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-rw-r--r--hb.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/hb.c b/hb.c
new file mode 100644
index 0000000..bc204d8
--- /dev/null
+++ b/hb.c
@@ -0,0 +1,149 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <X11/Xft/Xft.h>
+#include <hb.h>
+#include <hb-ft.h>
+
+#include "st.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 }
+
+void hbtransformsegment(XftFont *xfont, const Glyph *string, hb_codepoint_t *codepoints, int start, int length);
+hb_font_t *hbfindfont(XftFont *match);
+
+typedef struct {
+ XftFont *match;
+ hb_font_t *font;
+} HbFontMatch;
+
+static int hbfontslen = 0;
+static HbFontMatch *hbfontcache = NULL;
+
+/*
+ * Poplulate the array 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[] = { };
+
+void
+hbunloadfonts()
+{
+ for (int i = 0; i < hbfontslen; i++) {
+ hb_font_destroy(hbfontcache[i].font);
+ XftUnlockFace(hbfontcache[i].match);
+ }
+
+ if (hbfontcache != NULL) {
+ free(hbfontcache);
+ hbfontcache = NULL;
+ }
+ hbfontslen = 0;
+}
+
+hb_font_t *
+hbfindfont(XftFont *match)
+{
+ for (int 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 == NULL)
+ die("Failed to load Harfbuzz font.");
+
+ hbfontcache[hbfontslen].match = match;
+ hbfontcache[hbfontslen].font = font;
+ hbfontslen += 1;
+
+ return font;
+}
+
+void
+hbtransform(XftGlyphFontSpec *specs, const Glyph *glyphs, size_t len, int x, int y)
+{
+ int start = 0, length = 1, gstart = 0;
+ hb_codepoint_t *codepoints = calloc((unsigned int)len, sizeof(hb_codepoint_t));
+
+ for (int idx = 1, specidx = 1; idx < len; idx++) {
+ if (glyphs[idx].mode & ATTR_WDUMMY) {
+ length += 1;
+ continue;
+ }
+
+ if (specs[specidx].font != specs[start].font || ATTRCMP(glyphs[gstart], glyphs[idx]) || selected(x + idx, y) != selected(x + gstart, y)) {
+ hbtransformsegment(specs[start].font, glyphs, codepoints, gstart, length);
+
+ /* Reset the sequence. */
+ length = 1;
+ start = specidx;
+ gstart = idx;
+ } else {
+ length += 1;
+ }
+
+ specidx++;
+ }
+
+ /* EOL. */
+ hbtransformsegment(specs[start].font, glyphs, codepoints, gstart, length);
+
+ /* Apply the transformation to glyph specs. */
+ for (int i = 0, specidx = 0; i < len; i++) {
+ if (glyphs[i].mode & ATTR_WDUMMY)
+ continue;
+ if (glyphs[i].mode & ATTR_BOXDRAW) {
+ specidx++;
+ continue;
+ }
+
+ if (codepoints[i] != specs[specidx].glyph)
+ ((Glyph *)glyphs)[i].mode |= ATTR_LIGA;
+
+ specs[specidx++].glyph = codepoints[i];
+ }
+
+ free(codepoints);
+}
+
+void
+hbtransformsegment(XftFont *xfont, const Glyph *string, hb_codepoint_t *codepoints, int start, int length)
+{
+ hb_font_t *font = hbfindfont(xfont);
+ if (font == NULL)
+ return;
+
+ Rune rune;
+ ushort mode = USHRT_MAX;
+ hb_buffer_t *buffer = hb_buffer_create();
+ hb_buffer_set_direction(buffer, HB_DIRECTION_LTR);
+
+ /* Fill buffer with codepoints. */
+ for (int i = start; i < (start+length); i++) {
+ rune = string[i].u;
+ mode = string[i].mode;
+ if (mode & ATTR_WDUMMY)
+ rune = 0x0020;
+ hb_buffer_add_codepoints(buffer, &rune, 1, 0, 1);
+ }
+
+ /* Shape the segment. */
+ hb_shape(font, buffer, features, sizeof(features)/sizeof(hb_feature_t));
+
+ /* Get new glyph info. */
+ hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, NULL);
+
+ /* Write new codepoints. */
+ for (int i = 0; i < length; i++) {
+ hb_codepoint_t gid = info[i].codepoint;
+ codepoints[start+i] = gid;
+ }
+
+ /* Cleanup. */
+ hb_buffer_destroy(buffer);
+}