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			39 lines
		
	
	
		
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			39 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| 
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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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| This implementation uses [bmp-decoder](https://github.com/caj-johnson/bmp-decoder) library.
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| The pixels are read on demand (not the whole image is loaded) so using BMP images requires very little RAM.
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| 
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| If enabled in `lv_conf.h` by `LV_USE_BMP` LVGL will register a new image decoder automatically so BMP files can be directly used as image sources. For example:
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| ```
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| lv_img_set_src(my_img, "S:path/to/picture.bmp");
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| ```
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| 
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| Note that, a file system driver needs to registered to open images from files. Read more about it [here](https://docs.lvgl.io/master/overview/file-system.html) or just enable one in `lv_conf.h` with `LV_USE_FS_...`
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| 
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| ## Limitations
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| - Only BMP files are supported and BMP images as C array (`lv_img_dsc_t`) are not. It's because there is no practical differences between how the BMP files and LVGL's image format stores the image data.
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| - BMP files can be loaded only from file. If you want to store them in 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 `LV_COLOR_DEPTH`. Use GIMP to save the image in the required format.
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|   Both RGB888 and ARGB888 works with `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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| 
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| 
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| ## Example
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| ```eval_rst
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| 
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| .. include:: ../../examples/libs/bmp/index.rst
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| 
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| ```
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| 
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| ## API
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| 
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| ```eval_rst
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| 
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| .. doxygenfile:: lv_bmp.h
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|   :project: lvgl
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| 
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| ```
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