From eb83a3fd0f1f55910353bb6cb329b1a7f7d5137c Mon Sep 17 00:00:00 2001
From: Fabrizio Caruso <fabrizio_caruso@hotmail.com>
Date: Sun, 6 Oct 2019 13:41:02 +0200
Subject: [PATCH] Improve helloworld example for Supervision

---
 samples/supervisionhello.c | 73 +++++++++++++++++++++-----------------
 1 file changed, 41 insertions(+), 32 deletions(-)

diff --git a/samples/supervisionhello.c b/samples/supervisionhello.c
index 5996d219f..c1832179a 100755
--- a/samples/supervisionhello.c
+++ b/samples/supervisionhello.c
@@ -1,17 +1,15 @@
 #include <supervision.h>
 #include <peekpoke.h>
 
-#define SV_OFFSET 0x0A
-#define SV_INIT_POSITION (SV_VIDEO+0x0A*48+0x0A)
-
-unsigned char h_char[] = {0x66,0x66,0x66,0x7e,0x66,0x66,0x66,0x00};
-unsigned char e_char[] = {0x7e,0x60,0x60,0x78,0x60,0x60,0x7e,0x00};
-unsigned char l_char[] = {0x60,0x60,0x60,0x60,0x60,0x60,0x7e,0x00};
-unsigned char o_char[] = {0x3c,0x66,0x66,0x66,0x66,0x66,0x3c,0x00};
-unsigned char w_char[] = {0x63,0x63,0x63,0x6b,0x7f,0x77,0x63,0x00};
-unsigned char r_char[] = {0x7c,0x66,0x66,0x7c,0x78,0x6c,0x66,0x00};
-unsigned char d_char[] = {0x78,0x6c,0x66,0x66,0x66,0x6c,0x78,0x00};
+#define BYTES_PER_LINE 48
 
+const unsigned char h_char[] = {0x66,0x66,0x66,0x7E,0x66,0x66,0x66,0x00};
+const unsigned char e_char[] = {0x7E,0x60,0x60,0x78,0x60,0x60,0x7E,0x00};
+const unsigned char l_char[] = {0x60,0x60,0x60,0x60,0x60,0x60,0x7E,0x00};
+const unsigned char o_char[] = {0x3C,0x66,0x66,0x66,0x66,0x66,0x3C,0x00};
+const unsigned char w_char[] = {0x63,0x63,0x63,0x6B,0x7F,0x77,0x63,0x00};
+const unsigned char r_char[] = {0x7C,0x66,0x66,0x7C,0x78,0x6C,0x66,0x00};
+const unsigned char d_char[] = {0x78,0x6C,0x66,0x66,0x66,0x6C,0x78,0x00};
 
 void clear_screen(void)
 {
@@ -23,37 +21,48 @@ void clear_screen(void)
     }
 }
 
-unsigned char bit_reverse_lookup[16] = 
+unsigned char reversed_map_one_to_two_lookup[16] = 
 {
-    0x0, 0x8, 0x4, 0xC, 0x2, 0xA, 0x6, 0xE,
-    0x1, 0x9, 0x5, 0xD, 0x3, 0xB, 0x7, 0xF 
+    0x00, 0xC0, 0x30, 0xF0, 0x0C, 0xCC, 0x3C, 0xFC,
+    0x03, 0xC3, 0x33, 0xF3, 0x0F, 0xCF, 0x3F, 0xFF
 };
 
-unsigned char bit_reverse(unsigned char n) 
+unsigned char left_map_one_to_two(unsigned char n)
 {
-    return (bit_reverse_lookup[n&0b1111] << 4) | bit_reverse_lookup[n>>4];
+    return reversed_map_one_to_two_lookup[n >> 4];
+}
+
+unsigned char right_map_one_to_two(unsigned char n)
+{
+    return reversed_map_one_to_two_lookup[n&0x0F];
+}
+
+void display_char(const unsigned char x, const unsigned char y, const unsigned char *ch)
+{
+    unsigned char k;
+    
+    for(k=0;k<8;++k)
+    { \
+        SV_VIDEO[2*(y)+BYTES_PER_LINE*k+BYTES_PER_LINE*(x<<3)]    = left_map_one_to_two(ch[k]); 
+        SV_VIDEO[2*(y)+BYTES_PER_LINE*k+BYTES_PER_LINE*(x<<3)+1]  = right_map_one_to_two(ch[k]); 
+    } 
 }
 
 int main()
-{
-    unsigned char i;
-    
+{    
     clear_screen();
     
-    for(i=0;i<8;++i)
-    {
-        POKE(SV_INIT_POSITION+1 +i*48,bit_reverse(h_char[i]));
-        POKE(SV_INIT_POSITION+2 +i*48,bit_reverse(e_char[i]));
-        POKE(SV_INIT_POSITION+3 +i*48,bit_reverse(l_char[i]));
-        POKE(SV_INIT_POSITION+4 +i*48,bit_reverse(l_char[i]));
-        POKE(SV_INIT_POSITION+5 +i*48,bit_reverse(o_char[i]));
-        
-        POKE(SV_INIT_POSITION+7 +i*48,bit_reverse(w_char[i]));
-        POKE(SV_INIT_POSITION+8 +i*48,bit_reverse(o_char[i]));
-        POKE(SV_INIT_POSITION+9 +i*48,bit_reverse(r_char[i]));
-        POKE(SV_INIT_POSITION+10+i*48,bit_reverse(l_char[i]));
-        POKE(SV_INIT_POSITION+11+i*48,bit_reverse(d_char[i]));        
-    }
+    display_char(3,2, h_char);
+    display_char(3,3, e_char);
+    display_char(3,4, l_char);
+    display_char(3,5, l_char);
+    display_char(3,6, o_char);
+    
+    display_char(3,8, w_char);
+    display_char(3,9, o_char);
+    display_char(3,10,r_char);
+    display_char(3,11,l_char);
+    display_char(3,12,d_char);    
 
     while(1) {};