From 9c912ffb85fd17ddc5c82b317e9795734f5e9a49 Mon Sep 17 00:00:00 2001
From: Ain <41307858+nero@users.noreply.github.com>
Date: Wed, 3 Oct 2018 07:16:54 +0000
Subject: [PATCH] Add sample framebuffer shifting code

---
 drivers/framebuffer.c | 29 +++++++++++++++++++++++++++++
 drivers/framebuffer.h | 10 ++++++----
 pingpong.c            | 17 ++++++++++++++++-
 3 files changed, 51 insertions(+), 5 deletions(-)

diff --git a/drivers/framebuffer.c b/drivers/framebuffer.c
index 82ecab4..3859211 100644
--- a/drivers/framebuffer.c
+++ b/drivers/framebuffer.c
@@ -2,3 +2,32 @@
 #include "framebuffer.h"
 
 FRAMEBUFFER;
+
+#if FB_DEPTH==1
+
+void fb_fill(uint8_t c) {
+  memset(framebuffer, c, sizeof(framebuffer[0][0]) * FB_HEIGHT * FB_WIDTH_BYTES);
+}
+
+void fb_shift(uint16_t newcol) {
+  int x, y;
+  uint8_t transfer = 0, tmp = 0;
+  for (y = 0; y < FB_HEIGHT; y++) {
+    for (x = FB_WIDTH_BYTES - 1; x >= 0; x--) {
+      tmp = transfer;
+      transfer = (framebuffer[y][x] & 1);
+      framebuffer[y][x] = (framebuffer[y][x] >> 1) | (tmp << 7);
+    }
+    transfer = 0;
+    FB_SET(FB_WIDTH - 1, y, newcol & 1);
+    newcol = newcol >> 1;
+  }
+}
+
+#elif FB_DEPTH==8
+
+void fb_fill(uint8_t c) {
+  memset(framebuffer, c, sizeof(framebuffer[0][0]) * FB_HEIGHT * FB_WIDTH);
+}
+
+#endif
diff --git a/drivers/framebuffer.h b/drivers/framebuffer.h
index e1f05b9..d6e24d6 100644
--- a/drivers/framebuffer.h
+++ b/drivers/framebuffer.h
@@ -1,4 +1,5 @@
 #include <stdint.h>
+#include <string.h>
 
 #define CEILDIV(x, y) (((x)+((y)-1))/(y))
 
@@ -7,20 +8,21 @@
 #define FB_WIDTH_BYTES CEILDIV(FB_WIDTH, 8)
 #define FRAMEBUFFER uint8_t framebuffer[FB_HEIGHT][FB_WIDTH_BYTES];
 #define FB_SET(w,h,c) if (c) { \
-    framebuffer[h][w>>3] |= (1 << (w & 7)); \
+    framebuffer[h][(w)>>3] |= (1 << ((w) & 7)); \
   } else { \
-    framebuffer[h][w>>3] &= ~(1 << (w & 7)); \
+    framebuffer[h][(w)>>3] &= ~(1 << ((w) & 7)); \
   }
-#define FB_CLEAR() memset(framebuffer, 0, sizeof(framebuffer[0][0]) * FB_HEIGHT * FB_WIDTH_BYTES);
 
 #elif FB_DEPTH==8
 
 #define FRAMEBUFFER uint8_t framebuffer][FB_HEIGHT][FB_WIDTH];
 #define FB_SET(w,h,c) framebuffer[h][w] = c
-#define FB_CLEAR() memset(framebuffer, 0, sizeof(framebuffer[0][0]) * FB_HEIGHT * FB_WIDTH);
 
 #endif
 
 #ifndef DONT_DECLARE_FRAMEBUFFER
 extern FRAMEBUFFER
 #endif
+
+void fb_fill(uint8_t c);
+void fb_shift();
diff --git a/pingpong.c b/pingpong.c
index c3ab4a6..f03ba1c 100644
--- a/pingpong.c
+++ b/pingpong.c
@@ -1,9 +1,11 @@
 #include <util/delay.h>
 #include "drivers/framebuffer.h"
 
-int main(void) {
+void ani_recorder(unsigned int count) {
   int8_t px, py, mx, my;
 
+  fb_fill(0);
+
   px = 0;
   py = 0;
   mx = 1;
@@ -24,9 +26,11 @@ int main(void) {
 
     if (py >= FB_HEIGHT - 1) {
       my = -1;
+      count --;
     }
 
     FB_SET(px,py,0);
+    if (!count) return;
     px += mx;
     py += my;
     FB_SET(px,py,1);
@@ -34,3 +38,14 @@ int main(void) {
     _delay_ms(50);
   }
 }
+
+int main() {
+  uint16_t i = 0;
+  while(1) {
+    ani_recorder(4);
+    for (i = 0; i < 256; i++) {
+      _delay_ms(50);
+      fb_shift(i);
+    }
+  }
+}