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mirror of https://github.com/esphome/esphome.git synced 2025-04-17 16:20:31 +01:00
Jesse Hills 7fccc9ff86
[online_image] Add binary bmp support (#8116)
Co-authored-by: guillempages <guillempages@users.noreply.github.com>
2025-01-23 15:10:19 +13:00

119 lines
3.7 KiB
C++

#pragma once
#include "esphome/core/color.h"
namespace esphome {
namespace online_image {
enum DecodeError : int {
DECODE_ERROR_INVALID_TYPE = -1,
DECODE_ERROR_UNSUPPORTED_FORMAT = -2,
DECODE_ERROR_OUT_OF_MEMORY = -3,
};
class OnlineImage;
/**
* @brief Class to abstract decoding different image formats.
*/
class ImageDecoder {
public:
/**
* @brief Construct a new Image Decoder object
*
* @param image The image to decode the stream into.
*/
ImageDecoder(OnlineImage *image) : image_(image) {}
virtual ~ImageDecoder() = default;
/**
* @brief Initialize the decoder.
*
* @param download_size The total number of bytes that need to be downloaded for the image.
*/
virtual void prepare(uint32_t download_size) { this->download_size_ = download_size; }
/**
* @brief Decode a part of the image. It will try reading from the buffer.
* There is no guarantee that the whole available buffer will be read/decoded;
* the method will return the amount of bytes actually decoded, so that the
* unread content can be moved to the beginning.
*
* @param buffer The buffer to read from.
* @param size The maximum amount of bytes that can be read from the buffer.
* @return int The amount of bytes read. It can be 0 if the buffer does not have enough content to meaningfully
* decode anything, or negative in case of a decoding error.
*/
virtual int decode(uint8_t *buffer, size_t size) = 0;
/**
* @brief Request the image to be resized once the actual dimensions are known.
* Called by the callback functions, to be able to access the parent Image class.
*
* @param width The image's width.
* @param height The image's height.
* @return true if the image was resized, false otherwise.
*/
bool set_size(int width, int height);
/**
* @brief Fill a rectangle on the display_buffer using the defined color.
* Will check the given coordinates for out-of-bounds, and clip the rectangle accordingly.
* In case of binary displays, the color will be converted to binary as well.
* Called by the callback functions, to be able to access the parent Image class.
*
* @param x The left-most coordinate of the rectangle.
* @param y The top-most coordinate of the rectangle.
* @param w The width of the rectangle.
* @param h The height of the rectangle.
* @param color The fill color
*/
void draw(int x, int y, int w, int h, const Color &color);
bool is_finished() const { return this->decoded_bytes_ == this->download_size_; }
protected:
OnlineImage *image_;
// Initializing to 1, to ensure it is distinguishable from initial "decoded_bytes_".
// Will be overwritten anyway once the download size is known.
uint32_t download_size_ = 1;
uint32_t decoded_bytes_ = 0;
double x_scale_ = 1.0;
double y_scale_ = 1.0;
};
class DownloadBuffer {
public:
DownloadBuffer(size_t size) : size_(size) {
this->buffer_ = this->allocator_.allocate(size);
this->reset();
}
virtual ~DownloadBuffer() { this->allocator_.deallocate(this->buffer_, this->size_); }
uint8_t *data(size_t offset = 0);
uint8_t *append() { return this->data(this->unread_); }
size_t unread() const { return this->unread_; }
size_t size() const { return this->size_; }
size_t free_capacity() const { return this->size_ - this->unread_; }
size_t read(size_t len);
size_t write(size_t len) {
this->unread_ += len;
return this->unread_;
}
void reset() { this->unread_ = 0; }
protected:
RAMAllocator<uint8_t> allocator_{};
uint8_t *buffer_;
size_t size_;
/** Total number of downloaded bytes not yet read. */
size_t unread_;
};
} // namespace online_image
} // namespace esphome