Cubemap Rendering Script

From GameStudio Wiki

When you press C, a cubemap which can be used for skies or for cubic environment mapping will be created. To achieve better quality (anti-aliasing) you could render the cube in a higher resolution and scale it down in your image editing program.

Note: Before you can use this script, create the file render.tga in your game directory. This file must be saved in tga 32 bit

source

savedir="output";
var_nsave fh;
bmap* canvas;
bmap* b_render1;
bmap* b_render2;
bmap* b_render3;
bmap* b_render4;
bmap* b_render5;
bmap* b_render6;
var cubenumber = 0;
var directions[18] = 180, 0, 0, 90, 0, 0, 0, 0, 0, -90, 0, 0, 90, -90, 0, 90, 90, 0;
string tempstring1;
string tempstring2;
string _ts_;

//----------------------------------------------------------------------------- write_cubemap
function write8(byte) // write char
{
  file_asc_write(fh, byte);
}

function write16(short) // write unsigned short
{
  file_asc_write(fh, short&255);
  file_asc_write(fh, (short>>8)&255);
}

function str_padding(str, number, padding)
{
  str_for_num(_ts_, number);
  var i = 0;
  i = padding - str_len(_ts_);
  while(i > 0)
  {
     str_cat(str, "0");
     i-=1;
  }
  str_cat(str, _ts_);
}

function write_cubemap()
{
  var i;
  var xx;
  var yy;
  var format;
  var pixel;
  var pixelalpha;
  var canvas_size[2];
  
  canvas_size.x = bmap_width(b_render1);
  canvas_size.y = bmap_height(b_render1);
  format = bmap_lock(b_render1, 0);
  bmap_lock(b_render2, 0);
  bmap_lock(b_render3, 0);
  bmap_lock(b_render4, 0);
  bmap_lock(b_render5, 0);
  bmap_lock(b_render6, 0);
  
  str_cpy(tempstring1, "cubemap");
  str_padding(tempstring1, cubenumber, 4);
  str_cat(tempstring1, "+6.tga");
  fh = file_open_write(tempstring1);
  cubenumber+=1;
  //--------------------------------------------------------write header
  write8(0);
  write8(0);
  write8(2); // image type
  write16(0);
  write16(0);
  write8(0);
  write16(0);
  write16(0);
  write16(canvas_size.x * 6); // width
  write16(canvas_size.y); // height
  write8(24); // color depth
  write8(0);
  //--------------------------------------------------------write image data
  yy = canvas_size.y - 1;
  while(yy >= 0)
  {
     i = 0;
     while(i < 6)
     {
        if(i==0){canvas=b_render1;}
        if(i==1){canvas=b_render2;}
        if(i==2){canvas=b_render3;}
        if(i==3){canvas=b_render4;}
        if(i==4){canvas=b_render5;}
        if(i==5){canvas=b_render6;}
        xx = 0;
        while(xx < canvas_size.x)
        {
           pixel = pixel_for_bmap(canvas, xx, yy);
           pixel_to_vec(temp, pixelalpha, format, pixel);
           write8(temp.x); // b
           write8(temp.y); // g
           write8(temp.z); // r
           xx+=1;
        }
        i+=1;
     }
     yy-=1;
  }
  file_close(fh);
  bmap_unlock(b_render1);
  bmap_unlock(b_render2);
  bmap_unlock(b_render3);
  bmap_unlock(b_render4);
  bmap_unlock(b_render5);
  bmap_unlock(b_render6);
}

//----------------------------------------------------------------------------- capture_cubemap
function capture_cubemap
{
  var old_arc;
  var old_x;
  var old_y;
  var old_screen;
  
  b_render1 = bmap_create("render.tga"); // use a 256x256 tga for example -> determines cube map size
  b_render2 = bmap_create("render.tga");
  b_render3 = bmap_create("render.tga");
  b_render4 = bmap_create("render.tga");
  b_render5 = bmap_create("render.tga");
  b_render6 = bmap_create("render.tga");
  
  old_arc = camera.arc;
  old_x = screen_size.x;
  old_y = screen_size.y;
  old_screen = video_screen;
  
  camera.arc = 90;
  video_set(256, 256, 32, 2); // should be same resolution as render.tga
  
  freeze_mode = on;
  vec_set(camera.pan, directions[0]); wait(1); bmap_for_screen(b_render1,1,0);
  vec_set(camera.pan, directions[3]); wait(1); bmap_for_screen(b_render2,1,0);
  vec_set(camera.pan, directions[6]); wait(1); bmap_for_screen(b_render3,1,0);
  vec_set(camera.pan, directions[9]); wait(1); bmap_for_screen(b_render4,1,0);
  vec_set(camera.pan, directions[12]); wait(1); bmap_for_screen(b_render5,1,0);
  vec_set(camera.pan, directions[15]); wait(1); bmap_for_screen(b_render6,1,0);
  freeze_mode = off;
  
  wait(1);
  write_cubemap();
  
  wait(1);
  camera.arc = old_arc;
  video_set(old_x, old_y, 32, old_screen);
}

on_c=capture_cubemap;