1 files changed, 54 insertions, 0 deletions
diff --git a/src/debug.rs b/src/debug.rs
new file mode 100644
index 0000000..d19dbec
--- /dev/null
+++ b/src/debug.rs
@@ -0,0 +1,54 @@
+use bedrock_core::*;
+
+use std::time::Instant;
+
+macro_rules! yellow { () => { eprint!("\x1b[33m") };}
+macro_rules! normal { () => { eprint!("\x1b[0m" ) };}
+
+
+pub struct DebugState {
+    pub enabled: bool,
+    last_cycle: usize,
+    last_mark: Instant,
+}
+
+impl DebugState {
+    pub fn new(enabled: bool) -> Self {
+        Self {
+            enabled,
+            last_cycle: 0,
+            last_mark: Instant::now(),
+        }
+    }
+
+    pub fn print(&self, string: &str) {
+        if self.enabled {
+            println!("{}", string);
+        }
+    }
+
+    pub fn debug_summary(&mut self, core: &BedrockCore) {
+        eprintln!("\n PC: 0x{:04x}   Cycles: {} (+{} in {:.2?})",
+            core.mem.pc, core.cycle,
+            core.cycle.saturating_sub(self.last_cycle),
+            self.last_mark.elapsed(),
+        );
+        eprint!("WST: ");
+        debug_stack(&core.wst, 0x10);
+        eprint!("RST: ");
+        debug_stack(&core.rst, 0x10);
+
+        self.last_cycle = core.cycle;
+        self.last_mark = Instant::now();
+    }
+}
+
+
+fn debug_stack(stack: &Stack, len: usize) {
+    for i in 0..len {
+        if i == stack.sp as usize { yellow!(); }
+        eprint!("{:02x} ", stack.mem[i]);
+    }
+    normal!();
+    eprintln!();
+}