Added BMP header reader in D language

5 files changed, 119 insertions, 0 deletions

diff --git a/README.md b/README.md
index 01c639e..e2dfcb9 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,7 @@ running it.
 | [zig-elf](./zig-elf)                   | zig-0.14.0 | Read execution header of Elf64 format in Zig.                  |
 | [c-bluetooth](./c-bluetooth)           | clang-17   | Scans for all Bluetooth devices.                               |
 | [d-x11](./d-x11)                       | dmd-2.110  | Uses X11 to create a basic window without any bindings needed. |
+| [d-bmp-header](./d-bmp-header)         | dmd-2.110  | Reads BMP image header and prints the information out.         |
 
 ## License
 
diff --git a/d-bmp-header/.gitignore b/d-bmp-header/.gitignore
new file mode 100644
index 0000000..87e54c2
--- /dev/null
+++ b/d-bmp-header/.gitignore
@@ -0,0 +1,2 @@
+main
+*.o
diff --git a/d-bmp-header/Makefile b/d-bmp-header/Makefile
new file mode 100644
index 0000000..10a123e
--- /dev/null
+++ b/d-bmp-header/Makefile
@@ -0,0 +1,5 @@
+main: main.d
+	dmd main.d
+
+run:
+	./main image.bmp
diff --git a/d-bmp-header/image.bmp b/d-bmp-header/image.bmp
new file mode 100644
index 0000000..b061f2d
--- /dev/null
+++ b/d-bmp-header/image.bmp
diff --git a/d-bmp-header/main.d b/d-bmp-header/main.d
new file mode 100644
index 0000000..c8fcaf0
--- /dev/null
+++ b/d-bmp-header/main.d
@@ -0,0 +1,111 @@
+import std.stdio;
+import std.file;
+import std.format;
+import std.string;
+import std.range;
+import std.algorithm;
+import std.array;
+import std.math;
+
+// BMP file header (14 bytes).
+struct BitmapFileHeader {
+	char[2] signature;      // "BM" signature
+	uint fileSize;          // Size of the file in bytes
+	ushort reserved1;       // Reserved (0)
+	ushort reserved2;       // Reserved (0)
+	uint dataOffset;        // Offset to the start of image data
+}
+
+// BMP info header (40 bytes for BITMAPINFOHEADER).
+struct BitmapInfoHeader {
+	uint size;              // Size of this header (40 bytes)
+	int width;              // Image width in pixels
+	int height;             // Image height in pixels
+	ushort planes;          // Number of color planes (must be 1)
+	ushort bitsPerPixel;    // Bits per pixel (1, 4, 8, 16, 24, or 32)
+	uint compression;       // Compression method (0 = none, 1 = RLE-8, 2 = RLE-4)
+	uint imageSize;         // Size of the image data in bytes
+	int xPixelsPerMeter;    // Horizontal resolution (pixels per meter)
+	int yPixelsPerMeter;    // Vertical resolution (pixels per meter)
+	uint colorsUsed;        // Number of colors in the palette
+	uint importantColors;   // Number of important colors used (0 = all)
+}
+
+// RGB pixel structure.
+struct RGB {
+	ubyte blue;
+	ubyte green;
+	ubyte red;
+
+	string toString() const {
+		return format("RGB(%d, %d, %d)", red, green, blue);
+	}
+}
+
+void main(string[] args) {
+	if (args.length < 2) {
+		writeln("Usage: main <filename.bmp>");
+		return;
+	}
+
+	string fileName = args[1];
+
+	try {
+		// Read the file.
+		auto file = File(fileName, "rb");
+
+		// Read the BMP file header.
+		BitmapFileHeader fileHeader;
+		file.rawRead((&fileHeader)[0..1]);
+
+		// Check if it's a valid BMP file
+		if (fileHeader.signature != "BM") {
+			writeln("Error: Not a valid BMP file");
+			return;
+		}
+
+		// Read the BMP info header.
+		BitmapInfoHeader infoHeader;
+		file.rawRead((&infoHeader)[0..1]);
+
+		// Display header information.
+		writeln("BMP File Header Information:");
+		writefln("  Signature: %s", fileHeader.signature);
+		writefln("  File Size: %d bytes", fileHeader.fileSize);
+		writefln("  Data Offset: %d bytes", fileHeader.dataOffset);
+
+		writeln("\nBMP Info Header Information:");
+		writefln("  Header Size: %d bytes", infoHeader.size);
+		writefln("  Image Width: %d pixels", infoHeader.width);
+		writefln("  Image Height: %d pixels", infoHeader.height);
+		writefln("  Color Planes: %d", infoHeader.planes);
+		writefln("  Bits Per Pixel: %d", infoHeader.bitsPerPixel);
+
+		// Display compression method.
+		string compressionMethod;
+		switch (infoHeader.compression) {
+			case 0: compressionMethod = "None (BI_RGB)"; break;
+			case 1: compressionMethod = "RLE-8 (BI_RLE8)"; break;
+			case 2: compressionMethod = "RLE-4 (BI_RLE4)"; break;
+			case 3: compressionMethod = "Bitfields (BI_BITFIELDS)"; break;
+			default: compressionMethod = format("Unknown (%d)", infoHeader.compression);
+		}
+		writefln("  Compression: %s", compressionMethod);
+
+		writefln("  Image Size: %d bytes", infoHeader.imageSize);
+		writefln("  Horizontal Resolution: %d pixels/meter", infoHeader.xPixelsPerMeter);
+		writefln("  Vertical Resolution: %d pixels/meter", infoHeader.yPixelsPerMeter);
+		writefln("  Colors Used: %d", infoHeader.colorsUsed);
+		writefln("  Important Colors: %d", infoHeader.importantColors);
+
+		// Calculate color depth information.
+		int numColors = (infoHeader.bitsPerPixel <= 8) ? (1 << infoHeader.bitsPerPixel) : 0;
+		if (numColors > 0) {
+			writefln("  Color Palette: %d colors", numColors);
+		} else {
+			writefln("  Color Palette: None (direct color)");
+		}
+	} catch (Exception e) {
+		writefln("Error reading BMP file: %s", e.msg);
+	}
+}