bugfix: don't rely on Screen_bottom1 while scrolling

Dependencies

• [2] YTSPVDZH first successful pagedown test, first bug found by test
• [3] 242L3OQX bugfix: ensure Cursor_line is always on a text line
• [4] BYG5CEMV support for naming points
• [5] QYIFOHW3 first test!
• [6] 2RXZ3PGO beginning of a new approach to scroll+wrap
• [7] 3QNOKBFM beginnings of a test harness
• [8] PFT5Y2ZY move
• [9] DLQMM265 scroll past first page
• [10] AVTNUQYR basic test-enabled framework
• [*] BULPIBEG beginnings of a module for the text editor
• [*] 3TFEAQSW start using some globals
• [*] OTIBCAUJ love2d scaffold
• [*] 7IKRRESB longer names for indices in long loops
• [*] IRV65LZP fold variables for screen dimensions into the app framework
• [*] CVGE3SIG I feel confident now that page-down is working.

Change contents

• edit in text.lua at line 12
  [13.50]

  [12.109]
  + print('text.draw')
• replacement in text.lua at line 130
  [2.1173]→[2.1173:1336](∅→∅)
  − App.screen.init{width=50, height=45}

  − Lines = load_array{'abc',

  − '```lines', '```',

  − 'def',

  − 'ghi'}
  [2.1173]

  [2.1336]
  + App.screen.init{width=50, height=80}

  + Lines = load_array{'abc', -- height 15

  + '```lines', '```', -- height 25

  + 'def', -- height 15

  + 'ghi'} -- height 15
• replacement in text.lua at line 142
  [2.1590]→[2.1590:1722](∅→∅)
  − local drawing_height = App.screen.width / 2 -- default

  − -- initially the screen displays the first line and part of the drawing
  [2.1590]

  [2.1722]
  + local text height = 15

  + local drawing_height = 20 + App.screen.width / 2 -- default

  + -- initially the screen displays the first line and the drawing

  + -- 15px margin + 15px line1 + 10px margin + 25px drawing + 10px margin = 75px < screen height 80px
• edit in text.lua at line 150
  [2.1902]

  [2.1902]
  + -- 15px margin + 10px margin + 25px drawing + 10px margin + 15px line3 = 75px < screen height 80px
• edit in text.lua at line 152
  [2.1939]

  [2.1939]
  + print('test: top:', Screen_top1.line)
• edit in text.lua at line 155
  [2.2053]→[2.2053:2148](∅→∅)
  − y = y + line_height

  − App.screen.check(y, 'ghi', 'F - test_pagedown_skip_drawings/screen:2')
• edit in text.lua at line 424
  [3.87]

  [3.6682]
  + local y = 15 -- top margin
• edit in text.lua at line 429
  [3.186]

  [3.6764]
  + print('cursor skips', Cursor1.line)

  + y = y + 20 + Drawing.pixels(Lines[Cursor1.line].h)
• replacement in text.lua at line 438
  [3.408]→[3.6871:6916](∅→∅)
  − if Cursor1.line > Screen_bottom1.line then
  [3.408]

  [2.2154]
  + --? print(y, App.screen.height, App.screen.height-math.floor(15*Zoom))

  + if y > App.screen.height - math.floor(15*Zoom) then

  + --? if Cursor1.line > Screen_bottom1.line then
• edit in main.lua at line 125
  [15.44]

  [2.2297]
  + print(y, line_index, line)
• edit in main.lua at line 128
  [16.404]

  [3.9247]
  + print('a')
• edit in main.lua at line 231
  [3.1627]→[2.2495:2544](∅→∅)
  − print('setting top to', Screen_bottom1.line)
• edit in main.lua at line 233
  [17.562]

  [3.9557]
  + print('setting top to', Screen_top1.line)
• edit in main.lua at line 237
  [3.1020]

  [3.1721]
  + print('top now', Screen_top1.line)
• replacement in app.lua at line 96
  [3.4434]→[2.2843:2885](∅→∅)
  − -- App.run_after_keypress('pagedown')
  [3.4434]

  [3.4475]
  + -- App.run_after_keychord('pagedown')