From 2a32309f9cfc602d478229a6fe8562996a4652c9 Mon Sep 17 00:00:00 2001
From: Nicholas Noll <nbnoll@eml.cc>
Date: Sat, 9 Oct 2021 10:38:34 -0700
Subject: fix(term): forgot harfbuzz file

---
 sys/cmd/term/hb.c | 147 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 147 insertions(+)
 create mode 100644 sys/cmd/term/hb.c

(limited to 'sys')

diff --git a/sys/cmd/term/hb.c b/sys/cmd/term/hb.c
new file mode 100644
index 0000000..4aed59b
--- /dev/null
+++ b/sys/cmd/term/hb.c
@@ -0,0 +1,147 @@
+#include "term.h"
+
+#include <X11/Xft/Xft.h>
+#include <hb-ft.h>
+
+#define FEATURE(c1,c2,c3,c4) { .tag = HB_TAG(c1,c2,c3,c4), .value = 1, .start = HB_FEATURE_GLOBAL_START, .end = HB_FEATURE_GLOBAL_END }
+
+hb_font_t *hbfindfont(XftFont *match);
+void hbtransformsegment(XftFont *xfont, const Letter *glyph, rune *codepoints, int start, int end);
+
+typedef struct 
+{
+    XftFont *match;
+    hb_font_t *font;
+} HbFontMatch;
+
+static int hbfontslen = 0;
+static HbFontMatch *hbfontcache = nil;
+
+/* 
+ * Replace 0 with a list of font features, wrapped in FEATURE macro, e.g. 
+ * FEATURE('c', 'a', 'l', 't'), FEATURE('d', 'l', 'i', 'g')
+ */
+hb_feature_t features[] = { 0 };
+
+void
+hbunloadfonts()
+{
+    int i;
+    for(i = 0; i < hbfontslen; i++) {
+        hb_font_destroy(hbfontcache[i].font);
+        XftUnlockFace(hbfontcache[i].match);
+    }
+
+    if(hbfontcache != nil) {
+        free(hbfontcache);
+        hbfontcache = nil;
+    }
+
+    hbfontslen = 0;
+}
+
+hb_font_t *
+hbfindfont(XftFont *match)
+{
+    int i;
+    for (i = 0; i < hbfontslen; i++) {
+        if (hbfontcache[i].match == match)
+            return hbfontcache[i].font;
+    }
+
+    /* Font not found in cache, caching it now. */
+    hbfontcache = realloc(hbfontcache, sizeof(HbFontMatch) * (hbfontslen + 1));
+    FT_Face face = XftLockFace(match);
+    hb_font_t *font = hb_ft_font_create(face, NULL);
+    if(!font)
+        fatal("failed to load Harfbuzz font.");
+
+    hbfontcache[hbfontslen].match = match;
+    hbfontcache[hbfontslen].font = font;
+    hbfontslen += 1;
+
+    return font;
+}
+
+void
+hbtransform(XftGlyphFontSpec *specs, const Letter *glyphs, size_t len, int x, int y)
+{
+	int idx, specidx, start = 0, length = 1, gstart = 0;
+	rune *runes = calloc((unsigned int)len, sizeof(hb_codepoint_t));
+
+    for(idx = 1, specidx = 1; idx < len; idx++) {
+        if(glyphs[idx].mode & Gwdummy) {
+            length += 1;
+            continue;
+        }
+
+        if(specs[specidx].font != specs[start].font
+       || GLYPHCMP(glyphs[gstart], glyphs[idx])
+       || selected(x + idx, y) != selected(x + gstart, y)
+        ) {
+            hbtransformsegment(specs[start].font, glyphs, runes, gstart, length);
+            /* reset the sequence. */
+            length = 1;
+            start = specidx;
+            gstart = idx;
+        } else {
+            length += 1;
+        }
+
+        specidx++;
+    }
+
+    /* eol */
+    hbtransformsegment(specs[start].font, glyphs, runes, gstart, length);
+
+    /* apply the transformation to glyph specs. */
+    for(idx = 0, specidx = 0; idx < len; idx++) {
+        if(glyphs[idx].mode & Gwdummy)
+            continue;
+
+        if(runes[idx] != specs[specidx].glyph)
+            ((Letter *)glyphs)[idx].mode |= Gliga;
+
+        specs[specidx++].glyph = runes[idx];
+    }
+
+	free(runes);
+}
+
+void
+hbtransformsegment(XftFont *xfont, const Letter *glyph, rune *codepoints, int start, int len)
+{
+    hb_font_t *font = hbfindfont(xfont);
+    if(!font)
+        return;
+
+    int i;
+    rune r;
+    ushort mode = USHRT_MAX;
+    hb_buffer_t *buffer = hb_buffer_create();
+    hb_buffer_set_direction(buffer, HB_DIRECTION_LTR);
+
+    /* Fill buffer with codepoints. */
+    for(i=start; i < (start+len); i++) {
+        r = glyph[i].u;
+        mode = glyph[i].mode;
+        if(mode & Gwdummy)
+            r = 0x0020;
+        hb_buffer_add_codepoints(buffer, &r, 1, 0, 1);
+    }
+
+    /* Shape the segment. */
+    hb_shape(font, buffer, features, sizeof(features));
+
+    /* Get new glyph info. */
+    hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, NULL);
+
+    /* Write new codepoints. */
+    for(i = 0; i < len; i++) {
+        r = info[i].codepoint;
+        codepoints[start+i] = r;
+    }
+
+    /* Cleanup. */
+    hb_buffer_destroy(buffer);
+}
-- 
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