Removed MIX_AUDIO references + bugfix for SDL1 in audio callback

rbx need to be saved & restored

sdl.asm

 	%define SDL_QUIT 0x100
 	%define SDL_AUDIODEVICEADDED 0x1100
 %endif
-%ifdef MIX_AUDIO
-	Extern SDL_MixAudio
-	%define SDL_MAX_VOLUME 128
-%endif
 
 %define SDL_SWSURFACE 0
 

yaglitch.asm

 		event: resb 56
 		evt_cnt: resb 1
 	%endif
-	%ifdef MIX_AUDIO
-		cllbck_heap: resq 1
-		cllbck_heapsz: resw 1
-	%endif
 
 section .text
 global _start
 		;start audio
 		xor rdi, rdi
 		call SDL_PauseAudio
-%ifdef MIX_AUDIO
-	; init callback heap infos
-	mov rax, 0xc ; brk
-	xor rdi, rdi ; get heap start addr
-	mov [cllbck_heapsz], rdi
-	syscall
-	cmp rax, -1
-	je exit_fatal
-	mov [cllbck_heap], rax
-%endif
 
 loop_event:
 	xor rdi, rdi
 	je sdl_error ; error fetching event...
 	xor rdi, rdi
 	%ifdef SDL1
-			mov dil, [event]
+			mov dil, [event] ; 8bit evt
 			cmp dil, SDL_QUIT
 			je exit
 	%endif
 		add al, "A" - 10
 		ret
 
-%ifndef MIX_AUDIO
 ; simplest/shortes audio_callback : copy byte returned by run_glitch in *stream
 audio_cllbck:
 	; rdi -> *userdata
 	; rsi -> *stream
 	; rdx -> stream_len
-	%ifdef SDL2
-		push rbx ; strange, but nescessary...
-	%endif
+		push rbx ; stores rbx
 		mov rcx, rdx
 		mov rdi, rsi
 		.loop:
 			pop rcx
 			inc dword [t]
 			loop .loop
-	%ifdef SDL2
-		pop rbx ; if rbx change SDL2 segfault :/
-	%endif
+		pop rbx ; rbx restore
 		ret
-%endif
-%ifdef MIX_AUDIO
-; another version of the audio callback using heap to store the data
-; and SDL_MixAudio to copy data in *stream
-audio_cllbck:
-	; rdi -> *userdata
-	; rsi -> *stream
-	; rdx -> stream_len
-	push rbx
-	mov rcx, [cllbck_heapsz]
-	cmp rcx, rdx
-	jle .heap_brk
-	.continue:
-		mov rdi, [cllbck_heap]
-		push rdx ; len
-		push rdi
-		push rsi ; *stream, dst
-		mov rcx, rdx
-		.pop_loop: ; populating heap with glitch datas
-			push rcx
-			push rdi
-			call run_glitch
-			pop rdi
-			stosb
-			pop rcx
-			inc dword [t]
-			loop .pop_loop
-		pop rdi ; *stream
-		pop rsi ; heap_start
-		pop rdx ; len
-		mov rcx, SDL_MAX_VOLUME
-		pop rbx
-		ret
-	.heap_brk: ; resize heap to handle 
-		push rdi
-		push rsi
-		push rdx
-		mov rdi, [cllbck_heap]
-		add rdi, rdx
-		sub rdi, rcx
-		mov rax, 0xc ; brk
-		syscall
-		mov [cllbck_heap], rax
-		pop rdx
-		pop rsi
-		pop rdi
-		jmp .continue
-%endif
 
 run_glitch:
 	; Run the glitch_pgm