From d70b8303b17b21a6161f0e83a8f4c16db8a63df6 Mon Sep 17 00:00:00 2001
From: Irmen de Jong <irmen@razorvine.net>
Date: Wed, 13 Nov 2024 20:26:04 +0100
Subject: [PATCH] added sprites.reset() to remove sprites from the screen

---
 compiler/res/prog8lib/cx16/sprites.p8 | 16 ++++++++++++++++
 docs/source/todo.rst                  |  2 ++
 examples/test.p8                      | 15 +++++++++++----
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/compiler/res/prog8lib/cx16/sprites.p8 b/compiler/res/prog8lib/cx16/sprites.p8
index b85ae74ac..e4ee38b7b 100644
--- a/compiler/res/prog8lib/cx16/sprites.p8
+++ b/compiler/res/prog8lib/cx16/sprites.p8
@@ -34,6 +34,22 @@ sprites {
         cx16.vpoke(1, sprite_reg+7, height_flag<<6 | width_flag<<4 | palette_offset&15) ; 64x64 pixels, palette offset
     }
 
+    sub reset(ubyte spritenum_start, ubyte count)  {
+        ; resets all sprite attributes for the given sprite range
+        ; this removes these sprites from the screen completely
+        ; (without disabling sprites globally so the mouse cursor remains visible)
+        if spritenum_start > 127
+            return
+        if count + spritenum_start > 128
+            return
+        cx16.VERA_CTRL   = $00
+        cx16.VERA_ADDR_H = $11
+        cx16.VERA_ADDR   = VERA_SPRITEREGS + spritenum_start * $0008
+        repeat count {
+            unroll 8 cx16.VERA_DATA0 = $00
+        }
+    }
+
     sub data(ubyte spritenum, ubyte bank, uword addr) {
         addr >>= 5
         addr |= (bank as uword)<<11
diff --git a/docs/source/todo.rst b/docs/source/todo.rst
index 15ceea66a..dc2e9f2f5 100644
--- a/docs/source/todo.rst
+++ b/docs/source/todo.rst
@@ -2,6 +2,8 @@ TODO
 ====
 
 
+- make "block address must be at least program load address + 20 (to allow for startup logic)" more flexible;  the 20 should be a constant in the compilation target
+
 ...
 
 
diff --git a/examples/test.p8 b/examples/test.p8
index eebff9d94..47531cd53 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -1,12 +1,19 @@
+%import sprites
 %import textio
 %option no_sysinit
 %zeropage basicsafe
 
 main {
     sub start() {
-        txt.print_uwhex(sys.progstart(), true)
-        txt.spc()
-        txt.print_uwhex(sys.progend(), true)
-        txt.nl()
+        ubyte sprite
+
+        for sprite in 1 to 99 {
+            sys.wait(1)
+            sprites.init(sprite, 0, 0, sprites.SIZE_8, sprites.SIZE_8, sprites.COLORS_256, 0)
+            sprites.pos(sprite, 10 + sprite*10, 10+sprite*4)
+        }
+
+        sprites.reset(1, 100)
+
     }
 }