Three different ways to generate gradients

[Yet Another Troll]

Should work on resolutions between the default 640x400 and 16K. Tested on Windows 10 and Android, various versions. Needs some (a lot of) cleanup

#!/lbin/ybasic

! Demo some ways to show purrty gradients and how they work

! All this redundant math must have made some kind of sense
! to my acute bronchitis addled little mind but I dunno what

Program Colors

 OpenW 1
 Pause 0.05
 ClearW
 ShowPage

 Get_Screensize sx%, sy%, sw%, sh%
 Get_Geometry 1, wx%, wy%, ww%, wh%

 Print "Screen", sx%, sy%, sw%, sh%
 Print "Window", wx%, wy%, ww%, wh%

 ! Are there differences in the visible area between platforms?
 Color Color_RGB(0, 1, 0)
 PBox -1, -1, ww% + 2, wh% + 2
 ! ShowPage
 ! Pause 0.1

 w% = ww% / 3

 For x% = 0 To w% - 1

  ! Red to green

  ! Linear
  Color Color_RGB((w% - x%) / w%, x% / w%, 0)
  Draw 0 * w% + x%, wh% * 0 / 6 To 0 * w% + x%, wh% * 2 / 6
  Color Color_RGB(1, 0, 0)
  Plot 0 * w% + x%, ((w% - x%) / w%) * -wh% / 3 + wh% / 3 + wh% * 0 / 6
  Color Color_RGB(0, 1, 0)
  Plot 0 * w% + x%, (x% / w%) * -wh% / 3 + wh% / 3 + wh% * 0 / 6

  ! Trig
  Color Color_RGB(Cos(x% * Pi / 2 / w%), Sin(x% * Pi / 2 / w%), 0)
  Draw 0 * w% + x%, wh% * 2 / 6 To 0 * w% + x%, wh% * 4 / 6
  Color Color_RGB(1, 0, 0)
  Plot 0 * w% + x%, Cos(x% * Pi / 2 / w%) * -wh% / 3 + wh% / 3 + wh% * 2 / 6
  Color Color_RGB(0, 1, 0)
  Plot 0 * w% + x%, Sin(x% * Pi / 2 / w%) * -wh% / 3 + wh% / 3 + wh% * 2 / 6

  ! Green to blue

  ! Linear
  Color Color_RGB(0, (w% - x%) / w%, x% / w%)
  Draw 1 * w% + x%, wh% * 0 / 6 To 1 * w% + x%, wh% * 2 / 6
  Color Color_RGB(0, 1, 0)
  Plot 1 * w% + x%, ((w% - x%) / w%) * -wh% / 3 + wh% / 3 + wh% * 0 / 6
  Color Color_RGB(0, 0, 1)
  Plot 1 * w% + x%, (x% / w%) * -wh% / 3 + wh% / 3 + wh% * 0 / 6

  ! Trig
  Color Color_RGB(0, Cos(x% * Pi / 2 / w%), Sin(x% * Pi / 2 / w%))
  Draw 1 * w% + x%, wh% * 2 / 6 To 1 * w% + x%, wh% * 4 / 6
  Color Color_RGB(0, 1, 0)
  Plot 1 * w% + x%, Cos(x% * Pi / 2 / w%) * -wh% / 3 + wh% / 3 + wh% * 2 / 6
  Color Color_RGB(0, 0, 1)
  Plot 1 * w% + x%, Sin(x% * Pi / 2 / w%) * -wh% / 3 + wh% / 3 + wh% * 2 / 6

  ! Blue back to red

  ! Linear
  Color Color_RGB(x% / w%, 0, (w% - x%) / w%)
  Draw 2 * w% + x%, wh% * 0 / 6 To 2 * w% + x%, wh% * 2 / 6
  Color Color_RGB(0, 0, 1)
  Plot 2 * w% + x%, ((w% - x%) / w%) * -wh% / 3 + wh% / 3 + wh% * 0 / 6
  Color Color_RGB(1, 0, 0)
  Plot 2 * w% + x%, (x% / w%) * -wh% / 3 + wh% / 3 + wh% * 0 / 6

  ! Trig
  Color Color_RGB(Sin(x% * Pi / 2 / w%), 0, Cos(x% * Pi / 2 / w%))
  Draw 2 * w% + x%, wh% * 2 / 6 To 2 * w% + x%, wh% * 4 / 6
  Color Color_RGB(0, 0, 1)
  Plot 2 * w% + x%, Cos(x% * Pi / 2 / w%) * -wh% / 3 + wh% / 3 + wh% * 2 / 6
  Color Color_RGB(1, 0, 0)
  Plot 2 * w% + x%, Sin(x% * Pi / 2 / w%) * -wh% / 3 + wh% / 3 + wh% * 2 / 6

 Next x%

 w1% = ww% / 6

 For x% = 0 To w1%

  ! Red to Yellow(?)
  Color Color_RGB(1, x% / w1%, 0)
  Draw 0 * w1% + x%, wh% * 4 / 6 To 0 * w1% + x%, wh% * 6 / 6
  Color Color_RGB(1, 0, 0)
  Plot 0 * w1% + x%, wh% * 4 / 6
  Color Color_RGB(0, 1, 0)
  Plot 0 * w1% + x%, (x% / w1%) * -wh% / 3 + wh% / 3 + wh% * 4 / 6

  ! Yellow(?) to Green
  Color Color_RGB((w1% - x%) / w1%, 1, 0)
  Draw 1 * w1% + x%, wh% * 4 / 6 To 1 * w1% + x%, wh% * 6 / 6
  Color Color_RGB(1, 0, 0)
  Plot 1 * w1% + x%, ((w1% - x%) / w1%) * -wh% / 3 + wh% / 3 + wh% * 4 / 6
  Color Color_RGB(0, 1, 0)
  Plot 1 * w1% + x%, wh% * 4 / 6

  ! Green to Aqua(?)
  Color Color_RGB(0, 1, x% / w1%)
  Draw 2 * w1% + x%, wh% * 4 / 6 To 2 * w1% + x%, wh% * 6 / 6
  Color Color_RGB(0, 1, 0)
  Plot 2 * w1% + x%, wh% * 4 / 6
  Color Color_RGB(0, 0, 1)
  Plot 2 * w1% + x%, (x% / w1%) * -wh% / 3 + wh% / 3 + wh% * 4 / 6

  ! Aqua(?) to Blue
  Color Color_RGB(0, (w1% - x%) / w1%, 1)
  Draw 3 * w1% + x%, wh% * 4 / 6 To 3 * w1% + x%, wh% * 6 / 6
  Color Color_RGB(0, 1, 0)
  Plot 3 * w1% + x%, ((w1% - x%) / w1%) * -wh% / 3 + wh% / 3 + wh% * 4 / 6
  Color Color_RGB(0, 0, 1)
  Plot 3 * w1% + x%, wh% * 4 / 6

  ! Blue to Violet(?)
  Color Color_RGB(x% / w1%, 0, 1)
  Draw 4 * w1% + x%, wh% * 4 / 6 To 4 * w1% + x%, wh% * 6 / 6
  Color Color_RGB(0, 0, 1)
  Plot 4 * w1% + x%, wh% * 4 / 6
  Color Color_RGB(1, 0, 0)
  Plot 4 * w1% + x%, (x% / w1%) * -wh% / 3 + wh% / 3 + wh% * 4 / 6

  ! Violet(?) back to Red
  Color Color_RGB(1, 0, (w1% - x%) / w1%)
  Draw 5 * w1% + x%, wh% * 4 / 6 To 5 * w1% + x%, wh% * 6 / 6
  Color Color_RGB(0, 0, 1)
  Plot 5 * w1% + x%, ((w1% - x%) / w1%) * -wh% / 3 + wh% / 3 + wh% * 4 / 6
  Color Color_RGB(1, 0, 0)
  Plot 5 * w1% + x%, wh% * 4 / 6

 Next x%

 ! Captions

 SetFont Right$("Living LARGE", 5) ! No effect in Windows?
 Color Color_RGB(0.8, 0.8, 0.8), Color_RGB(0, 0, 0, 0)
 Text 10, wh% * 1 / 6, "Linear"
 Text 10, wh% * 3 / 6, "Trig"
 Text 10, wh% * 5 / 6, "Brighter"

 ShowPage

 If Android?
  Pause 20
 EndIf

 Print wx%, wy%, ww%, wh%, x%, w%, w1%

 Print 
 Print "OK"
End