Finish map, mapper handling for keyboard events

We still need to revise the test code we currently have for handling
keyboard functions; I imagine some code will need to be removed.

include/apple2.h

@@ -305,12 +305,10 @@ typedef struct {
     vm_8bit memory_mode;
 
     /*
-     * The last_key field is the ASCII value of the last key that was
-     * pressed. We also have a simple boolean value to determine if the
-     * strobe is set (it always is when the key is pressed, and stays
-     * that way until someone reads the "any-key-down" soft switch).
+     * We have a simple boolean value to determine if the strobe is set
+     * (it always is when the key is pressed, and stays that way until
+     * someone reads the "any-key-down" soft switch).
      */
-    vm_8bit last_key;
     bool strobe;
 
     /*

include/apple2.kb.h

@@ -2,6 +2,10 @@
 #define _APPLE2_KB_H_
 
 #include "apple2.h"
+#include "vm_screen.h"
 #include "vm_segment.h"
 
+extern void apple2_kb_map(vm_segment *);
+extern SEGMENT_READER(apple2_kb_switch_read);
+
 #endif

include/vm_screen.h

@@ -5,6 +5,7 @@
 #include <SDL.h>
 
 #include "vm_area.h"
+#include "vm_bits.h"
 
 typedef struct {
     /*
@@ -31,10 +32,12 @@ typedef struct {
     int ycoords;
 
     /*
-     * This is true when a key is pressed, and false if not. We
-     * determine this from an SDL_PollEvent() call.
+     * Hang onto the last key pressed and the status of whether a key
+     * is pressed right now or not.
      */
+    vm_8bit last_key;
     bool key_pressed;
+
 } vm_screen;
 
 extern bool vm_screen_active(vm_screen *);

sources.cmake

@@ -4,6 +4,7 @@ set(erc_sources
 	apple2.dbuf.c
 	apple2.dd.c
 	apple2.draw.c
+	apple2.kb.c
 	apple2.mem.c
 	apple2.pc.c
 	log.c

src/apple2.kb.c

@@ -4,6 +4,23 @@
 
 #include "apple2.kb.h"
 
+/*
+ * This mapper is considerably simpler than most, because it handles
+ * only two addresses and only read maps. It merely performs the mapping
+ * for keyboard switches.
+ */
+void
+apple2_kb_map(vm_segment *seg)
+{
+    vm_segment_read_map(seg, 0xC000, apple2_kb_switch_read);
+    vm_segment_read_map(seg, 0xC010, apple2_kb_switch_read);
+}
+
+/*
+ * This mapper handles reads to switches that report info on the
+ * keyboard state. Note that there is no write switch function; there
+ * are only reads that need to be handled.
+ */
 SEGMENT_READER(apple2_kb_switch_read)
 {
     apple2 *mach = (apple2 *)_mach;
@@ -50,4 +67,8 @@ SEGMENT_READER(apple2_kb_switch_read)
             // pressed down.
             return 0;
     }
+
+    // This can only happen if we were mapped to an address we weren't
+    // prepared to handle
+    return 0;
 }

src/apple2.mem.c

@@ -4,9 +4,10 @@
 
 #include "apple2.bank.h"
 #include "apple2.dbuf.h"
-#include "apple2.pc.h"
 #include "apple2.h"
+#include "apple2.kb.h"
 #include "apple2.mem.h"
+#include "apple2.pc.h"
 #include "objstore.h"
 
 static size_t switch_reads[] = {
@@ -49,8 +50,13 @@ apple2_mem_map(apple2 *mach, vm_segment *segment)
     // Here we handle the 80STORE bit for our display buffers.
     apple2_dbuf_map(segment);
 
+    // All of our peripheral card (PC) mapper functions are handled
+    // here.
     apple2_pc_map(segment);
 
+    // And this handles our keyboard soft switches
+    apple2_kb_map(segment);
+
     // We will do the mapping for the zero page and stack addresses.
     // Accessing those addresses can be affected by bank-switching, but
     // those addresses do not actually exist in the capital

src/vm_screen.c

@@ -175,16 +175,16 @@ vm_screen_active(vm_screen *screen)
         ch = '\0';
 
         // It seems we may have pressed a key...
-        if (event.key) {
+        if (event.type == SDL_KEYDOWN || event.type == SDL_KEYUP) {
             // The sym field is of type SDL_Keycode; this type, however,
             // maps roughly to Unicode, which of course maps roughly to
             // ASCII in the low range.
-            ch = (char)event.key->keysym.sym;
+            ch = (char)event.key.keysym.sym;
 
             // If we had shift pressed, we need to uppercase the
             // character.
-            if (event.key->keysym.mod & KMOD_LSHIFT ||
-                event.key->keysym.mod & KMOD_RSHIFT
+            if (event.key.keysym.mod & KMOD_LSHIFT ||
+                event.key.keysym.mod & KMOD_RSHIFT
                ) {
                 ch = toupper(ch);
             }