4.2  Functions

snip-class      SNIPCLASS

This snipclass is used for saved cache image snips.

(make-argb (vectorof rational[between 0 & 255]) int)      CONSTRUCTOR

Constructs a new argb value. The vector has four entries for each pixel, an alpha, red, green, and blue value. The int specifies the width of the image; the height is the size of the vector, divided by 4, divided by the width.

(argb-vector argb)      SELECTOR

Extracts the vector from an argb

(argb-width argb)      SELECTOR

Extracts the width from an argb.

(argb? any)      PREDICATE

Tests if its argument is an argb.

(overlay-bitmap dx dy color-bitmap mask-bitmap)      PROCEDURE

Builds a new argb after overlaying color-bitmap (with masking based on mask-bitmap) onto argb at (dx, dy) from the top-left.

(build-bitmap draw w h)      PROCEDURE

Builds a bitmap with width w and height h, using the procedure draw. The procedure should accept one argument, dc<%>, and return void.

(flatten-bitmap bitmap)      PROCEDURE

Builds a new bitmap that flattens the original bitmap with its mask, producing a bitmap that has no mask, and looks the way that bitmap would draw (when drawn with the mask).

(argb->cache-image-snip argb number number)      PROCEDURE

Builds a new cache-image-snip% based on the contents of argb, using the two numbers as the pinhole.

(argb->bitmap argb)      PROCEDURE

Builds a bitmap that draws the same way as argb; the alpha pixels are put into the bitmap's get-loaded-mask bitmap.