Простейшее чтение BMP-файла. Логика вынесена в класс.

bmpimage.cpp

@@ -0,0 +1,68 @@
+#include "bmpimage.h"
+
+BMPImage::BMPImage(BitmapFileHeader &fileHeader, BITMAPINFOHEADER &infoHeader, Pixel **pixelArray) {
+    this->fileHeader = fileHeader;
+    this->infoHeader = infoHeader;
+    this->pixelArray = pixelArray;
+}
+
+const uint32_t &BMPImage::width() const { return this->infoHeader.BitmapWidth; }
+
+const uint32_t &BMPImage::height() const { return this->infoHeader.BitmapHeight; }
+
+void BMPImage::write(const std::string &filename) {
+    {
+        std::ofstream ofs(filename, std::ios_base::binary);
+        ofs.write((char *) &this->fileHeader, sizeof(this->fileHeader));
+        ofs.write((char *) &this->infoHeader, sizeof(this->infoHeader));
+        uint32_t byteByRow = this->infoHeader.BitmapWidth * 3;
+        uint8_t padding = 4 - this->infoHeader.BitmapWidth % 4;
+        for (int i = 0; i < this->infoHeader.BitmapHeight; ++i) {
+            ofs.write((char *) pixelArray[i], byteByRow);
+            if (padding != 4) ofs.write(PADDING_ZEROES, padding); // Write padding
+        }
+    }
+}
+
+BMPImage readBMPImage(const std::string &filename) {
+    BitmapFileHeader bitmapFileHeader;
+    BITMAPINFOHEADER bitmapInfoHeader;
+    Pixel **pixelArray;
+    uint32_t DIB_Header_Size;
+    {
+        std::ifstream ifs(filename, std::ios_base::binary);
+        if (!ifs.good()) {
+            throw std::runtime_error("File read error");
+        }
+        ifs.seekg(0, std::ios::beg);
+        ifs.read((char *) &bitmapFileHeader, sizeof(bitmapFileHeader));
+        ifs.read((char *) &DIB_Header_Size, sizeof(DIB_Header_Size));
+    }
+    if (DIB_Header_Size != 40) {
+        throw std::runtime_error("Invalid header");
+    }
+    {
+        std::ifstream ifs(filename, std::ios_base::binary);
+        if (!ifs.good()) {
+            throw std::runtime_error("File read error");
+        }
+        ifs.seekg(14, std::ios::beg);
+        ifs.read((char *) &bitmapInfoHeader, sizeof(bitmapInfoHeader));
+    }
+    pixelArray = new Pixel *[bitmapInfoHeader.BitmapHeight];
+    {
+        std::ifstream ifs(filename, std::ios_base::binary);
+        if (!ifs.good()) {
+            throw std::runtime_error("File read error");
+        }
+        ifs.seekg(bitmapFileHeader.imageDataOffset, std::ios::beg);
+        uint32_t byteByRow = bitmapInfoHeader.BitmapWidth * 3;
+        uint8_t padding = 4 - bitmapInfoHeader.BitmapWidth % 4;
+        for (int i = 0; i < bitmapInfoHeader.BitmapHeight; ++i) {
+            pixelArray[i] = new Pixel[bitmapInfoHeader.BitmapWidth];
+            ifs.read((char *) pixelArray[i], byteByRow);
+            if (padding != 4) ifs.seekg(padding, std::ios_base::cur); // Skip padding
+        }
+    }
+    return {bitmapFileHeader, bitmapInfoHeader, pixelArray};
+}