PONScripter "flowtext" example by dsp2003

;mode800

*define

defsub flowtext

effect 9,10,500

numalias text_string,50
numalias glyph_width,51
numalias x_coord,52
numalias y_coord,53
numalias s_width,54
numalias text_char,55
numalias text_len,56
numalias sp_f,57
numalias sp_l,58
numalias sp_n,59
numalias sp_width,60
numalias sp_fpos,61
numalias sp_curpos,62
numalias sp_e,63

game

*start

flowtext "Non-unicode text",20,50,800
flowtext "Кириллический текст",20,50,800
flowtext "Mixed-текст вперемешку",20,50,800

reset

end

*flowtext

 ; reading paremeters passed to our custom flowtext function
 ; $text_string - text string
 ; %glyph_width - glyph width
 ; %y_coord - y coordinate
 ; %s_width - screen width
 getparam $text_string,%glyph_width,%y_coord,%s_width

 ; Sets %text_len to the length of $text_string
 len %text_len,$text_string

 ; Set the first sprite slot number
 mov %sp_f,60
 ; Copy the value to new variable, and add length of string
 mov %sp_l,%sp_f
 add %sp_l,%text_len-1

 ; Creating letter sprites

 ; Calculating total width of sprites
 mov %sp_width,%text_len
 mul %sp_width,%glyph_width
 ; Calculating first sprite's position
 mov %sp_fpos,%s_width
 sub %sp_fpos,%sp_width
 div %sp_fpos,2

 ; Assign value to sprite coord accumulator
 mov %sp_curpos,%sp_fpos

 for %sp_n=%sp_f to %sp_l
  ; Extracting 1 character from the string
  mov %sp_e,%sp_n-%sp_f
  mid $text_char,$text_string,%sp_e,1

  mov %x_coord,%sp_curpos

  ; Output sprite: number,text,x,y,alpha
  lsph %sp_n,":S#ffffff$text_char",%x_coord,%y_coord,255

  ; Increasing accumulator
  add %sp_curpos,%glyph_width

 next

 ; Sprites display: fade in, then fade out

 for %sp_n=%sp_f to %sp_l
  vsp %sp_n,1:print 9
 next

 for %sp_n=%sp_f to %sp_l
  vsp %sp_n,0:print 9
 next

return