From 24634637b24d144ffdf5ae6b5fb56e289126706f Mon Sep 17 00:00:00 2001
From: Trevor Merritt <trevor.merritt@gmail.com>
Date: Sun, 6 Oct 2024 12:32:18 -0400
Subject: [PATCH] video rendering might work.  cant focus

---
 emma/src/chip8/instructions.rs |  9 +++++----
 emma/src/chip8/video.rs        | 17 +++++++++++------
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/emma/src/chip8/instructions.rs b/emma/src/chip8/instructions.rs
index 67a0c3e..d8eaa45 100644
--- a/emma/src/chip8/instructions.rs
+++ b/emma/src/chip8/instructions.rs
@@ -598,7 +598,6 @@ impl Chip8CpuInstructions {
             Chip8CpuInstructions::DrawVxVyNibble(x, y, n) => {
                 // Display n-byte sprite starting at memory location I at (Vx, Vy), set VF = collision.
 
-
                 // The interpreter reads n bytes from memory, starting at the address stored in I.
 
 
@@ -770,7 +769,7 @@ impl Chip8CpuInstructions {
 mod test {
     use dimensioned::typenum::assert_type;
     use ratatui::crossterm::execute;
-    use crate::chip8::system_memory::{CHIP8FONT_0, CHIP8FONT_1, CHIP8FONT_9};
+    use crate::chip8::system_memory::{CHIP8FONT_0, CHIP8FONT_1, CHIP8FONT_2, CHIP8FONT_9};
     use super::*;
 
     #[test]
@@ -1408,6 +1407,7 @@ mod test {
         let y_register = 0x2;
         let x_offset = 1;
         let y_offset = 2;
+        let char_offset = 0x0A;
 
         // use the font characters to draw to video memory
 //        assert_eq!(x.memory.peek(0x0), CHIP8FONT_0[0]);
@@ -1419,7 +1419,7 @@ mod test {
         // now lets set the X and Y to 1,2
         x.registers.poke(x_register, x_offset);
         x.registers.poke(y_register, y_offset);
-        x.registers.poke_i(0x5);
+        x.registers.poke_i(char_offset);
         // we are using 5 rows.
         Chip8CpuInstructions::DrawVxVyNibble(x_register as u16, y_register as u16, 5).execute(&mut x);
 
@@ -1431,13 +1431,14 @@ mod test {
         // 5,2->5,9
       //  let byte_to_check = CHIP8FONT_0[0];
         for row_in_sprite in 0..5 {
-            let row_data = CHIP8FONT_1[row_in_sprite];
+            let row_data = CHIP8FONT_2[row_in_sprite];
             for bit_in_byte in 0..8 {
                 let data_offset = (x_offset + row_in_sprite as u8) * 64 + (bit_in_byte + y_offset);
                 let should_be_set = (row_data.shr(bit_in_byte) & 0x1) == 1;
                 println!("DATA_OFFSET FOR {}x{} is {} when offsetting by {}x{} and should be {} working with byte {:08b}",
                          bit_in_byte, row_in_sprite, data_offset, x_offset, y_offset, should_be_set, row_data);
                 //          assert_eq!(should_be_set, );
+                assert_eq!(should_be_set, x.video_memory.peek(data_offset as u16));
             }
         }
     }
diff --git a/emma/src/chip8/video.rs b/emma/src/chip8/video.rs
index 7ee1a77..1b5bab5 100644
--- a/emma/src/chip8/video.rs
+++ b/emma/src/chip8/video.rs
@@ -28,7 +28,12 @@ impl Chip8Video {
     }
 
     pub fn poke(&mut self, address: u16, new_value: bool) -> Self {
-        println!("**VIDEO** POKING {new_value} TO {address}");
+        let col = address % 64;
+        let row = address / 32;
+        let old_value = self.memory[address as usize];
+        if old_value != new_value {
+            println!("**VIDEO** TOGGLING {new_value} TO {address} / {col}x{row}");
+        }
         self.memory[address as usize] = new_value;
         self.to_owned()
     }
@@ -57,11 +62,11 @@ impl Chip8Video {
     pub fn format_as_string(self) -> String {
         let mut output = String::new();
         for row in 0..32 {
-            let row_offset = row * 32;
+            let row_offset = row * 64;
             for column in 0..64 {
                 let data_position = row_offset + column;
-        //        println!("DP  {} {} {} {}", data_position, row, row_offset, column);
                 output += if self.memory[data_position] {
+                    println!("DOT AT OFFSET:{row_offset} {row}x{column} {data_position:03x}/{data_position}");
                     "*"
                 } else {
                     " "
@@ -72,8 +77,6 @@ impl Chip8Video {
       //  println!("{}", output);
         output
     }
-
-
 }
 
 impl Default for Chip8Video {
@@ -197,6 +200,9 @@ mod test {
         assert!(!v.peek(0x03));
         assert!(!v.peek(0x05));
         assert!(!v.peek(0x07));
+        for i in 0x8..CHIP8_VIDEO_MEMORY {
+            assert!(!v.peek(i as u16));
+        }
     }
 
     #[test]
@@ -307,6 +313,5 @@ mod test {
         assert!(v.peek(0xC5));
         assert!(!v.peek(0xC6));
         assert!(v.peek(0xC7));
-
     }
 }