// Centered Multiline Text - GMEM
//@gmem=XR_SelTrackItemsNotes

/**
 * Video Processor Preset: Centered Multiline Text - GMEM
 * Author: X-Raym, Fabian, JT
 * Author URI: https://www.extremraym.com
 * About: Mod from Fabian's Centered Multiline Text and JT: Essential Text Overlay, but with GMEM support
 * Licence: GPL v3
 * Version: 1.1
 * Version Date: 2023-09-26
 */

// USER CONFIG AREA

font ="Futura";

// END OF USER CONFIG AREA

//@param1:size 'Text height' 0.1 0.01 0.3 0.1 0.01
//@param2:xpos 'X offset' 0.0 -1 1.0 0.5 0.01
//@param3:ypos 'Y position' 0.5 -0.5 1.5 0.5 0.01

//@param5:txtr 'Text R' 1 0 1 0.5 0.01
//@param6:txtg 'Text G' 1 0 1 0.5 0.01
//@param7:txtb 'Text B' 1 0 1 0.5 0.01
//@param8:fga 'Text opacity' 1 0 1 0.5 0.01

//@param10:border 'BG Size' 0.25 -0.5 15 2 0.25
//@param11:bgred 'BG R' 0 0 1 0.5 0.01
//@param12:bggreen 'BG G' 0 0 1 0.5 0.01 
//@param13:bgblue 'BG B' 0 0 1 0.5 0.01 
//@param14:bga 'BG opacity' 0 0 1 0.5 0.01

// https://forum.cockos.com/showthread.php?t=214162
function gmem_read_string(index, output) local(offset, buf) (
  offset = 0;
  buf = #;

  while (
    gmem[index] ? (
      str_setchar(buf, offset, gmem[index]);
      offset += 1;
      index  += 1;
    ) : 0;
  );
  
  strcpy_substr(output, buf, 0, offset); // truncates the output
);

// Thanks Fabian's for the centered multiline print functions!
function printc(str)
(
  gfx_str_measure(str, txtw, txth);
  gfx_x = (project_w - txtw)/2 + xpos * project_w;
  
  gfx_str_draw(str, gfx_x, gfx_y);
  txth; // return text height
);

function dosplit(fmt, txt)
(
  ptr = 0;
  strcpy(ptr, txt);
  count = 0;
  while
  (
    retval = match(fmt, ptr, ptr+2, ptr+1);
    ptr += 2;
    count += 1;
    retval;
  );
  strcpy(ptr-1, ptr-2);
  count; // return number of strings
);

// Init
text = #; // or #whatever
gmem_read_string(0, text); // set to string to override
gfx_blit(0,1);

// Measure text
gfx_setfont(size*project_h,font);
gfx_str_measure(text,txtw,txth);
yt = (project_h- txth*(1+border*2))*ypos;

// Draw background
gfx_r =(bgred); gfx_g =(bggreen); gfx_b =(bgblue);
gfx_set(bgred,bggreen,bgblue,bga);
gfx_fillrect(0, yt, project_w, txth*(1+border*2));

// Draw text
gfx_r =(txtr); gfx_g =(txtg); gfx_b =(txtb);
gfx_set(txtr,txtg,txtb,fga);

#fmt = "%s\n%s";
count = dosplit(#fmt, text);
gfx_y = yt+txth*border;
loop(count,
  gfx_y += printc(2*count-1);
  count -= 1;
);