______       _          _   _       _                    _____     _ 
|  _  \     | |        | \ | |     | |                  |____ |   | |
| | | |_   _| | _____  |  \| |_   _| | _____ _ __ ___       / / __| |
| | | | | | | |/ / _ \ | . ` | | | | |/ / _ \ '_ ` _ \      \ \/ _` |
| |/ /| |_| |   <  __/ | |\  | |_| |   <  __/ | | | | | .___/ / (_| |
|___/  \__,_|_|\_\___| \_| \_/\__,_|_|\_\___|_| |_| |_| \____/ \__,_|

----------------------------------------------------------------------------


Original sources used https://github.com/rohit-n/chocolate_duke3D 
Fixed SDL 1.2 issue in Engine/src/display.c   to build on pkgsrc and riscv64 

    //CODE EXPLORATION
    //Used only to write the last palette to file.
    memcpy(lastPalette, palettebuffer, 768);

    for (i = 0; i < 256; i++){
        sdlp->b = (Uint8) ((((float) *p++) / 63.0) * 255.0);
        sdlp->g = (Uint8) ((((float) *p++) / 63.0) * 255.0);
        sdlp->r = (Uint8) ((((float) *p++) / 63.0) * 255.0);
        sdlp->unused = *p++;   /* This byte is unused in BUILD, too. */
        sdlp++;


Installation (make sure you have bootsrapped pkgsrc)  :    
 
export PATH=$PATH:/usr/pkg/bin
export PATH=$PATH:/usr/pkg/sbin
PKG_PATH="http://astr0baby.online/riscv64/DevTerm-R01/All"
export PKG_PATH
pkg_add cduke  


# Download DukeNukem3D data  to some directory and extract it 

# On the Devterm R01 the best performance is with the following options 

export SDL_AUDIODRIVER=disk
export  SDL_DISKAUDIOFILE=/dev/null
/usr/pkg/bin/chocolate-duke3d