From 4e25d91ce59e4ee35b7fc44425eea416c5ba7a76 Mon Sep 17 00:00:00 2001
From: Dan Ballard <dan@mindstab.net>
Date: Wed, 29 Jun 2011 00:59:16 -0700
Subject: [PATCH] dded cycling rainbow and start of transform code

---
 3bb-1.lisp | 62 ++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 51 insertions(+), 11 deletions(-)

diff --git a/3bb-1.lisp b/3bb-1.lisp
index 7fa9b1e..435ec04 100644
--- a/3bb-1.lisp
+++ b/3bb-1.lisp
@@ -5,20 +5,60 @@
        (progn ,@body)
      (continue () :report "Continue")))
 
+(let ((time-units (/ 1.0 internal-time-units-per-second)))
+  (defun wall-time (&key (offset 0))
+    (+ (* (get-internal-real-time) time-units)
+       offset)))
+
+(defvar *start-time* (wall-time))
+
+(defun shift-color (time) 
+  (values 
+   ;;; red
+   (/ (+ (* (sin (+ (* 0.3 time) 0)) 127) 128) 255)
+   ;;; green
+   (/ (+ (* (sin (+ (* 0.3 time) (* 2/3 PI))) 127 ) 128) 255)
+   ;;; blue
+   (/ (+ (* (sin (+ (* 0.3 time) (* 4/3 PI))) 127) 128) 255)))
+
+(defparameter *t1* '( (-0.5 -0.5 0) (0 0.5 0) (0.5 -0.5 0)))
+
+(defun rotate-vertex (v time)
+    (list (+ (first v) (/ (sin time) 2)) (+ (second v) (/ (cos time) 2))   (third v)))
+
+(defun rotate-triangle (tri time)
+  (list (rotate-vertex (first tri) time)
+	(rotate-vertex (second tri) time)
+	(rotate-vertex (third tri) time)))
+
 (defun draw ()
   "draw a frame"
-  (gl:clear :color-buffer-bit)
+  (let* ((time (- (wall-time) *start-time*))
+	(t1 (rotate-triangle *t1* time)))
+    ;;;(setf *last-time* (wall-time))
+ 
+;      (format t "~a ~a: ~a ~a ~a~%" *start-time* time red green blue)
+      (gl:clear :color-buffer-bit)
   ;;; draw a triangle
-  (gl:with-primitive :triangles
-    (gl:color 1 0 0)
-    (gl:vertex 0 0 0)
-    (gl:color 0 1 0)
-    (gl:vertex 0.5 1 0)
-    (gl:color 0 0 1)
-    (gl:vertex 1 0 0))
-  ;; finish the frame
-  (gl:flush)
-  (sdl:update-display))
+      (gl:with-primitive :triangles
+	(multiple-value-bind (red green blue) (shift-color time)
+	  (gl:color red green blue))
+	(multiple-value-bind (v1 v2 v3) (values-list (first t1))
+	  (gl:vertex v1 v2 v3))
+	(multiple-value-bind (green blue red) (shift-color time)
+	  (gl:color red green blue))
+	(multiple-value-bind (v1 v2 v3) (values-list (second t1))
+	  (gl:vertex v1 v2 v3))
+	(multiple-value-bind (blue green red) (shift-color time)
+	  (gl:color red green blue))
+	(multiple-value-bind (v1 v2 v3) (values-list (third t1))
+	  (gl:vertex v1 v2 v3)))
+
+    ;; finish the frame
+    (gl:flush)
+    (sdl:update-display)))
+
+
 
 (defun main-loop () 
   (sdl:with-init ()