From 9c216ac95e5803031ca6d3aad1fab9f0ded48ccc Mon Sep 17 00:00:00 2001
From: Wei-ju Wu <weiju.wu@gmail.com>
Date: Mon, 26 Sep 2016 16:25:39 -0700
Subject: [PATCH] added movement to sprites

also, waitmouse is now C function instead of inline assembly
---
 hardware/common.c  |  9 +++++++++
 hardware/common.h  |  9 ++++++---
 hardware/sprites.c | 29 ++++++++++++++++++++++++++++-
 3 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/hardware/common.c b/hardware/common.c
index fc857ce..34b51cb 100644
--- a/hardware/common.c
+++ b/hardware/common.c
@@ -1,3 +1,4 @@
+/* C version of How To Code 7 http://aminet.net/package/docs/misc/howtocode7 */
 #include <clib/graphics_protos.h>
 #include <clib/intuition_protos.h>
 #include <exec/execbase.h>
@@ -82,3 +83,11 @@ void reset_display(void)
     custom.cop1lc = (ULONG) ((struct GfxBase *) GfxBase)->copinit;
     RethinkDisplay();
 }
+
+#define PRA_FIR0_BIT (1 << 6)
+
+void waitmouse(void)
+{
+    volatile UBYTE *ciaa_pra = (volatile UBYTE *) 0xbfe001;
+    while ((*ciaa_pra & PRA_FIR0_BIT) != 0) ;
+}
diff --git a/hardware/common.h b/hardware/common.h
index 9d72001..ac2a64d 100644
--- a/hardware/common.h
+++ b/hardware/common.h
@@ -3,6 +3,11 @@
 #define __COMMON_DEFS_H__
 
 // Custom Chip Registers
+#define BLTDDAT       0x000
+#define DMACONR       0x002
+#define VPOSR         0x004
+#define VHPOSR        0x006
+
 #define DMACON        0x096
 #define BPL1PTH       0x0e0
 #define BPL1PTL       0x0e2
@@ -65,8 +70,6 @@
 
 extern BOOL init_display(void);
 extern void reset_display(void);
-
-// VBCC Inline assembly
-void waitmouse(void) = "waitmouse:\n\tbtst\t#6,$bfe001\n\tbne\twaitmouse";
+extern void waitmouse(void);
 
 #endif /* __COMMON_DEFS_H__ */
diff --git a/hardware/sprites.c b/hardware/sprites.c
index 54372cc..4e009dd 100644
--- a/hardware/sprites.c
+++ b/hardware/sprites.c
@@ -49,6 +49,11 @@ static UWORD __chip sprite_data[] = {
     0x0000, 0x0000
 };
 
+volatile UBYTE *ciaa_pra = (volatile UBYTE *) 0xbfe001;
+volatile UBYTE *custom_vhposr= (volatile UBYTE *) 0xdff006;
+#define PRA_FIR0_BIT (1 << 6)
+#define DELAY 1
+
 int main(int argc, char **argv)
 {
     struct Task *current_task = FindTask(NULL);
@@ -89,7 +94,29 @@ int main(int argc, char **argv)
     custom.dmacon  = 0x83a0;  // Bitplane + Copper + Sprite DMA activate
     custom.copjmp1 = 1;
 
-    waitmouse();
+    // wait for mouse button
+    UBYTE hstart = 0x60;
+    UBYTE vstart = 0x6d;
+    UBYTE vstop = 0x72;
+    int incx = 1, minx = 0x60, maxx = 0x90;
+    int incy = 1, miny = 0x6d, maxy = 0x90;
+    int delay = DELAY;
+
+    while ((*ciaa_pra & PRA_FIR0_BIT) != 0) {
+        // PAL vblank test
+        while (*custom_vhposr != 0x00) ;
+        delay--;
+        if (delay == 0) {
+            delay = DELAY;
+            hstart += incx;
+            vstart += incy;
+            if (hstart >= maxx || hstart <= minx) incx = -incx;
+            if (vstart >= maxy || vstart <= miny) incy = -incy;
+        }
+        vstop = vstart + 5;
+        sprite_data[0] = (vstart << 8) | hstart;
+        sprite_data[1] = vstop << 8;
+    }
 
     reset_display();
     return 0;