Add type sets for repeating caption settings

Rather than declaring the same settings (font, size, margin…) over
and over, a type set can be created in `_site.toml` and referenced
in the GIF source.

README.markdown

@@ -193,10 +193,31 @@ array, supporting multiple captions in a GIF.
   `caption` reports the x,y position actually used
 * `anchor` is the [alignment of the text][an] relative to the `placement`;
   default is `la`
+* `type` is the caption type set to use, described below
 
 [col]: https://pillow.readthedocs.io/en/stable/reference/ImageColor.html
 [an]: https://pillow.readthedocs.io/en/stable/handbook/text-anchors.html
 
+#### Caption type sets
+
+Rather than multiple GIF configuration files all having identical settings for
+font, size, margin…, type sets can be used. Caption type sets are defined in
+the `_site.toml`:
+
+    [type_set.zim_shout]
+    align     = 'center'
+    font      = 'anteb-extrablack.otf'
+    margin    = '20'
+    placement = 'bc'
+    size      = '48'
+
+Then a caption only needs to declare the type to have all of the type set
+values applied. Note, any values in the source TOML take precedence, acting
+as overrides to the type set.
+
+    [[caption]]
+    type      = 'zim_shout'
+    placement = 'br'
 
 ### Note on colours
 

bin/make_gif

@@ -8,6 +8,7 @@ DEFAULT_WIDTH=480
 DEFAULT_FPS=10
 DEFAULT_COLOURS=64
 DEBUG="${GIF_DEBUG:-}"
+TYPE_SETS="${GIF_TYPE_SETS:-source/_site.toml}"
 green=$'\e'[32m
 cyan=$'\e'[36m
 magenta=$'\e'[35m
@@ -72,15 +73,15 @@ function main {
     if [ "$num_captions" -gt 0 ]; then
         for index in $(seq 1 $num_captions); do
             caption_text="$(toml $toml caption.text $index)"
-            caption_placement="$(toml $toml caption.placement $index)"
-            caption_size="$(toml $toml caption.size $index)"
-            caption_margin="$(toml $toml caption.margin $index)"
-            caption_font="$(toml $toml caption.font $index)"
-            caption_colour="$(toml $toml caption.colour $index)"
-            caption_strokew="$(toml $toml caption.stroke_width $index)"
-            caption_strokecol="$(toml $toml caption.stroke_colour $index)"
-            caption_align="$(toml $toml caption.align $index)"
-            caption_anchor="$(toml $toml caption.anchor $index)"
+            caption_placement="$(get_caption_key $toml $index placement)"
+            caption_size="$(get_caption_key $toml $index size)"
+            caption_margin="$(get_caption_key $toml $index margin)"
+            caption_font="$(get_caption_key $toml $index font)"
+            caption_colour="$(get_caption_key $toml $index colour)"
+            caption_strokew="$(get_caption_key $toml $index stroke_width)"
+            caption_strokecol="$(get_caption_key $toml $index stroke_colour)"
+            caption_align="$(get_caption_key $toml $index align)"
+            caption_anchor="$(get_caption_key $toml $index anchor)"
             caption \
                 ${output_width:-$DEFAULT_WIDTH} \
                 $output_height \
@@ -433,6 +434,20 @@ function get_stats_mode {
     echo "stats_mode=${output_mode:-diff}"
 }
 
+function get_caption_key {
+    local toml="$1"
+    local index="$2"
+    local key="$3"
+
+    local set="$(toml $toml caption.type $index)"
+    local set_value="$(toml $TYPE_SETS type_set.$set.$key)"
+    local value="$(toml $toml caption.$key $index)"
+
+    [ -n "$value" ] \
+        && echo "$value" \
+        || echo "$set_value"
+}
+
 function size_in_mb {
     local bytes="$1"
     echo "$(echo 4k $bytes 1048576 / p | dc)"

source/_site.toml

@@ -9,3 +9,17 @@ future = false
 "/invader-zim/not-now-son.gif" = "/invader-zim/the-nightmare-begins/not-now-son.tn.gif"
 "/invader-zim/not-now-son.tn.gif" = "/invader-zim/the-nightmare-begins/not-now-son.tn.gif"
 "/tags/dib/" = "/tags/dib-membrane/"
+
+[type_set.zim_shout]
+align     = 'center'
+font      = 'anteb-extrablack.otf'
+margin    = '20'
+placement = 'bc'
+size      = '48'
+
+[type_set.zim_speak]
+align     = 'center'
+font      = 'anteb-regular.otf'
+margin    = '20'
+placement = 'bc'
+size      = '28'

tests/config/captions_type.toml

@@ -0,0 +1,29 @@
+[video]
+source   = 'youtube'
+file     = 'HU2ftCitvyQ'
+ext      = 'mp4'
+start    = '120'
+duration = '1'
+
+[output]
+colours  = '96'
+fps      = '18'
+
+[[caption]]
+text = 'And the climb'
+from = '0'
+to   = '0.3'
+type = 'normal'
+
+[[caption]]
+text = 'is going'
+from = '0.31'
+to   = '0.6'
+type = 'large'
+
+[[caption]]
+text = 'Where no man has gone before'
+from = '0.61'
+to   = '0.9'
+type = 'normal'
+font = 'assistant-extrabold.ttf'

tests/config/type_sets.toml

@@ -0,0 +1,9 @@
+[type_set.normal]
+font      = 'assistant-semibold.ttf'
+placement = 'bc'
+size      = '40'
+
+[type_set.large]
+font      = 'assistant-semibold.ttf'
+placement = 'bc'
+size      = '100'

tests/make_gifs.bats

@@ -108,6 +108,23 @@ reset=$'\e'[0m
     diff -u $BATS_TMPDIR/output.gif tests/gifs/captions.gif
 }
 
+@test generate_captions_type_set {
+    [ $(uname) != 'Darwin' ] && skip "Not macOS"
+
+    GIF_TYPE_SETS=tests/config/type_sets.toml \
+        run make_gif tests/config/captions_type.toml $BATS_TMPDIR/output.gif
+    echo "$output"
+
+    [ "${lines[1]}" == '  " font_size=40 placement=[121, 305] And the climb' ]
+    [ "${lines[2]}" == '  " font_size=100 placement=[75, 243] is going' ]
+    [ "${lines[3]}" == "  \" ${magenta}font_size=32${reset} placement=[19, 313] Where no man has gone before" ]
+    [ "${lines[4]}" == "    102 colours (96 initially)" ]
+
+    [ "$status" -eq 0 ]
+    # cp $BATS_TMPDIR/output.gif tests/gifs/captions_type.gif
+    diff -u $BATS_TMPDIR/output.gif tests/gifs/captions_type.gif
+}
+
 @test generate_captions_noscale {
     [ $(uname) != 'Darwin' ] && skip "Not macOS"