Add ability to debug separate from pausing

Also, pausing just pauses now; no debugger prompt is shown. ALT+P
toggles pausing, so just hit it again to unpause. Also, when things are
paused, you can perform other keyboard events (like quitting).

include/apple2/apple2.h

@@ -339,6 +339,13 @@ struct apple2 {
      */
     bool paused;
 
+    /*
+     * When this and the paused fields are true, then we will print a
+     * debug prompt and allow the user to work with the machine through
+     * that.
+     */
+    bool debug;
+
     /*
      * If this is true, then we will disassemble opcodes as we execute.
      */

include/apple2/event.h

@@ -3,7 +3,8 @@
 
 #include "vm_event.h"
 
-extern void apple2_event_init();
+extern EVENT_DO(apple2_event_debug);
 extern EVENT_DO(apple2_event_pause);
+extern void apple2_event_init();
 
 #endif

src/apple2/apple2.c

@@ -48,14 +48,9 @@ apple2_create(int width, int height)
         return NULL;
     }
 
-    // By default, we have no strobe set; it should only be set when a
-    // key is pressed
     mach->strobe = false;
-
-    // Yes, please do execute opcodes to begin with
     mach->paused = false;
-
-    // Don't print opcodes by default
+    mach->debug = false;
     mach->disasm = false;
 
     // Forward set these to NULL in case we fail to build the machine
@@ -357,8 +352,7 @@ apple2_run_loop(apple2 *mach)
             mach->paused = true;
         }
 
-        // If we're paused, then just re-loop until we're not
-        if (mach->paused) {
+        if (mach->debug) {
             if (mach->selected_drive) {
                 mach->selected_drive->locked = true;
             }
@@ -376,6 +370,10 @@ apple2_run_loop(apple2 *mach)
             }
 
             free(input);
+        }
+
+        if (mach->paused) {
+            vm_event_poll(mach->screen);
             continue;
         }
 

src/apple2/debug.c

@@ -328,6 +328,7 @@ DEBUG_CMD(resume)
     apple2_debug_unbreak(mach->cpu->PC);
 
     mach->paused = false;
+    mach->debug = false;
 }
 
 /*

src/apple2/event.c

@@ -17,16 +17,18 @@ void
 apple2_event_init()
 {
     vm_di_set(VM_PAUSE_FUNC, apple2_event_pause);
+    vm_di_set(VM_DEBUG_FUNC, apple2_event_debug);
 }
 
 EVENT_DO(apple2_event_pause)
 {
     apple2 *mach = (apple2 *)_mach;
-    mach->paused = true;
+    mach->paused = !mach->paused;
 }
 
 EVENT_DO(apple2_event_debug)
 {
     apple2 *mach = (apple2 *)_mach;
+    mach->debug = true;
     mach->paused = true;
 }

src/vm_event.c

@@ -108,6 +108,10 @@ vm_event_keyboard_special(vm_event *ev, char ch)
                 ev->screen->should_exit = true;
                 break;
 
+            case 'd':
+                vm_event_do(VM_DEBUG_FUNC);
+                break;
+
             case 'p':
                 vm_event_do(VM_PAUSE_FUNC);
                 break;