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-rw-r--r--2d/color.scm87
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+;;; guile-2d
+;;; Copyright (C) 2013 David Thompson <dthompson2@worcester.edu>
+;;;
+;;; Guile-2d is free software: you can redistribute it and/or modify it
+;;; under the terms of the GNU Lesser General Public License as
+;;; published by the Free Software Foundation, either version 3 of the
+;;; License, or (at your option) any later version.
+;;;
+;;; Guile-2d is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;;; Lesser General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU Lesser General Public
+;;; License along with this program. If not, see
+;;; <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; Color.
+;;
+;;; Code:
+
+(define-module (2d color)
+ #:use-module (figl gl)
+ #:use-module (srfi srfi-9)
+ #:use-module (srfi srfi-1)
+ #:export (<color>
+ make-color
+ color?
+ color-r
+ color-g
+ color-b
+ color-a
+ apply-color
+ rgba
+ rgb
+ white
+ black
+ red
+ green
+ blue
+ magenta))
+
+(define-record-type <color>
+ (make-color r g b a)
+ color?
+ (r color-r)
+ (g color-g)
+ (b color-b)
+ (a color-a))
+
+(define (apply-color color)
+ (gl-color (color-r color)
+ (color-g color)
+ (color-b color)
+ (color-a color)))
+
+(define (color-component color-code offset)
+ (let ((mask (ash #xff offset)))
+ (/ (ash (logand mask color-code)
+ (- offset))
+ 255.0)))
+
+(define (rgba color-code)
+ "Translates an RGBA format color code into a color object. For
+example: #xffffffff will return a color with RGBA values 1, 1, 1, 1."
+ (make-color (color-component color-code 24)
+ (color-component color-code 16)
+ (color-component color-code 8)
+ (color-component color-code 0)))
+
+(define (rgb color-code)
+ "Translates an RGB format color code into a color object. For
+example: #xffffff will return a color with RGBA values 1, 1, 1, 1."
+ (make-color (color-component color-code 16)
+ (color-component color-code 8)
+ (color-component color-code 0)
+ 1))
+
+;; Pre-defined colors.
+(define white (rgb #xffffff))
+(define black (rgb #x000000))
+(define red (rgb #xff0000))
+(define green (rgb #x00ff00))
+(define blue (rgb #x0000ff))
+(define magenta (rgb #xff00ff))