/**
  * @file lv_font_fmt_txt.c
  *
  */
 
 /*********************
  *      INCLUDES
  *********************/
 #include "lv_font.h"
 #include "lv_font_fmt_txt.h"
 #include "../misc/lv_assert.h"
 #include "../misc/lv_types.h"
 #include "../misc/lv_gc.h"
 #include "../misc/lv_log.h"
 #include "../misc/lv_utils.h"
 #include "../misc/lv_mem.h"
 
 /*********************
  *      DEFINES
  *********************/
 
 /**********************
  *      TYPEDEFS
  **********************/
 typedef enum {
     RLE_STATE_SINGLE = 0,
     RLE_STATE_REPEATE,
     RLE_STATE_COUNTER,
 } rle_state_t;
 
 /**********************
  *  STATIC PROTOTYPES
  **********************/
 static uint32_t get_glyph_dsc_id(const lv_font_t * font, uint32_t letter);
 static int8_t get_kern_value(const lv_font_t * font, uint32_t gid_left, uint32_t gid_right);
 static int32_t unicode_list_compare(const void * ref, const void * element);
 static int32_t kern_pair_8_compare(const void * ref, const void * element);
 static int32_t kern_pair_16_compare(const void * ref, const void * element);
 
 #if LV_USE_FONT_COMPRESSED
     static void decompress(const uint8_t * in, uint8_t * out, lv_coord_t w, lv_coord_t h, uint8_t bpp, bool prefilter);
     static inline void decompress_line(uint8_t * out, lv_coord_t w);
     static inline uint8_t get_bits(const uint8_t * in, uint32_t bit_pos, uint8_t len);
     static inline void bits_write(uint8_t * out, uint32_t bit_pos, uint8_t val, uint8_t len);
     static inline void rle_init(const uint8_t * in,  uint8_t bpp);
     static inline uint8_t rle_next(void);
 #endif /*LV_USE_FONT_COMPRESSED*/
 
 /**********************
  *  STATIC VARIABLES
  **********************/
 #if LV_USE_FONT_COMPRESSED
     static uint32_t rle_rdp;
     static const uint8_t * rle_in;
     static uint8_t rle_bpp;
     static uint8_t rle_prev_v;
     static uint8_t rle_cnt;
     static rle_state_t rle_state;
 #endif /*LV_USE_FONT_COMPRESSED*/
 
 /**********************
  * GLOBAL PROTOTYPES
  **********************/
 
 /**********************
  *      MACROS
  **********************/
 
 /**********************
  *   GLOBAL FUNCTIONS
  **********************/
 
 /**
  * Used as `get_glyph_bitmap` callback in LittelvGL's native font format if the font is uncompressed.
  * @param font pointer to font
  * @param unicode_letter a unicode letter which bitmap should be get
  * @return pointer to the bitmap or NULL if not found
  */
 const uint8_t * lv_font_get_bitmap_fmt_txt(const lv_font_t * font, uint32_t unicode_letter)
 {
     if(unicode_letter == '\t') unicode_letter = ' ';
 
     lv_font_fmt_txt_dsc_t * fdsc = (lv_font_fmt_txt_dsc_t *)font->dsc;
     uint32_t gid = get_glyph_dsc_id(font, unicode_letter);
     if(!gid) return NULL;
 
     const lv_font_fmt_txt_glyph_dsc_t * gdsc = &fdsc->glyph_dsc[gid];
 
     if(fdsc->bitmap_format == LV_FONT_FMT_TXT_PLAIN) {
         return &fdsc->glyph_bitmap[gdsc->bitmap_index];
     }
     /*Handle compressed bitmap*/
     else {
 #if LV_USE_FONT_COMPRESSED
         static size_t last_buf_size = 0;
         if(LV_GC_ROOT(_lv_font_decompr_buf) == NULL) last_buf_size = 0;
 
         uint32_t gsize = gdsc->box_w * gdsc->box_h;
         if(gsize == 0) return NULL;
 
         uint32_t buf_size = gsize;
         /*Compute memory size needed to hold decompressed glyph, rounding up*/
         switch(fdsc->bpp) {
             case 1:
                 buf_size = (gsize + 7) >> 3;
                 break;
             case 2:
                 buf_size = (gsize + 3) >> 2;
                 break;
             case 3:
                 buf_size = (gsize + 1) >> 1;
                 break;
             case 4:
                 buf_size = (gsize + 1) >> 1;
                 break;
         }
 
         if(last_buf_size < buf_size) {
             uint8_t * tmp = lv_mem_realloc(LV_GC_ROOT(_lv_font_decompr_buf), buf_size);
             LV_ASSERT_MALLOC(tmp);
             if(tmp == NULL) return NULL;
             LV_GC_ROOT(_lv_font_decompr_buf) = tmp;
             last_buf_size = buf_size;
         }
 
         bool prefilter = fdsc->bitmap_format == LV_FONT_FMT_TXT_COMPRESSED ? true : false;
         decompress(&fdsc->glyph_bitmap[gdsc->bitmap_index], LV_GC_ROOT(_lv_font_decompr_buf), gdsc->box_w, gdsc->box_h,
                    (uint8_t)fdsc->bpp, prefilter);
         return LV_GC_ROOT(_lv_font_decompr_buf);
 #else /*!LV_USE_FONT_COMPRESSED*/
         LV_LOG_WARN("Compressed fonts is used but LV_USE_FONT_COMPRESSED is not enabled in lv_conf.h");
         return NULL;
 #endif
     }
 
     /*If not returned earlier then the letter is not found in this font*/
     return NULL;
 }
 
 /**
  * Used as `get_glyph_dsc` callback in LittelvGL's native font format if the font is uncompressed.
  * @param font_p pointer to font
  * @param dsc_out store the result descriptor here
  * @param letter a UNICODE letter code
  * @return true: descriptor is successfully loaded into `dsc_out`.
  *         false: the letter was not found, no data is loaded to `dsc_out`
  */
 bool lv_font_get_glyph_dsc_fmt_txt(const lv_font_t * font, lv_font_glyph_dsc_t * dsc_out, uint32_t unicode_letter,
                                    uint32_t unicode_letter_next)
 {
     bool is_tab = false;
     if(unicode_letter == '\t') {
         unicode_letter = ' ';
         is_tab = true;
     }
     lv_font_fmt_txt_dsc_t * fdsc = (lv_font_fmt_txt_dsc_t *)font->dsc;
     uint32_t gid = get_glyph_dsc_id(font, unicode_letter);
     if(!gid) return false;
 
     int8_t kvalue = 0;
     if(fdsc->kern_dsc) {
         uint32_t gid_next = get_glyph_dsc_id(font, unicode_letter_next);
         if(gid_next) {
             kvalue = get_kern_value(font, gid, gid_next);
         }
     }
 
     /*Put together a glyph dsc*/
     const lv_font_fmt_txt_glyph_dsc_t * gdsc = &fdsc->glyph_dsc[gid];
 
     int32_t kv = ((int32_t)((int32_t)kvalue * fdsc->kern_scale) >> 4);
 
     uint32_t adv_w = gdsc->adv_w;
     if(is_tab) adv_w *= 2;
 
     adv_w += kv;
     adv_w  = (adv_w + (1 << 3)) >> 4;
 
     dsc_out->adv_w = adv_w;
     dsc_out->box_h = gdsc->box_h;
     dsc_out->box_w = gdsc->box_w;
     dsc_out->ofs_x = gdsc->ofs_x;
     dsc_out->ofs_y = gdsc->ofs_y;
     dsc_out->bpp   = (uint8_t)fdsc->bpp;
     dsc_out->is_placeholder = false;
 
     if(is_tab) dsc_out->box_w = dsc_out->box_w * 2;
 
     return true;
 }
 
 /**
  * Free the allocated memories.
  */
 void _lv_font_clean_up_fmt_txt(void)
 {
 #if LV_USE_FONT_COMPRESSED
     if(LV_GC_ROOT(_lv_font_decompr_buf)) {
         lv_mem_free(LV_GC_ROOT(_lv_font_decompr_buf));
         LV_GC_ROOT(_lv_font_decompr_buf) = NULL;
     }
 #endif
 }
 
 /**********************
  *   STATIC FUNCTIONS
  **********************/
 
 static uint32_t get_glyph_dsc_id(const lv_font_t * font, uint32_t letter)
 {
     if(letter == '\0') return 0;
 
     lv_font_fmt_txt_dsc_t * fdsc = (lv_font_fmt_txt_dsc_t *)font->dsc;
 
     /*Check the cache first*/
     if(fdsc->cache && letter == fdsc->cache->last_letter) return fdsc->cache->last_glyph_id;
 
     uint16_t i;
     for(i = 0; i < fdsc->cmap_num; i++) {
 
         /*Relative code point*/
         uint32_t rcp = letter - fdsc->cmaps[i].range_start;
         if(rcp > fdsc->cmaps[i].range_length) continue;
         uint32_t glyph_id = 0;
         if(fdsc->cmaps[i].type == LV_FONT_FMT_TXT_CMAP_FORMAT0_TINY) {
             glyph_id = fdsc->cmaps[i].glyph_id_start + rcp;
         }
         else if(fdsc->cmaps[i].type == LV_FONT_FMT_TXT_CMAP_FORMAT0_FULL) {
             const uint8_t * gid_ofs_8 = fdsc->cmaps[i].glyph_id_ofs_list;
             glyph_id = fdsc->cmaps[i].glyph_id_start + gid_ofs_8[rcp];
         }
         else if(fdsc->cmaps[i].type == LV_FONT_FMT_TXT_CMAP_SPARSE_TINY) {
             uint16_t key = rcp;
             uint16_t * p = _lv_utils_bsearch(&key, fdsc->cmaps[i].unicode_list, fdsc->cmaps[i].list_length,
                                              sizeof(fdsc->cmaps[i].unicode_list[0]), unicode_list_compare);
 
             if(p) {
                 lv_uintptr_t ofs = p - fdsc->cmaps[i].unicode_list;
                 glyph_id = fdsc->cmaps[i].glyph_id_start + ofs;
             }
         }
         else if(fdsc->cmaps[i].type == LV_FONT_FMT_TXT_CMAP_SPARSE_FULL) {
             uint16_t key = rcp;
             uint16_t * p = _lv_utils_bsearch(&key, fdsc->cmaps[i].unicode_list, fdsc->cmaps[i].list_length,
                                              sizeof(fdsc->cmaps[i].unicode_list[0]), unicode_list_compare);
 
             if(p) {
                 lv_uintptr_t ofs = p - fdsc->cmaps[i].unicode_list;
                 const uint16_t * gid_ofs_16 = fdsc->cmaps[i].glyph_id_ofs_list;
                 glyph_id = fdsc->cmaps[i].glyph_id_start + gid_ofs_16[ofs];
             }
         }
 
         /*Update the cache*/
         if(fdsc->cache) {
             fdsc->cache->last_letter = letter;
             fdsc->cache->last_glyph_id = glyph_id;
         }
         return glyph_id;
     }
 
     if(fdsc->cache) {
         fdsc->cache->last_letter = letter;
         fdsc->cache->last_glyph_id = 0;
     }
     return 0;
 
 }
 
 static int8_t get_kern_value(const lv_font_t * font, uint32_t gid_left, uint32_t gid_right)
 {
     lv_font_fmt_txt_dsc_t * fdsc = (lv_font_fmt_txt_dsc_t *)font->dsc;
 
     int8_t value = 0;
 
     if(fdsc->kern_classes == 0) {
         /*Kern pairs*/
         const lv_font_fmt_txt_kern_pair_t * kdsc = fdsc->kern_dsc;
         if(kdsc->glyph_ids_size == 0) {
             /*Use binary search to find the kern value.
              *The pairs are ordered left_id first, then right_id secondly.*/
             const uint16_t * g_ids = kdsc->glyph_ids;
             uint16_t g_id_both = (gid_right << 8) + gid_left; /*Create one number from the ids*/
             uint16_t * kid_p = _lv_utils_bsearch(&g_id_both, g_ids, kdsc->pair_cnt, 2, kern_pair_8_compare);
 
             /*If the `g_id_both` were found get its index from the pointer*/
             if(kid_p) {
                 lv_uintptr_t ofs = kid_p - g_ids;
                 value = kdsc->values[ofs];
             }
         }
         else if(kdsc->glyph_ids_size == 1) {
             /*Use binary search to find the kern value.
              *The pairs are ordered left_id first, then right_id secondly.*/
             const uint32_t * g_ids = kdsc->glyph_ids;
             uint32_t g_id_both = (gid_right << 16) + gid_left; /*Create one number from the ids*/
             uint32_t * kid_p = _lv_utils_bsearch(&g_id_both, g_ids, kdsc->pair_cnt, 4, kern_pair_16_compare);
 
             /*If the `g_id_both` were found get its index from the pointer*/
             if(kid_p) {
                 lv_uintptr_t ofs = kid_p - g_ids;
                 value = kdsc->values[ofs];
             }
 
         }
         else {
             /*Invalid value*/
         }
     }
     else {
         /*Kern classes*/
         const lv_font_fmt_txt_kern_classes_t * kdsc = fdsc->kern_dsc;
         uint8_t left_class = kdsc->left_class_mapping[gid_left];
         uint8_t right_class = kdsc->right_class_mapping[gid_right];
 
         /*If class = 0, kerning not exist for that glyph
          *else got the value form `class_pair_values` 2D array*/
         if(left_class > 0 && right_class > 0) {
             value = kdsc->class_pair_values[(left_class - 1) * kdsc->right_class_cnt + (right_class - 1)];
         }
 
     }
     return value;
 }
 
 static int32_t kern_pair_8_compare(const void * ref, const void * element)
 {
     const uint8_t * ref8_p = ref;
     const uint8_t * element8_p = element;
 
     /*If the MSB is different it will matter. If not return the diff. of the LSB*/
     if(ref8_p[0] != element8_p[0]) return (int32_t)ref8_p[0] - element8_p[0];
     else return (int32_t) ref8_p[1] - element8_p[1];
 
 }
 
 static int32_t kern_pair_16_compare(const void * ref, const void * element)
 {
     const uint16_t * ref16_p = ref;
     const uint16_t * element16_p = element;
 
     /*If the MSB is different it will matter. If not return the diff. of the LSB*/
     if(ref16_p[0] != element16_p[0]) return (int32_t)ref16_p[0] - element16_p[0];
     else return (int32_t) ref16_p[1] - element16_p[1];
 }
 
 #if LV_USE_FONT_COMPRESSED
 /**
  * The compress a glyph's bitmap
  * @param in the compressed bitmap
  * @param out buffer to store the result
  * @param px_num number of pixels in the glyph (width * height)
  * @param bpp bit per pixel (bpp = 3 will be converted to bpp = 4)
  * @param prefilter true: the lines are XORed
  */
 static void decompress(const uint8_t * in, uint8_t * out, lv_coord_t w, lv_coord_t h, uint8_t bpp, bool prefilter)
 {
     uint32_t wrp = 0;
     uint8_t wr_size = bpp;
     if(bpp == 3) wr_size = 4;
 
     rle_init(in, bpp);
 
     uint8_t * line_buf1 = lv_mem_buf_get(w);
 
     uint8_t * line_buf2 = NULL;
 
     if(prefilter) {
         line_buf2 = lv_mem_buf_get(w);
     }
 
     decompress_line(line_buf1, w);
 
     lv_coord_t y;
     lv_coord_t x;
 
     for(x = 0; x < w; x++) {
         bits_write(out, wrp, line_buf1[x], bpp);
         wrp += wr_size;
     }
 
     for(y = 1; y < h; y++) {
         if(prefilter) {
             decompress_line(line_buf2, w);
 
             for(x = 0; x < w; x++) {
                 line_buf1[x] = line_buf2[x] ^ line_buf1[x];
                 bits_write(out, wrp, line_buf1[x], bpp);
                 wrp += wr_size;
             }
         }
         else {
             decompress_line(line_buf1, w);
 
             for(x = 0; x < w; x++) {
                 bits_write(out, wrp, line_buf1[x], bpp);
                 wrp += wr_size;
             }
         }
     }
 
     lv_mem_buf_release(line_buf1);
     lv_mem_buf_release(line_buf2);
 }
 
 /**
  * Decompress one line. Store one pixel per byte
  * @param out output buffer
  * @param w width of the line in pixel count
  */
 static inline void decompress_line(uint8_t * out, lv_coord_t w)
 {
     lv_coord_t i;
     for(i = 0; i < w; i++) {
         out[i] = rle_next();
     }
 }
 
 /**
  * Read bits from an input buffer. The read can cross byte boundary.
  * @param in the input buffer to read from.
  * @param bit_pos index of the first bit to read.
  * @param len number of bits to read (must be <= 8).
  * @return the read bits
  */
 static inline uint8_t get_bits(const uint8_t * in, uint32_t bit_pos, uint8_t len)
 {
     uint8_t bit_mask;
     switch(len) {
         case 1:
             bit_mask = 0x1;
             break;
         case 2:
             bit_mask = 0x3;
             break;
         case 3:
             bit_mask = 0x7;
             break;
         case 4:
             bit_mask = 0xF;
             break;
         case 8:
             bit_mask = 0xFF;
             break;
         default:
             bit_mask = (uint16_t)((uint16_t) 1 << len) - 1;
     }
 
     uint32_t byte_pos = bit_pos >> 3;
     bit_pos = bit_pos & 0x7;
 
     if(bit_pos + len >= 8) {
         uint16_t in16 = (in[byte_pos] << 8) + in[byte_pos + 1];
         return (in16 >> (16 - bit_pos - len)) & bit_mask;
     }
     else {
         return (in[byte_pos] >> (8 - bit_pos - len)) & bit_mask;
     }
 }
 
 /**
  * Write `val` data to `bit_pos` position of `out`. The write can NOT cross byte boundary.
  * @param out buffer where to write
  * @param bit_pos bit index to write
  * @param val value to write
  * @param len length of bits to write from `val`. (Counted from the LSB).
  * @note `len == 3` will be converted to `len = 4` and `val` will be upscaled too
  */
 static inline void bits_write(uint8_t * out, uint32_t bit_pos, uint8_t val, uint8_t len)
 {
     if(len == 3) {
         len = 4;
         switch(val) {
             case 0:
                 val = 0;
                 break;
             case 1:
                 val = 2;
                 break;
             case 2:
                 val = 4;
                 break;
             case 3:
                 val = 6;
                 break;
             case 4:
                 val = 9;
                 break;
             case 5:
                 val = 11;
                 break;
             case 6:
                 val = 13;
                 break;
             case 7:
                 val = 15;
                 break;
         }
     }
 
     uint16_t byte_pos = bit_pos >> 3;
     bit_pos = bit_pos & 0x7;
     bit_pos = 8 - bit_pos - len;
 
     uint8_t bit_mask = (uint16_t)((uint16_t) 1 << len) - 1;
     out[byte_pos] &= ((~bit_mask) << bit_pos);
     out[byte_pos] |= (val << bit_pos);
 }
 
 static inline void rle_init(const uint8_t * in,  uint8_t bpp)
 {
     rle_in = in;
     rle_bpp = bpp;
     rle_state = RLE_STATE_SINGLE;
     rle_rdp = 0;
     rle_prev_v = 0;
     rle_cnt = 0;
 }
 
 static inline uint8_t rle_next(void)
 {
     uint8_t v = 0;
     uint8_t ret = 0;
 
     if(rle_state == RLE_STATE_SINGLE) {
         ret = get_bits(rle_in, rle_rdp, rle_bpp);
         if(rle_rdp != 0 && rle_prev_v == ret) {
             rle_cnt = 0;
             rle_state = RLE_STATE_REPEATE;
         }
 
         rle_prev_v = ret;
         rle_rdp += rle_bpp;
     }
     else if(rle_state == RLE_STATE_REPEATE) {
         v = get_bits(rle_in, rle_rdp, 1);
         rle_cnt++;
         rle_rdp += 1;
         if(v == 1) {
             ret = rle_prev_v;
             if(rle_cnt == 11) {
                 rle_cnt = get_bits(rle_in, rle_rdp, 6);
                 rle_rdp += 6;
                 if(rle_cnt != 0) {
                     rle_state = RLE_STATE_COUNTER;
                 }
                 else {
                     ret = get_bits(rle_in, rle_rdp, rle_bpp);
                     rle_prev_v = ret;
                     rle_rdp += rle_bpp;
                     rle_state = RLE_STATE_SINGLE;
                 }
             }
         }
         else {
             ret = get_bits(rle_in, rle_rdp, rle_bpp);
             rle_prev_v = ret;
             rle_rdp += rle_bpp;
             rle_state = RLE_STATE_SINGLE;
         }
 
     }
     else if(rle_state == RLE_STATE_COUNTER) {
         ret = rle_prev_v;
         rle_cnt--;
         if(rle_cnt == 0) {
             ret = get_bits(rle_in, rle_rdp, rle_bpp);
             rle_prev_v = ret;
             rle_rdp += rle_bpp;
             rle_state = RLE_STATE_SINGLE;
         }
     }
 
     return ret;
 }
 #endif /*LV_USE_FONT_COMPRESSED*/
 
 /** Code Comparator.
  *
  *  Compares the value of both input arguments.
  *
  *  @param[in]  pRef        Pointer to the reference.
  *  @param[in]  pElement    Pointer to the element to compare.
  *
  *  @return Result of comparison.
  *  @retval < 0   Reference is less than element.
  *  @retval = 0   Reference is equal to element.
  *  @retval > 0   Reference is greater than element.
  *
  */
 static int32_t unicode_list_compare(const void * ref, const void * element)
 {
     return ((int32_t)(*(uint16_t *)ref)) - ((int32_t)(*(uint16_t *)element));
 }

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