git.y1.nz

commit cf215fde947968e0220ee3436d17de9b8845132c
parent 1b2e703fe811b251dc964d3f1f9fc8fd80043b75
Author: Toxa <untoxa@mail.ru>
Date:   Fri, 16 Jul 2021 19:42:44 +0300

hide_sprites_range() and example

Diffstat:
M
gbdk-lib/examples/gb/metasprites/metasprites.c
2
+-
M
gbdk-lib/include/gb/metasprites.h
6
++++++
M
gbdk-lib/libc/gb/Makefile
2
+-
A
gbdk-lib/libc/gb/metasprites_hide_spr.s
68
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

4 files changed, 76 insertions(+), 2 deletions(-)
diff --git a/gbdk-lib/examples/gb/metasprites/metasprites.c b/gbdk-lib/examples/gb/metasprites/metasprites.c
@@ -127,7 +127,7 @@ void main(void) {
             };
 
         // Hide rest of the hardware sprites, because amount of sprites differ between animation frames.
-        for (uint8_t i = hiwater; i < 40; i++) shadow_OAM[i].y = 0;
+	hide_sprites_range(hiwater, 40);        
 
         // Y Axis: update velocity (reduce speed) if no U/D button pressed
         if (!(PosF & ACC_Y)) {
diff --git a/gbdk-lib/include/gb/metasprites.h b/gbdk-lib/include/gb/metasprites.h
@@ -95,6 +95,12 @@ static uint8_t __move_metasprite_hflip(uint8_t id, uint8_t x, uint8_t y);
 static uint8_t __move_metasprite_hvflip(uint8_t id, uint8_t x, uint8_t y);
 static void __hide_metasprite(uint8_t id);
 
+/**
+ * Hides all hardware sprites in range from <= X < to
+ * @param from start OAM index
+ * @param to finish OAM index
+ */ 
+void hide_sprites_range(UINT8 from, UINT8 to) __preserves_regs(b, c);
 
 /** Moves metasprite to the absolute position x and y
 
diff --git a/gbdk-lib/libc/gb/Makefile b/gbdk-lib/libc/gb/Makefile
@@ -31,7 +31,7 @@ ASSRC =	cgb.s cgb_palettes.s cgb_compat.s \
 	mode.s clock.s \
 	get_t.s set_t.s init_vram.s \
 	fill_rect.s fill_rect_bk.s fill_rect_wi.s \
-	metasprites.s metasprites_flip.s metasprites_hide.s \
+	metasprites.s metasprites_flip.s metasprites_hide.s metasprites_hide_spr.s \
 	set_tile_submap.s set_win_tile_submap.s \
 	gb_decompress.s gb_decompress_tiles.s \
 	heap.s \
diff --git a/gbdk-lib/libc/gb/metasprites_hide_spr.s b/gbdk-lib/libc/gb/metasprites_hide_spr.s
@@ -0,0 +1,68 @@
+        .include    "global.s"
+
+        .title  "Metasprites"
+        .module Metasprites
+
+        .globl  ___render_shadow_OAM
+
+        .area   _CODE
+
+; void hide_sprites_range(UINT8 from, UINT8 to)
+
+_hide_sprites_range::
+        ldhl    sp, #2
+        ld      a, (hl+)
+
+        add     a
+        add     a
+        ld      e, a
+
+        ld      a, (hl-)
+        sub     (hl)
+
+        ret     c
+        ret     z
+
+        ld      hl, #___render_shadow_OAM
+        ld      h, (hl)
+        ld      l, e
+
+        ld      de, #4
+
+        rra                     ; carry is never set here, because of ret c above
+        jr      nc, 0$
+
+        ld      (hl), d
+        add     hl, de
+
+        ret     z               ; z is not affected by 16-bit add
+
+0$:
+        rra                     ; carry is never set here, because of ret c above
+        jr      nc, 1$
+
+        ld      (hl), d
+        add     hl, de
+
+        ld      (hl), d
+        add     hl, de
+
+        ret     z               ; z is not affected by 16-bit add
+
+1$:
+        ld      (hl), d
+        add     hl, de
+
+        ld      (hl), d
+        add     hl, de
+
+        ld      (hl), d
+        add     hl, de
+
+        ld      (hl), d
+        add     hl, de
+
+        dec     a
+        jr      nz, 1$
+
+        ret

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