From 9f09be93a93ac2570da23bc07f36558b232b7e79 Mon Sep 17 00:00:00 2001
From: Peter Evans <peter@modul8r.com>
Date: Wed, 7 Mar 2018 16:20:29 -0600
Subject: [PATCH] Implement (true? better?) framerate cycle

---
 include/apple2.draw.h |  3 ++-
 include/apple2.h      |  3 ++-
 src/apple2.c          |  1 +
 src/apple2.dbuf.c     |  2 +-
 src/apple2.draw.c     | 25 +++++++++++++++++++++++++
 5 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/include/apple2.draw.h b/include/apple2.draw.h
index 86e73f5..2c1b9fa 100644
--- a/include/apple2.draw.h
+++ b/include/apple2.draw.h
@@ -4,7 +4,8 @@
 #include "apple2.h"
 #include "vm_bits.h"
 
-extern void apple2_draw_pixel(apple2 *, vm_16bit);
+extern void apple2_draw(apple2 *);
 extern void apple2_draw_40col(apple2 *);
+extern void apple2_draw_pixel(apple2 *, vm_16bit);
 
 #endif
diff --git a/include/apple2.h b/include/apple2.h
index 1ebd61d..1a94e83 100644
--- a/include/apple2.h
+++ b/include/apple2.h
@@ -350,13 +350,14 @@ extern bool apple2_is_double_video(apple2 *);
 extern int apple2_boot(apple2 *);
 extern void apple2_clear_strobe(apple2 *);
 extern void apple2_free(apple2 *);
+extern void apple2_notify_refresh(apple2 *);
 extern void apple2_press_key(apple2 *, vm_8bit);
 extern void apple2_release_key(apple2 *);
 extern void apple2_reset(apple2 *);
 extern void apple2_run_loop(apple2 *);
 extern void apple2_set_bank_switch(apple2 *, vm_8bit);
 extern void apple2_set_color(apple2 *, int);
-extern void apple2_set_memory_mode(apple2 *, vm_8bit);
 extern void apple2_set_display(apple2 *, vm_8bit);
+extern void apple2_set_memory_mode(apple2 *, vm_8bit);
 
 #endif
diff --git a/src/apple2.c b/src/apple2.c
index 549b5b0..76cd814 100644
--- a/src/apple2.c
+++ b/src/apple2.c
@@ -391,6 +391,7 @@ apple2_run_loop(apple2 *mach)
         mos6502_execute(mach->cpu);
 
         if (vm_screen_dirty(mach->screen)) {
+            apple2_draw(mach);
             vm_screen_refresh(mach->screen);
         }
     }
diff --git a/src/apple2.dbuf.c b/src/apple2.dbuf.c
index c1220e0..93a33de 100644
--- a/src/apple2.dbuf.c
+++ b/src/apple2.dbuf.c
@@ -100,7 +100,7 @@ SEGMENT_WRITER(apple2_dbuf_write)
     segment->memory[addr] = value;
 
     if (mach->display_mode & DISPLAY_TEXT) {
-        apple2_draw_40col(mach);
+        apple2_notify_refresh(mach);
     }
 }
 
diff --git a/src/apple2.draw.c b/src/apple2.draw.c
index 2db81ca..c79cb25 100644
--- a/src/apple2.draw.c
+++ b/src/apple2.draw.c
@@ -102,3 +102,28 @@ apple2_draw_40col(apple2 *mach)
         apple2_text_draw(mach, addr);
     }
 }
+
+/*
+ * Find the right draw method for the machine, based on its display
+ * mode, and use that to refresh the screen.
+ */
+void
+apple2_draw(apple2 *mach)
+{
+    if (mach->display_mode & DISPLAY_TEXT) {
+        apple2_draw_40col(mach);
+    }
+}
+
+/*
+ * Tell the screen that it has a change ready to be displayed. This
+ * function will not immediately redraw the screen, and when the screen
+ * is redrawn is up to our framerate cycle.
+ */
+void
+apple2_notify_refresh(apple2 *mach)
+{
+    if (mach && mach->screen) {
+        mach->screen->dirty = true;
+    }
+}