Lambda8 Save

Lambda8

Lambda8 is a Fantasy computer that uses Lisp as its system language.

It's implemented in C using SDL 2.0.

A demo "game" is included.

This software is alpha state. In particular, loading files from disk is mostly a developing stage functionality.

The machine

The screen has a resolution of 256x128, with 4 bits of depth, rendered at 768x384 (3x). Colours are chosen from a 16-colour palette.

These are the available primitives in Lisp:

• (pix x y c)

  Renders a pixel at coordinates x,y in color c

• (define-sprite filename)

  Loads a sprite into memory from a file on disk. Returns a number which identifies the texture.

• (spr id x y w h)

  Renders the sprite identified by id at coordinates x,y with a size of w,h

• (line x y x2 y2 c)

  Draws a line from x,y to x2,y2 using color c

• (rect x y x2 y2 c)

  Draws a filled rectangle from x,y to x2,y2 using color c

• (rectb x y x2 y2 c)

  Draws a rectangle from x,y to x2,y2 using color c

• (circ x y r c)

  Draws a filled circle centered on x,y with radius r using color c

• (circb x y r c)

  Draws a circle centered on x,y with radius r using color c

• (cls n)

  Clears the screen using color n

• (define-sfx filename)

  Loads a sound effect into memory from a file on disk. Returns a number which identifies the sfx.

• (sfx id)

  Plays the sound effect identified by id.

• (printxy text x y c)

  Prints the text at x,y in color c

Core library

Lambda8 packs a core library with the following functions (defined in Lisp):

• (btn n)

  Returns #t if button n is pressed

• (btnp n)

  Returns #t if button n is pressed but wasn't pressed the previous frame (prevents repetition)

• (filter p ls)

  Returns a new list with the elements that satisfy predicate p, in the same order

• (collideAABB a b)

  Returns #t if the bounding boxes of sprites a and b are overlapping

• (make-sprite filename-or-id x y w h)

  Creates a new sprite object. It can either load a new texture from a file, or use the ID of an already loaded texture.