%D \module
%D   [       file=mp-thrd.mpxl,
%D        version=2026.05.01,
%D          title=\CONTEXT\ \METAPOST\ graphics,
%D       subtitle=Scene based 3D plotting,
%D         author=Mikael Sundqvist & Hans Hagen & Chat 5.5]
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

if known metafun_loaded_thrd : endinput ; fi ;

newinternal boolean metafun_loaded_thrd ; metafun_loaded_thrd := true ; immutable metafun_loaded_thrd ;

runscript("lua.registercode('mlib-thr.lmt')");

presetparameters "lmtthreedscene" [
    bytemap     = 1,
  % crop        = true,
    maxfragment = 0,
  % width       = 600,
  % height      = 600,
  % bytewidth   = "",
  % byteheight  = "",
    supersample = 1,
    resolution  = 300,
    projection  = "perspective",
    eye         = (3,-4,2),
    target      = (0,0,0),
    up          = (0,0,1),
    forward     = (0,0,0),
    fov         = 45,
    light       = (-1,-1,-1),
    intensity   = 1,
 %  stipple     = [
 %      edgeboost        = .20,
 %      gamma            = 1.25,
 %      errorthreshold   = .5,
 %      dotradius        = 0,
 %      levels           = 2,
 %      tonedots         = true,
 %      outline          = false,
 %      outlinethreshold = .85,
 %      outlineradius    = 0,
 %      color            = black,
 %      backgroundcolor  = white
 %  ]
] ;

presetparameters "lmtthreedmaterial" [
    name      = "default",
    diffuse   = (.7,.7,.7),
    specular  = (0,0,0),
    shininess = 10,
    ambient   = .18,
    twosided  = false,
    opacity   = 1,
    ontop     = false,
    dx        = 0,
    dy        = 0,
] ;

presetparameters "lmtthreedsurface" [
    kind     = "graph",
    id       = "surface",
    code     = "0",
    dfdx     = "",
    dfdy     = "",
    normal   = "smooth",
    xstep    = "",
    ystep    = "",
    xmin     = -1,
    xmax     =  1,
    ymin     = -1,
    ymax     =  1,
    nx       = 32,
    ny       = 32,
    material = "default"
] ;

presetparameters "lmtthreedparametricsurface" [
    kind          = "parametric",
    id            = "surface",
    x             = "u",
    y             = "v",
    z             = "0",
    xu            = "",
    yu            = "",
    zu            = "",
    xv            = "",
    yv            = "",
    zv            = "",
    normal        = "smooth",
    umin          = 0,
    umax          = 2pi,
    vmin          = 0,
    vmax          = 2pi,
    nu            = 64,
    nv            = 32,
    ustep         = "",
    vstep         = "",
    width         = .35,
    boundary      = false,
    boundarycolor = black,
    boundarywidth = .5, % -1,
    material      = "default"
] ;

presetparameters "lmtthreedimplicitsurface" [
    kind     = "implicit",
    id       = "surface",
    code     = "x*x + y*y + z*z - 1",
    dfdx     = "",
    dfdy     = "",
    dfdz     = "",
    normal   = "smooth",
    xmin     = -1,
    xmax     =  1,
    ymin     = -1,
    ymax     =  1,
    zmin     = -1,
    zmax     =  1,
    nx       = "",
    ny       = "",
    nz       = "",
    iso      = 0,
    material = "default"
] ;

presetparameters "lmtthreedexternalsurface" [
    kind     = "external",
    id       = "surface",
  % filename = "",
    scale    = 1,
  % normal   = "smooth",
    material = "default"
] ;

presetparameters "lmtthreedinternalsurface" [
    kind     = "internal",
    id       = "surface",
  % name     = "",
    scale    = 1,
  % normal   = "smooth",
    material = "default"
] ;

presetparameters "lmtthreedplane" [
    kind     = "plane",
    id       = "plane",
    normal   = (0,0,1),
    center   = (0,0,0),
    usize    = 2,
    vsize    = 2,
    material = "default"
] ;

presetparameters "lmtthreedcurve" [
    kind     = "curve",
    id       = "curve",
    x        = "t",
    y        = "0",
    z        = "0",
    tmin     = 0,
    tmax     = 1,
    nt       = 64,
  % tstep    = 0,
    material = "default"
] ;

presetparameters "lmtthreedintersection" [
    kind     = "intersection",
    id       = "intersection",
    first    = "surface",
    second   = "plane",
    nx       = 0,
    ny       = 0,
    material = "default"
] ;

presetparameters "lmtthreedvisiblegrid" [
    id     = "",
    origin = (0,0,0),
    uaxis  = (1,0,0),
    vaxis  = (0,1,0),
    umin   = -1,
    umax   =  1,
    ustep  = .25,
    vmin   = -1,
    vmax   =  1,
    vstep  = .25,
    color  = black,
    width  = -1
] ;

presetparameters "lmtthreedvisibleaxis" [
    id     = "",
    origin = (0,0,0),
    xaxis  = (1,0,0),
    yaxis  = (0,1,0),
    zaxis  = (0,0,1),
    xmin   = -1,
    xmax   =  1,
    ymin   = -1,
    ymax   =  1,
    zmin   =  0,
    zmax   =  1,
    color  = black,
    width  = -1
] ;

presetparameters "lmtthreedvisibleticks" [
    id       = "",
    origin   = (0,0,0),
    axis     = (1,0,0),
    tickaxis = (0,1,0),
    first    = -1,
    last     =  1,
    step     =  1,
    size     = .1,
    color    = black,
    width    = -1
] ;

presetparameters "lmtthreedvisiblespecial" [
    id       = "",
  % from     = (0,0,0),
  % to       = (0,0,0),
  % at       = (0,0,0),
    color    = black,
    width    = -1
] ;

presetparameters "lmtthreedvisiblesegment" [
    id     = "",
    first  = (0,0,0),
    second = (1,0,0),
    color  = black,
    width  = -1
] ;

newscriptindex mfid_scene_width   ; mfid_scene_width   := scriptindex "lmt_scene_width" ;
newscriptindex mfid_scene_height  ; mfid_scene_height  := scriptindex "lmt_scene_height" ;
newscriptindex mfid_scene_bytemap ; mfid_scene_bytemap := scriptindex "lmt_scene_bytemap" ;

def lmt_scene_width   = runscript mfid_scene_width   enddef ;
def lmt_scene_height  = runscript mfid_scene_height  enddef ;
def lmt_scene_bytemap = runscript mfid_scene_bytemap enddef ;

% newscriptindex mfid_scene_overlay_path_count ; mfid_scene_overlay_path_count := scriptindex "lmt_scene_overlay_path_count" ;
% newscriptindex mfid_scene_overlay_path_data  ; mfid_scene_overlay_path_data  := scriptindex "lmt_scene_overlay_path_data"  ;
% newscriptindex mfid_scene_overlay_path_width ; mfid_scene_overlay_path_width := scriptindex "lmt_scene_overlay_path_width" ;
% newscriptindex mfid_scene_overlay_path_color ; mfid_scene_overlay_path_color := scriptindex "lmt_scene_overlay_path_color" ;

% def lmt_scene_overlay_path_count          = runscript mfid_scene_overlay_path_count   enddef ;
% def lmt_scene_overlay_path_data  (expr j) = runscript mfid_scene_overlay_path_data  j enddef ;
% def lmt_scene_overlay_path_width (expr j) = runscript mfid_scene_overlay_path_width j enddef ;
% def lmt_scene_overlay_path_color (expr j) = runscript mfid_scene_overlay_path_color j enddef ;

newscriptindex mfid_scene_project_point    ; mfid_scene_project_point    := scriptindex "lmt_scene_project_point" ;
newscriptindex mfid_scene_calculate_normal ; mfid_scene_calculate_normal := scriptindex "lmt_scene_calculate_normal" ;
newscriptindex mfid_scene_project_visible  ; mfid_scene_project_visible  := scriptindex "lmt_scene_project_visible" ;

def lmt_scene_project_point     expr    j  = runscript mfid_scene_project_point    j enddef ;
def lmt_scene_calculate_normal (expr n, j) = runscript mfid_scene_calculate_normal n j enddef ;
def lmt_scene_project_visible   expr    j  = runscript mfid_scene_project_visible  j enddef ;

let lmt_scene_point   = lmt_scene_project_point   ;
let lmt_scene_normal  = lmt_scene_calculate_normal ;
let lmt_scene_visible = lmt_scene_project_visible ;

def lmt_scene_material     = applyparameters "lmtthreedmaterial"          "lmt_scene_do_material"     enddef ;
def lmt_scene_parametric   = applyparameters "lmtthreedparametricsurface" "lmt_scene_do_parametric"   enddef ;
def lmt_scene_implicit     = applyparameters "lmtthreedimplicitsurface"   "lmt_scene_do_implicit"     enddef ;
def lmt_scene_internal     = applyparameters "lmtthreedinternalsurface"   "lmt_scene_do_internal"     enddef ;
def lmt_scene_external     = applyparameters "lmtthreedexternalsurface"   "lmt_scene_do_external"     enddef ;
def lmt_scene_surface      = applyparameters "lmtthreedsurface"           "lmt_scene_do_surface"      enddef ;
def lmt_scene_plane        = applyparameters "lmtthreedplane"             "lmt_scene_do_plane"        enddef ;
def lmt_scene_curve        = applyparameters "lmtthreedcurve"             "lmt_scene_do_curve"        enddef ;
def lmt_scene_intersection = applyparameters "lmtthreedintersection"      "lmt_scene_do_intersection" enddef ;

vardef lmt_scene_do_material     = lua.mp.lmt_scene_set_material    () ; enddef ;
vardef lmt_scene_do_parametric   = lua.mp.lmt_scene_set_parametric  () ; enddef ;
vardef lmt_scene_do_implicit     = lua.mp.lmt_scene_set_implicit    () ; enddef ;
vardef lmt_scene_do_internal     = lua.mp.lmt_scene_set_internal    () ; enddef ;
vardef lmt_scene_do_external     = lua.mp.lmt_scene_set_external    () ; enddef ;
vardef lmt_scene_do_surface      = lua.mp.lmt_scene_set_surface     () ; enddef ;
vardef lmt_scene_do_plane        = lua.mp.lmt_scene_set_plane       () ; enddef ;
vardef lmt_scene_do_curve        = lua.mp.lmt_scene_set_curve       () ; enddef ;
vardef lmt_scene_do_intersection = lua.mp.lmt_scene_set_intersection() ; enddef ;

def lmt_scene_segment    = applyparameters "lmtthreedvisiblesegment" "lmt_scene_do_segment" enddef ;
def lmt_scene_grid       = applyparameters "lmtthreedvisiblegrid"    "lmt_scene_do_grid"    enddef ;
def lmt_scene_axis       = applyparameters "lmtthreedvisibleaxis"    "lmt_scene_do_axis"    enddef ;
def lmt_scene_ticks      = applyparameters "lmtthreedvisibleticks"   "lmt_scene_do_ticks"   enddef ;
def lmt_scene_special    = applyparameters "lmtthreedvisiblespecial" "lmt_scene_do_special" enddef ;

vardef lmt_scene_do_segment = lua.mp.lmt_scene_overlay_segment() ; enddef ;
vardef lmt_scene_do_grid    = lua.mp.lmt_scene_overlay_grid   () ; enddef ;
vardef lmt_scene_do_axis    = lua.mp.lmt_scene_overlay_axis   () ; enddef ;
vardef lmt_scene_do_ticks   = lua.mp.lmt_scene_overlay_ticks  () ; enddef ;
vardef lmt_scene_do_special = lua.mp.lmt_scene_overlay_special() ; enddef ;

% this will change:
%
% proper begin /end
% no lmt variables

% todo : tick labels
% todo : axis labels
% todo : get position
% todo : push/pop parameters
% todo : cleanup results

boolean lmt_scene_rendered ; lmt_scene_rendered := false ;
numeric lmt_scene_nesting  ; lmt_scene_nesting  := 0 ;

def lmt_load_mlib_thr =
    runscript("lua.registercode('mlib-thr.lmt')");
    let lmt_load_mlib_thr = relax ;
enddef ;

def lmt_scene_start =
    lmt_load_mlib_lsy ;
    applyparameters "lmtthreedscene" "lmt_scene_do_start"
enddef ;

def lmt_scene_do_start =
    if lmt_scene_nesting = 0 :
        lua.mp.lmt_scene_manage_prepare() ;
        lmt_scene_rendered := false ;
    fi ;
    lmt_scene_nesting := lmt_scene_nesting + 1 ;
enddef ;

def lmt_scene_render =
    if not lmt_scene_rendered and (lmt_scene_nesting = 1) :
        lua.mp.lmt_scene_manage_render() ;
        lmt_scene_flush_bytemap ;
      % lmt_scene_flush_paths ;
      % lmt_scene_flush_labels ;
        lmt_scene_rendered := true ;
    fi ;
enddef ;

def lmt_scene_stop =
    lmt_scene_render ;
    lmt_scene_nesting := lmt_scene_nesting - 1 ;
    if lmt_scene_nesting = 0 :
         lua.mp.lmt_scene_manage_reset() ;
    fi
enddef ;

numeric lmt_scene_final_width ;
numeric lmt_scene_final_height ;

def lmt_scene_flush_bytemap =
    begingroup ;
        save p; path p ; p := unitsquare
            xyscaled (lmt_scene_width,lmt_scene_height)
            if (hasparameter "lmtthreedscene" "width") :
                if (hasparameter "lmtthreedscene" "height") :
                    xsized (getparameter "lmtthreedscene" "width"),getparameter "lmtthreedscene" "height"))
                else :
                    xsized (getparameter "lmtthreedscene" "width")
                fi
            elseif (hasparameter "lmtthreedscene" "height") :
                ysized (getparameter "lmtthreedscene" "height")
            fi
        ;
        lmt_final_width  := bbwidth (p) ;
        lmt_final_height := bbheight(p) ;
    endgroup ;
    draw unitsquare
        xyscaled(lmt_final_width,lmt_final_height)
        withbytemap (lmt_scene_bytemap)
        withbytemasked 255
        withpen pencircle scaled 0
    ;
enddef ;

def lmt_scene_project_point expr j =
    (
        (runscript mfid_scene_project_point j)
            xscaled (lmt_final_width /lmt_scene_width )
            yscaled (lmt_final_height/lmt_scene_height)
    )
enddef ;

vardef lmt_scene_bounds =
    unitsquare xyscaled(lmt_final_width,lmt_final_height)
enddef ;

let lmt_scene_point = lmt_scene_project_point ;