paint

mouse-driven vector paint on the graphics card

NAME
    paint - mouse-driven vector paint on the graphics card

SYNOPSIS
    paint [-d | -w]

DESCRIPTION
    A little vector editor: pick a primitive and a colour from the
    on-screen palette, rubber-band shapes onto the canvas, drop fills
    into closed outlines, and erase mistakes one shape at a time. The
    drawing is a DISPLAY LIST -- shapes, not pixels -- which is what
    makes erase possible: the last shape is popped and the canvas
    replays. It is driven by the MOUSE: move the crosshair, click a
    swatch or tool in the palette strip, press-drag-release to draw, and
    click the red X to quit. The keyboard keeps only editing shortcuts.

    With -d (how desk launches it), quitting chains back to desk via
    SYS_EXEC instead of exiting to the shell. With -w (how wdesk, the
    resident-kernel desktop, launches it) quitting re-execs "wdesk -r",
    resuming that desktop with its windows intact. With neither flag,
    quitting returns to the shell.

MOUSE
    The mouse arrives as xterm SGR reports on the console (from a
    terminal with mouse reporting, from the emulator's -W browser
    mouse-pad, or from a real PS/2 mouse). The crosshair follows the
    pointer everywhere -- including up over the palette strip, so you
    can see what you are about to click. Then:

    move              the crosshair follows the pointer
    press-drag-release  draw the current tool (Line/Box/Circle); for
                      Fill, a press drops at the pointer
    click a swatch    select that colour
    click a tool cell select Line / Box / Circle / Fill
    click the red X   quit (the close-box at the right of the strip)
    right-click       cancel a rubber-band in progress

    Line and box rubber-band from the press point to the release. Circle
    presses at the CENTRE; the radius is the larger of the drag's x/y
    distance. Position lands at terminal-CELL resolution, mapped through
    the size the terminal reports (80x24 assumed if it stays silent).
    The current tool and colour are bracketed in the palette strip and
    echoed on the console.

KEYS (editing shortcuts; movement and selection are the mouse's job)
    SPACE             anchor the shape, then (second press) commit it;
                      for Fill: drop at the crosshair
    x                 cancel a rubber-band in progress
    e (or u)          erase the LAST shape and replay the rest
    n                 new drawing (clear the canvas)
    q                 quit

FILL
    The drop must land on background inside a CLOSED outline. paint
    probes rightward from the drop point to find the enclosing
    outline's colour, then issues the PGC's AREABC: the selected
    colour flood-fills, bounded by pixels of the outline's colour. A
    drop on a coloured pixel, or in a region open to the right, is
    refused. A fill is a shape like any other: erase removes it, and
    a replayed fill re-probes nothing -- its boundary colour was
    recorded at drop time.

NOTES
    The palette strip is protected by the card itself: the drawing
    session runs with WINDOW/VWPORT set to the canvas, so every
    stroke, ghost and fill clips at the canvas edge. The crosshair
    and rubber-bands draw in LINFUN complement mode -- drawing one
    twice restores the screen exactly, over any colours -- and solid
    commits return to replace mode. Circles cap at radius 255 (the
    PGC ELIPSE rule); a drawing holds up to 150 shapes.

SEE ALSO
    desk, wdesk, gl, basic (GRAPHICS), gfx, image

See also: desk, wdesk, gl, basic, gfx, image

The text of man paint on P8X (os/man/paint in the repository). All commands