esp-idf/examples/common_components/qrcode/include/qrcode.h

// Copyright 2020 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#pragma once

#include <esp_err.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
  * @brief  QR Code handle used by the display function
  */
typedef const uint8_t * esp_qrcode_handle_t;

/**
  * @brief  QR Code configuration options
  */
typedef struct {
    void (*display_func)(esp_qrcode_handle_t qrcode);   /**< Function called for displaying the QR Code after encoding is complete */
    int max_qrcode_version;                             /**< Max QR Code Version to be used. Range: 2 - 40 */
    int qrcode_ecc_level;                               /**< Error Correction Level for QR Code */
} esp_qrcode_config_t;

/**
  * @brief  Error Correction Level in a QR Code Symbol
  */
enum {
    ESP_QRCODE_ECC_LOW,     /**< QR Code Error Tolerance of 7% */
    ESP_QRCODE_ECC_MED,     /**< QR Code Error Tolerance of 15% */
    ESP_QRCODE_ECC_QUART,   /**< QR Code Error Tolerance of 25% */
    ESP_QRCODE_ECC_HIGH     /**< QR Code Error Tolerance of 30% */
};

/**
  * @brief  Encodes the given string into a QR Code and calls the display function
  *
  * @attention 1. Can successfully encode a UTF-8 string of up to 2953 bytes or an alphanumeric
  *               string of up to 4296 characters or any digit string of up to 7089 characters
  *
  * @param  cfg   Configuration used for QR Code encoding.
  * @param  text  String to encode into a QR Code.
  *
  * @return
  *    - ESP_OK: succeed
  *    - ESP_FAIL: Failed to encode string into a QR Code
  *    - ESP_ERR_NO_MEM: Failed to allocate buffer for given max_qrcode_version
  */
esp_err_t esp_qrcode_generate(esp_qrcode_config_t *cfg, const char *text);

/**
  * @brief  Displays QR Code on the console
  *
  * @param  qrcode  QR Code handle used by the display function.
  */
void esp_qrcode_print_console(esp_qrcode_handle_t qrcode);

/**
  * @brief  Returns the side length of the given QR Code
  *
  * @param  qrcode  QR Code handle used by the display function.
  *
  * @return
  *    - val[21, 177]: Side length of QR Code
  */
int esp_qrcode_get_size(esp_qrcode_handle_t qrcode);

/**
  * @brief  Returns the Pixel value for the given coordinates
  *         False indicates White and True indicates Black
  *
  * @attention 1. Coordinates for top left corner are (x=0, y=0)
  * @attention 2. For out of bound coordinates false (White) is returned
  *
  * @param  qrcode  QR Code handle used by the display function.
  * @param  x  X-Coordinate of QR Code module
  * @param  y  Y-Coordinate of QR Code module
  *
  * @return
  *    - true: (x, y) Pixel is Black
  *    - false: (x, y) Pixel is White
  */
bool esp_qrcode_get_module(esp_qrcode_handle_t qrcode, int x, int y);

#define ESP_QRCODE_CONFIG_DEFAULT() (esp_qrcode_config_t) { \
    .display_func = esp_qrcode_print_console, \
    .max_qrcode_version = 10, \
    .qrcode_ecc_level = ESP_QRCODE_ECC_LOW, \
}

#ifdef __cplusplus
}
#endif