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55 lines
1.5 KiB
ReStructuredText
55 lines
1.5 KiB
ReStructuredText
.. _bmp:
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===========
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BMP decoder
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===========
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This extension allows the use of BMP images in LVGL.
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Library source: https://github.com/caj-johnson/bmp-decoder
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The pixels are read on demand (not the whole image is loaded)
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so using BMP images requires very little RAM.
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If enabled in ``lv_conf.h`` by :c:macro:`LV_USE_BMP` LVGL will register a new
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image decoder automatically so BMP files can be directly used as image
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sources. For example:
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.. code:: c
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lv_image_set_src(my_img, "S:path/to/picture.bmp");
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Note that, a file system driver needs to registered to open images from
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files. Read more about it :ref:`overview_file_system` or just
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enable one in ``lv_conf.h`` with ``LV_USE_FS_...``
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.. _bmp_limitations:
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Limitations
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-----------
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- Only BMP files are supported and BMP images as C array
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(:c:struct:`lv_image_dsc_t`) are not. It's because there is no practical
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differences between how the BMP files and LVGL's image format stores
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the image data.
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- BMP files can be loaded only from file. If you want to store them in
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flash it's better to convert them to C array with `LVGL's image converter <https://lvgl.io/tools/imageconverter>`__.
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- The BMP files color format needs to match with :c:macro:`LV_COLOR_DEPTH`.
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Use GIMP to save the image in the required format. Both RGB888 and
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ARGB888 works with :c:macro:`LV_COLOR_DEPTH` ``32``
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- Palette is not supported.
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- Because not the whole image is read in can not be zoomed or rotated.
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.. _bmp_example:
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Example
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-------
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.. include:: ../examples/libs/bmp/index.rst
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.. _bmp_api:
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API
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---
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