SpriteLoader Class Reference
[Game Objects and Event Loop]

Class to handle loading all necessary data for a sprite. More...

#include <spriteloader.h>

List of all members.

Public Member Functions

SpriteLoader (const char *fname, const char *path="")

Loads a file specifying a sprite.

bool Load (const char *fname, const char *path="")

Attempts to parse a .spr file and load the specified data.

bool Good ()

Tells if the load was successful.

Sprite * GetSprite (Sprite *sprite=NULL)

Creates or converts a sprite to configuration data.

int YFrames () const

Returns # of y frames.

int XFrames () const

Returns # of x frames.

Uint8 R () const

Returns red transparency color.

Uint8 G () const

Returns blue transparency color.

Uint8 B () const

Returns green transparency color.

bitmask ** Bmask () const

Returns bitmasks.

SDL_Surface * GetSurface () const

Returns the loaded image.

ColType Layer () const

Returns the parsed collision layer mask.

ColType Index () const

Returns the parsed collision index mask.

int DrawLayer () const

Returns drawing layer.

~SpriteLoader ()

Destructor, frees all loaded data.

Protected Member Functions

bool ProcessLine (const char *buf)

Processes a single line from sprite-config file.

void Reset ()

Frees all data and returns variables to blank state.

Protected Attributes

bitmask ** bmask

Collison bitmasks.

SDL_Surface * image

Image.

int r

Transparency color.

int g

Transparency color.

int b

Transparency color.

int drawlayer

Drawing layer.

Uint32 colindex

Collision index mask. Uint32 so sscanf can use it.

Uint32 colmask

Collision layer mask. Uint32 so sscanf can use it.

bool good

Status - true=successful load, false=error.

bool loadbitmask

true means create collision bitmask from image

char imagename [300]

String containing image file name.

int xframes

Integers specifying number of rows and columns in image.

int yframes

Integers specifying number of rows and columns in image.

Sfxp framerate

Fixed point integer specifying frame rate.

Detailed Description


  I began to realize that, with images, frames, bitmasks, layers,
  collision masks, positions, etc. etc. etc. all in one sprite,
  that was a heck of a lot of data to squeeze through a constructor,
  and quite tricky to get all in one place at once..

  so I broke the sprite's initialization procedure down into a whole
  bunch of Init_Something() functions, and created this class
  to handle the tricky task of getting all the data ready for the
  sprite itself.

  It works by loading a sprite configuration file, which contains
  information on drawing layers, animation frames, collision masks and
  bitmasks, image names, and so forth.  The file is parsed, the data
  loaded, and once all that is done you can create as many identical
  sprites as you want from it.  This also allows you to create dozens
  of sprites of whatever kind you want, sharing the exact same data,
  cutting down on data duplication quite a bit.

  The config files are 100% pure ASCII, so notepad users rejoice.  
  Here is the syntax of a .spr config file:

  # This is a comment line
  IMAGE           "faces.png
  FRAMES          2       2
  FRAMERATE       10
  DRAWLAYER       1
  # Collision layer 0, can collide with layer 0
  COLLAYER        0       0
  BITMASK
  TRANSCOLOR      255     0       255

  I think we can all guess what IMAGE does.  Frames tells it how many
  X and Y frames there are in the image(assumes 1*1 if not present).
             This is what it the frame order in a 2*2 image would be.
  +---+---+  The next one, FRAMERATE, also does the obvious, except
  | 0 | 1 |  it's a fixed-point number, not a straight integer;  in
  +---+---+  it's current incarnation with 10 fractional bits, that
  | 2 | 3 |  number means it advances 10/1024 frames per millisecond,
  +---+---+  or approximately 10 frames per second.

  DRAWLAYER is simply the sprite's position in the drawing
  order.  Lower layers get drawn last.

  COLLAYER is a bit tricky, but makes sense if you think about it
it inhabits collision layer 0, and can collide with layer 0.  
  Ergo it can collide with identical sprites.  You can specify as 
  many layers to collide with as you want(like COLLAYER 0 0 1 2 3 4 ) 
  but a sprite can only INHABIT one layer.

  TRANSCOLOR is used to specify the image's color key, i.e. the 
  precise RGB color that should be considered transparent.  It's a 
  good idea to make your images with some insane color as the 
  colorkey, like pure magenta(RGB255,0,255);  it helps hunt down
  stubborn supposed-to-be-transparent pixels better than dark colors, 
  or even black.

  BITMASK is a paramaterless option that tells SpriteLoader to 
  convert the image frames into collision bitmasks, used for 
  pixel-level collision detection.  By colorkey, transparent pixels
  are assumed to be empty space and opaque ones solid.

Definition at line 114 of file spriteloader.h.