1 files changed, 88 insertions, 0 deletions
diff --git a/scroll/include/player.s b/scroll/include/player.s
new file mode 100644
index 0000000..95d710d
--- /dev/null
+++ b/scroll/include/player.s
@@ -0,0 +1,88 @@
+;; This is the player code that gets re-used on all scrolling examples. This
+;; will show a meta-sprite made up of four sprites that make up diskun. You can
+;; move this player with the arrows, and the movement will be pretty basic (1
+;; pixel each time). Furthermore, the sprite handles collision with background
+;; elements (TODO), which is shared across all the scrolling examples.
+;;
+;; The sprite is stored in OAM memory $200-$20F, and the $30 and $31 memory
+;; addresses are used for keeping up with the screen coordinates.
+.scope Player
+    m_screen_x = $30
+    m_screen_y = $31
+
+    .proc init
+        lda #40
+        sta m_screen_x
+        sta m_screen_y
+
+        lda #$01
+        sta $201
+        lda #$02
+        sta $205
+        lda #$11
+        sta $209
+        lda #$12
+        sta $20D
+
+        lda #0
+        sta $202
+        sta $206
+        sta $20A
+        sta $20E
+
+        rts
+    .endproc
+
+    .proc update
+        jsr update_coordinates
+        jsr update_sprites
+        rts
+    .endproc
+
+    .proc update_coordinates
+        lda #Joypad::BUTTON_UP
+        and Joypad::m_buttons1
+        beq @check_down
+        dec m_screen_y
+        jmp @check_left
+    @check_down:
+        lda #Joypad::BUTTON_DOWN
+        and Joypad::m_buttons1
+        beq @check_left
+        inc m_screen_y
+    @check_left:
+        lda #Joypad::BUTTON_LEFT
+        and Joypad::m_buttons1
+        beq @check_right
+        dec m_screen_x
+        rts
+    @check_right:
+        lda #Joypad::BUTTON_RIGHT
+        and Joypad::m_buttons1
+        beq @end
+        inc m_screen_x
+    ;; TODO: move scroll
+    @end:
+        rts
+    .endproc
+
+    .proc update_sprites
+        lda m_screen_x
+        sta $203
+        sta $20B
+        clc
+        adc #8
+        sta $207
+        sta $20F
+
+        lda m_screen_y
+        sta $200
+        sta $204
+        clc
+        adc #8
+        sta $208
+        sta $20C
+
+        rts
+    .endproc
+.endscope