add input

3 files changed, 81 insertions, 23 deletions

diff --git a/Makefile b/Makefile
index 2d93a73..981bed2 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,8 @@ main: main.asm border.asm utils.asm
 	nasm -f elf64 -g main.asm -o build/main.o
 	nasm -f elf64 -g border.asm -o build/border.o
 	nasm -f elf64 -g utils.asm -o build/utils.o
-	ld build/main.o build/border.o build/utils.o -o main
+	nasm -f elf64 -g input.asm -o build/input.o
+	ld build/main.o build/border.o build/utils.o build/input.o -o main
 
 clean:
 	rm -r main build/
diff --git a/input.asm b/input.asm
new file mode 100644
index 0000000..b80b509
--- /dev/null
+++ b/input.asm
@@ -0,0 +1,47 @@
+section .bss
+    input_buffer resb 1
+
+section .text
+    global input
+    extern direction
+    extern exit
+
+input:
+    call read_input
+    call handle_input
+    ret
+
+handle_input:
+    mov al, byte [input_buffer]
+    cmp al, 'w'
+    je _input_up
+    cmp al, 's'
+    je _input_down
+    cmp al, 'a'
+    je _input_left
+    cmp al, 'd'
+    je _input_right
+    cmp al, 27 ; escape
+    je exit
+    ret
+
+_input_up:
+    mov byte [direction], 3
+    ret
+_input_down:
+    mov byte [direction], 1
+    ret
+_input_left:
+    mov byte [direction], 2
+    ret
+_input_right:
+    mov byte [direction], 0
+    ret
+
+read_input:
+    mov rax, 0           
+    mov rdi, 0           
+    mov rsi, input_buffer
+    mov rdx, 1          
+    syscall
+    ret
diff --git a/main.asm b/main.asm
index 1ba1eb5..d0e1e3a 100644
--- a/main.asm
+++ b/main.asm
@@ -15,14 +15,12 @@ section .data
     ;   3
     ; 2 x 0
     ;   1
+    global direction
     direction db 0
 
     timespec dq 0 
              dq 500000000
 
-section .bss
-    buffer resb 1
-
 section .rodata
     ; width and height of the playable area
     ; (without the borders)
@@ -32,6 +30,7 @@ section .rodata
     height db 30
 
 section .text
+    extern input
     extern draw_border
     extern write_byte
     extern clear_screen
@@ -39,6 +38,7 @@ section .text
     extern move_cursor_right
     extern move_cursor_down
     global _start 
+    global exit
 
 draw_snake:
     push rbx
@@ -62,6 +62,30 @@ _11:call move_cursor_down
     call reset_cursor
     ret
 
+move_snake:
+    cmp byte [direction], 0
+    je _move_right
+    cmp byte [direction], 1
+    je _move_down
+    cmp byte [direction], 2
+    je _move_left
+    cmp byte [direction], 3
+    je _move_up
+    ret
+
+_move_right:
+    inc byte [snake]
+    ret
+_move_down:
+    inc byte [snake+1]
+    ret
+_move_left:
+    dec byte [snake]
+    ret
+_move_up:
+    dec byte [snake+1]
+    ret
+
 _start:
     mov byte [snake], 5
     mov byte [snake+1], 5
@@ -71,30 +95,16 @@ main_loop:
     call draw_border
     call draw_snake
 
-    lea rdi, [timespec]    ; Pointer to timespec struct (rdi)
-    xor rsi, rsi           ; NULL (no remaining time)
-    mov rax, 35            ; Syscall number for nanosleep
+    mov rax, 35            
+    lea rdi, [timespec]   
+    xor rsi, rsi           
     syscall
 
-    inc byte [snake]
+    call input
+    call move_snake
 
     jmp main_loop
 
-;    mov rax, 0           ; Syscall for read
-;    mov rdi, 0           ; stdin
-;    mov rsi, buffer      ; Address of the buffer
-;    mov rdx, 1           ; Read 1 byte
-;    syscall
-
-    ; If a key was pressed, store it in `input`
-;    test rax, rax        ; Check if any input was received
-;    jz exit         ; If no input, skip
-
-
-;    mov al, byte [buffer]; Load the input character
-    ;mov rax, 'x'
-;    call write_byte
-
 exit: ; exit syscall with return code 0
     mov rax, 60                     
     xor rdi, rdi