# lv_draw_label.h (/api/draw/lv_draw_label_h)



<RelatedHeaders name="lv_draw_label_private.h" isPrivate="false" />

<ApiSummary functions="9" structs="2" typedefs="1" macros="1" />

Functions [#functions]

<ApiTabs items="[&#x22;Getters (1)&#x22;,&#x22;Other (8)&#x22;]">
  <ApiTab value="Getters (1)">
    <ApiMember kind="function" name="lv_draw_task_get_label_dsc" file="draw/lv_draw_label.h" line="173" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L173">
      lv_draw_task_get_label_dsc [#lv_draw_task_get_label_dsc]

      Try to get a label draw descriptor from a draw task.

      ```c title=" " lineNumbers=1
      lv_draw_label_dsc_t * lv_draw_task_get_label_dsc(lv_draw_task_t *task)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name   | Type                                                         | Description |
      | ------ | ------------------------------------------------------------ | ----------- |
      | `task` | <ApiLink name="lv_draw_task_t" display="lv_draw_task_t *" /> | draw task   |

      **Returns:** <ApiLink name="lv_draw_label_dsc_t" display="lv_draw_label_dsc_t *" /> — the task's draw descriptor or NULL if the task is not of type LV\_DRAW\_TASK\_TYPE\_LABEL
    </ApiMember>
  </ApiTab>

  <ApiTab value="Other (8)">
    <ApiMember kind="function" name="lv_draw_letter_dsc_init" file="draw/lv_draw_label.h" line="160" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L160">
      lv_draw_letter_dsc_init [#lv_draw_letter_dsc_init]

      ```c title=" " lineNumbers=1
      void lv_draw_letter_dsc_init(lv_draw_letter_dsc_t *dsc)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name  | Type                                                                     |
      | ----- | ------------------------------------------------------------------------ |
      | `dsc` | <ApiLink name="lv_draw_letter_dsc_t" display="lv_draw_letter_dsc_t *" /> |
    </ApiMember>

    <ApiMember kind="function" name="lv_draw_label_dsc_init" file="draw/lv_draw_label.h" line="166" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L166">
      lv_draw_label_dsc_init [#lv_draw_label_dsc_init]

      Initialize a label draw descriptor

      ```c title=" " lineNumbers=1
      void lv_draw_label_dsc_init(lv_draw_label_dsc_t *dsc)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name  | Type                                                                   | Description                  |
      | ----- | ---------------------------------------------------------------------- | ---------------------------- |
      | `dsc` | <ApiLink name="lv_draw_label_dsc_t" display="lv_draw_label_dsc_t *" /> | pointer to a draw descriptor |
    </ApiMember>

    <ApiMember kind="function" name="lv_draw_glyph_dsc_init" file="draw/lv_draw_label.h" line="180" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L180">
      lv_draw_glyph_dsc_init [#lv_draw_glyph_dsc_init]

      Initialize a glyph draw descriptor. Used internally.

      ```c title=" " lineNumbers=1
      void lv_draw_glyph_dsc_init(lv_draw_glyph_dsc_t *dsc)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name  | Type                                                                   | Description                  |
      | ----- | ---------------------------------------------------------------------- | ---------------------------- |
      | `dsc` | <ApiLink name="lv_draw_glyph_dsc_t" display="lv_draw_glyph_dsc_t *" /> | pointer to a draw descriptor |
    </ApiMember>

    <ApiMember kind="function" name="lv_draw_label" file="draw/lv_draw_label.h" line="188" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L188">
      lv_draw_label [#lv_draw_label]

      Create a draw task to render a text

      ```c title=" " lineNumbers=1
      void lv_draw_label(lv_layer_t *layer, const lv_draw_label_dsc_t *dsc, const lv_area_t *coords)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name     | Type                                                                         | Description                  |
      | -------- | ---------------------------------------------------------------------------- | ---------------------------- |
      | `layer`  | <ApiLink name="lv_layer_t" display="lv_layer_t *" />                         | pointer to a layer           |
      | `dsc`    | <ApiLink name="lv_draw_label_dsc_t" display="const lv_draw_label_dsc_t *" /> | pointer to draw descriptor   |
      | `coords` | <ApiLink name="lv_area_t" display="const lv_area_t *" />                     | coordinates of the character |
    </ApiMember>

    <ApiMember kind="function" name="lv_draw_character" file="draw/lv_draw_label.h" line="198" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L198">
      lv_draw_character [#lv_draw_character]

      Create a draw task to render a single character

      ```c title=" " lineNumbers=1
      void lv_draw_character(lv_layer_t *layer, lv_draw_label_dsc_t *dsc, const lv_point_t *point, uint32_t unicode_letter)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name             | Type                                                                   | Description                |
      | ---------------- | ---------------------------------------------------------------------- | -------------------------- |
      | `layer`          | <ApiLink name="lv_layer_t" display="lv_layer_t *" />                   | pointer to a layer         |
      | `dsc`            | <ApiLink name="lv_draw_label_dsc_t" display="lv_draw_label_dsc_t *" /> | pointer to draw descriptor |
      | `point`          | <ApiLink name="lv_point_t" display="const lv_point_t *" />             | position of the label      |
      | `unicode_letter` | <ApiLink name="uint32_t" />                                            | the letter to draw         |
    </ApiMember>

    <ApiMember kind="function" name="lv_draw_letter" file="draw/lv_draw_label.h" line="207" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L207">
      lv_draw_letter [#lv_draw_letter]

      Draw a single letter

      ```c title=" " lineNumbers=1
      void lv_draw_letter(lv_layer_t *layer, lv_draw_letter_dsc_t *dsc, const lv_point_t *point)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name    | Type                                                                     | Description                |
      | ------- | ------------------------------------------------------------------------ | -------------------------- |
      | `layer` | <ApiLink name="lv_layer_t" display="lv_layer_t *" />                     | pointer to a layer         |
      | `dsc`   | <ApiLink name="lv_draw_letter_dsc_t" display="lv_draw_letter_dsc_t *" /> | pointer to draw descriptor |
      | `point` | <ApiLink name="lv_point_t" display="const lv_point_t *" />               | position of the label      |
    </ApiMember>

    <ApiMember kind="function" name="lv_draw_label_iterate_characters" file="draw/lv_draw_label.h" line="218" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L218">
      lv_draw_label_iterate_characters [#lv_draw_label_iterate_characters]

      Should be used during rendering the characters to get the position and other parameters of the characters

      ```c title=" " lineNumbers=1
      void lv_draw_label_iterate_characters(lv_draw_task_t *t, const lv_draw_label_dsc_t *dsc, const lv_area_t *coords, lv_draw_glyph_cb_t cb)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name     | Type                                                                         | Description                                       |
      | -------- | ---------------------------------------------------------------------------- | ------------------------------------------------- |
      | `t`      | <ApiLink name="lv_draw_task_t" display="lv_draw_task_t *" />                 | pointer to a draw task                            |
      | `dsc`    | <ApiLink name="lv_draw_label_dsc_t" display="const lv_draw_label_dsc_t *" /> | pointer to draw descriptor                        |
      | `coords` | <ApiLink name="lv_area_t" display="const lv_area_t *" />                     | coordinates of the label                          |
      | `cb`     | <ApiLink name="lv_draw_glyph_cb_t" />                                        | a callback to call to draw each glyphs one by one |
    </ApiMember>

    <ApiMember kind="function" name="lv_draw_unit_draw_letter" file="draw/lv_draw_label.h" line="237" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L237">
      lv_draw_unit_draw_letter [#lv_draw_unit_draw_letter]

      Draw a single letter using the provided draw unit, glyph descriptor, position, font, and callback.

      This function is responsible for rendering a single character from a text string, applying the necessary styling described by the glyph descriptor (`dsc`). It handles the retrieval of the glyph's description, checks its visibility within the clipping area, and invokes the callback (`cb`) to render the glyph at the specified position (`pos`) using the given font (`font`).

      ```c title=" " lineNumbers=1
      void lv_draw_unit_draw_letter(lv_draw_task_t *t, lv_draw_glyph_dsc_t *dsc, const lv_point_t *pos, const lv_font_t *font, uint32_t letter, lv_draw_glyph_cb_t cb)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name     | Type                                                                   | Description                                                             |
      | -------- | ---------------------------------------------------------------------- | ----------------------------------------------------------------------- |
      | `t`      | <ApiLink name="lv_draw_task_t" display="lv_draw_task_t *" />           | Pointer to the drawing task.                                            |
      | `dsc`    | <ApiLink name="lv_draw_glyph_dsc_t" display="lv_draw_glyph_dsc_t *" /> | Pointer to the descriptor containing styling for the glyph to be drawn. |
      | `pos`    | <ApiLink name="lv_point_t" display="const lv_point_t *" />             | Pointer to the point coordinates where the letter should be drawn.      |
      | `font`   | <ApiLink name="lv_font_t" display="const lv_font_t *" />               | Pointer to the font containing the glyph.                               |
      | `letter` | <ApiLink name="uint32_t" />                                            | The Unicode code point of the letter to be drawn.                       |
      | `cb`     | <ApiLink name="lv_draw_glyph_cb_t" />                                  | Callback function to execute the actual rendering of the glyph.         |
    </ApiMember>
  </ApiTab>
</ApiTabs>

Structs [#structs]

<ApiMember kind="struct" name="lv_draw_label_dsc_t">
  lv_draw_label_dsc_t [#lv_draw_label_dsc_t]

  | Member                 | Type                                                                     | Description                                                                                                            |
  | ---------------------- | ------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------- |
  | `base`                 | <ApiLink name="lv_draw_dsc_base_t" />                                    |                                                                                                                        |
  | `text`                 | `const char *`                                                           | The text to draw                                                                                                       |
  | `text_size`            | <ApiLink name="lv_point_t" />                                            | The size of the text                                                                                                   |
  | `font`                 | <ApiLink name="lv_font_t" display="const lv_font_t *" />                 | The font to use. Fallback fonts are also handled.                                                                      |
  | `color`                | <ApiLink name="lv_color_t" />                                            | Color of the text                                                                                                      |
  | `line_space`           | <ApiLink name="int32_t" />                                               | Extra space between the lines                                                                                          |
  | `letter_space`         | <ApiLink name="int32_t" />                                               | Extra space between the characters                                                                                     |
  | `ofs_x`                | <ApiLink name="int32_t" />                                               | Offset the text with this value horizontally                                                                           |
  | `ofs_y`                | <ApiLink name="int32_t" />                                               | Offset the text with this value vertically                                                                             |
  | `rotation`             | <ApiLink name="int32_t" />                                               | Rotation of the letters in 0.1 degree unit                                                                             |
  | `sel_start`            | <ApiLink name="uint32_t" />                                              | The first characters index for selection (not byte index). `LV_DRAW_LABEL_NO_TXT_SEL` for no selection                 |
  | `sel_end`              | <ApiLink name="uint32_t" />                                              | The last characters's index for selection (not byte index). `LV_DRAW_LABEL_NO_TXT_SEL` for no selection                |
  | `sel_color`            | <ApiLink name="lv_color_t" />                                            | Color of the selected characters                                                                                       |
  | `sel_bg_color`         | <ApiLink name="lv_color_t" />                                            | Background color of the selected characters                                                                            |
  | `text_length`          | <ApiLink name="uint32_t" />                                              | The number of characters to render. 0: means render until reaching the `\0` termination.                               |
  | `align`                | <ApiLink name="lv_text_align_t" />                                       | The alignment of the text `LV_TEXT_ALIGN_LEFT/RIGHT/CENTER`                                                            |
  | `bidi_dir`             | <ApiLink name="lv_base_dir_t" />                                         | The base direction. Used when type setting Right-to-left (e.g. Arabic) texts                                           |
  | `opa`                  | <ApiLink name="lv_opa_t" />                                              | Opacity of the text in 0...255 range. LV\_OPA\_TRANSP, LV\_OPA\_10, LV\_OPA\_20, .. LV\_OPA\_COVER can be used as well |
  | `outline_stroke_opa`   | <ApiLink name="lv_opa_t" />                                              | Letter outline stroke opacity                                                                                          |
  | `decor`                | <ApiLink name="lv_text_decor_t" />                                       | Text decoration, e.g. underline                                                                                        |
  | `flag`                 | <ApiLink name="lv_text_flag_t" />                                        | Some flags to control type setting                                                                                     |
  | `text_local`           | <ApiLink name="uint8_t" />                                               | 1: malloc a buffer and copy `text` there. 0: `text` will be valid during rendering.                                    |
  | `text_static`          | <ApiLink name="uint8_t" />                                               | Indicate that the text is constant and its pointer can be safely saved e.g. in a cache.                                |
  | `has_bided`            | <ApiLink name="uint8_t" />                                               | 1: already executed lv\_bidi\_process\_paragraph. 0: has not been executed lv\_bidi\_process\_paragraph.               |
  | `hint`                 | <ApiLink name="lv_draw_label_hint_t" display="lv_draw_label_hint_t *" /> | Pointer to an externally stored struct where some data can be cached to speed up rendering                             |
  | `outline_stroke_color` | <ApiLink name="lv_color_t" />                                            |                                                                                                                        |
  | `outline_stroke_width` | <ApiLink name="int32_t" />                                               |                                                                                                                        |
</ApiMember>

<TypeUsedBy name="lv_draw_label_dsc_t" count="12">
  * `lv_obj_init_draw_label_dsc` — param `draw_dsc`
  * `lv_draw_eve_label` — param `dsc`
  * `lv_draw_label_dsc_init` — param `dsc`
  * `lv_draw_label` — param `dsc`
  * `lv_draw_character` — param `dsc`
  * `lv_draw_label_iterate_characters` — param `dsc`
  * `lv_draw_nanovg_label` — param `dsc`
  * `lv_draw_nema_gfx_label` — param `dsc`
  * `lv_draw_dave2d_label` — param `dsc`
  * `lv_draw_sdl_label` — param `dsc`
  * `lv_draw_sw_label` — param `dsc`
  * `lv_draw_vg_lite_label` — param `dsc`
</TypeUsedBy>

<ApiMember kind="struct" name="lv_draw_letter_dsc_t">
  lv_draw_letter_dsc_t [#lv_draw_letter_dsc_t]

  | Member                 | Type                                                     | Description |
  | ---------------------- | -------------------------------------------------------- | ----------- |
  | `base`                 | <ApiLink name="lv_draw_dsc_base_t" />                    |             |
  | `unicode`              | <ApiLink name="uint32_t" />                              |             |
  | `font`                 | <ApiLink name="lv_font_t" display="const lv_font_t *" /> |             |
  | `color`                | <ApiLink name="lv_color_t" />                            |             |
  | `rotation`             | <ApiLink name="int32_t" />                               |             |
  | `scale_x`              | <ApiLink name="int32_t" />                               |             |
  | `scale_y`              | <ApiLink name="int32_t" />                               |             |
  | `skew_x`               | <ApiLink name="int32_t" />                               |             |
  | `skew_y`               | <ApiLink name="int32_t" />                               |             |
  | `pivot`                | <ApiLink name="lv_point_t" />                            |             |
  | `opa`                  | <ApiLink name="lv_opa_t" />                              |             |
  | `decor`                | <ApiLink name="lv_text_decor_t" />                       |             |
  | `blend_mode`           | <ApiLink name="lv_blend_mode_t" />                       |             |
  | `outline_stroke_opa`   | <ApiLink name="lv_opa_t" />                              |             |
  | `outline_stroke_width` | <ApiLink name="int32_t" />                               |             |
  | `outline_stroke_color` | <ApiLink name="lv_color_t" />                            |             |
</ApiMember>

<TypeUsedBy name="lv_draw_letter_dsc_t" count="5">
  * `lv_draw_letter_dsc_init` — param `dsc`
  * `lv_draw_letter` — param `dsc`
  * `lv_draw_nanovg_letter` — param `dsc`
  * `lv_draw_sw_letter` — param `dsc`
  * `lv_draw_vg_lite_letter` — param `dsc`
</TypeUsedBy>

Typedefs [#typedefs]

<ApiMember kind="typedef" name="lv_draw_glyph_cb_t" file="draw/lv_draw_label.h" line="153" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L153">
  lv_draw_glyph_cb_t [#lv_draw_glyph_cb_t]

  ```c title=" " lineNumbers=1
  typedef void(* lv_draw_glyph_cb_t) (lv_draw_task_t *t, lv_draw_glyph_dsc_t *dsc, lv_draw_fill_dsc_t *fill_dsc, const lv_area_t *fill_area)
  ```

  Passed as a parameter to `lv_draw_label_iterate_characters` to draw the characters one by one
</ApiMember>

<TypeUsedBy name="lv_draw_glyph_cb_t" count="2">
  * `lv_draw_label_iterate_characters` — param `cb`
  * `lv_draw_unit_draw_letter` — param `cb`
</TypeUsedBy>

Macros [#macros]

<ApiMember kind="macro" name="LV_DRAW_LABEL_NO_TXT_SEL" file="draw/lv_draw_label.h" line="26" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/draw/lv_draw_label.h#L26">
  LV_DRAW_LABEL_NO_TXT_SEL [#lv_draw_label_no_txt_sel]

  ```c title=" " lineNumbers=1
  #define LV_DRAW_LABEL_NO_TXT_SEL (0xFFFF)
  ```
</ApiMember>

Dependencies [#dependencies]

<FileIncludes includes="[&#x22;lv_draw.h&#x22;, &#x22;lv_draw_rect.h&#x22;, &#x22;lv_bidi.h&#x22;, &#x22;lv_text.h&#x22;, &#x22;lv_color.h&#x22;, &#x22;lv_style.h&#x22;]" includedBy="[&#x22;lv_obj_draw.h&#x22;, &#x22;lv_draw_eve_private.h&#x22;, &#x22;lv_draw_label_private.h&#x22;, &#x22;lv_draw_nanovg_private.h&#x22;, &#x22;lv_draw_dave2d.h&#x22;, &#x22;lv_draw_sdl.h&#x22;, &#x22;lv_draw_sw.h&#x22;, &#x22;lv_draw_vg_lite.h&#x22;]" transitiveIncludes="[&#x22;lv_anim.h&#x22;, &#x22;lv_area.h&#x22;, &#x22;lv_array.h&#x22;, &#x22;lv_assert.h&#x22;, &#x22;lv_color_op.h&#x22;, &#x22;lv_conf_internal.h&#x22;, &#x22;lv_conf_kconfig.h&#x22;, &#x22;lv_draw_buf.h&#x22;, &#x22;lv_event.h&#x22;, &#x22;lv_ext_data.h&#x22;, &#x22;lv_flex.h&#x22;, &#x22;lv_font.h&#x22;, &#x22;lv_fs.h&#x22;, &#x22;lv_grad.h&#x22;, &#x22;lv_grid.h&#x22;, &#x22;lv_image_decoder.h&#x22;, &#x22;lv_image_dsc.h&#x22;, &#x22;lv_layout.h&#x22;, &#x22;lv_ll.h&#x22;, &#x22;lv_log.h&#x22;, &#x22;lv_math.h&#x22;, &#x22;lv_matrix.h&#x22;, &#x22;lv_mem.h&#x22;, &#x22;lv_palette.h&#x22;, &#x22;lv_profiler.h&#x22;, &#x22;lv_profiler_builtin.h&#x22;, &#x22;lv_sprintf.h&#x22;, &#x22;lv_string.h&#x22;, &#x22;lv_style_gen.h&#x22;, &#x22;lv_symbol_def.h&#x22;, &#x22;lv_tick.h&#x22;, &#x22;lv_timer.h&#x22;, &#x22;lv_types.h&#x22;]" />