From e73f4861161e20dc2c2ea7eeca798ea4df6087e0 Mon Sep 17 00:00:00 2001
From: Wolfgang Hottgenroth <wolfgang.hottgenroth@icloud.com>
Date: Sat, 2 Mar 2024 18:49:44 +0100
Subject: [PATCH] changed pixels considered in showCanvas

---
 test01.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/test01.c b/test01.c
index 377ecfe..1ad4c96 100644
--- a/test01.c
+++ b/test01.c
@@ -50,10 +50,18 @@ void showCanvas() {
   for (uint8_t y = 0; y < CANVAS_HEIGHT; y++) {
     for (uint8_t x = 0; x < CANVAS_WIDTH; x++) {
       printf("%02x ", canvas[x][y]);
-      canvas[x][y] &= ~0x80;
     }
     printf("\n");
   }
+  printf("Changed pixels: ");
+  for (uint8_t y = 0; y < CANVAS_HEIGHT; y++) {
+    for (uint8_t x = 0; x < CANVAS_WIDTH; x++) {
+      if (canvas[x][y] & 0x80) {
+        canvas[x][y] &= ~0x80;
+        printf("0x%02x,0x%02x=0x%02x ", x, y, canvas[x][y]);
+      }
+    }
+  }
   printf("\n");
 }
 
@@ -82,33 +90,33 @@ void initObject(t_shape shape, uint8_t x, uint8_t y) {
 }
 
 void drawObject() { 
+  // the bit7 set marks changed pixels
   if (object.initial == 0) {
     // wipe
     switch (object.shape) {
       case e_O:
         switch (object.last_rotation) {
           case 0:
-            canvas[object.last_x][object.last_y] = 0;
-            canvas[object.last_x][object.last_y+1] = 0;
-            canvas[object.last_x+1][object.last_y] = 0;
-            canvas[object.last_x+1][object.last_y+1] = 0;
+            canvas[object.last_x][object.last_y] = 0 | 0x80;
+            canvas[object.last_x][object.last_y+1] = 0 | 0x80;
+            canvas[object.last_x+1][object.last_y] = 0 | 0x80;
+            canvas[object.last_x+1][object.last_y+1] = 0 | 0x80;
             break;
         }
         break;
       case e_I:
         switch (object.last_rotation) {
           case 0:
-            canvas[object.last_x][object.last_y] = 0;
-            canvas[object.last_x][object.last_y+1] = 0;
-            canvas[object.last_x][object.last_y+2] = 0;
-            canvas[object.last_x][object.last_y+3] = 0;
+            canvas[object.last_x][object.last_y] = 0 | 0x80;
+            canvas[object.last_x][object.last_y+1] = 0 | 0x80;
+            canvas[object.last_x][object.last_y+2] = 0 | 0x80;
+            canvas[object.last_x][object.last_y+3] = 0 | 0x80;
             break;
         }
         break;
     }
   }
   // draw
-  // the bit7 set marks changed pixels
   switch (object.shape) {
     case e_O:
       switch (object.rotation) {