From 2f50827c3d2bb48e79f202cd084de08b5ad65732 Mon Sep 17 00:00:00 2001
From: "Juan J. Martinez" <jjm@usebox.net>
Date: Sat, 6 May 2023 12:06:02 +0100
Subject: Implement hardware blitter

---
 example.asm | 85 +++++++++++++++++--------------------------------------------
 1 file changed, 24 insertions(+), 61 deletions(-)

(limited to 'example.asm')

diff --git a/example.asm b/example.asm
index 2ab0ee7..cffef5e 100644
--- a/example.asm
+++ b/example.asm
@@ -61,71 +61,34 @@ int_handler:
     iret
 
 draw_sprite:
-    push y
-    ld y, 16
-    ld [sp + 0], y
+    ; blitter in settings mode
+    ld x, 128
+    ld a, 0xb0
+    port a, x
 
-    ; src
-    ld a, >sprite
-    ld x, <sprite
-
-    ; dst
-    ld b, 0xdb
-    ld y, 56
-line:
-    push x
-    ld x, [a : x]
-
-    ; any color with index > 15
-    ; is transparent
-    cmp x, 16
-    bnc
-    jmp transparent
-
-    ld [b : y], x
-
-transparent:
-    pop x
-
-    inc x
-    bo
+    ; setup
     inc a
-
-    inc y
-
-    push y
-    ld y, [sp + 1]
-    dec y
-    ld [sp + 1], y
-    pop y
-
-    bnz
-    jmp line
-
-    add y, 112
-    bo
-    inc b
-
-    cmp x, <end_sprite
-    bnz
-    jmp next_row
-    cmp a, >end_sprite
-    bz
-    jmp done
-
-next_row:
-    push y
-    ld y, 16
-    ld [sp + 1], y
-    pop y
-
-    jmp line
-
-done:
-    pop y
+    ; source
+    ld x, <sprite
+    port a, x
+    ld x, >sprite
+    port a, x
+    ; destination (56, 56)
+    ld x, 56
+    port a, x
+    port a, x
+    ; size 16x16
+    ld x, 16
+    port a, x
+    port a, x
+
+    ; now blit
+    dec a
+    ld x, 3
+    ; 3: write with transparent color support
+    port a, x
     ret
 
 sprite:
     .incpng "assets/icon.png"
-end_sprite:
 
-- 
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