Katsu is a light cross-platform C library for 2D video game programming. It includes an API for 2D rendering, a simple input system, and sound output. Tile renderers of old school computers and video game consoles are the basis for Katsu's 2D rendering capabilities.
- 4bpp 8x8 pixel tile format
- 128 Color palettes, 16 colors each
- 16 64x64 tilemaps
- Affine transformations for tilemaps and sprite
- Horizontal line effects
- Window effects
- Other old-school effects (Mosaic, palette manipulation, etc.)
Katsu is meant to be used as a static library since it's so small, to build Katsu and it's tools (these will be placed in the tools folder) from source do the following:
If you are using Visual Studio you must set up the Visual Studio enviroment variables (this can be done in Windows Terminal by selecting the VS enviroment in the arrow dropdown menu). Then just run the build_win.bat batch file, this creates the static library lib/Katsu.lib.
Run the make command, this will generate the static library lib/libkatsu.a.
Simply copy the static library to your project's lib folder, you must also copy the include/katsu to your project's include folder.
The following is a very basic example for creating a window and controlling the back color with the directional pad and the A button:
#include <katsu/kt.h>
int main() {
KTColor bcolor = {0x00, 0x80, 0x00, 0x00};
/* Init Katsu */
if (kt_Init()) {
return 0;
}
/* Loop forever */
while (1) {
kt_Poll(); /* Poll joypads and window events */
/* Get the held buttons of the first joypad */
u32 btns = kt_JoyButtonHeld(0);
/* Use the bits to modify the R and B components */
bcolor.r += ((btns >> JOY_BIT_RIGHT) & 0x1) - ((btns >> JOY_BIT_LEFT) & 0x1);
bcolor.b += ((btns >> JOY_BIT_DOWN) & 0x1) - ((btns >> JOY_BIT_UP) & 0x1);
/* Swap G and B components of the back color if A is held */
if (btns & JOY_A) {
kt_BackColor(bcolor);
} else {
KTColor bcolor_alt = {bcolor.r, bcolor.b, bcolor.g, 0};
kt_BackColor(bcolor_alt);
}
kt_Draw(); /* Draw the image */
}
return 0;
}You will need MSVC installed, link with User32.lib, Gdi32.lib, Opengl32.lib, Xinput9_1_0.lib (or Xinput1_4.lib) and Katsu.lib. If you are using the console/terminal you should set your environment to use MSVC. Then compile with:
$> cl -Tc <your_source_code> -I".\include" -link User32.lib Gdi32.lib Opengl32.lib Xinput9_1_0.lib lib\Katsu.lib -OUT:mygame.exe
$> mygame.exe
Development packages for X11, OpenGL, and PipeWire are needed when compiling your project. You can download them from your package manager as libx11-dev, libgl1-mesa-dev and libpipewire-0.3-dev for Debian-based distros or as libX11-devel, mesa-libGL-devel and pipewire-devel for RedHat-based distros. After they are installed, you can compile and run from the terminal with:
$> gcc <your_source_code> -o mygame -I./include -I/usr/include/pipewire-0.3 -I/usr/include/spa-0.2 -D_REENTRANT -L./lib -lGL -lpipewire-0.3 -lX11 -lm -ldl -lkatsu
$> ./mygame
All Katsu applications use the same 11 keys from the keyboard:
- The four arrow keys and Z, X, A, S, Q, W, D, E, Enter, and RightShift
- Press Esc to exit form full screen
To compile the documentation you will need to have doxygen installed, then run, the generated HTML will be located in the new docs folder:
$> make docs
The Katsu Developer Manual is a work-in-progress, the current version can be found here:
Katsu asks for particular formats; if you want to create assets that follow these
formats, you must make your own tools (though a Katsu asset builder is planned). For simple
tile generation, you can use the kt-image tool found inside the tools folder after
building Katsu, this tool can read most image files and generate Katsu's 4bpp paletted format.
There might exist some 4bpp tile editors out there tho.
For creating tilemaps, a simple file exporter for the Tiled 2D map editor can be found in tools/tiled-extension (see it's readme for more information).
The Katsu project is and will always be free!
If you liked Katsu and you want to support its development with a donation, you can do so here:
