Graphics

Some basic graphics words are provided.

Bitmaps

These words are convenience words to go along with Allegro's bitmap functions.

bmpw ( bmp -- n ) get Allegro bitmap width bmph ( bmp -- n ) get Allegro bitmap height bmpwh( bmp -- w h ) get Allegro bitmap dimensions hold> ( -- <code> ) Enable bitmap holding for rest of colon definition loadbmp ( adr c -- bmp ) Load a bitmap from a file savebmp ( bmp adr c -- ) Save a bitmap to a file -bmp ( bmp -- ) Destroy a bitmap

Blending

: blend  ( op src dest aop asrc adest -- )
: blend>  ( op src dest aop asrc adest -- <code> )

These words enable a given blending mode. blend> restores the previous blending mode after the code body.

Here are some pre-made constants you can pass to blend>:

interp-src Standard alpha blending. add-src Additive blending. write-src Writes red, green, blue, AND alpha. (I.e. no blending.)

Transforms

Standard 4x4 matrix supported by Allegro.

/transform ( -- n# ) Size of transform (16 cells) transform ( -- <name> ) Create a named transform identity ( transform -- ) Reset a transform

Pen

The pen represents the current x,y position for drawing.

at( x y -- ) +at ( x y -- ) at@ ( -- x y ) penx ( -- adr ) peny ( -- adr )