mirror of
https://github.com/daveallie/crosspoint-reader.git
synced 2026-02-04 14:47:37 +03:00
b8e61130f2
Address review comments #2, #3, and #10: - Extract duplicated bayer4x4 matrix, applyBayerDither4Level(), and drawPixelWithRenderMode() into shared DitherUtils.h - Extract duplicated PixelCache struct into shared PixelCache.h so both JPEG and PNG decoders use the same implementation - Add MAX_CACHE_BYTES (256KB) size limit to PixelCache::allocate() to proactively guard against oversized allocations on embedded targets
84 lines
2.5 KiB
C++
84 lines
2.5 KiB
C++
#pragma once
|
|
|
|
#include <HardwareSerial.h>
|
|
#include <SDCardManager.h>
|
|
#include <SdFat.h>
|
|
#include <stdint.h>
|
|
|
|
#include <cstring>
|
|
#include <string>
|
|
|
|
// Cache buffer for storing 2-bit pixels (4 levels) during decode.
|
|
// Packs 4 pixels per byte, MSB first.
|
|
struct PixelCache {
|
|
uint8_t* buffer;
|
|
int width;
|
|
int height;
|
|
int bytesPerRow;
|
|
int originX; // config.x - to convert screen coords to cache coords
|
|
int originY; // config.y
|
|
|
|
PixelCache() : buffer(nullptr), width(0), height(0), bytesPerRow(0), originX(0), originY(0) {}
|
|
|
|
static constexpr size_t MAX_CACHE_BYTES = 256 * 1024; // 256KB limit for embedded targets
|
|
|
|
bool allocate(int w, int h, int ox, int oy) {
|
|
width = w;
|
|
height = h;
|
|
originX = ox;
|
|
originY = oy;
|
|
bytesPerRow = (w + 3) / 4; // 2 bits per pixel, 4 pixels per byte
|
|
size_t bufferSize = (size_t)bytesPerRow * h;
|
|
if (bufferSize > MAX_CACHE_BYTES) {
|
|
Serial.printf("[%lu] [IMG] Cache buffer too large: %d bytes for %dx%d (limit %d)\n", millis(), bufferSize, w, h,
|
|
MAX_CACHE_BYTES);
|
|
return false;
|
|
}
|
|
buffer = (uint8_t*)malloc(bufferSize);
|
|
if (buffer) {
|
|
memset(buffer, 0, bufferSize);
|
|
Serial.printf("[%lu] [IMG] Allocated cache buffer: %d bytes for %dx%d\n", millis(), bufferSize, w, h);
|
|
}
|
|
return buffer != nullptr;
|
|
}
|
|
|
|
void setPixel(int screenX, int screenY, uint8_t value) {
|
|
if (!buffer) return;
|
|
int localX = screenX - originX;
|
|
int localY = screenY - originY;
|
|
if (localX < 0 || localX >= width || localY < 0 || localY >= height) return;
|
|
|
|
int byteIdx = localY * bytesPerRow + localX / 4;
|
|
int bitShift = 6 - (localX % 4) * 2; // MSB first: pixel 0 at bits 6-7
|
|
buffer[byteIdx] = (buffer[byteIdx] & ~(0x03 << bitShift)) | ((value & 0x03) << bitShift);
|
|
}
|
|
|
|
bool writeToFile(const std::string& cachePath) {
|
|
if (!buffer) return false;
|
|
|
|
FsFile cacheFile;
|
|
if (!SdMan.openFileForWrite("IMG", cachePath, cacheFile)) {
|
|
Serial.printf("[%lu] [IMG] Failed to open cache file for writing: %s\n", millis(), cachePath.c_str());
|
|
return false;
|
|
}
|
|
|
|
uint16_t w = width;
|
|
uint16_t h = height;
|
|
cacheFile.write(&w, 2);
|
|
cacheFile.write(&h, 2);
|
|
cacheFile.write(buffer, bytesPerRow * height);
|
|
cacheFile.close();
|
|
|
|
Serial.printf("[%lu] [IMG] Cache written: %s (%dx%d, %d bytes)\n", millis(), cachePath.c_str(), width, height,
|
|
4 + bytesPerRow * height);
|
|
return true;
|
|
}
|
|
|
|
~PixelCache() {
|
|
if (buffer) {
|
|
free(buffer);
|
|
buffer = nullptr;
|
|
}
|
|
}
|
|
};
|