From 5fc06a177be5dc1c1fb42cb90716ce21d4087ad1 Mon Sep 17 00:00:00 2001
From: themancalledjakob <jakob@jrkb.land>
Date: Thu, 30 Mar 2023 16:19:13 +0200
Subject: [PATCH] glyph pairs for interpolation

---
 src/Atlas.cpp | 93 ++++++++++++++++++++++++++++++++++++++++++++++++---
 src/Atlas.h   |  7 ++++
 2 files changed, 95 insertions(+), 5 deletions(-)

diff --git a/src/Atlas.cpp b/src/Atlas.cpp
index e6ae7e6..9b7f04f 100644
--- a/src/Atlas.cpp
+++ b/src/Atlas.cpp
@@ -1,5 +1,6 @@
 #include "Atlas.h"
 #include "conversion.h"
+#include "edge-coloring.h"
 #include "import-font.h"
 
 namespace ofxMsdfgen {
@@ -184,6 +185,16 @@ bool Atlas::generate(){
                     //}
                 }
 
+                int vgi = 0;
+                for(const auto & vg : variationGlyphs){
+                    const unsigned char cp = vg.getCodepoint();
+                    GlyphVariationKey key;
+                    key.character = cp;
+                    key.variation = variation;
+                    glyphGeometryMap[key] = glyphs.size() + vgi;
+                    vgi++;
+                }
+
                 glyphs.insert(glyphs.end(),
                               variationGlyphs.begin(),
                               variationGlyphs.end());
@@ -192,10 +203,18 @@ bool Atlas::generate(){
             }
             // Apply MSDF edge coloring. See edge-coloring.h for other coloring strategies.
             for(msdf_atlas::GlyphGeometry & glyph : glyphs){
-                //FIXME: we do not need to inverse y axis, something else is wrong
+                // NOTE: const_cast is potentially evil,
+                // but like this we can use clipper for preprocessing shapes
                 // msdfgen::Shape & shape = const_cast <msdfgen::Shape &>(glyph.getShape());
+                // then convert Shape to ofPolyline and use getResampledBySpacing
+                // to convert it into straight lines
+                // then use clipper2 to union the shapes
+                // convert back into ofPolyline and then Shape
+                // or directly into Shape
+                //
+                // don't do this:
                 // shape.inverseYAxis = true;
-                glyph.edgeColoring(&msdfgen::edgeColoringInkTrap, // strategy
+                glyph.edgeColoring(&msdfgen::edgeColoringSimple, // strategy
                                    settings.maxCornerAngle,       // angleThreshold
                                    0);                            // seed
             }
@@ -277,12 +296,76 @@ const GlyphGeometry & Atlas::getGlyphGeometry(unsigned char character){
 const GlyphGeometry & Atlas::getGlyphGeometry(unsigned char character,
                                               FontVariation variation){
     // FIXME: error handling?
-    //GlyphVariationKey key = {character, variation};
-    //int index = glyphGeometryMap[key];
-    return glyphGeometries[0];
+    float smallestDistance = FLT_MAX;
+    int closestIndex = 0;
+    int i = 0;
+    for(const auto & v : variationSteps){
+        float distance = abs(v.value - variation.value);
+        if(distance < smallestDistance){
+            smallestDistance = distance;
+            closestIndex = i;
+        }
+        i++;
+    }
+    const auto & closestVariation = variationSteps[closestIndex];
+    GlyphVariationKey key = {character, closestVariation};
+    int index = glyphGeometryMap[key];
+    return glyphGeometries[index];
+}
+
+bool Atlas::getGlyphGeometryPair(const unsigned char character,
+                                 const FontVariation variation,
+                                 GlyphGeometry & a,
+                                 GlyphGeometry & b,
+                                 float & mix){
+    float smallestDistanceDown = -1 * FLT_MAX;
+    float smallestDistanceUp = FLT_MAX;
+    int closestIndexDown = 0;
+    int closestIndexUp = 0;
+    int i = 0;
+    for(const auto & v : variationSteps){
+        float distance = v.value - variation.value;
+        if(distance <= 0){
+            if(distance > smallestDistanceDown){
+                closestIndexDown = i;
+                smallestDistanceDown = distance;
+            }
+        }else{
+            if(distance < smallestDistanceUp){
+                closestIndexUp = i;
+                smallestDistanceUp = distance;
+            }
+        }
+        i++;
+    }
+
+    {
+        float total = abs(smallestDistanceUp) + abs(smallestDistanceDown);
+        //mix = ofMap(abs(smallestDistanceDown), 0, total, 0, 1);
+        mix = total == 0 || smallestDistanceDown == 0 ? 0 : abs(smallestDistanceDown) / total;
+    }
+    if(mix < 0 || mix > 1){
+        ofLogError("Atlas::getGlyphGeometryPair")
+            << "mix out of range.\n"
+            << "sorry for the shitty error message, just check the code";
+        return false;
+    }
+    const auto & closestVariationUp = variationSteps[closestIndexUp];
+    const auto & closestVariationDown = variationSteps[closestIndexDown];
+    GlyphVariationKey glyphKeyUp = {character, closestVariationUp};
+    GlyphVariationKey glyphKeyDown = {character, closestVariationDown};
+    int index_a = glyphGeometryMap[glyphKeyDown];
+    int index_b = glyphGeometryMap[glyphKeyUp];
+    a = glyphGeometries[index_a];
+    b = glyphGeometries[index_b];
+
+    return true;
 }
 
 const FontGeometry & Atlas::getFontGeometry(){
     return fontGeometry;
 }
+const vector <ofxMsdfgen::FontVariationAxis> & Atlas::getVariationAxesAvailable(){
+    return variationAxesAvailable;
+}
 }
diff --git a/src/Atlas.h b/src/Atlas.h
index a2429f1..0396094 100644
--- a/src/Atlas.h
+++ b/src/Atlas.h
@@ -93,8 +93,15 @@ class Atlas {
         const GlyphGeometry & getGlyphGeometry(unsigned char character);
         const GlyphGeometry & getGlyphGeometry(unsigned char character,
                                                FontVariation variation);
+        bool getGlyphGeometryPair(const unsigned char character,
+                                  const FontVariation variation,
+                                  GlyphGeometry & a,
+                                  GlyphGeometry & b,
+                                  float & mix);
+
         //const GlyphGeometry & getGlyphGeometry(GlyphVariationKey key);
         const FontGeometry & getFontGeometry();
+        const vector <FontVariationAxis> & getVariationAxesAvailable();
         AtlasSettings settings;
         msdfgen::FontHandle * font;
         msdfgen::FreetypeHandle * ft;