add personal notes for measuring text

src/量測文字.txt

@@ -0,0 +1,62 @@
+import * as fontkit from "fontkit";
+var font = await fontkit.openSync('/home/yoxem/桌面/TMP/ts-playground/aliputtat/LinLibertine_DR.otf');
+var run = font.layout('a̍h',undefined, undefined, undefined, "ltr");
+
+for (var i=0;i<=2;i++){
+console.log(run.glyphs[i]._metrics);
+console.log(run.glyphs[i].bbox); // bounding box
+console.log(run.glyphs[i].advanceWidth);
+}
+
+
+/*結果：
+
+假設文字大小為16(px)（=12pt），則下面的數字單位為
+16/1000 px = [文字pt值]*(4/3)/1000 px
+454 即 454*16/1000 px；1140即1140*16/1000 px等等。
+*/
+
+{
+  advanceWidth: 454, // 游標前進的長度
+  advanceHeight: 1140, // 游標往下的長度
+  leftBearing: 42, 
+  topBearing: 475
+}
+$f34600ab9d7f70d8$export$2e2bcd8739ae039 {
+  minX: 42, // 文字最左邊的x座標
+  minY: -10, // 文字最下邊的y座標
+  maxX: 441, // 文字最右邊的座標
+  maxY: 419 // 文字最上的座標
+
+}
+//文字glyph字圖寬度 = (441-42)*16/1000 px
+//文字glyph字圖高度 = (419-(-10))*16/1000 px
+
+
+454
+{
+  advanceWidth: 0,
+  advanceHeight: 1140,
+  leftBearing: -181,
+  topBearing: 184
+}
+$f34600ab9d7f70d8$export$2e2bcd8739ae039 {
+  minX: -181,
+  minY: 548,
+  maxX: -127,
+  maxY: 710
+}
+0
+{
+  advanceWidth: 511,
+  advanceHeight: 1140,
+  leftBearing: 18,
+  topBearing: 196
+}
+$f34600ab9d7f70d8$export$2e2bcd8739ae039 {
+  minX: 18.5,
+  minY: -5,
+  maxX: 499.75,
+  maxY: 698
+}
+511

參考資料-Harfbuzz如何使用.py

@@ -1,34 +0,0 @@
-import sys
-
-import uharfbuzz as hb
-
-
-fontfile = sys.argv[1]
-text = sys.argv[2]
-
-blob = hb.Blob.from_file_path(fontfile)
-face = hb.Face(blob)
-font = hb.Font(face)
-
-px = 96
-scale = 1000000.0/952997
-font.scale = (px *scale* 1024, px*scale * 1024)
-
-buf = hb.Buffer()
-buf.add_str(text)
-buf.guess_segment_properties()
-
-features = {"kern": True, "liga": True}
-hb.shape(font, buf, features)
-
-infos = buf.glyph_infos
-positions = buf.glyph_positions
-
-for info, pos in zip(infos, positions):
-    gid = info.codepoint
-    cluster = info.cluster
-    x_advance = pos.x_advance / 1024
-    y_advance = pos.y_advance / 1024
-    x_offset = pos.x_offset / 1024
-    y_offset = pos.y_offset /1024
-    print(f"gid{gid}={cluster}@{x_advance},{y_offset}+{x_advance},{y_advance}")