pixie

pixie is a simple vector display emulator for Linux. It can show 256 intensities of green color (0=black). You can send commands to pixie using a named pipe.

Changes

19-Feb-2022  Pixie now supports raster operation
14-Feb-2022  Added support for pages and backgroud "color"
10-Feb-2022  Added the blit mode (XOR or COPY)
09-Feb-2022  Added optional line pattern.
07-Feb-2022  First version.

Compile

make

Use

pixie [--width n] [--height m] [--title s] [pipe]

Default resolution is 1024x512, default title is pixie and default named pipe is /tmp/pixie.pipe.

Example

pixie --width 330 --height 410 --title Vectrex /tmp/pixie.pipe

When you run pixie it will block the terminal until you press Ctrl+C or send commands to the named pipe. Therefore you will need to open two terminals: one for pixie and one for sending commands.

Commands

You can send pixie following basic commands

Pages

PAGE WRITE n ... Sets write page (page on which commands draw)

PAGE DISPLAY n ... Sets display page (page which is shown)

Default page is one. Pages are dynamically allocated. Pixie allows up to ten pages.

Color Commands

INK c ... Sets fore color (pen) intensity (0-255)

PAPER c ... Set back color (paper) intensity (0-255)

Screen

CLS ... Clear current

BLIT XOR ... Set XOR mode for blitting

BLIT COPY ... Set normal mode for blitting

Default blitting is copy.

Drawing

PIXEL x,y ... Draws pixel at x,y. Respects blit mode and fore and back colors.

LINE x0,y0,x1,y1[,pattern] ... Draws line from x0,y0 to x1,y1. Last parameter is bit pattern i.e. dotted line is 01010101.

RASTER x,y VALUES v1[,v2]+ ... Write raster bits (1 bit=1 pixel) to x,y.

Example

echo PAPER 32 > /tmp/pixie.pipe
echo CLS > /tmp/pixie.pipe
echo PAGE WRITE 1 > /tmp/pixie.pipe
echo PAPER 0 >/tmp/pixie.pipe
echo INK 128 > /tmp/pixie.pipe
echo LINE 10,10,200,10 > /tmp/pixie.pipe
echo LINE 200,10,200,200,85 >/tmp/pixie.pipe
echo LINE 200,200,10,200,15 >/tmp/pixie.pipe
echo INK 255 > /tmp/pixie.pipe
echo LINE 10,200,10,10 > /tmp/pixie.pipe
echo PAGE DISPLAY 1 > /tmp/pixie.pipe
echo WRITE RASTER 10,10 VALUES 85,85,85 > /tmp/pixie.pipe

Using pixie from C

Use standard file functions to write to pixie.

#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdarg.h>

#define PIXIE_PIPE          "/tmp/pixie.pipe"
#define MAX_PIXIE_BUFFER    32

static int _fd=0;
static char _buffer[MAX_PIXIE_BUFFER];

void pxopen() {
    if ( (_fd = open(PIXIE_PIPE, O_WRONLY)) < 0)
        exit(1);
}

void pxclose() {
    close(_fd);
}

void pxwrite(const char *format, ...) {
    va_list argptr;
    va_start(argptr, format);
    vsprintf(_buffer, format, argptr);
    write(_fd,_buffer,strlen(_buffer));
    va_end(argptr);
}

void cls() {
    pxwrite("C\n");;
}

void line(int x0,int y0, int x1, int y1) {
    pxwrite("L%d,%d,%d,%d,%d\n",x0,y0,x1,y1,_g.line_style);
}

Why pixie?

To simulate procedural programming environment on an event driven GUI. You can, for example, develop vector game prototypes for 8-bit machines on Linux, or test your drawing algorithms on pixie.

To do

My wish list includes (in this order) raster operations, colors, and a retro CRT shader. Stay tuned.