From 0e91218ff89aee9a24d7cd577de37b0f1bb8331a Mon Sep 17 00:00:00 2001
From: Robin Watts <robin.watts@artifex.com>
Date: Wed, 10 Feb 2016 14:54:23 +0000
Subject: Refactor node shaping code.
We walk the text in a node to shape it in 2 different places
in the code. Reformulate the code so that the 'walking' logic
is commoned up.
---
source/html/html-layout.c | 294 +++++++++++++++++++++-------------------------
1 file changed, 131 insertions(+), 163 deletions(-)
diff --git a/source/html/html-layout.c b/source/html/html-layout.c
index fdabe93b..2735dfeb 100644
--- a/source/html/html-layout.c
+++ b/source/html/html-layout.c
@@ -543,100 +543,137 @@ static void measure_image(fz_context *ctx, fz_html_flow *node, float max_w, floa
node->h = node->content.image->h * s;
}
-static void measure_word(fz_context *ctx, fz_html_flow *node, float em, hb_buffer_t *hb_buf)
+typedef struct string_walker
{
- fz_font *font, *next_font;
+ fz_context *ctx;
+ hb_buffer_t *hb_buf;
+ int r2l;
+ const char *start;
+ const char *end;
+ const char *s;
+ fz_font *base_font;
+ int script;
+ fz_font *font;
+ fz_font *next_font;
hb_glyph_position_t *glyph_pos;
- unsigned int glyph_count, i;
- int max_x, x;
- const char *s, *start, *end;
+ unsigned int glyph_count;
+ int scale;
+} string_walker;
+
+static void init_string_walker(fz_context *ctx, string_walker *walker, hb_buffer_t *hb_buf, int r2l, fz_font *font, int script, const char *text)
+{
+ walker->ctx = ctx;
+ walker->hb_buf = hb_buf;
+ walker->r2l = r2l;
+ walker->start = text;
+ walker->end = text;
+ walker->s = text;
+ walker->base_font = font;
+ walker->script = script;
+ walker->font = NULL;
+ walker->next_font = NULL;
+}
+
+static int walk_string(string_walker *walker)
+{
+ fz_context *ctx = walker->ctx;
FT_Face face;
int fterr;
- int scale;
- em = fz_from_css_number(node->style->font_size, em, em);
- node->x = 0;
- node->y = 0;
- node->w = 0;
- node->h = fz_from_css_number_scale(node->style->line_height, em, em, em);
+ walker->start = walker->end;
+ walker->end = walker->s;
+ walker->font = walker->next_font;
+
+ if (*walker->start == 0)
+ return 0;
- start = end = s = node->content.text;
- font = NULL;
- while (*start)
+ /* Run through the string, encoding chars until we find one
+ * that requires a different fallback font. */
+ while (*walker->s)
{
- /* Run through the string, encoding chars until we find one
- * that requires a different fallback font. */
- while (*s)
- {
- int c;
+ int c;
- s += fz_chartorune(&c, s);
- (void)fz_encode_character_with_fallback(ctx, node->style->font, c, node->script, &next_font);
- if (next_font != font)
- {
- if (font != NULL)
- break;
- font = next_font;
- }
- end = s;
+ walker->s += fz_chartorune(&c, walker->s);
+ (void)fz_encode_character_with_fallback(ctx, walker->base_font, c, walker->script, &walker->next_font);
+ if (walker->next_font != walker->font)
+ {
+ if (walker->font != NULL)
+ break;
+ walker->font = walker->next_font;
}
+ walker->end = walker->s;
+ }
- fz_try(ctx)
- {
- hb_lock(ctx);
+ fz_try(ctx)
+ {
+ hb_lock(ctx);
- /* So, shape from start to end in font */
- face = font->ft_face;
- scale = face->units_per_EM;
- fterr = FT_Set_Char_Size(face, scale, scale, 72, 72);
- if (fterr)
- fz_throw(ctx, FZ_ERROR_GENERIC, "Failure sizing font (%d)", fterr);
+ /* So, shape from start to end in font */
+ face = walker->font->ft_face;
+ walker->scale = face->units_per_EM;
+ fterr = FT_Set_Char_Size(face, walker->scale, walker->scale, 72, 72);
+ if (fterr)
+ fz_throw(ctx, FZ_ERROR_GENERIC, "Failure sizing font (%d)", fterr);
- if (font->shaper == NULL)
- font->shaper = (void *)hb_ft_font_create(face, NULL);
+ if (walker->font->shaper == NULL)
+ walker->font->shaper = (void *)hb_ft_font_create(face, NULL);
- hb_buffer_clear_contents(hb_buf);
- hb_buffer_set_direction(hb_buf, node->char_r2l ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
- /* We don't know script or language, so leave them blank */
- /* hb_buffer_set_script(hb_buf, HB_SCRIPT_LATIN); */
- /* hb_buffer_set_language(hb_buf, hb_language_from_string("en", strlen("en"))); */
+ hb_buffer_clear_contents(walker->hb_buf);
+ hb_buffer_set_direction(walker->hb_buf, walker->r2l ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
+ /* We don't know script or language, so leave them blank */
+ /* hb_buffer_set_script(hb_buf, HB_SCRIPT_LATIN); */
+ /* hb_buffer_set_language(hb_buf, hb_language_from_string("en", strlen("en"))); */
- /* First put the text content into a harfbuzz buffer
- * labelled with the position within the word. */
- hb_buffer_add_utf8(hb_buf, start, end - start, 0, -1);
- hb_buffer_guess_segment_properties(hb_buf);
+ /* First put the text content into a harfbuzz buffer
+ * labelled with the position within the word. */
+ hb_buffer_add_utf8(walker->hb_buf, walker->start, walker->end - walker->start, 0, -1);
+ hb_buffer_guess_segment_properties(walker->hb_buf);
- /* Now shape that buffer */
- hb_shape(font->shaper, hb_buf, NULL, 0);
+ /* Now shape that buffer */
+ hb_shape(walker->font->shaper, walker->hb_buf, NULL, 0);
- glyph_pos = hb_buffer_get_glyph_positions(hb_buf, &glyph_count);
- }
- fz_always(ctx)
- {
- hb_unlock(ctx);
- }
- fz_catch(ctx)
- {
- fz_rethrow(ctx);
- }
+ walker->glyph_pos = hb_buffer_get_glyph_positions(walker->hb_buf, &walker->glyph_count);
+ }
+ fz_always(ctx)
+ {
+ hb_unlock(ctx);
+ }
+ fz_catch(ctx)
+ {
+ fz_rethrow(ctx);
+ }
+ return 1;
+}
+
+static void measure_word(fz_context *ctx, fz_html_flow *node, float em, hb_buffer_t *hb_buf)
+{
+ unsigned int i;
+ int max_x, x;
+ string_walker walker;
+
+ em = fz_from_css_number(node->style->font_size, em, em);
+ node->x = 0;
+ node->y = 0;
+ node->w = 0;
+ node->h = fz_from_css_number_scale(node->style->line_height, em, em, em);
+
+ init_string_walker(ctx, &walker, hb_buf, node->char_r2l, node->style->font, node->script, node->content.text);
+ while (walk_string(&walker))
+ {
max_x = 0;
x = 0;
- for (i = 0; i < glyph_count; i++)
+ for (i = 0; i < walker.glyph_count; i++)
{
int lx;
- x += glyph_pos[i].x_advance;
- lx = x + glyph_pos[i].x_offset;
+ x += walker.glyph_pos[i].x_advance;
+ lx = x + walker.glyph_pos[i].x_offset;
if (lx > max_x)
max_x = lx;
}
- start = end;
- end = s;
- font = next_font;
-
- node->w += max_x * em / scale;
+ node->w += max_x * em / walker.scale;
}
node->em = em;
@@ -988,18 +1025,12 @@ static float layout_block(fz_context *ctx, fz_html *box, fz_html *top, float em,
static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float page_bot, fz_device *dev, const fz_matrix *ctm, hb_buffer_t *hb_buf)
{
- fz_font *font, *next_font;
fz_html_flow *node;
fz_text *text;
fz_matrix trm;
- const char *s;
- const char *t;
- const char *start;
- const char *end;
float color[3];
- int c, scale, fterr;
+ int c;
float node_scale;
- FT_Face face;
float w, lx, ly;
/* FIXME: HB_DIRECTION_TTB? */
@@ -1020,10 +1051,10 @@ static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float p
if (node->type == FLOW_WORD)
{
int idx;
- unsigned int gp, glyph_count;
+ unsigned int gp;
hb_glyph_info_t *glyph_info;
- hb_glyph_position_t *glyph_pos;
float x, y;
+ string_walker walker;
if (node->content.text == NULL)
continue;
@@ -1040,77 +1071,16 @@ static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float p
x = node->x;
y = node->y;
w = node->w;
- start = end = s = node->content.text;
- font = NULL;
- while (*start)
+ init_string_walker(ctx, &walker, hb_buf, node->char_r2l, node->style->font, node->script, node->content.text);
+ while (walk_string(&walker))
{
- /* Run through the string, encoding chars until we find one
- * that requires a different fallback font. */
- while (*s)
- {
- int c;
-
- s += fz_chartorune(&c, s);
- (void)fz_encode_character_with_fallback(ctx, node->style->font, c, node->script, &next_font);
- if (next_font != font)
- {
- if (font != NULL)
- break;
- font = next_font;
- }
- end = s;
- }
-
- fz_try(ctx)
- {
- hb_lock(ctx);
-
- /* So, shape from start to end in font */
- face = font->ft_face;
- scale = face->units_per_EM;
- fterr = FT_Set_Char_Size(face, scale, scale, 72, 72);
- if (fterr)
- fz_throw(ctx, FZ_ERROR_GENERIC, "Failure sizing font (%d)", fterr);
-
- if (font->shaper == NULL)
- font->shaper = (void *)hb_ft_font_create(face, NULL);
-
- hb_buffer_clear_contents(hb_buf);
- hb_buffer_set_direction(hb_buf, node->char_r2l ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
- /* We don't know script or language, so leave them blank */
- /* hb_buffer_set_script(hb_buf, HB_SCRIPT_LATIN); */
- /* hb_buffer_set_language(hb_buf, hb_language_from_string("en", strlen("en"))); */
-
- /* First put the text content into a harfbuzz buffer
- * labelled with the position within the word. */
- hb_buffer_add_utf8(hb_buf, start, end - start, 0, -1);
- hb_buffer_guess_segment_properties(hb_buf);
-
- face = font->ft_face;
- scale = face->units_per_EM;
- fterr = FT_Set_Char_Size(face, scale, scale, 72, 72);
- if (fterr)
- fz_throw(ctx, FZ_ERROR_GENERIC, "Failure sizing font (%d)", fterr);
-
- /* Now shape that buffer */
- hb_shape(font->shaper, hb_buf, NULL, 0);
-
- glyph_info = hb_buffer_get_glyph_infos(hb_buf, &glyph_count);
- glyph_pos = hb_buffer_get_glyph_positions(hb_buf, &glyph_count);
- }
- fz_always(ctx)
- {
- hb_unlock(ctx);
- }
- fz_catch(ctx)
- {
- fz_rethrow(ctx);
- }
-
+ const char *t;
#ifdef DEBUG_HARFBUZZ
+ int c;
+
printf("fragment: ");
- t = start;
- while (t != end)
+ t = walker.start;
+ while (t != walker.end)
{
t += fz_chartorune(&c, t);
if (c >= 127)
@@ -1120,6 +1090,7 @@ static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float p
}
printf("\n");
#endif /* DEBUG_HARFBUZZ */
+ glyph_info = hb_buffer_get_glyph_infos(hb_buf, &walker.glyph_count);
/* Now offset the glyph_info with the correct positions.
* Harfbuzz always gives us the shaped glyphs for plotting in l2r
@@ -1128,15 +1099,15 @@ static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float p
* of ordering we resolve the positions here. The nasty thing is
* that we right the resolved positions back into the Harfbuzz
* buffer with a change of type. */
- node_scale = node->em / scale;
+ node_scale = node->em / walker.scale;
lx = 0;
ly = 0;
- for (gp = 0; gp < glyph_count; gp++)
+ for (gp = 0; gp < walker.glyph_count; gp++)
{
- hb_glyph_position_t *p = &glyph_pos[gp];
+ hb_glyph_position_t *p = &walker.glyph_pos[gp];
#ifdef DEBUG_HARFBUZZ
- hb_glyph_info_t *g = &glyph_info[gp];
+ hb_glyph_info_t *g = &walker.glyph_info[gp];
printf("glyph: %x(%d) @ %d %d + %d %d",
g->codepoint, g->cluster, p->x_offset, p->y_offset,
@@ -1154,9 +1125,9 @@ static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float p
if (node->char_r2l)
{
w -= lx * node_scale;
- for (gp = 0; gp < glyph_count; gp++)
+ for (gp = 0; gp < walker.glyph_count; gp++)
{
- hb_glyph_position_t *p = &glyph_pos[gp];
+ hb_glyph_position_t *p = &walker.glyph_pos[gp];
*(float *)(&p->x_offset) += w;
}
}
@@ -1169,7 +1140,7 @@ static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float p
/* Now read the data back out again, and turn it into
* glyph/ucs pairs to go to fz_text */
idx = 0;
- t = start;
+ t = walker.start;
if (node->style->visibility == V_VISIBLE)
{
while (*t)
@@ -1177,46 +1148,43 @@ static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float p
int l = fz_chartorune(&c, t);
t += l;
- for (gp = 0; gp < glyph_count; gp++)
+ for (gp = 0; gp < walker.glyph_count; gp++)
{
hb_glyph_info_t *g = &glyph_info[gp];
- hb_glyph_position_t *p = &glyph_pos[gp];
+ hb_glyph_position_t *p = &walker.glyph_pos[gp];
if (g->cluster != idx)
continue;
trm.e = *(float *)&p->x_offset;
trm.f = *(float *)&p->y_offset;
- fz_add_text(ctx, text, font, 0, &trm, g->codepoint, c);
+ fz_add_text(ctx, text, walker.font, 0, &trm, g->codepoint, c);
break;
}
- if (gp == glyph_count)
+ if (gp == walker.glyph_count)
{
/* We failed to find a glyph for this codepoint, presumably
* because we've been shaped away into another. We can't afford
* to just drop the codepoint as this will upset text extraction.
*/
- fz_add_text(ctx, text, font, 0, &trm, -1, c);
+ fz_add_text(ctx, text, walker.font, 0, &trm, -1, c);
}
else
{
/* We've send the codepoint and glyph. Make sure there aren't
* more glyphs to come from the same codepoint. */
- for (gp++ ;gp < glyph_count; gp++)
+ for (gp++ ;gp < walker.glyph_count; gp++)
{
hb_glyph_info_t *g = &glyph_info[gp];
- hb_glyph_position_t *p = &glyph_pos[gp];
+ hb_glyph_position_t *p = &walker.glyph_pos[gp];
if (g->cluster != idx)
continue;
trm.e = *(float *)&p->x_offset;
trm.f = *(float *)&p->y_offset;
- fz_add_text(ctx, text, font, 0, &trm, g->codepoint, -1);
+ fz_add_text(ctx, text, walker.font, 0, &trm, g->codepoint, -1);
}
}
idx += l;
}
}
- start = end;
- end = s;
- font = next_font;
}
fz_fill_text(ctx, dev, text, ctm, fz_device_rgb(ctx), color, 1);
fz_drop_text(ctx, text);
--
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