Added readme.md

readme.md

@@ -1,5 +1,143 @@
 # BmpPP
-Run `configure.sh MyAwesomeLibrary` to give your project a name.
+A simple, easy to use BMP image interface for C++!
+
+Disclaimer!!:
+> This is in no way, shape or form complete or compatible with every possible bmp!
+> It does exactly what I need it to do, and that is to convert most bmp images to pixel buffers, convert between rgb/rgba/bw pixel buffers and write it all back to a bmp image.
+> I am just publishing this in case someone wants to do said things and does not care about incompatibilities with some bmps.
+ 
+## Basic Usage
+*Assuming:
+```c++
+using namespace Leonetienne::BmpPP;
+using namespace Eule;
+```
+
+##### Read image
+```c++
+BMP bmp("cute.bmp");
+
+// or
+BMP bmp;
+bmp.Read("cute.bmp");
+```
+
+##### Write image
+```c++
+bmp.Write("cute.bmp");
+```
+
+##### Create a new image
+```c++
+// RGBA image
+BMP bmp(Vector2i(800, 600));
+
+// RGBA image
+BMP bmp(Vector2i(800, 600), Colormode::RGBA);
+
+// RGB image
+BMP bmp(Vector2i(800, 600), Colormode::RGB);
+```
+
+##### Edit pixel data
+```c++
+// Set pixel grayscale value
+bmp.SetPixel(Vector2i(60, 50), 128);
+
+// Set pixel rgb value
+bmp.SetPixel(Vector2i(60, 50), 255, 128, 128);
+
+// Set pixel rgba value
+bmp.SetPixel(Vector2i(60, 50), 255, 128, 128, 64);
+```
+
+##### Get pixel data
+```c++
+// Assuming image is RGBA
+std::uint8_t* pixel = bmp.GetPixel(Vector2i(60, 50));
+
+std::uint8_t* r = pixel[0];
+std::uint8_t* g = pixel[1];
+std::uint8_t* b = pixel[2];
+std::uint8_t* a = pixel[3];
+```
+
+##### Convert between RGB and RGBA
+```c++
+// This is RGBA
+BMP bmp(Vector2i(800, 600), Colormode::RGBA);
+
+// Now it is RGB
+bmp.ConvertTo(Colormode::RGB);
+
+// And vica versa...
+```
+
+##### Mirror images
+```c++
+// Mirror horizontally
+BMP mirroredImage_hor = image.MirrorHorizontally();
+
+// Mirror vertically
+BMP mirroredImage_ver = image.MirrorVertically();
+```
+
+##### Rotate images
+```c++
+// Rotate by 90 degrees, clockwise
+BMP rotatedImage = image.Rotate90degClockwise();
+
+// Rotate by 90 degrees, counterclockwise
+BMP rotatedImage = image.Rotate90degCounterclockwise();
+
+// Rotate by 180 degrees
+BMP rotatedImage = image.Rotate180deg();
+```
+
+##### Crop images
+```c++
+// Extract the region topleft={25, 60}, size={150, 200}
+BMP cropped = bmp.Crop(Vector2i(25, 60), Vector2i(150, 200));
+```
+
+##### Fill channels
+```c++
+// Want to set the entire ALPHA channel to 255?
+bmp.FillChannel(3, 255);
+
+// Obviously: red->0, green->1, blue->2, alpha->3
+```
+
+##### Swapping channels
+```c++
+// Convert BGR to RGB, by swapping the red and blue channels.
+bmp.SwapChannels(0, 2);
+```
+
+##### Feed in existing pixel buffer
+```c++
+// OK, this is a bit more complex, but here's how to do it
+
+// This is assumed to be an RGBA pixel buffer, formatted like:
+// RGBARGBARGBARGBARGBARGBARGBA, with pixels in the same row lying next to each other in memory.
+std::vector<std::uint8_t> yourPixelbuffer;
+
+// Create a BMP instance with your resolution, and color mode
+BMP bmp(Vector2i(img_height, img_width), Colormode::RGBA);
+
+// Quick safety check, that the pixel buffer sizes do indeed match
+if (yourPixelbuffer.size() != bmp.GetPixelbufferSize())
+    throw "Something is definitely wrong!!!";
+
+// All good. Let's copy the bytes over
+std::copy(
+    yourPixelbuffer.cbegin(),
+    yourPixelbuffer.cend(),
+    bmp.data()
+);
+
+// Done.
+```
 
 # LICENSE
 ```