From 0d7aab2375e6bb06e89dad851550b283a1ff805c Mon Sep 17 00:00:00 2001 From: Harley Acheson Date: Fri, 20 Aug 2021 17:48:42 -0700 Subject: Refactor: BLF Kerning Cache After Use Optimization of font kerning by only caching kerning values after a pair is encountered. Also saves unscaled values so they don't have to be rebuilt between font size changes. See D12274 for more details and speed comparison. Differential Revision: https://developer.blender.org/D12274 Reviewed by Campbell Barton --- source/blender/blenfont/intern/blf.c | 1 - source/blender/blenfont/intern/blf_font.c | 96 +++++++++++++--------- source/blender/blenfont/intern/blf_glyph.c | 50 ----------- source/blender/blenfont/intern/blf_internal.h | 4 - .../blender/blenfont/intern/blf_internal_types.h | 9 +- 5 files changed, 62 insertions(+), 98 deletions(-) (limited to 'source/blender/blenfont') diff --git a/source/blender/blenfont/intern/blf.c b/source/blender/blenfont/intern/blf.c index 9168e7aa19c..2f9eb0753ac 100644 --- a/source/blender/blenfont/intern/blf.c +++ b/source/blender/blenfont/intern/blf.c @@ -108,7 +108,6 @@ void BLF_cache_clear(void) FontBLF *font = global_font[i]; if (font) { blf_glyph_cache_clear(font); - blf_kerning_cache_clear(font); } } } diff --git a/source/blender/blenfont/intern/blf_font.c b/source/blender/blenfont/intern/blf_font.c index 00d3cfb09eb..02847b74df1 100644 --- a/source/blender/blenfont/intern/blf_font.c +++ b/source/blender/blenfont/intern/blf_font.c @@ -308,17 +308,6 @@ void blf_font_size(FontBLF *font, unsigned int size, unsigned int dpi) blf_glyph_cache_release(font); } -static void blf_font_ensure_ascii_kerning(FontBLF *font, GlyphCacheBLF *gc) -{ - if (font->kerning_cache || !FT_HAS_KERNING(font->face)) { - return; - } - font->kerning_cache = blf_kerning_cache_find(font); - if (!font->kerning_cache) { - font->kerning_cache = blf_kerning_cache_new(font, gc); - } -} - /* Fast path for runs of ASCII characters. Given that common UTF-8 * input will consist of an overwhelming majority of ASCII * characters. @@ -348,6 +337,31 @@ BLI_INLINE GlyphBLF *blf_utf8_next_fast( return g; } +/* Convert a FreeType 26.6 value representing an unscaled design size to pixels. + * This is an exact copy of the scaling done inside FT_Get_Kerning when called + * with FT_KERNING_DEFAULT, including arbitrary resizing for small fonts. + */ +static int blf_unscaled_F26Dot6_to_pixels(FontBLF *font, FT_Pos value) +{ + /* Scale value by font size using integer-optimized multiplication. */ + FT_Long scaled = FT_MulFix(value, font->face->size->metrics.x_scale); + + /* FreeType states that this '25' has been determined heuristically. */ + if (font->face->size->metrics.x_ppem < 25) { + scaled = FT_MulDiv(scaled, font->face->size->metrics.x_ppem, 25); + } + + /* Copies of internal FreeType macros needed here. */ +#define FT_PIX_FLOOR(x) ((x) & ~FT_TYPEOF(x) 63) +#define FT_PIX_ROUND(x) FT_PIX_FLOOR((x) + 32) + + /* Round to even 64ths, then divide by 64. */ + return FT_PIX_ROUND(scaled) >> 6; + +#undef FT_PIX_FLOOR +#undef FT_PIX_ROUND +} + BLI_INLINE void blf_kerning_step_fast(FontBLF *font, const GlyphBLF *g_prev, const GlyphBLF *g, @@ -355,18 +369,28 @@ BLI_INLINE void blf_kerning_step_fast(FontBLF *font, const uint c, int *pen_x_p) { - /* `blf_font_ensure_ascii_kerning(font, gc);` must be called before this function. */ - BLI_assert(font->kerning_cache != NULL || !FT_HAS_KERNING(font->face)); + if (FT_HAS_KERNING(font->face) && g_prev != NULL) { + FT_Vector delta = {KERNING_ENTRY_UNSET}; - if (g_prev != NULL && FT_HAS_KERNING(font->face)) { + /* Get unscaled kerning value from our cache if ASCII. */ if ((c_prev < KERNING_CACHE_TABLE_SIZE) && (c < GLYPH_ASCII_TABLE_SIZE)) { - *pen_x_p += font->kerning_cache->ascii_table[c][c_prev]; + delta.x = font->kerning_cache->ascii_table[c][c_prev]; } - else { - FT_Vector delta; - if (FT_Get_Kerning(font->face, g_prev->idx, g->idx, FT_KERNING_DEFAULT, &delta) == 0) { - *pen_x_p += (int)delta.x >> 6; - } + + /* If not ASCII or not found in cache, ask FreeType for kerning. */ + if (UNLIKELY(delta.x == KERNING_ENTRY_UNSET)) { + /* Note that this function sets delta values to zero on any error. */ + FT_Get_Kerning(font->face, g_prev->idx, g->idx, FT_KERNING_UNSCALED, &delta); + } + + /* If ASCII we save this value to our cache for quicker access next time. */ + if ((c_prev < KERNING_CACHE_TABLE_SIZE) && (c < GLYPH_ASCII_TABLE_SIZE)) { + font->kerning_cache->ascii_table[c][c_prev] = delta.x; + } + + if (delta.x != 0) { + /* Convert unscaled design units to pixels and move pen. */ + *pen_x_p += blf_unscaled_F26Dot6_to_pixels(font, delta.x); } } } @@ -388,8 +412,6 @@ static void blf_font_draw_ex(FontBLF *font, return; } - blf_font_ensure_ascii_kerning(font, gc); - blf_batch_draw_begin(font); while ((i < len) && str[i]) { @@ -435,8 +457,6 @@ static void blf_font_draw_ascii_ex( GlyphCacheBLF *gc = blf_glyph_cache_acquire(font); - blf_font_ensure_ascii_kerning(font, gc); - blf_batch_draw_begin(font); while ((c = *(str++)) && len--) { @@ -536,8 +556,6 @@ static void blf_font_draw_buffer_ex(FontBLF *font, int chx, chy; int y, x; - blf_font_ensure_ascii_kerning(font, gc); - /* another buffer specific call for color conversion */ while ((i < len) && str[i]) { @@ -694,8 +712,6 @@ size_t blf_font_width_to_strlen( GlyphCacheBLF *gc = blf_glyph_cache_acquire(font); const int width_i = (int)width; - blf_font_ensure_ascii_kerning(font, gc); - for (i_prev = i = 0, width_new = pen_x = 0, g_prev = NULL, c_prev = 0; (i < len) && str[i]; i_prev = i, width_new = pen_x, c_prev = c, g_prev = g) { g = blf_utf8_next_fast(font, gc, str, &i, &c); @@ -725,8 +741,6 @@ size_t blf_font_width_to_rstrlen( GlyphCacheBLF *gc = blf_glyph_cache_acquire(font); const int width_i = (int)width; - blf_font_ensure_ascii_kerning(font, gc); - i = BLI_strnlen(str, len); s = BLI_str_find_prev_char_utf8(str, &str[i]); i = (size_t)((s != NULL) ? s - str : 0); @@ -778,8 +792,6 @@ static void blf_font_boundbox_ex(FontBLF *font, box->ymin = 32000.0f; box->ymax = -32000.0f; - blf_font_ensure_ascii_kerning(font, gc); - while ((i < len) && str[i]) { g = blf_utf8_next_fast(font, gc, str, &i, &c); @@ -869,8 +881,6 @@ static void blf_font_wrap_apply(FontBLF *font, GlyphCacheBLF *gc = blf_glyph_cache_acquire(font); - blf_font_ensure_ascii_kerning(font, gc); - struct WordWrapVars { int wrap_width; size_t start, last[2]; @@ -1123,8 +1133,6 @@ static void blf_font_boundbox_foreach_glyph_ex(FontBLF *font, return; } - blf_font_ensure_ascii_kerning(font, gc); - while ((i < len) && str[i]) { i_curr = i; g = blf_utf8_next_fast(font, gc, str, &i, &c); @@ -1205,7 +1213,9 @@ void blf_font_free(FontBLF *font) blf_glyph_cache_free(gc); } - blf_kerning_cache_clear(font); + if (font->kerning_cache) { + MEM_freeN(font->kerning_cache); + } FT_Done_Face(font->face); if (font->filename) { @@ -1246,7 +1256,6 @@ static void blf_font_fill(FontBLF *font) font->dpi = 0; font->size = 0; BLI_listbase_clear(&font->cache); - BLI_listbase_clear(&font->kerning_caches); font->kerning_cache = NULL; #if BLF_BLUR_ENABLE font->blur = 0; @@ -1307,6 +1316,17 @@ FontBLF *blf_font_new(const char *name, const char *filename) font->name = BLI_strdup(name); font->filename = BLI_strdup(filename); blf_font_fill(font); + + if (FT_HAS_KERNING(font->face)) { + /* Create kerning cache table and fill with value indicating "unset". */ + font->kerning_cache = MEM_mallocN(sizeof(KerningCacheBLF), __func__); + for (uint i = 0; i < KERNING_CACHE_TABLE_SIZE; i++) { + for (uint j = 0; j < KERNING_CACHE_TABLE_SIZE; j++) { + font->kerning_cache->ascii_table[i][j] = KERNING_ENTRY_UNSET; + } + } + } + return font; } diff --git a/source/blender/blenfont/intern/blf_glyph.c b/source/blender/blenfont/intern/blf_glyph.c index 5fb69251466..6cdf5fc5996 100644 --- a/source/blender/blenfont/intern/blf_glyph.c +++ b/source/blender/blenfont/intern/blf_glyph.c @@ -55,56 +55,6 @@ #include "BLI_math_vector.h" #include "BLI_strict_flags.h" -KerningCacheBLF *blf_kerning_cache_find(FontBLF *font) -{ - return (KerningCacheBLF *)font->kerning_caches.first; -} - -/* Create a new glyph cache for the current kerning mode. */ -KerningCacheBLF *blf_kerning_cache_new(FontBLF *font, GlyphCacheBLF *gc) -{ - KerningCacheBLF *kc = MEM_mallocN(sizeof(KerningCacheBLF), __func__); - kc->next = NULL; - kc->prev = NULL; - - GlyphBLF *g_table[KERNING_CACHE_TABLE_SIZE]; - for (uint i = 0; i < KERNING_CACHE_TABLE_SIZE; i++) { - GlyphBLF *g = blf_glyph_search(gc, i); - if (UNLIKELY(g == NULL)) { - FT_UInt glyph_index = FT_Get_Char_Index(font->face, i); - g = blf_glyph_add(font, gc, glyph_index, i); - } - g_table[i] = g; - } - - memset(kc->ascii_table, 0, sizeof(kc->ascii_table)); - for (uint i = 0; i < KERNING_CACHE_TABLE_SIZE; i++) { - GlyphBLF *g = g_table[i]; - if (g == NULL) { - continue; - } - for (uint j = 0; j < KERNING_CACHE_TABLE_SIZE; j++) { - GlyphBLF *g_prev = g_table[j]; - if (g_prev == NULL) { - continue; - } - FT_Vector delta; - if (FT_Get_Kerning(font->face, g_prev->idx, g->idx, FT_KERNING_DEFAULT, &delta) == 0) { - kc->ascii_table[i][j] = (int)delta.x >> 6; - } - } - } - - BLI_addhead(&font->kerning_caches, kc); - return kc; -} - -void blf_kerning_cache_clear(FontBLF *font) -{ - font->kerning_cache = NULL; - BLI_freelistN(&font->kerning_caches); -} - GlyphCacheBLF *blf_glyph_cache_find(FontBLF *font, unsigned int size, unsigned int dpi) { GlyphCacheBLF *p; diff --git a/source/blender/blenfont/intern/blf_internal.h b/source/blender/blenfont/intern/blf_internal.h index 35a6d019eac..ab2a26b1e06 100644 --- a/source/blender/blenfont/intern/blf_internal.h +++ b/source/blender/blenfont/intern/blf_internal.h @@ -121,10 +121,6 @@ int blf_font_count_missing_chars(struct FontBLF *font, void blf_font_free(struct FontBLF *font); -struct KerningCacheBLF *blf_kerning_cache_find(struct FontBLF *font); -struct KerningCacheBLF *blf_kerning_cache_new(struct FontBLF *font, struct GlyphCacheBLF *gc); -void blf_kerning_cache_clear(struct FontBLF *font); - struct GlyphCacheBLF *blf_glyph_cache_find(struct FontBLF *font, unsigned int size, unsigned int dpi); diff --git a/source/blender/blenfont/intern/blf_internal_types.h b/source/blender/blenfont/intern/blf_internal_types.h index caa10b2b125..38d7d7b6e21 100644 --- a/source/blender/blenfont/intern/blf_internal_types.h +++ b/source/blender/blenfont/intern/blf_internal_types.h @@ -34,6 +34,9 @@ /* Number of characters in KerningCacheBLF.table. */ #define KERNING_CACHE_TABLE_SIZE 128 +/* A value in the kerning cache that indicates it is not yet set. */ +#define KERNING_ENTRY_UNSET INT_MAX + typedef struct BatchBLF { struct FontBLF *font; /* can only batch glyph from the same font */ struct GPUBatch *batch; @@ -50,7 +53,6 @@ typedef struct BatchBLF { extern BatchBLF g_batch; typedef struct KerningCacheBLF { - struct KerningCacheBLF *next, *prev; /** * Cache a ascii glyph pairs. Only store the x offset we are interested in, * instead of the full #FT_Vector since it's not used for drawing at the moment. @@ -223,10 +225,7 @@ typedef struct FontBLF { */ ListBase cache; - /* list of kerning cache for this font. */ - ListBase kerning_caches; - - /* current kerning cache for this font and kerning mode. */ + /* Cache of unscaled kerning values. Will be NULL if font does not have kerning. */ KerningCacheBLF *kerning_cache; /* freetype2 lib handle. */ -- cgit v1.2.3