/** * @file lv_image_decoder.h * */ #ifndef LV_IMAGE_DECODER_H #define LV_IMAGE_DECODER_H #ifdef __cplusplus extern "C" { #endif /********************* * INCLUDES *********************/ #include "../lv_conf_internal.h" #include "lv_draw_buf.h" #include "../misc/lv_fs.h" #include "../misc/lv_types.h" #include "../misc/lv_area.h" #include "../misc/cache/lv_cache.h" /********************* * DEFINES *********************/ /********************** * TYPEDEFS **********************/ /** * Source of image.*/ typedef enum { LV_IMAGE_SRC_VARIABLE, /** Binary/C variable*/ LV_IMAGE_SRC_FILE, /** File in filesystem*/ LV_IMAGE_SRC_SYMBOL, /** Symbol (@ref lv_symbol_def.h)*/ LV_IMAGE_SRC_UNKNOWN, /** Unknown source*/ } lv_image_src_t; /** * Get info from an image and store in the `header` * @param decoder pointer to decoder object * @param dsc pointer to decoder descriptor * @param header store the info here * @return LV_RESULT_OK: info written correctly; LV_RESULT_INVALID: failed */ typedef lv_result_t (*lv_image_decoder_info_f_t)(lv_image_decoder_t * decoder, lv_image_decoder_dsc_t * dsc, lv_image_header_t * header); /** * Open an image for decoding. Prepare it as it is required to read it later * @param decoder pointer to the decoder the function associated with * @param dsc pointer to decoder descriptor. `src`, `color` are already initialized in it. */ typedef lv_result_t (*lv_image_decoder_open_f_t)(lv_image_decoder_t * decoder, lv_image_decoder_dsc_t * dsc); /** * Decode `full_area` pixels incrementally by calling in a loop. Set `decoded_area` values to `LV_COORD_MIN` on first call. * Required only if the "open" function can't return with the whole decoded pixel array. * @param decoder pointer to the decoder the function associated with * @param dsc pointer to decoder descriptor * @param full_area input parameter. the full area to decode after enough subsequent calls * @param decoded_area input+output parameter. set the values to `LV_COORD_MIN` for the first call and to reset decoding. * the decoded area is stored here after each call. * @return LV_RESULT_OK: ok; LV_RESULT_INVALID: failed or there is nothing left to decode */ typedef lv_result_t (*lv_image_decoder_get_area_cb_t)(lv_image_decoder_t * decoder, lv_image_decoder_dsc_t * dsc, const lv_area_t * full_area, lv_area_t * decoded_area); /** * Close the pending decoding. Free resources etc. * @param decoder pointer to the decoder the function associated with * @param dsc pointer to decoder descriptor */ typedef void (*lv_image_decoder_close_f_t)(lv_image_decoder_t * decoder, lv_image_decoder_dsc_t * dsc); /********************** * GLOBAL PROTOTYPES **********************/ /** * Get information about an image. * Try the created image decoder one by one. Once one is able to get info that info will be used. * @param src the image source. Can be * 1) File name: E.g. "S:folder/img1.png" (The drivers needs to registered via `lv_fs_drv_register()`) * 2) Variable: Pointer to an `lv_image_dsc_t` variable * 3) Symbol: E.g. `LV_SYMBOL_OK` * @param header the image info will be stored here * @return LV_RESULT_OK: success; LV_RESULT_INVALID: wasn't able to get info about the image */ lv_result_t lv_image_decoder_get_info(const void * src, lv_image_header_t * header); /** * Open an image. * Try the created image decoders one by one. Once one is able to open the image that decoder is saved in `dsc` * @param dsc describes a decoding session. Simply a pointer to an `lv_image_decoder_dsc_t` variable. * @param src the image source. Can be * 1) File name: E.g. "S:folder/img1.png" (The drivers needs to registered via `lv_fs_drv_register())`) * 2) Variable: Pointer to an `lv_image_dsc_t` variable * 3) Symbol: E.g. `LV_SYMBOL_OK` * @param args args about how the image should be opened. * @return LV_RESULT_OK: opened the image. `dsc->decoded` and `dsc->header` are set. * LV_RESULT_INVALID: none of the registered image decoders were able to open the image. */ lv_result_t lv_image_decoder_open(lv_image_decoder_dsc_t * dsc, const void * src, const lv_image_decoder_args_t * args); /** * Decode `full_area` pixels incrementally by calling in a loop. Set `decoded_area` to `LV_COORD_MIN` on first call. * @param dsc image decoder descriptor * @param full_area input parameter. the full area to decode after enough subsequent calls * @param decoded_area input+output parameter. set the values to `LV_COORD_MIN` for the first call and to reset decoding. * the decoded area is stored here after each call. * @return LV_RESULT_OK: success; LV_RESULT_INVALID: an error occurred or there is nothing left to decode */ lv_result_t lv_image_decoder_get_area(lv_image_decoder_dsc_t * dsc, const lv_area_t * full_area, lv_area_t * decoded_area); /** * Close a decoding session * @param dsc pointer to `lv_image_decoder_dsc_t` used in `lv_image_decoder_open` */ void lv_image_decoder_close(lv_image_decoder_dsc_t * dsc); /** * Create a new image decoder * @return pointer to the new image decoder */ lv_image_decoder_t * lv_image_decoder_create(void); /** * Delete an image decoder * @param decoder pointer to an image decoder */ void lv_image_decoder_delete(lv_image_decoder_t * decoder); /** * Get the next image decoder in the linked list of image decoders * @param decoder pointer to an image decoder or NULL to get the first one * @return the next image decoder or NULL if no more image decoder exists */ lv_image_decoder_t * lv_image_decoder_get_next(lv_image_decoder_t * decoder); /** * Set a callback to get information about the image * @param decoder pointer to an image decoder * @param info_cb a function to collect info about an image (fill an `lv_image_header_t` struct) */ void lv_image_decoder_set_info_cb(lv_image_decoder_t * decoder, lv_image_decoder_info_f_t info_cb); /** * Set a callback to open an image * @param decoder pointer to an image decoder * @param open_cb a function to open an image */ void lv_image_decoder_set_open_cb(lv_image_decoder_t * decoder, lv_image_decoder_open_f_t open_cb); /** * Set a callback to a decoded line of an image * @param decoder pointer to an image decoder * @param read_line_cb a function to read a line of an image */ void lv_image_decoder_set_get_area_cb(lv_image_decoder_t * decoder, lv_image_decoder_get_area_cb_t read_line_cb); /** * Set a callback to close a decoding session. E.g. close files and free other resources. * @param decoder pointer to an image decoder * @param close_cb a function to close a decoding session */ void lv_image_decoder_set_close_cb(lv_image_decoder_t * decoder, lv_image_decoder_close_f_t close_cb); lv_cache_entry_t * lv_image_decoder_add_to_cache(lv_image_decoder_t * decoder, lv_image_cache_data_t * search_key, const lv_draw_buf_t * decoded, void * user_data); /** * Check the decoded image, make any modification if decoder `args` requires. * @note A new draw buf will be allocated if provided `decoded` is not modifiable or stride mismatch etc. * @param dsc pointer to a decoder descriptor * @param decoded pointer to a decoded image to post process to meet dsc->args requirement. * @return post processed draw buffer, when it differs with `decoded`, it's newly allocated. */ lv_draw_buf_t * lv_image_decoder_post_process(lv_image_decoder_dsc_t * dsc, lv_draw_buf_t * decoded); /********************** * MACROS **********************/ #ifdef __cplusplus } /*extern "C"*/ #endif #endif /*LV_IMAGE_DECODER_H*/