add rudimentary variation animation

example/src/gpufont/font.hpp

@@ -61,6 +61,22 @@ class Font {
     };
 
     public:
+/// A structure to model a given axis of a variable font.
+        struct FontVariationAxisParameters {
+            /// The name of the variation axis.
+            const char * name;
+            /// The axis's minimum coordinate value.
+            double minValue;
+            /// The axis's maximum coordinate value.
+            double maxValue;
+            /// The axis's default coordinate value. FreeType computes meaningful default values for Adobe MM fonts.
+            double defaultValue;
+        };
+
+        struct FontVariationAxis {
+            const char * name;
+            double value;
+        };
 
         static bool setFontVariationAxis(FT_Library & library, FT_Face & face, const char * name, double coordinate){
             bool success = false;
@@ -89,24 +105,34 @@ class Font {
             return success;
         }
 
-//bool listFontVariationAxes(std::vector<FontVariationAxis> &axes, FreetypeHandle *library, FontHandle *font) {
+        bool setFontVariationAxis(FT_Library & library, const std::string & name, float coordinate){
-        //if (font->face->face_flags&FT_FACE_FLAG_MULTIPLE_MASTERS) {
+            return Font::setFontVariationAxis(library, face, name.c_str(), coordinate);
-        //FT_MM_Var *master = NULL;
+        }
-        //if (FT_Get_MM_Var(font->face, &master))
+
-        //return false;
+        static bool listFontVariationAxes(std::vector <FontVariationAxisParameters> & axes, FT_Library & library, FT_Face & face){
-        //axes.resize(master->num_axis);
+            if(face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS){
-        //for (FT_UInt i = 0; i < master->num_axis; i++) {
+                FT_MM_Var * master = NULL;
-        //FontVariationAxis &axis = axes[i];
+                if(FT_Get_MM_Var(face, &master)){
-        //axis.name = master->axis[i].name;
+                    return false;
-        //axis.minValue = master->axis[i].minimum;
+                }
-        //axis.maxValue = master->axis[i].maximum;
+                axes.resize(master->num_axis);
-        //axis.defaultValue = master->axis[i].def;
+                for(FT_UInt i = 0; i < master->num_axis; i++){
-        //}
+                    FontVariationAxisParameters & axis = axes[i];
-        //FT_Done_MM_Var(library->library, master);
+                    axis.name = master->axis[i].name;
-        //return true;
+                    axis.minValue = F16DOT16_TO_DOUBLE(master->axis[i].minimum);
-        //}
+                    axis.maxValue = F16DOT16_TO_DOUBLE(master->axis[i].maximum);
-        //return false;
+                    axis.defaultValue = F16DOT16_TO_DOUBLE(master->axis[i].def);
-//}
+                }
+                FT_Done_MM_Var(library, master);
+                return true;
+            }
+            return false;
+        }
+
+        bool listFontVariationAxes(std::vector <FontVariationAxisParameters> & axes, FT_Library & library){
+            return Font::listFontVariationAxes(axes, library, face);
+        }
+
         static FT_Face loadFace(FT_Library library, const std::string & filename, std::string & error){
             FT_Face face = NULL;
 
@@ -291,10 +317,16 @@ class Font {
             uploadBuffers();
         }
 
-        void prepareGlyphsForText(const std::string & text){
+        void prepareGlyphsForText(const std::string & text, bool forceChange = false){
             // TODO: do not duplicate glyphs
             bool changed = false;
 
+            if(forceChange){
+                bufferGlyphs.clear();
+                bufferCurves.clear();
+                glyphs.clear();
+            }
+
             for(const char * textIt = text.c_str(); *textIt != '\0';){
                 uint32_t charcode = decodeCharcode(&textIt);
 
@@ -328,9 +360,6 @@ class Font {
                 // dynamic, the buffers could be overallocated and only the added
                 // data could be uploaded.
                 uploadBuffers();
-                //cout << "glyphs changed" << endl;
-            }else{
-                //cout << "glyphs not changed" << endl;
             }
         }
 

example/src/ofApp.cpp

@@ -5,6 +5,7 @@
 #include "ofRectangle.h"
 #include "ofTexture.h"
 #include "ofUtils.h"
+#include <iomanip>
 
 #ifdef TARGET_EMSCRIPTEN
  #include <GLES/gl.h>
@@ -36,9 +37,9 @@ bla bla bla
 void ofApp::setup(){
     mainText_full = "A";
     mainText = R"DONE(abcdefghijklmnopqrstuvqxyz
-ABCDEFGHIJKLMNOP)DONE";
+ABCDEFGHIJKLMNOPQRSTUVWXYZ
-//QRSTUVWXYZ
+0123456789",.!@#$%^&*()_+=-[]{})DONE";
-//0123456789",.!@#$%^&*()_+=-[]{})DONE";
+    mainText = "something is a sentence if words are being concerning which";
     mainText_full = R"DONE(Some things are hard to write about. Take soil,
 for instance. Soil, Oxford dictionary reads, “is the
 upper layer of earth in which plants grow, a black or
@@ -106,6 +107,15 @@ start. I hope to capture something essential.)DONE";
                       font,
                       bb);
 
+    font->listFontVariationAxes(fontVariationAxesParameters, library);
+    cout << currentFontPath << " : fontVariationAxes :" << endl;
+    for(const auto & axis : fontVariationAxesParameters){
+        cout << std::fixed << std::setprecision(10) << axis.name << " :\n"
+             << "\tmin: " << std::to_string(axis.minValue)
+             << "\tmax: " << std::to_string(axis.maxValue)
+             << "\tdefault: " << std::to_string(axis.defaultValue) << endl;
+        fontVariationAxes.push_back({axis.name, axis.defaultValue});
+    }
 
     transform = Transform();
 
@@ -135,7 +145,20 @@ start. I hope to capture something essential.)DONE";
 
 //--------------------------------------------------------------
 void ofApp::update(){
-
+    float animationSpeed = ofMap(sin(ofGetElapsedTimef() * 0.01), -1, 1, 0.0, 2);
+    float threshold = 5.0;
+    for(int i = 0; i < fontVariationAxes.size(); i++){
+        Font::FontVariationAxis & axis = fontVariationAxes[i];
+        Font::FontVariationAxisParameters & axisParams = fontVariationAxesParameters[i];
+        double newValue = ofMap(sin(ofGetElapsedTimef() * animationSpeed),
+                                -1, 1,
+                                axisParams.minValue, axisParams.maxValue);
+        if(abs(newValue - axis.value) > threshold){
+            font->setFontVariationAxis(library, axis.name, newValue);
+            axis.value = newValue;
+            font->prepareGlyphsForText(mainText, true);
+        }
+    }
 }
 
 //--------------------------------------------------------------

example/src/ofApp.h

@@ -89,6 +89,7 @@ class ofApp : public ofBaseApp {
         string currentFontPath;
         string mainText;
         string mainText_full;
+        string mainText_hitch;
 
         float helpFontBaseSize = 20.0f;
 
@@ -150,4 +151,8 @@ class ofApp : public ofBaseApp {
             "data/celines-fonts/tonkaflowers-Regular.otf",
             "data/celines-fonts/Version-3-var.ttf"
         };
+
+        std::vector <Font::FontVariationAxisParameters> fontVariationAxesParameters;
+        std::vector <Font::FontVariationAxis> fontVariationAxes;
+
 };