Expose metadata in protobuf

Pull what's applicable from #97 into
this commit.

Author: tristen

proto/glyphs.proto

@@ -10,7 +10,7 @@ option optimize_for = LITE_RUNTIME;
 message glyph {
     required uint32 id = 1;
 
-    // A signed distance field of the glyph with a border of 3 pixels.
+    // A signed distance field of a glyph with buffer documented in metadata.
     optional bytes bitmap = 2;
 
     // Glyph metrics.
@@ -21,11 +21,25 @@ message glyph {
     required uint32 advance = 7;
 }
 
-// Stores fontstack information and a list of faces.
+// Stores a face with glyphs and optional metadata.
 message fontstack {
-    required string name = 1;
-    required string range = 2;
-    repeated glyph glyphs = 3;
+    repeated Glyph glyphs = 1;
+
+    // Store SDF metadata.
+    message Metadata {
+        optional uint32 size = 1;
+        optional uint32 buffer = 2;
+        optional float cutoff = 3;
+        optional float scale = 4;
+    }
+
+    optional Metadata metadata = 2;
+
+    optional string family_name = 3;
+    optional string style_name = 4;
+    optional double ascender = 5;
+    optional double descender = 6;
+    optional double line_height = 7;
 }
 
 message glyphs {

src/glyphs.cpp

@@ -309,17 +309,29 @@ void RangeAsync(uv_work_t* req) {
             if (ft_face->family_name) {
                 llmr::glyphs::fontstack* mutable_fontstack = glyphs.add_stacks();
                 if (ft_face->style_name) {
-                    mutable_fontstack->set_name(std::string(ft_face->family_name) + " " + std::string(ft_face->style_name));
+                    mutable_fontstack->set_family_name(std::string(ft_face->family_name) + " " + std::string(ft_face->style_name));
                 } else {
-                    mutable_fontstack->set_name(std::string(ft_face->family_name));
+                    mutable_fontstack->set_family_name(std::string(ft_face->family_name));
                 }
 
-                mutable_fontstack->set_range(std::to_string(baton->start) + "-" + std::to_string(baton->end));
+                // TODO mutable_fontstack->set_range(std::to_string(baton->start) + "-" + std::to_string(baton->end));
+                mutable_fontstack->set_family_name(ft_face->family_name);
+                mutable_fontstack->set_style_name(ft_face->style_name);
+                mutable_fontstack->set_ascender(ft_face->ascender);
+                mutable_fontstack->set_descender(ft_face->descender);
+                mutable_fontstack->set_line_height(ft_face->height);
+
+                // Add metadata to face.
+                mbgl::glyphs::Face::Metadata mutable_metadata = mutable_face->metadata();
+                mutable_metadata.set_size(char_size);
+                mutable_metadata.set_buffer(buffer_size);
+                mutable_metadata.set_cutoff(cutoff_size);
+                mutable_metadata.set_scale(scale_factor);
 
                 const double scale_factor = 1.0;
 
                 // Set character sizes.
-                double size = 24 * scale_factor;
+                double size = char_size * scale_factor;
                 FT_Set_Char_Size(ft_face, 0, static_cast<FT_F26Dot6>(size * (1 << 6)), 0, 0);
 
                 for (std::vector<uint32_t>::size_type x = 0; x != baton->chars.size(); x++) {
@@ -332,7 +344,7 @@ void RangeAsync(uv_work_t* req) {
                     if (!char_index) continue;
 
                     glyph.glyph_index = char_index;
-                    sdf_glyph_foundry::RenderSDF(glyph, 24, 3, 0.25, ft_face);
+                    sdf_glyph_foundry::RenderSDF(glyph, char_size, buffer_size, cutoff_size, ft_face);
 
                     // Add glyph to fontstack.
                     llmr::glyphs::glyph* mutable_glyph = mutable_fontstack->add_glyphs();

src/glyphs.hpp

@@ -1,5 +1,4 @@
-#ifndef NODE_FONTNIK_GLYPHS_HPP
-#define NODE_FONTNIK_GLYPHS_HPP
+#pragma once
 
 #include "glyphs.pb.h"
 #include <nan.h>
@@ -15,4 +14,15 @@ void AfterRange(uv_work_t* req);
 
 } // namespace node_fontnik
 
-#endif // NODE_FONTNIK_GLYPHS_HPP
+void RenderSDF(glyph_info &glyph,
+               int size,
+               int buffer,
+               float cutoff,
+               FT_Face ft_face);
+
+const static int char_size = 24;
+const static int buffer_size = 3;
+const static float cutoff_size = 0.25;
+const static float scale_factor = 1.0;
+
+} // namespace node_fontnik