feat(freetype): support bold and italic (#2824)

* feat(freetype):support bold and italic

* fix(format): replace code-format.sh with code-format.py

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

.github/workflows/check_style.yml

@@ -18,7 +18,7 @@ jobs:
           sudo apt-get update -y -qq
           sudo apt-get install astyle
       - name: Format code
-        run: ./code-format.sh
+        run: python code-format.py
         working-directory: scripts
       - name: Check that repository is clean
         run: git diff --exit-code || (echo "Please apply the preceding diff to your code or run scripts/code-format.sh"; false)

docs/libs/freetype.md

@@ -1,6 +1,6 @@
 ```eval_rst
 .. include:: /header.rst 
-:github_url: |github_link_base|/libs/bmp.md
+:github_url: |github_link_base|/libs/freetype.md
 ```
 
 # FreeType support
@@ -19,11 +19,33 @@ Interface to [FreeType](https://www.freetype.org/) to generate font bitmaps run
 
 Enable `LV_USE_FREETYPE` in `lv_conf.h`.
 
-See the examples below.
+To cache the glyphs from the opened fonts set  `LV_FREETYPE_CACHE_SIZE >= 0` and then use the following macros for detailed configuration:
+1. `LV_FREETYPE_CACHE_SIZE`:maximum memory(bytes) used to cache font bitmap, outline, character maps, etc. 0 means use the system default value, less than 0 means disable cache.Note: that this value does not account for managed FT_Face and FT_Size objects.
+1. `LV_FREETYPE_CACHE_FT_FACES`:maximum number of opened FT_Face objects managed by this cache instance.0 means use the system default value.Only useful when LV_FREETYPE_CACHE_SIZE >= 0.
+1. `LV_FREETYPE_CACHE_FT_SIZES`:maximum number of opened FT_Size objects managed by this cache instance. 0 means use the system default value.Only useful when LV_FREETYPE_CACHE_SIZE >= 0.
+
+When you are sure that all the used fonts size will not be greater than 256, you can enable `LV_FREETYPE_SBIT_CACHE`, which is much more memory efficient for small bitmaps.
+
+You can use `lv_ft_font_init()` to create FreeType fonts. It returns `true` to indicate success, at the same time, the `font` member of `lv_ft_info_t` will be filled with a  pointer to an lvgl font, and you can use it like any lvgl font.
+
+Font style supports bold and italic, you can use the following macro to set:
+1. `FT_FONT_STYLE_NORMAL`:default style.
+1. `FT_FONT_STYLE_ITALIC`:Italic style
+1. `FT_FONT_STYLE_BOLD`:bold style
+
+They can be combined.eg:`FT_FONT_STYLE_BOLD | FT_FONT_STYLE_ITALIC`.
 
 Note that, the FreeType extension doesn't use LVGL's file system. 
 You can simply pass the path to the font as usual on your operating system or platform.
 
+## Example
+```eval_rst
+
+.. include:: ../../examples/libs/freetype/index.rst
+
+```
+
+
 ## Learn more
 - FreeType [tutorial](https://www.freetype.org/freetype2/docs/tutorial/step1.html) 
 - LVGL's [font interface](https://docs.lvgl.io/v7/en/html/overview/font.html#add-a-new-font-engine)

examples/libs/freetype/lv_example_freetype_1.c

@@ -12,7 +12,10 @@ void lv_example_freetype_1(void)
     info.name = "./lvgl/examples/libs/freetype/arial.ttf";
     info.weight = 24;
     info.style = FT_FONT_STYLE_NORMAL;
-    lv_ft_font_init(&info);
+    info.mem = NULL;
+    if(!lv_ft_font_init(&info)) {
+        LV_LOG_ERROR("create failed.");
+    }
 
     /*Create style with the new font*/
     static lv_style_t style;

lv_conf_template.h

@@ -576,6 +576,16 @@
 #if LV_USE_FREETYPE
     /*Memory used by FreeType to cache characters [bytes] (-1: no caching)*/
     #define LV_FREETYPE_CACHE_SIZE (16 * 1024)
+    #if LV_FREETYPE_CACHE_SIZE >= 0
+        /* 1: bitmap cache use the sbit cache, 0:bitmap cache use the image cache. */
+        /* sbit cache:it is much more memory efficient for small bitmaps(font size < 256) */
+        /* if font size >= 256, must be configured as image cache */
+        #define LV_FREETYPE_SBIT_CACHE 0
+        /* Maximum number of opened FT_Face/FT_Size objects managed by this cache instance. */
+        /* (0:use system defaults) */
+        #define LV_FREETYPE_CACHE_FT_FACES 0
+        #define LV_FREETYPE_CACHE_FT_SIZES 0
+    #endif
 #endif
 
 /*Rlottie library*/

scripts/code-format.py

@@ -0,0 +1,5 @@
+#!/usr/bin/env python3
+
+import os
+
+os.system('astyle --options=code-format.cfg "../src/*.c,*.h"')

scripts/code-format.sh

@@ -1 +0,0 @@
-astyle --options=code-format.cfg "../src/*.c,*.h"

src/extra/libs/freetype/lv_freetype.c

@@ -14,6 +14,8 @@
 #include FT_GLYPH_H
 #include FT_CACHE_H
 #include FT_SIZES_H
+#include FT_IMAGE_H
+#include FT_OUTLINE_H
 
 /*********************
  *      DEFINES
@@ -67,8 +69,16 @@ static FT_Library library;
 #if LV_FREETYPE_CACHE_SIZE >= 0
     static FTC_Manager cache_manager;
     static FTC_CMapCache cmap_cache;
+    static FT_Face current_face = NULL;
+
+    #if LV_FREETYPE_SBIT_CACHE
         static FTC_SBitCache sbit_cache;
         static FTC_SBit sbit;
+    #else
+        static FTC_ImageCache image_cache;
+        static FT_Glyph       image_glyph;
+    #endif
+
 #else
     static lv_faces_control_t face_control;
 #endif
@@ -104,11 +114,19 @@ bool lv_freetype_init(uint16_t max_faces, uint16_t max_sizes, uint32_t max_bytes
         goto Fail;
     }
 
+#if LV_FREETYPE_SBIT_CACHE
     error = FTC_SBitCache_New(cache_manager, &sbit_cache);
     if(error) {
         LV_LOG_ERROR("Failed to open sbit cache");
         goto Fail;
     }
+#else
+    error = FTC_ImageCache_New(cache_manager, &image_cache);
+    if(error) {
+        LV_LOG_ERROR("Failed to open image cache");
+        goto Fail;
+    }
+#endif
 
     return true;
 Fail:
@@ -176,6 +194,36 @@ static FT_Error font_face_requester(FTC_FaceID face_id,
     return FT_Err_Ok;
 }
 
+static bool get_bold_glyph(const lv_font_t * font, FT_Face face,
+                           FT_UInt glyph_index, lv_font_glyph_dsc_t * dsc_out)
+{
+    if(FT_Load_Glyph(face, glyph_index, FT_LOAD_DEFAULT)) {
+        return false;
+    }
+
+    lv_font_fmt_ft_dsc_t * dsc = (lv_font_fmt_ft_dsc_t *)(font->dsc);
+    if(face->glyph->format == FT_GLYPH_FORMAT_OUTLINE) {
+        if(dsc->style & FT_FONT_STYLE_BOLD) {
+            int strength = 1 << 6;
+            FT_Outline_Embolden(&face->glyph->outline, strength);
+        }
+    }
+
+    if(FT_Render_Glyph(face->glyph, FT_RENDER_MODE_NORMAL)) {
+        return false;
+    }
+
+    dsc_out->adv_w = (face->glyph->metrics.horiAdvance >> 6);
+    dsc_out->box_h = face->glyph->bitmap.rows;         /*Height of the bitmap in [px]*/
+    dsc_out->box_w = face->glyph->bitmap.width;         /*Width of the bitmap in [px]*/
+    dsc_out->ofs_x = face->glyph->bitmap_left;         /*X offset of the bitmap in [pf]*/
+    dsc_out->ofs_y = face->glyph->bitmap_top -
+                     face->glyph->bitmap.rows;         /*Y offset of the bitmap measured from the as line*/
+    dsc_out->bpp = 8;         /*Bit per pixel: 1/2/4/8*/
+
+    return true;
+}
+
 static bool get_glyph_dsc_cb_cache(const lv_font_t * font,
                                    lv_font_glyph_dsc_t * dsc_out, uint32_t unicode_letter, uint32_t unicode_letter_next)
 {
@@ -192,20 +240,51 @@ static bool get_glyph_dsc_cb_cache(const lv_font_t * font,
 
     lv_font_fmt_ft_dsc_t * dsc = (lv_font_fmt_ft_dsc_t *)(font->dsc);
 
-    FT_Face face;
-    FTC_ImageTypeRec desc_sbit_type;
     FTC_FaceID face_id = (FTC_FaceID)dsc->face_id;
-    FTC_Manager_LookupFace(cache_manager, face_id, &face);
+    FT_Size face_size;
+    struct FTC_ScalerRec_ scaler;
+    scaler.face_id = face_id;
+    scaler.width = dsc->height;
+    scaler.height = dsc->height;
+    scaler.pixel = 1;
+    if(FTC_Manager_LookupSize(cache_manager, &scaler, &face_size) != 0) {
+        return false;
+    }
 
-    desc_sbit_type.face_id = face_id;
+    FT_Face face = face_size->face;
-    desc_sbit_type.flags = FT_LOAD_RENDER | FT_LOAD_TARGET_NORMAL;
-    desc_sbit_type.height = dsc->height;
-    desc_sbit_type.width = dsc->height;
     FT_UInt charmap_index = FT_Get_Charmap_Index(face->charmap);
     FT_UInt glyph_index = FTC_CMapCache_Lookup(cmap_cache, face_id, charmap_index, unicode_letter);
-    FT_Error error = FTC_SBitCache_Lookup(sbit_cache, &desc_sbit_type, glyph_index, &sbit, NULL);
+    dsc_out->is_placeholder = glyph_index == 0;
+
+    if(dsc->style & FT_FONT_STYLE_ITALIC) {
+        FT_Matrix italic_matrix;
+        italic_matrix.xx = 1 << 16;
+        italic_matrix.xy = 0x5800;
+        italic_matrix.yx = 0;
+        italic_matrix.yy = 1 << 16;
+        FT_Set_Transform(face, &italic_matrix, NULL);
+    }
+
+    if(dsc->style & FT_FONT_STYLE_BOLD) {
+        current_face = face;
+        if(!get_bold_glyph(font, face, glyph_index, dsc_out)) {
+            current_face = NULL;
+            return false;
+        }
+        goto end;
+    }
+
+    FTC_ImageTypeRec desc_type;
+    desc_type.face_id = face_id;
+    desc_type.flags = FT_LOAD_RENDER | FT_LOAD_TARGET_NORMAL;
+    desc_type.height = dsc->height;
+    desc_type.width = dsc->height;
+
+#if LV_FREETYPE_SBIT_CACHE
+    FT_Error error = FTC_SBitCache_Lookup(sbit_cache, &desc_type, glyph_index, &sbit, NULL);
     if(error) {
         LV_LOG_ERROR("SBitCache_Lookup error");
+        return false;
     }
 
     dsc_out->adv_w = sbit->xadvance;
@@ -214,16 +293,53 @@ static bool get_glyph_dsc_cb_cache(const lv_font_t * font,
     dsc_out->ofs_x = sbit->left;    /*X offset of the bitmap in [pf]*/
     dsc_out->ofs_y = sbit->top - sbit->height; /*Y offset of the bitmap measured from the as line*/
     dsc_out->bpp = 8;               /*Bit per pixel: 1/2/4/8*/
-    dsc_out->is_placeholder = glyph_index == 0;
+#else
+    FT_Error error = FTC_ImageCache_Lookup(image_cache, &desc_type, glyph_index, &image_glyph, NULL);
+    if(error) {
+        LV_LOG_ERROR("ImageCache_Lookup error");
+        return false;
+    }
+    if(image_glyph->format != FT_GLYPH_FORMAT_BITMAP) {
+        LV_LOG_ERROR("Glyph_To_Bitmap error");
+        return false;
+    }
+
+    FT_BitmapGlyph glyph_bitmap = (FT_BitmapGlyph)image_glyph;
+    dsc_out->adv_w = (glyph_bitmap->root.advance.x >> 16);
+    dsc_out->box_h = glyph_bitmap->bitmap.rows;         /*Height of the bitmap in [px]*/
+    dsc_out->box_w = glyph_bitmap->bitmap.width;        /*Width of the bitmap in [px]*/
+    dsc_out->ofs_x = glyph_bitmap->left;                /*X offset of the bitmap in [pf]*/
+    dsc_out->ofs_y = glyph_bitmap->top -
+                     glyph_bitmap->bitmap.rows;         /*Y offset of the bitmap measured from the as line*/
+    dsc_out->bpp = 8;         /*Bit per pixel: 1/2/4/8*/
+#endif
+
+end:
+    if((dsc->style & FT_FONT_STYLE_ITALIC) && (unicode_letter_next == '\0')) {
+        dsc_out->adv_w = dsc_out->box_w + dsc_out->ofs_x;
+    }
 
     return true;
 }
 
 static const uint8_t * get_glyph_bitmap_cb_cache(const lv_font_t * font, uint32_t unicode_letter)
 {
-    LV_UNUSED(font);
     LV_UNUSED(unicode_letter);
+
+    lv_font_fmt_ft_dsc_t * dsc = (lv_font_fmt_ft_dsc_t *)(font->dsc);
+    if(dsc->style & FT_FONT_STYLE_BOLD) {
+        if(current_face && current_face->glyph->format == FT_GLYPH_FORMAT_BITMAP) {
+            return (const uint8_t *)(current_face->glyph->bitmap.buffer);
+        }
+        return NULL;
+    }
+
+#if LV_FREETYPE_SBIT_CACHE
     return (const uint8_t *)sbit->buffer;
+#else
+    FT_BitmapGlyph glyph_bitmap = (FT_BitmapGlyph)image_glyph;
+    return (const uint8_t *)glyph_bitmap->bitmap.buffer;
+#endif
 }
 
 static bool lv_ft_font_init_cache(lv_ft_info_t * info)
@@ -297,6 +413,7 @@ void lv_ft_font_destroy_cache(lv_font_t * font)
 
     lv_font_fmt_ft_dsc_t * dsc = (lv_font_fmt_ft_dsc_t *)(font->dsc);
     if(dsc) {
+        FTC_Manager_RemoveFaceID(cache_manager, (FTC_FaceID)dsc->face_id);
         lv_mem_free(dsc->face_id);
         lv_mem_free(dsc->font);
         lv_mem_free(dsc);
@@ -380,6 +497,22 @@ static bool get_glyph_dsc_cb_nocache(const lv_font_t * font,
         return false;
     }
 
+    if(face->glyph->format == FT_GLYPH_FORMAT_OUTLINE) {
+        if(dsc->style & FT_FONT_STYLE_BOLD) {
+            int strength = 1 << 6;
+            FT_Outline_Embolden(&face->glyph->outline, strength);
+        }
+
+        if(dsc->style & FT_FONT_STYLE_ITALIC) {
+            FT_Matrix italic_matrix;
+            italic_matrix.xx = 1 << 16;
+            italic_matrix.xy = 0x5800;
+            italic_matrix.yx = 0;
+            italic_matrix.yy = 1 << 16;
+            FT_Outline_Transform(&face->glyph->outline, &italic_matrix);
+        }
+    }
+
     error = FT_Render_Glyph(face->glyph, FT_RENDER_MODE_NORMAL);
     if(error) {
         return false;
@@ -393,6 +526,10 @@ static bool get_glyph_dsc_cb_nocache(const lv_font_t * font,
                      face->glyph->bitmap.rows;         /*Y offset of the bitmap measured from the as line*/
     dsc_out->bpp = 8;         /*Bit per pixel: 1/2/4/8*/
 
+    if((dsc->style & FT_FONT_STYLE_ITALIC) && (unicode_letter_next == '\0')) {
+        dsc_out->adv_w = dsc_out->box_w + dsc_out->ofs_x;
+    }
+
     return true;
 }
 

src/extra/lv_extra.c

@@ -71,9 +71,12 @@ void lv_extra_init(void)
 #endif
 
 #if LV_USE_FREETYPE
-    /*Init freetype library
+    /*Init freetype library*/
-     *Cache max 64 faces and 1 size*/
+#  if LV_FREETYPE_CACHE_SIZE >= 0
-    lv_freetype_init(0, 0, LV_FREETYPE_CACHE_SIZE);
+    lv_freetype_init(LV_FREETYPE_CACHE_FT_FACES, LV_FREETYPE_CACHE_FT_SIZES, LV_FREETYPE_CACHE_SIZE);
+#  else
+    lv_freetype_init(0, 0, 0);
+#  endif
 #endif
 
 #if LV_USE_FFMPEG

src/lv_conf_internal.h

@@ -1867,6 +1867,34 @@
             #define LV_FREETYPE_CACHE_SIZE (16 * 1024)
         #endif
     #endif
+    #if LV_FREETYPE_CACHE_SIZE >= 0
+        /* 1: bitmap cache use the sbit cache, 0:bitmap cache use the image cache. */
+        /* sbit cache:it is much more memory efficient for small bitmaps(font size < 256) */
+        /* if font size >= 256, must be configured as image cache */
+        #ifndef LV_FREETYPE_SBIT_CACHE
+            #ifdef CONFIG_LV_FREETYPE_SBIT_CACHE
+                #define LV_FREETYPE_SBIT_CACHE CONFIG_LV_FREETYPE_SBIT_CACHE
+            #else
+                #define LV_FREETYPE_SBIT_CACHE 0
+            #endif
+        #endif
+        /* Maximum number of opened FT_Face/FT_Size objects managed by this cache instance. */
+        /* (0:use system defaults) */
+        #ifndef LV_FREETYPE_CACHE_FT_FACES
+            #ifdef CONFIG_LV_FREETYPE_CACHE_FT_FACES
+                #define LV_FREETYPE_CACHE_FT_FACES CONFIG_LV_FREETYPE_CACHE_FT_FACES
+            #else
+                #define LV_FREETYPE_CACHE_FT_FACES 0
+            #endif
+        #endif
+        #ifndef LV_FREETYPE_CACHE_FT_SIZES
+            #ifdef CONFIG_LV_FREETYPE_CACHE_FT_SIZES
+                #define LV_FREETYPE_CACHE_FT_SIZES CONFIG_LV_FREETYPE_CACHE_FT_SIZES
+            #else
+                #define LV_FREETYPE_CACHE_FT_SIZES 0
+            #endif
+        #endif
+    #endif
 #endif
 
 /*Rlottie library*/