level.c

This include file contains often used, small level related functions, such as terrain tiling, placing entities on terrain, and generating an endless terrain level. The functions are simple enough to understand them at a glance. Examples of using them can be found in the infinite_terrain.c and weather.c samples. If you want to modify them, please edit a level.c copy in your work folder, and not the original file in the include folder.

level_loadendless (STRING* filename)

Parameters:

Example:

function main()
{
  level_loadendless("terrain.hmp"); 
  terrain_tile(level_ent);
  ent_createlayer("skycube+6.dds",SKY|CUBE|SHOW, 0);
  def_move(); // default movement from default.c
}

level_loadsplash (STRING* filename,STRING* bmapname,var mode)

Parameters:

Remarks:

• This is not a function, but a macro that uses wait() to make sure that the level is loaded before continuing.

Example:

function main()
{
  level_loadsplash("racetrack.wmb","racesplash.pcx",0); 
  tcar_race_start();
}

terrain_tile ( ENTITY* terrain)

Parameters:

terrain_fence ( ENTITY* terrain, var height)

Parameters:

terrain_raise ( ENTITY* terrain, var height)

Parameters:

Remarks:

ent_terrain_place ( ENTITY* ent, ENTITY* terrain, var minheight, var maxheight)

Parameters:

Remarks:

• When this function is called the first time, an array of terrain places is created for preventing that two entities are placed on the same spot. The array pointer is stored in skill61 (terrain_buffer) of the terrain entity. Before the level is changed or the terrain is removed, it should be freed through sys_free(terrain.terrain_buffer); . Otherwise it is automatically freed by sys_exit().
• The entity's final scale must be set before calling this function. Otherwise the entity is placed at a wrong height.
• If no free spot is found in the desired height range, the entity is placed elsewhere or on an already-occupied spot.

Example:

action place_me()
{
  vec_scale(my.scale_x,0.5+random(1.5));
  ent_terrain_place(me,level_ent,50,90);
}
 
function main()
{
  level_load("terrain.hmp"); 
  int i;
  for (i=0; i < 500; i++)
    ent_create("tree.mdl",NULL,place_me);
}	 

ent_seed (char* name, ENTITY* terrain, BMAP* mask, COLOR* color, var dist, var mode, EVENT act)

ent_seed (char* name, ENTITY* terrain, BMAP* mask, COLOR* color, var dist, EVENT act)

Parameters:

Returns:

Modifies:

Remarks:

• The ent_seed function creates the entities at random positions within their mask color, and places the lowest part of the entities on terrain ground.
• The act action can be used to give the entity a random angle or scale. For static entities, wait one frame (wait(1)) until the entity is placed before resetting the DYNAMIC flag.
• To speed up the placement of passable entities, like grass or vegetation sprites, set collision_mode to 0 before calling ent_seed, and set it back afterwards.
• Use mode 2 to rotate grass sprites parallel to slopes, which looks more realistic.
• Wait one frame in the entity action for setting angles or position, until these values are already set in the ent_seed function.
• A PCX image is best suited for the mask, as it requires the least amount of memory and disk space. PCX images are stored in 16 bit color depth by default, so the used mask colors should differ by 8 color steps at least.
• See ent_create for general remarks on creating entities.

Example:

#define COLOR_TREE vector(0,255,0)
#define COLOR_GRASS vector(255,255,0)
 
action place_tree()
{
  vec_scale(my.scale_x,1+random(0.5));
  my.eflags |= CLIP1;   // clip away at 50% LOD range
  wait(1);   // wait until it's placed by ent_seed
  my.z -= 5; // place it a little lower
  my.pan = random(360);
  my.tilt = random(20)-10;
  wait(1); // wait 1 frame after the last change, 
  my.emask &= ~DYNAMIC; // then make entity static for better performance
}

action place_grass()
{
  vec_scale(my.scale_x,0.75+random(0.5));
  my.flags |= PASSABLE | TRANSLUCENT;
  my.alpha = 70;
  my.eflags |= CLIP1; 
  wait(1);
  my.emask &= ~DYNAMIC;
}

function main()
{
  max_entities = 10000;
  level_load("terrain.hmp");
  BMAP* bSkin = bmap_create("terrain_vegetation.pcx");
  ent_seed("tree.mdl",level_ent,bSkin,COLOR_TREE,50,0,place_tree);
	wait(1); // let the place_tree actions terminate before creating more entities
  collision_mode = 0; // faster creation for PASSABLE entities
  ent_seed("grass.dds",level_ent,bSkin,COLOR_GRASS,30,2,place_grass);
  collision_mode = 1;
}

terrain_height ( ENTITY* terrain, VECTOR* position)

Parameters:

Returns:

terrain_pos( ENTITY* terrain,var x,var y,var z): VECTOR*

Parameters:

Returns:

Example:

function main()
{
  level_load("terrain.hmp"); 
  ent_create("tree.mdl",terrain_pos(NULL,100,100,-10),NULL); // plant the tree 10 units in the ground, at position (100,100). 
}

terrain_getpixel(ENTITY* terrain, var x, var y, BMAP* skin): COLOR*

Parameters:

Returns:

Example: See samples\weather.c

terrain_setpixel(ENTITY* terrain, var x, var y, BMAP* skin, COLOR* color)

Parameters:

Remarks:

Example: See samples\weather.c

See Also:

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