Merge pull request googlefonts#389 from googlefonts/colrv1

COLRv1 edition

Makefile

@@ -241,6 +241,11 @@ clean:
 	rm -f waveflag
 	rm -rf $(BUILD_DIR)
 
+# This prints the value of a Makefile variable: e.g. `make print-SELECTED_FLAGS`
+# will print the content of SELECTED_FLAGS.
+# Source: https://apprize.best/linux/gnu/3.html
+print-%: ; @echo $* = $($*)
+
 .SECONDARY: $(EMOJI_FILES) $(FLAG_FILES) $(RESIZED_FLAG_FILES) $(RENAMED_FLAG_FILES) \
   $(ALL_QUANTIZED_FILES) $(ALL_COMPRESSED_FILES)
 

colrv1/README.md

@@ -0,0 +1,21 @@
+# COLRv1 Build
+
+We assume the bitmap version with equivalent coverage exists and
+contains emojicompat metadata.
+
+## Build Steps
+
+1. Compile the COLRv1 fonts
+
+   ```shell
+   time nanoemoji *.toml
+   ```
+
+1. Post-process COLRv1 font for Android
+   * At time of writing only the noflags version is for Android
+
+   ```shell
+   # Assumed to be in a python3 environment with requirements.txt fulfilled
+   python colrv1_postproc.py colrv1/build/NotoColorEmoji-noflags.ttf \
+   	PATH_TO/NotoColorEmojiCompat.ttf
+   ```