feat(tiny_ttf): add glyph caching (#3703)

Co-authored-by: Gabor Kiss-Vamosi <kisvegabor@gmail.com>

docs/libs/index.md

@@ -12,6 +12,7 @@
    png
    gif
    freetype
+   tiny_ttf
    qrcode
    rlottie
    ffmpeg

docs/libs/tiny_ttf.md

@@ -12,6 +12,7 @@ However, if `LV_TINY_TTF_FILE_SUPPORT` is enabled, `lv_tiny_ttf_create_file(path
 
 After a font is created, you can change the size by using `lv_tiny_ttf_set_size(font, line_height)`.
 
+By default, a font will use up to 4KB of cache to speed up rendering glyphs. This maximum can be changed by using `lv_tiny_ttf_create_data_ex(data, data_size, line_height, cache_size)` or `lv_tiny_ttf_create_file_ex(path, line_height, cache_size)` (when available). The cache size is indicated in bytes.
 
 ## Example
 ```eval_rst

src/libs/tiny_ttf/lv_tiny_ttf.c

@@ -1,17 +1,220 @@
-#include "../../../lvgl.h"
-#include "../../misc/lv_gc.h"
+#include "lv_tiny_ttf.h"
 #if LV_USE_TINY_TTF
 #include <stdio.h>
-#include "lv_tiny_ttf.h"
+
+#ifndef LV_TINY_TTF_DEFAULT_CACHE_SIZE
+    #define LV_TINY_TTF_DEFAULT_CACHE_SIZE 4096
+#endif
+#ifndef LV_TINY_TTF_CACHE_BUCKETS
+    #define LV_TINY_TTF_CACHE_BUCKETS 16
+#endif
+
 #define STB_RECT_PACK_IMPLEMENTATION
+#define STBRP_STATIC
+#define STBTT_STATIC
 #define STB_TRUETYPE_IMPLEMENTATION
 #define STBTT_HEAP_FACTOR_SIZE_32 50
 #define STBTT_HEAP_FACTOR_SIZE_128 20
 #define STBTT_HEAP_FACTOR_SIZE_DEFAULT 10
 #define STBTT_malloc(x,u)  ((void)(u),lv_malloc(x))
 #define STBTT_free(x,u)    ((void)(u),lv_free(x))
+#define TTF_CACHE_MALLOC(x)  (lv_malloc(x))
+#define TTF_CACHE_REALLOC(x,y)  (lv_realloc(x,y))
+#define TTF_CACHE_FREE(x)    (lv_free(x))
+#define TTF_MALLOC(x)  (lv_malloc(x))
+#define TTF_FREE(x)    (lv_free(x))
+typedef void * ttf_cache_handle_t;
+typedef struct ttf_cache_entry {
+    int key;
+    unsigned long long age;
+    int size;
+    void * data;
+} ttf_cache_entry_t;
+typedef struct ttf_cache_bucket {
+    int capacity;
+    ttf_cache_entry_t * entries;
+} ttf_cache_bucket_t;
 
+typedef struct ttf_cache {
+    int max_size;
+    int bucket_size;
+    int total_size;
+    unsigned long long age;
+    ttf_cache_bucket_t * buckets;
+} ttf_cache_t;
 
+static unsigned long long ttf_cache_get_oldest_age(ttf_cache_handle_t * handle)
+{
+    ttf_cache_t * cache = (ttf_cache_t *)handle;
+    unsigned long long result = (unsigned long long) - 1;
+    for(int i = 0; i < cache->bucket_size; ++i) {
+        ttf_cache_bucket_t * bucket = &cache->buckets[i];
+        if(bucket->entries != NULL) {
+            for(int j = 0; j < bucket->capacity; ++j) {
+                ttf_cache_entry_t * entry = &bucket->entries[j];
+                if(entry->age != 0 && entry->age < result) {
+                    result = entry->age;
+                }
+            }
+        }
+    }
+    if(result == (unsigned long long) - 1) {
+        return 0;
+    }
+    return result;
+}
+static ttf_cache_handle_t ttf_cache_create(int max_size, int buckets)
+{
+    ttf_cache_t * result = (ttf_cache_t *)TTF_CACHE_MALLOC(sizeof(ttf_cache_t));
+    if(result == NULL) {
+        return NULL;
+    }
+    result->age = 1;
+    result->max_size = max_size;
+    result->total_size = 0;
+    result->bucket_size = buckets;
+    result->buckets = (ttf_cache_bucket_t *)TTF_CACHE_MALLOC(buckets * sizeof(ttf_cache_bucket_t));
+    if(result->buckets == NULL) {
+        TTF_CACHE_FREE(result);
+        return NULL;
+    }
+    for(int i = 0; i < buckets; ++i) {
+        result->buckets[i].capacity = 0;
+        result->buckets[i].entries = NULL;
+    }
+    return result;
+}
+static void * ttf_cache_get(ttf_cache_handle_t handle, int key)
+{
+    if(handle == NULL) {
+        return NULL;
+    }
+    ttf_cache_t * cache = (ttf_cache_t *)handle;
+    int ci = key % cache->bucket_size;
+    ttf_cache_bucket_t * bucket = &cache->buckets[ci];
+    for(int i = 0; i < bucket->capacity; ++i) {
+        ttf_cache_entry_t * entry = &bucket->entries[i];
+        if(entry->age != 0 && entry->key == key) {
+            entry->age = ++cache->age;
+            return entry->data;
+        }
+    }
+    return NULL;
+}
+static void * ttf_cache_add(ttf_cache_handle_t handle, int key, int size)
+{
+    if(handle == NULL) {
+        return NULL;
+    }
+    ttf_cache_t * cache = (ttf_cache_t *)handle;
+    int ci = key % cache->bucket_size;
+    ttf_cache_bucket_t * bucket = &cache->buckets[ci];
+    for(int i = 0; i < bucket->capacity; ++i) {
+        ttf_cache_entry_t * entry = &bucket->entries[i];
+        if(entry->age != 0 && entry->key == key) {
+            TTF_CACHE_FREE(entry->data);
+            cache->total_size -= entry->size;
+            entry->age = 0;
+            break;
+        }
+    }
+    while(cache->total_size > 0 && (cache->max_size < cache->total_size + size)) {
+        // expire entries
+        unsigned long long oldest = ttf_cache_get_oldest_age(handle);
+        if(oldest == 0) {
+            break;
+        }
+        for(int i = 0; i < cache->bucket_size; ++i) {
+            ttf_cache_bucket_t * bucket2 = &cache->buckets[i];
+            for(int j = 0; j < bucket2->capacity; ++j) {
+                ttf_cache_entry_t * entry = &bucket2->entries[j];
+                if(entry->age == oldest) {
+                    if(entry->data != NULL) {
+                        TTF_CACHE_FREE(entry->data);
+                        entry->data = NULL;
+                        entry->age = 0;
+                        cache->total_size -= entry->size;
+                        entry->size = 0;
+                        i = cache->bucket_size;
+                        break;
+                    }
+                }
+            }
+        }
+    }
+    if(bucket->entries == NULL) {
+        bucket->capacity = 4;
+        bucket->entries = (ttf_cache_entry_t *)TTF_CACHE_MALLOC(sizeof(ttf_cache_entry_t) * bucket->capacity);
+        if(bucket->entries == NULL) {
+            return NULL;
+        }
+        for(int i = 0; i < bucket->capacity; ++i) {
+            bucket->entries[i].age = 0;
+            bucket->entries[i].data = NULL;
+            bucket->entries[i].size = 0;
+        }
+    }
+    for(int i = 0; i < bucket->capacity; ++i) {
+        ttf_cache_entry_t * entry = &bucket->entries[i];
+        if(entry->age == 0) {
+            entry->data = TTF_CACHE_MALLOC(size);
+            if(entry->data == NULL) {
+                return NULL;
+            }
+            entry->size = size;
+            entry->age = cache->age;
+            entry->key = key;
+            cache->total_size += size;
+            return entry->data;
+        }
+    }
+    int newcap = bucket->capacity * 2;
+    ttf_cache_entry_t * te = (ttf_cache_entry_t *)TTF_CACHE_REALLOC(bucket->entries, sizeof(ttf_cache_entry_t) * newcap);
+    if(te == NULL) {
+        return NULL;
+    }
+    bucket->entries = te;
+    for(int i = bucket->capacity; i < newcap; ++i) {
+        bucket->entries[i].age = 0;
+        bucket->entries[i].data = NULL;
+        bucket->entries[i].size = 0;
+    }
+    void * result = TTF_CACHE_MALLOC(size);
+    bucket->entries[bucket->capacity].data = result;
+    if(result == NULL) {
+        return NULL;
+    }
+    bucket->entries[bucket->capacity].size = size;
+    bucket->entries[bucket->capacity].age = cache->age;
+    bucket->entries[bucket->capacity].key = key;
+    bucket->capacity = newcap;
+    return result;
+}
+
+static void ttf_cache_clear(ttf_cache_handle_t handle)
+{
+    if(handle == NULL) {
+        return;
+    }
+    ttf_cache_t * cache = (ttf_cache_t *)handle;
+    for(int i = 0; i < cache->bucket_size; ++i) {
+        ttf_cache_bucket_t * bucket = &cache->buckets[i];
+        if(bucket->entries != NULL) {
+            for(int j = 0; j < bucket->capacity; ++j) {
+                ttf_cache_entry_t * entry = &bucket->entries[j];
+                if(entry->age != 0 && entry->data != NULL) {
+                    TTF_CACHE_FREE(entry->data);
+                }
+            }
+            TTF_CACHE_FREE(cache->buckets[i].entries);
+        }
+    }
+}
+static void ttf_cache_destroy(ttf_cache_handle_t handle)
+{
+    ttf_cache_clear(handle);
+    TTF_CACHE_FREE((ttf_cache_t *)handle);
+}
 #if LV_TINY_TTF_FILE_SUPPORT !=0
 // a hydra stream that can be in memory or from a file
 typedef struct ttf_cb_stream {
@@ -63,9 +266,10 @@ typedef struct ttf_font_desc {
 #if LV_TINY_TTF_FILE_SUPPORT !=0
     ttf_cb_stream_t stream;
 #else
-    const unsigned char * stream;
+    const uint8_t * stream;
 #endif
     stbtt_fontinfo info;
+    ttf_cache_handle_t cache;
     float scale;
     int ascent;
     int descent;
@@ -115,53 +319,52 @@ static const uint8_t * ttf_get_glyph_bitmap_cb(const lv_font_t * font, uint32_t
 {
     ttf_font_desc_t * dsc = (ttf_font_desc_t *)font->dsc;
     const stbtt_fontinfo * info = (const stbtt_fontinfo *)&dsc->info;
-    static size_t buffer_size = 0;
-    int g1 = stbtt_FindGlyphIndex(info, (int)unicode_letter);
-    int x1, y1, x2, y2;
-    stbtt_GetGlyphBitmapBox(info, g1, dsc->scale, dsc->scale, &x1, &y1, &x2, &y2);
-    int w, h;
-    w = x2 - x1 + 1;
-    h = y2 - y1 + 1;
-    if(LV_GC_ROOT(_ttf_glyph_bitmap_buffer) == NULL) {
-        buffer_size = (size_t)(w * h);
-        LV_GC_ROOT(_ttf_glyph_bitmap_buffer) = (uint8_t *)lv_malloc(buffer_size);
-        if(LV_GC_ROOT(_ttf_glyph_bitmap_buffer) == NULL) {
-            buffer_size = 0;
+    uint8_t * buffer = (uint8_t *)ttf_cache_get(dsc->cache, unicode_letter);
+    if(buffer == NULL) {
+        int g1 = stbtt_FindGlyphIndex(info, (int)unicode_letter);
+        int x1, y1, x2, y2;
+        stbtt_GetGlyphBitmapBox(info, g1, dsc->scale, dsc->scale, &x1, &y1, &x2, &y2);
+        int w, h;
+        w = x2 - x1 + 1;
+        h = y2 - y1 + 1;
+        int buffer_size = w * h;
+        buffer = ttf_cache_add(dsc->cache, unicode_letter, buffer_size);
+        if(buffer == NULL) {
             return NULL;
         }
-        memset(LV_GC_ROOT(_ttf_glyph_bitmap_buffer), 0, buffer_size);
+        memset(buffer, 0, buffer_size);
+        stbtt_MakeGlyphBitmap(info, buffer, w, h, w, dsc->scale, dsc->scale, g1);
     }
-    else {
-        size_t s = w * h;
-        if(s > buffer_size) {
-            buffer_size = s;
-            LV_GC_ROOT(_ttf_glyph_bitmap_buffer) = (uint8_t *)lv_realloc(LV_GC_ROOT(_ttf_glyph_bitmap_buffer), buffer_size);
-            if(LV_GC_ROOT(_ttf_glyph_bitmap_buffer) == NULL) {
-                buffer_size = 0;
-                return NULL;
-            }
-            memset(LV_GC_ROOT(_ttf_glyph_bitmap_buffer), 0, buffer_size);
-        }
-    }
-    stbtt_MakeGlyphBitmap(info, LV_GC_ROOT(_ttf_glyph_bitmap_buffer), w, h, w, dsc->scale, dsc->scale, g1);
-    return LV_GC_ROOT(_ttf_glyph_bitmap_buffer); /*Or NULL if not found*/
+    return buffer; /*Or NULL if not found*/
 }
 
-static lv_font_t * lv_tiny_ttf_create(const char * path, const void * data, size_t data_size,  lv_coord_t line_height)
+static lv_font_t * lv_tiny_ttf_create(const char * path, const void * data, size_t data_size,  lv_coord_t line_height,
+                                      size_t cache_size)
 {
-
+    LV_UNUSED(data_size);
     if((path == NULL && data == NULL) || 0 >= line_height) {
         LV_LOG_ERROR("tiny_ttf: invalid argument\n");
         return NULL;
     }
-    ttf_font_desc_t * dsc = (ttf_font_desc_t *)lv_malloc(sizeof(ttf_font_desc_t));
+    if(cache_size < 1) {
+        cache_size = LV_TINY_TTF_DEFAULT_CACHE_SIZE;
+    }
+    ttf_font_desc_t * dsc = (ttf_font_desc_t *)TTF_MALLOC(sizeof(ttf_font_desc_t));
     if(dsc == NULL) {
         LV_LOG_ERROR("tiny_ttf: out of memory\n");
         return NULL;
     }
+    dsc->cache = ttf_cache_create(cache_size, LV_TINY_TTF_CACHE_BUCKETS);
+    if(dsc->cache == NULL) {
+        LV_LOG_ERROR("tiny_ttf: out of memory\n");
+        TTF_FREE(dsc);
+        return NULL;
+    }
 #if LV_TINY_TTF_FILE_SUPPORT !=0
     if(path != NULL) {
         if(LV_FS_RES_OK != lv_fs_open(&dsc->file, path, LV_FS_MODE_RD)) {
+            ttf_cache_destroy(dsc->cache);
+            TTF_FREE(dsc);
             LV_LOG_ERROR("tiny_ttf: unable to open %s\n", path);
             return NULL;
         }
@@ -174,25 +377,29 @@ static lv_font_t * lv_tiny_ttf_create(const char * path, const void * data, size
         dsc->stream.position = 0;
     }
     if(0 == stbtt_InitFont(&dsc->info, &dsc->stream, stbtt_GetFontOffsetForIndex(&dsc->stream, 0))) {
-        lv_free(dsc);
+        ttf_cache_destroy(dsc->cache);
+        TTF_FREE(dsc);
+
         LV_LOG_ERROR("tiny_ttf: init failed\n");
         return NULL;
     }
 
 #else
-    LV_UNUSED(data_size);
     dsc->stream = (const uint8_t *)data;
     if(0 == stbtt_InitFont(&dsc->info, dsc->stream, stbtt_GetFontOffsetForIndex(dsc->stream, 0))) {
-        lv_free(dsc);
+        ttf_cache_destroy(dsc->cache);
+        TTF_FREE(dsc);
         LV_LOG_ERROR("tiny_ttf: init failed\n");
         return NULL;
     }
+
 #endif
 
     float scale = stbtt_ScaleForPixelHeight(&dsc->info, line_height);
-    lv_font_t * out_font = (lv_font_t *)lv_malloc(sizeof(lv_font_t));
+    lv_font_t * out_font = (lv_font_t *)TTF_MALLOC(sizeof(lv_font_t));
     if(out_font == NULL) {
-        lv_free(dsc);
+        ttf_cache_destroy(dsc->cache);
+        TTF_FREE(dsc);
         LV_LOG_ERROR("tiny_ttf: out of memory\n");
         return NULL;
     }
@@ -211,14 +418,22 @@ static lv_font_t * lv_tiny_ttf_create(const char * path, const void * data, size
     return out_font;
 }
 #if LV_TINY_TTF_FILE_SUPPORT !=0
+lv_font_t * lv_tiny_ttf_create_file_ex(const char * path, lv_coord_t line_height, size_t cache_size)
+{
+    return lv_tiny_ttf_create(path, NULL, 0, line_height, cache_size);
+}
 lv_font_t * lv_tiny_ttf_create_file(const char * path, lv_coord_t line_height)
 {
-    return lv_tiny_ttf_create(path, NULL, 0, line_height);
+    return lv_tiny_ttf_create(path, NULL, 0, line_height, 0);
 }
 #endif
+lv_font_t * lv_tiny_ttf_create_data_ex(const void * data, size_t data_size, lv_coord_t line_height, size_t cache_size)
+{
+    return lv_tiny_ttf_create(NULL, data, data_size, line_height, cache_size);
+}
 lv_font_t * lv_tiny_ttf_create_data(const void * data, size_t data_size, lv_coord_t line_height)
 {
-    return lv_tiny_ttf_create(NULL, data, data_size, line_height);
+    return lv_tiny_ttf_create(NULL, data, data_size, line_height, 0);
 }
 void lv_tiny_ttf_set_size(lv_font_t * font, lv_coord_t line_height)
 {
@@ -228,6 +443,7 @@ void lv_tiny_ttf_set_size(lv_font_t * font, lv_coord_t line_height)
         dsc->scale = stbtt_ScaleForPixelHeight(&dsc->info, line_height);
         font->base_line = line_height - (lv_coord_t)(dsc->ascent * dsc->scale);
         font->underline_position = (uint8_t)line_height - dsc->descent;
+        ttf_cache_clear(dsc->cache);
     }
 }
 void lv_tiny_ttf_destroy(lv_font_t * font)
@@ -235,14 +451,15 @@ void lv_tiny_ttf_destroy(lv_font_t * font)
     if(font != NULL) {
         if(font->dsc != NULL) {
             ttf_font_desc_t * ttf = (ttf_font_desc_t *)font->dsc;
+            ttf_cache_destroy(ttf->cache);
 #if LV_TINY_TTF_FILE_SUPPORT !=0
             if(ttf->stream.file != NULL) {
                 lv_fs_close(&ttf->file);
             }
 #endif
-            lv_free(ttf);
+            TTF_FREE(ttf);
         }
-        lv_free(font);
+        TTF_FREE(font);
     }
 }
 #endif

src/libs/tiny_ttf/lv_tiny_ttf.h

@@ -31,11 +31,17 @@ extern "C" {
 #if LV_TINY_TTF_FILE_SUPPORT !=0
 // create a font from the specified file or path with the specified line height.
 lv_font_t * lv_tiny_ttf_create_file(const char * path, lv_coord_t line_height);
-#endif // LV_TINY_TTF_FILE_SUPPORT !=0
+
+// create a font from the specified file or path with the specified line height with the specified cache size.
+lv_font_t * lv_tiny_ttf_create_file_ex(const char * path, lv_coord_t line_height, size_t cache_size);
+#endif
 
 // create a font from the specified data pointer with the specified line height.
 lv_font_t * lv_tiny_ttf_create_data(const void * data, size_t data_size, lv_coord_t line_height);
 
+// create a font from the specified data pointer with the specified line height and the specified cache size.
+lv_font_t * lv_tiny_ttf_create_data_ex(const void * data, size_t data_size, lv_coord_t line_height, size_t cache_size);
+
 // set the size of the font to a new line_height
 void lv_tiny_ttf_set_size(lv_font_t * font, lv_coord_t line_height);
 

src/libs/tiny_ttf/stb_rect_pack.h

@@ -87,6 +87,12 @@ typedef int            stbrp_coord;
 #define STBRP__MAXVAL  0x7fffffff
 // Mostly for internal use, but this is the maximum supported coordinate value.
 
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+
 STBRP_DEF int stbrp_pack_rects(stbrp_context * context, stbrp_rect * rects, int num_rects);
 // Assign packed locations to rectangles. The rectangles are of type
 // 'stbrp_rect' defined below, stored in the array 'rects', and there
@@ -579,6 +585,10 @@ STBRP_DEF int stbrp_pack_rects(stbrp_context * context, stbrp_rect * rects, int
 }
 #endif
 
+#if defined(__GNUC__) || defined(__clang__)
+    #pragma GCC diagnostic pop
+#endif
+
 /*
 ------------------------------------------------------------------------------
 This software is available under 2 licenses -- choose whichever you prefer.

src/libs/tiny_ttf/stb_truetype_htcw.h

@@ -553,6 +553,11 @@ typedef struct {
     int size;
 } stbtt__buf;
 
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 //////////////////////////////////////////////////////////////////////////////
 //
 // TEXTURE BAKING API
@@ -5443,6 +5448,7 @@ STBTT_DEF int stbtt_CompareUTF8toUTF16_bigendian(const char * s1, int len1, cons
 
 #if defined(__GNUC__) || defined(__clang__)
     #pragma GCC diagnostic pop
+    #pragma GCC diagnostic pop
 #endif
 
 #endif // STB_TRUETYPE_IMPLEMENTATION