@ const FontGeometry & Atlas::getFontGeometry(){
 const vector <ofxMsdfgen::FontVariationAxis> & Atlas::getVariationAxesAvailable(){
     return variationAxesAvailable;
 }
+
+// private
+string Atlas::getAtlasPathDir(){
+    string fontPathNoData = fontPath;
+    ofStringReplace(fontPathNoData, "data/", "");
+    string atlasPath = "data/atlascache/" + fontPathNoData;
+    return atlasPath;
+}
+string Atlas::getAtlasPath(){
+    string atlasPath = getAtlasPathDir() + "/"
+                       + ofToString(settings.scale) + "_"
+                       + ofToString(settings.minimumScale) + "_"
+                       + ofToString(settings.maxInterpolationStepSize);
+    for(auto & ve : variationExtremes){
+        atlasPath += ve.name + "_" + ofToString(ve.value) + "_";
+    }
+    atlasPath += ".png";
+    return atlasPath;
+}
 }

src/Atlas.h

@@ -87,7 +87,8 @@ class Atlas {
         void setup(string _fontPath);
         void setup(string _fontPath, AtlasSettings _settings);
         void addVariations(vector <FontVariation> variations);
-        bool generate();
+        bool generate(bool useCache = true,
+                      bool saveToCache = false);
         const ofImage & getAtlasImage();
         const vector <GlyphGeometry> & getGlyphGeometries();
         const GlyphGeometry & getGlyphGeometry(unsigned char character);
@@ -106,6 +107,8 @@ class Atlas {
         msdfgen::FontHandle * font;
         msdfgen::FreetypeHandle * ft;
     private:
+        string getAtlasPathDir();
+        string getAtlasPath();
         string fontPath;
         ofImage atlasImage;
         vector <GlyphGeometry> glyphGeometries;