acme/ACME_Lib/cbm/multicolor.a

;ACME 0.97

!ifdef lib_cbm_multicolor_a !eof
lib_cbm_multicolor_a = 1

; this file contains macros to convert strings into bit patterns.
; the idea is to use four different characters to indicate the four
; different bit patterns of multicolor graphics, so mc sprites can be
; "drawn" in the source code even though ACME does not support any
; four-based number system. see the end of this file for an example.

; macro to set "digit" characters
; example:
; +mc_set " .o#"
!macro mc_set .s {
	!if is_number(.s) or is_list(.s) {
		!error "Argument to +mc_set must be a string."
	} else if len(.s) != 4 {
		!error "Argument to +mc_set must be four characters."
	} else {
		!set multicolor_alphabet = .s
	}
}

; macro to convert string to number
!macro mc_value ~.result, .in, .len {
	!ifndef multicolor_alphabet {
		!error "Called +mc_value before calling +mc_set."
	} else if is_number(.in) or is_list(.in) {
		!error "Argument to +mc_value must be a string."
	} else if len(.in) != .len {
		!error "Argument to +mc_value must have ", .len, " characters."
	} else {
		!set .result = 0
		!for .idx, 0, (.len / 2) - 1 {
			!set .char = .in[2 * .idx]	; get first of pair
			!if .char != .in[2 * .idx + 1] {	; compare to second
				!error "Characters in argument to +mc_value must be given in pairs."
			} else {
				!if .char = multicolor_alphabet[0] {
					!set .result = (.result << 2)
				} else if .char = multicolor_alphabet[1] {
					!set .result = (.result << 2) + 1
				} else if .char = multicolor_alphabet[2] {
					!set .result = (.result << 2) + 2
				} else if .char = multicolor_alphabet[3] {
					!set .result = (.result << 2) + 3
				} else {
					!error "Characters in argument to +mc_value must be from alphabet set via +mc_set."
				}
			}
		}
	}
}

; macro for a multicolor byte (for charsets)
!macro mc_8 .in {
	+mc_value ~.result, .in, 8
	!by .result
}

; macro for a multicolor sprite line
!macro mc_be24 .in {
	+mc_value ~.result, .in, 24
	!be24 .result
}

!eof
	; Here's an example on how to use this:
	!to "mc-sprites.prg", cbm
	*=$e00
	+mc_set " .o#"	; set four characters
	; and now use those four characters to "paint" the sprite:
	+mc_be24 "                        "
	+mc_be24 "..                    .."
	+mc_be24 "....                ...."
	+mc_be24 "......  ##....##  ......"
	+mc_be24 "  ....................  "
	+mc_be24 "  ....................  "
	+mc_be24 "    ................    "
	+mc_be24 "  ######........######  "
	+mc_be24 "  ..oo####....####oo..  "
	+mc_be24 "##..oo  ########  oo..##"
	+mc_be24 "....oo  oo....oo  oo...."
	+mc_be24 "......oooo....oooo......"
	+mc_be24 "........................"
	+mc_be24 "......oooo....oooo......"
	+mc_be24 "....oooooooooooooooo...."
	+mc_be24 "....  oooooooooooo  ...."
	+mc_be24 "..  ####oooooooo####  .."
	+mc_be24 "..  ######oooo######  .."
	+mc_be24 "    ######    ####      "
	+mc_be24 "    ######    ##        "
	+mc_be24 "                        "