Read actual register values

src/emulator/shrooms_vb_core.rs

@@ -55,6 +55,13 @@ bitflags! {
     }
 }
 
+#[derive(Clone, Copy, Debug)]
+pub enum VBRegister {
+    Program(u32),
+    System(u32),
+    PC,
+}
+
 type OnFrame = extern "C" fn(sim: *mut VB) -> c_int;
 
 #[link(name = "vb")]
@@ -77,6 +84,10 @@ extern "C" {
         right_stride_x: c_int,
         right_stride_y: c_int,
     );
+    #[link_name = "vbGetProgramCounter"]
+    fn vb_get_program_counter(sim: *mut VB) -> u32;
+    #[link_name = "vbGetProgramRegister"]
+    fn vb_get_program_register(sim: *mut VB, index: c_uint) -> i32;
     #[link_name = "vbGetSamples"]
     fn vb_get_samples(
         sim: *mut VB,
@@ -84,6 +95,8 @@ extern "C" {
         capacity: *mut c_uint,
         position: *mut c_uint,
     ) -> *mut c_void;
+    #[link_name = "vbGetSystemRegister"]
+    fn vb_get_system_register(sim: *mut VB, index: c_uint) -> i32;
     #[link_name = "vbGetUserData"]
     fn vb_get_user_data(sim: *mut VB) -> *mut c_void;
     #[link_name = "vbInit"]
@@ -291,6 +304,16 @@ impl Sim {
     pub fn set_keys(&mut self, keys: VBKey) {
         unsafe { vb_set_keys(self.sim, keys.bits()) };
     }
+
+    pub fn read_register(&mut self, register: VBRegister) -> u32 {
+        match register {
+            VBRegister::Program(index) => unsafe {
+                vb_get_program_register(self.sim, index) as u32
+            },
+            VBRegister::System(index) => unsafe { vb_get_system_register(self.sim, index) as u32 },
+            VBRegister::PC => unsafe { vb_get_program_counter(self.sim) },
+        }
+    }
 }
 
 impl Drop for Sim {