From 01622b0a4b554fc6b1def7e502ca2c71086e91bc Mon Sep 17 00:00:00 2001
From: "R. Steve McKown" <rsmckown@gmail.com>
Date: Mon, 5 Dec 2011 17:09:22 -0700
Subject: [PATCH] fade is working

---
 main.c | 123 ++++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 78 insertions(+), 45 deletions(-)

diff --git a/main.c b/main.c
index 4d11ee3..71693c5 100644
--- a/main.c
+++ b/main.c
@@ -12,23 +12,47 @@
 #include "buttons.h"
 #include "rgb.h"
 
-#define random_rgb()        rand()         /* ~ (0...255) << 7 */
-#define random_time()       (rand() >> 7)  /* 0...255 */
-#define min_incolor_time()  100
-#define min_fade_time()     100
+#define STEP_SIZE               64             /* ms */
+#define MIN_INCOLOR_STEPS       16
+#define MAX_INCOLOR_STEPS       57600
+#define MAX_FADE_STEPS          480
+#define reset_steps()           do { incolor_steps = 1; fade_steps = 0; } while (0)
+#define rand_u8()               (rand() >> 7)
+#define rand_u16()              (rand() << 8 + rand() >> 7)
+#if 1
+#define rand_incolor_steps()    MIN_INCOLOR_STEPS * 2
+#define rand_fade_steps()       16
+#else
+#define rand_incolor_steps()    (MIN_INCOLOR_STEPS + rand_u16() % \
+                                    (MAX_INCOLOR_STEPS - MIN_INCOLOR_STEPS))
+#define rand_fade_steps()       (1 + rand_u16() % MAX_FADE_STEPS)
+#endif
+#define leds_set(r,g,b,w)       rgb_set((r).value >> 8, \
+                                    (g).value >> 8, \
+                                    (b).value >> 8, \
+                                    (w).value >> 8)
+
+typedef struct {
+  unsigned value;
+  unsigned increment;
+  unsigned char remainder;
+} led_t;
+#define INIT_LED { 0, 0, 0 }
 
 int main(void)
 {
-    int red = 0, grn = 0, blu = 0; //, wht = 0;
-    int fadestep_red, fadestep_grn, fadestep_blu; //, fadestep_wht;
-    unsigned incolor_time = 0;
-    unsigned fade_time = 0;
+    led_t red = INIT_LED;
+    led_t grn = INIT_LED;
+    led_t blu = INIT_LED;
+    led_t wht = INIT_LED;
     unsigned char fast = 0;
+    unsigned incolor_steps;
+    unsigned fade_steps;
 
     pic_init();
     buttons_init();
     rgb_init();
-    srand(27);
+    reset_steps();
 
     if (buttons_on())
       rgb_on();
@@ -40,56 +64,65 @@ int main(void)
             if (buttons & IN_PUSHBTN) {
               if (!fast) {
                 fast = 1;
-                incolor_time = 0;
-                fade_time = 0;
+                reset_steps();
               } else
                 fast = 0;
             }
 
-            if (fade_time) {
-              red += fadestep_red;
-              grn += fadestep_grn;
-              blu += fadestep_blu;
-              //wht += fadestep_wht;
-              rgb_set(red >> 7, grn >> 7, blu >> 7, 0); // wht >> 7);
-              fade_time--;
-            } else if (incolor_time)
-              incolor_time--;
-            else /* fade_time == 0 && incolor_time == 0 */ {
-              int newr, newg, newb, neww;
-
-              /* Determine next color state */
-              newr = random_rgb();
-              newg = random_rgb();
-              newb = random_rgb();
-              //neww = random_rgb();
-
-              /* Calculate new incolor_time and fade_time */
-              if (buttons & IN_ROCKERA) {
-                incolor_time = 1 + random_time();
-                fade_time = 1;
-              } else /* (buttons & IN_ROCKERB) */ {
-                incolor_time = min_incolor_time() + random_time() / 2;
-                fade_time = min_fade_time() + random_time() / 2;
+            if (fade_steps) {
+              fade_steps--;
+              /* Continue the in-progress fade */
+              red.value += red.increment;
+              grn.value += grn.increment;
+              blu.value += blu.increment;
+              wht.value += wht.increment;
+              if (fade_steps == 0) {
+                red.value += red.remainder;
+                grn.value += grn.remainder;
+                blu.value += blu.remainder;
+                wht.value += wht.remainder;
               }
+              leds_set(red, grn, blu, wht);
+            } else if (--incolor_steps == 0) {
+              unsigned newr, newg, newb, neww;
+
+              /* Next led color.  All off is not a valid option. */
+              do {
+                newr = rand() << 8;
+                newg = rand() << 8;
+                newb = rand() << 8;
+                neww = rand() << 8;
+              } while (newr == 0 && newg == 0 && newb == 0 && neww == 0);
 
+              /* Next incolor and fade steps */
+              incolor_steps = rand_incolor_steps();
+              fade_steps = (buttons & IN_ROCKERA) ? 1 : rand_fade_steps();
               if (fast) {
-                incolor_time = 1 + incolor_time / 8;
-                fade_time = 1 + fade_time / 8;
+                incolor_steps = 1 + incolor_steps / 8;
+                if (buttons & IN_ROCKERB)
+                  fade_steps = 1 + fade_steps / 8;
               }
 
-              fadestep_red = (newr - red) / fade_time;
-              fadestep_grn = (newg - red) / fade_time;
-              fadestep_blu = (newb - red) / fade_time;
-              //fadestep_wht = (neww - red) / fade_time;
+              /* Compute increment and remainder for each led */
+              red.increment = newr / fade_steps;
+              red.remainder = newr - red.increment * fade_steps;
+              grn.increment = newg / fade_steps;
+              grn.remainder = newg - grn.increment * fade_steps;
+              blu.increment = newb / fade_steps;
+              blu.remainder = newb - blu.increment * fade_steps;
+              wht.increment = neww / fade_steps;
+              wht.remainder = neww - wht.increment * fade_steps;
             }
-            __delay_ms(50);
+            __delay_ms(STEP_SIZE); /* step should be start to start... */
         } else {
             rgb_off();
             buttons_sleep();
-            incolor_time = 0;
-            fade_time = 0;
+            reset_steps();
             rgb_on();
+            red.value = 0;
+            grn.value = 0;
+            blu.value = 0;
+            wht.value = 0;
         }
     }
     return 0;
-- 
2.39.2