Playground

Potential example game.

5 files changed, 401 insertions, 0 deletions

diff --git a/game/Makefile b/game/Makefile
new file mode 100644
index 0000000..9014844
--- /dev/null
+++ b/game/Makefile
@@ -0,0 +1,15 @@
+
+BIN	:= game.tr8
+SRCS	:= $(wildcard *.asm) $(wildcard assets/*.png)
+
+game.tr8: $(SRCS)
+	../tr8as main.asm $(BIN)
+
+run: $(BIN)
+	../tr8vm $<
+
+clean:
+	rm -f $(BIN)
+
+.PHONY: clean run
+
diff --git a/game/assets/player.png b/game/assets/player.png
new file mode 100644
index 0000000..13b7242
--- /dev/null
+++ b/game/assets/player.png
diff --git a/game/entities.asm b/game/entities.asm
new file mode 100644
index 0000000..fa9d8fd
--- /dev/null
+++ b/game/entities.asm
@@ -0,0 +1,263 @@
+;
+; Simple array based entity system
+;
+
+.equ ET_NONE    0
+.equ ET_PLAYER  1
+.equ ET_ENEMY   2
+.equ ET_END     0xff
+
+.equ ET_BG      0xa000
+
+entities_erase:
+    ; bg is stored in ET_BG addr
+    ld b, >ET_BG
+    push b
+
+    ld x, <entities
+    ld a, >entities
+
+entities_erase_next:
+    ld y, [a : x]
+    cmp y, ET_END
+    bz
+    jmp entities_erase_done
+
+    ; write, no transparent
+    ld y, 1
+    push y
+
+    ; dst: x
+    inc x
+    bo
+    inc a
+    ld y, [a : x]
+    push y
+
+    ; dst: y
+    inc x
+    bo
+    inc a
+    ld y, [a : x]
+    push y
+
+    ; src: saved bg
+    ld y, [sp + 3]
+    push y
+    ld y, 0
+    push y
+
+    call entities_blt
+
+    pop y
+    pop y
+    pop y
+    pop y
+    pop y
+
+    ; next entity
+    add x, 5
+    bo
+    inc a
+
+    pop b
+    inc b
+    push b
+
+    jmp entities_erase_next
+
+entities_erase_done:
+    pop a
+    ret
+
+entities_update:
+    ld x, <entities
+    ld a, >entities
+
+entities_update_next:
+    ld y, [a : x]
+    cmp y, ET_END
+    bz
+    ret
+
+    push a
+    push x
+
+    add x, 5
+    bo
+    inc a
+
+    ld y, [a : x]
+    inc x
+    bo
+    inc a
+    ld b, [a : x]
+    inc x
+    bo
+    inc a
+
+    ld x, [sp + 0]
+    ld a, [sp + 1]
+
+    ; entity update
+    push a
+    push x
+    call [b : y]
+    pop x
+    pop x
+
+    pop x
+    pop a
+
+    add x, 7
+    bo
+    inc a
+
+    jmp entities_update_next
+
+entities_draw:
+    ; bg is stored in ET_BG addr
+    ld b, >ET_BG
+    push b
+
+    ld x, <entities
+    ld a, >entities
+
+entities_draw_next:
+    ld y, [a : x]
+    cmp y, ET_END
+    bz
+    jmp entities_draw_done
+
+    inc x
+    bo
+    inc a
+    ; save x addr for later
+    push a
+    push x
+
+    ; save bg
+
+    ; read, no transparent
+    ld y, 4
+    push y
+
+    ; dst: x
+    ld y, [a : x]
+    push y
+
+    ; dst: y
+    inc x
+    bo
+    inc a
+    ld y, [a : x]
+    push y
+
+    ; dst: save bg
+    ld y, [sp + 5]
+    push y
+    ld y, 0
+    push y
+
+    call entities_blt
+
+    pop y
+    pop y
+    pop y
+    pop y
+    pop y
+
+    ; draw sprite
+
+    ; x addr
+    pop x
+    pop a
+
+    ; write, transparent
+    ld y, 3
+    push y
+
+    ; dst: x
+    ld y, [a : x]
+    push y
+
+    ; dst: y
+    inc x
+    bo
+    inc a
+    ld y, [a : x]
+    push y
+
+    ; src: the sprite
+    inc x
+    bo
+    inc a
+    ld y, [a : x]
+    inc x
+    bo
+    inc a
+    ld b, [a : x]
+    push b
+    push y
+
+    call entities_blt
+
+    pop y
+    pop y
+    pop y
+    pop y
+    pop y
+
+    ; next entity
+    add x, 3
+    bo
+    inc a
+
+    pop b
+    inc b
+    push b
+
+    jmp entities_draw_next
+
+entities_draw_done:
+    pop a
+    ret
+
+; sp: write mode
+;     y coord
+;     x coord
+;     addr
+entities_blt:
+    ; settings mode
+    ld y, 128
+    ld b, 0xb0
+    port b, y
+
+    ; setup
+    inc b
+
+    ; addr
+    ld y, [sp + 2]
+    port b, y
+    ld y, [sp + 3]
+    port b, y
+
+    ; x
+    ld y, [sp + 5]
+    port b, y
+    ; y
+    ld y, [sp + 4]
+    port b, y
+
+    ; 16x16
+    ld y, 16
+    port b, y
+    port b, y
+
+    ; blit
+    dec b
+    ; write mode
+    ld y, [sp + 6]
+    port b, y
+    ret
+
diff --git a/game/main.asm b/game/main.asm
new file mode 100644
index 0000000..3062ead
--- /dev/null
+++ b/game/main.asm
@@ -0,0 +1,75 @@
+.org 0
+
+.equ INT_VECTOR 0xff00
+
+    call init
+
+game_loop:
+    halt
+
+    call entities_erase
+    call entities_update
+    call entities_draw
+
+    jmp game_loop
+
+init:
+    ; setup an int handler so we
+    ; can use the frame int to sync
+    ld a, >INT_VECTOR
+    ld x, <INT_VECTOR
+    ld b, <int_handler
+    ld [a : x], b
+    inc x
+    ld b, >int_handler
+    ld [a : x], b
+
+    ; enable interrupts
+    cif
+
+    halt
+
+    ; pattern for the BG
+    ld b, 15
+    ld a, 0xbf
+    ld x, 0
+    ld y, 0x40
+fill_loop:
+    ld [a : x], b
+    xor b, 5
+    inc x
+    bno
+    jmp fill_loop
+    inc a
+    dec y
+    bnz
+    jmp fill_loop
+
+    call entities_draw
+
+    ret
+
+int_handler:
+    iret
+
+.include "entities.asm"
+.include "player.asm"
+
+;
+; entity data
+;
+entities:
+    ; type
+    .db ET_PLAYER
+    ; x, y
+    .db 0, 0
+    .dw player_sprite
+    .dw player_update
+
+    ; end of list
+    .db ET_END
+
+; sprite data
+player_sprite:
+    .incpng "assets/player.png"
+
diff --git a/game/player.asm b/game/player.asm
new file mode 100644
index 0000000..4a6537f
--- /dev/null
+++ b/game/player.asm
@@ -0,0 +1,48 @@
+;
+; player update code
+;
+
+player_update:
+    ld x, [sp + 2]
+    ld a, [sp + 3]
+
+    ; read controller 1
+    ld b, 0xf0
+    port b, b
+
+    inc x
+    bo
+    inc a
+    ; x coord
+    ld y, [a : x]
+
+    ; left
+    bit b, 4
+    bz
+    dec y
+    ; right
+    bit b, 5
+    bz
+    inc y
+
+    ld [a : x], y
+
+    inc x
+    bo
+    inc a
+    ; y coord
+    ld y, [a : x]
+
+    ; up
+    bit b, 2
+    bz
+    dec y
+    ; down
+    bit b, 3
+    bz
+    inc y
+
+    ld [a : x], y
+
+    ret
+