[TextServer] Save advances rounding remainders to prevent rounding error accumulation.

This commit is contained in:
bruvzg 2024-06-16 10:46:23 +03:00
parent e2fc6d38cb
commit dc8d7ef43e
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@ -6052,6 +6052,7 @@ void TextServerAdvanced::_shape_run(ShapedTextDataAdvanced *p_sd, int64_t p_star
unsigned int last_cluster_index = 0;
bool last_cluster_valid = true;
double adv_rem = 0.0;
for (unsigned int i = 0; i < glyph_count; i++) {
if ((i > 0) && (last_cluster_id != glyph_info[i].cluster)) {
if (p_direction == HB_DIRECTION_RTL || p_direction == HB_DIRECTION_BTT) {
@ -6097,21 +6098,31 @@ void TextServerAdvanced::_shape_run(ShapedTextDataAdvanced *p_sd, int64_t p_star
gl.index = glyph_info[i].codepoint;
if (gl.index != 0) {
_ensure_glyph(fd, fss, gl.index | mod);
if (subpos) {
gl.x_off = (double)glyph_pos[i].x_offset / (64.0 / scale);
} else if (p_sd->orientation == ORIENTATION_HORIZONTAL) {
gl.x_off = Math::round(adv_rem + ((double)glyph_pos[i].x_offset / (64.0 / scale)));
} else {
gl.x_off = Math::round((double)glyph_pos[i].x_offset / (64.0 / scale));
}
if (p_sd->orientation == ORIENTATION_HORIZONTAL) {
gl.y_off = -Math::round((double)glyph_pos[i].y_offset / (64.0 / scale));
} else {
gl.y_off = -Math::round(adv_rem + ((double)glyph_pos[i].y_offset / (64.0 / scale)));
}
if (p_sd->orientation == ORIENTATION_HORIZONTAL) {
if (subpos) {
gl.advance = (double)glyph_pos[i].x_advance / (64.0 / scale) + ea;
} else {
gl.advance = Math::round((double)glyph_pos[i].x_advance / (64.0 / scale) + ea);
double full_adv = adv_rem + ((double)glyph_pos[i].x_advance / (64.0 / scale) + ea);
gl.advance = Math::round(full_adv);
adv_rem = full_adv - gl.advance;
}
} else {
gl.advance = -Math::round((double)glyph_pos[i].y_advance / (64.0 / scale));
double full_adv = adv_rem + ((double)glyph_pos[i].y_advance / (64.0 / scale));
gl.advance = -Math::round(full_adv);
adv_rem = full_adv + gl.advance;
}
if (subpos) {
gl.x_off = (double)glyph_pos[i].x_offset / (64.0 / scale);
} else {
gl.x_off = Math::round((double)glyph_pos[i].x_offset / (64.0 / scale));
}
gl.y_off = -Math::round((double)glyph_pos[i].y_offset / (64.0 / scale));
if (p_sd->orientation == ORIENTATION_HORIZONTAL) {
gl.y_off += _font_get_baseline_offset(gl.font_rid) * (double)(_font_get_ascent(gl.font_rid, gl.font_size) + _font_get_descent(gl.font_rid, gl.font_size));
} else {