From 7a7b5ddd1188de6fcdb16a8c55a07f0ba70232e9 Mon Sep 17 00:00:00 2001
From: Johannes Wolf <mail@johannes-wolf.com>
Date: Fri, 19 Apr 2024 15:29:50 +0200
Subject: [PATCH] WIP

---
 apps/find_plane.lua | 111 ++++++++++++++++++++++++++++++++++++++------
 1 file changed, 98 insertions(+), 13 deletions(-)

diff --git a/apps/find_plane.lua b/apps/find_plane.lua
index 9c62f3c..f86ffd3 100644
--- a/apps/find_plane.lua
+++ b/apps/find_plane.lua
@@ -1,6 +1,10 @@
 local apps       = require 'apps.apps'
+local matrix     = require 'matrix'
+local advice     = require 'advice'
 local ask        = require('dialog.input').display_sync
 local choice     = require('dialog.choice').display_sync
+local choice     = require('dialog.choice').display_sync
+local matrix_ed  = require('rpn.matrixeditor').display_sync
 local expr       = require 'expressiontree'
 local sym        = require 'ti.sym'
 
@@ -31,17 +35,41 @@ local function ask_vector(title, dim)
    end
 end
 
-local function run_plane_3pt(stack)
-   local pts = {}
-   for i = 1, 3 do
-      local pt = ask_vector("Point " .. tostring(i))
-      if not pt then
-         return
+local function ask_n_vectors(ctrl, names)
+   local mat = matrix.new(4, 5)
+   mat:set(1,1," ")
+   mat:set(2,1,"x")
+   mat:set(3,1,"y")
+   mat:set(4,1,"z")
+   mat:resize(4, 1 + #names)
+   for n = 1, #names do
+      mat:set(1, 1 + n, tostring(names[n]))
+   end
+
+   local function setup_dlg(dlg)
+      local grid = dlg.grid
+      grid:set_header(1,1)
+      grid:set_selection(2,2)
+      dlg.grid_resize(4, 1 + #names)
+   end
+
+   local res = matrix_ed(ctrl, mat, setup_dlg)
+   if res then
+      local vecs = {}
+      for n = 1, #names do
+         table.insert(vecs, {
+             mat:get(2, n + 1),
+             mat:get(3, n + 1),
+             mat:get(4, n + 1),
+         })
       end
-      table.insert(pts, pt)
+      return vecs
    end
+end
 
-   local a, b, c = pts[1], pts[2], pts[3]
+-- Find plane equation from 3 pts
+local function run_plane_3pt(ctrl, stack)
+   local a, b, c = table.unpack(ask_n_vectors(ctrl, {"a", "b", "c"}))
    local ab = math.evalStr(table_to_vec(a) .. "-" .. table_to_vec(b))
    local ac = math.evalStr(table_to_vec(a) .. "-" .. table_to_vec(c))
    local n = math.evalStr("crossp(" .. ab .. "," .. ac .. ")")
@@ -52,15 +80,63 @@ local function run_plane_3pt(stack)
    local res_p = "x = " .. table_to_vec(a) .. " + s*" .. ab .. " + t*" .. ac
    local res_n = "(x - " .. table_to_vec(a) .. ") " .. sym.CDOT .. " " .. n
 
-   local store = choice { title = 'Results', items = {
-      { title = 'E: ' .. res_c, align = -1, result = 'c', seq = {'c'} },
+   local action = choice { title = 'Results', items = {
+      { title = 'E: ' .. res_c, align = -1, result = 'c' },
       { title = 'E: ' .. res_p, align = -1, result = 'p' },
       { title = 'E: ' .. res_n, align = -1, result = 'n' },
-      { title = 'Exit', result = false},
+      { title = 'Store...', result = 'store' },
+      { title = 'Exit', result = 'done' },
    }}
 
-   if store == 'c' then
+   if action == 'store' then
+      local sym = ask { title = 'Variable', text = 'E1' }
+      if sym and #sym > 0 then
+         stack:push_infix(res_c)
+         stack:push_infix(sym)
+         stack:push_operator('=:')
+      end
+   elseif action == 'c' then
       stack:push_infix(res_c)
+   elseif action == 'done' then
+      return
+   end
+end
+
+-- Find intersection point or distance between two lines
+local function run_2lines(ctrl, stack)
+   local function vec_str(l)
+      return string.format("[[%s,%s,%s]]", table.unpack(l))
+   end
+
+   local p1, d1, p2, d2 = table.unpack(ask_n_vectors(ctrl, {"p1", "d1", "p2", "d2"}))
+   if p1 then
+      local vp1, vd1 = vec_str(p1), vec_str(d1)
+      local vp2, vd2 = vec_str(p2), vec_str(d2)
+
+      local eq1 = vp1 .. "+a*".. vd1
+      local eq2 = vp2 .. "+b*".. vd2
+
+      local isection = "solve(" .. eq1 .. "=" .. eq2 .. ",a,b)"
+      local parallel = "solve(" .. vd1 .. "=t*" .. vd2 .. ",t)"
+      local n = math.evalStr("crossp(" .. vd1 .. "," .. vd2 .. ")")
+      local n1 = math.evalStr("crossp(" .. vd1 .. "," .. n .. ")")
+      local n2 = math.evalStr("crossp(" .. vd2 .. "," .. n .. ")")
+      local nearest1 = string.format("%s+(dotp(%s-%s,%s)/dotp(%s,%s))*%s",
+        vp1, vp2, vp1, n2, vd1, n2, vd1)
+      local nearest2 = string.format("%s+(dotp(%s-%s,%s)/dotp(%s,%s))*%s",
+        vp2, vp1, vp2, n1, vd2, n1, vd2)
+      local distance = "norm(" .. nearest1 .. "-" .. nearest2 ..")"
+
+      local r_isection = math.evalStr(isection)
+      local r_parallel = math.evalStr(parallel)
+      print(r_isection)
+      print(r_parallel)
+
+      if r_isection ~= 'false' then
+         return
+      else
+         return
+      end
    end
 end
 
@@ -71,5 +147,14 @@ local function run_angle_2vec(stack)
    stack:push_infix("arccos(dotp(" .. a .. "," .. b .. ")/(norm(" .. a .. "*norm(" .. b ..  "))")
 end
 
+local function run_dist_2pt(stack)
+   local a = table_to_vec(ask_vector("Point A"))
+   local b = table_to_vec(ask_vector("Point B"))
+
+   stack:push_infix("norm(" .. b .. "-" .. a .. ")")
+end
+
 apps.add('plane - 3pt', 'Plane - 3 Points', run_plane_3pt)
-apps.add('angle - 2vec', 'Angle - 2 Vectors', run_angle_2vec)
\ No newline at end of file
+apps.add('angle - 2vec', 'Angle - 2 Vectors', run_angle_2vec)
+apps.add('dist - 2pt',   'Dist. - 2 Points', run_dist_2pt)
+apps.add('2line',   '2line', run_2lines)