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311 | ; @file
; @ingroup ixlib
; @brief Hand-written software sample mixer.
;
; Address range 446f74-4471ff, originally assembled as a separate object.
; The retail routine uses MASM's D1 shift-by-one encodings and short
; branches. INT3 fill before it aligns the object to four bytes.
; Keep the C++ names of the shared state; the callable entry uses C linkage.
.386
.model flat, c
option casemap:none
extern syscall ?aVoices@@3PAUIxVoice@@A:byte
extern syscall ?nVoiceCount@@3HA:dword
extern syscall ?nStreamCount@@3HA:dword
public ix_dspv_mix
.code
; Function start: 0x00446F74
; void ix_dspv_mix(void *outputBuffer, unsigned int outputBytes);
ix_dspv_mix proc
push ebp
mov ebp, esp
push eax
push ebx
push ecx
push edx
push esi
push edi
mov eax, 0
mov edi, dword ptr [ebp + 8]
mov ecx, dword ptr [ebp + 0Ch]
shr ecx, 2
rep stosd
mov ebx, offset ?aVoices@@3PAUIxVoice@@A
mov ecx, dword ptr [?nVoiceCount@@3HA]
add ecx, dword ptr [?nStreamCount@@3HA]
voice_loop:
mov eax, dword ptr [ebx]
test eax, 2
jz next_voice
push ecx
mov edi, dword ptr [ebp + 8]
mov ecx, dword ptr [ebp + 0Ch]
shr ecx, 2
mov esi, dword ptr [ebx + 4]
test eax, 8
jnz mix_16bit
test eax, 10h
jnz mix_8bit_stereo
mix_8bit_mono_sample:
mov al, byte ptr [esi]
mov dl, al
imul byte ptr [ebx + 17h]
rol eax, 10h
mov al, dl
imul byte ptr [ebx + 16h]
mix_8bit_mono_accumulate:
mov edx, dword ptr [edi]
add ax, dx
jno mix_8bit_mono_left_done
jnc mix_8bit_mono_left_positive
mov ax, 8000h
jmp mix_8bit_mono_left_done
mix_8bit_mono_left_positive:
mov ax, 7FFFh
mix_8bit_mono_left_done:
ror eax, 10h
ror edx, 10h
add ax, dx
jno mix_8bit_mono_right_done
jnc mix_8bit_mono_right_positive
mov ax, 8000h
jmp mix_8bit_mono_right_done
mix_8bit_mono_right_positive:
mov ax, 7FFFh
mix_8bit_mono_right_done:
rol eax, 10h
mov dword ptr [edi], eax
add edi, 4
dec ecx
jz voice_done
mov edx, 0
mov dx, word ptr [ebx + 10h]
add dx, word ptr [ebx + 12h]
mov word ptr [ebx + 10h], dx
and word ptr [ebx + 10h], 0FFh
shr dx, 8
jz mix_8bit_mono_accumulate
add esi, edx
cmp esi, dword ptr [ebx + 0Ch]
jl mix_8bit_mono_sample
test dword ptr [ebx], 4
jz stop_voice
mov esi, dword ptr [ebx + 8]
jmp mix_8bit_mono_sample
mix_8bit_stereo:
cmp esi, dword ptr [ebx + 0Ch]
jge mix_8bit_stereo_at_end
mix_8bit_stereo_sample:
mov al, byte ptr [esi + 1]
imul byte ptr [ebx + 17h]
rol eax, 10h
mov al, byte ptr [esi]
imul byte ptr [ebx + 16h]
mix_8bit_stereo_accumulate:
mov edx, dword ptr [edi]
add ax, dx
jno mix_8bit_stereo_left_done
jnc mix_8bit_stereo_left_positive
mov ax, 8000h
jmp mix_8bit_stereo_left_done
mix_8bit_stereo_left_positive:
mov ax, 7FFFh
mix_8bit_stereo_left_done:
ror eax, 10h
ror edx, 10h
add ax, dx
jno mix_8bit_stereo_right_done
jnc mix_8bit_stereo_right_positive
mov ax, 8000h
jmp mix_8bit_stereo_right_done
mix_8bit_stereo_right_positive:
mov ax, 7FFFh
mix_8bit_stereo_right_done:
rol eax, 10h
mov dword ptr [edi], eax
add edi, 4
dec ecx
jz voice_done
mov edx, 0
mov dx, word ptr [ebx + 10h]
add dx, word ptr [ebx + 12h]
mov word ptr [ebx + 10h], dx
and word ptr [ebx + 10h], 0FFh
shr dx, 8
jz mix_8bit_stereo_accumulate
shl dx, 1
add esi, edx
jmp mix_8bit_stereo
mix_8bit_stereo_at_end:
test dword ptr [ebx], 4
jz stop_voice
mov esi, dword ptr [ebx + 8]
jmp mix_8bit_stereo_sample
mix_16bit:
test eax, 10h
jnz mix_16bit_stereo
mix_16bit_mono:
cmp esi, dword ptr [ebx + 0Ch]
jge mix_16bit_mono_at_end
mix_16bit_mono_sample:
mov ax, word ptr [esi]
push ax
imul word ptr [ebx + 1Ah]
mov ax, dx
rol eax, 10h
pop ax
imul word ptr [ebx + 18h]
mov ax, dx
mix_16bit_mono_accumulate:
mov edx, dword ptr [edi]
add ax, dx
jno mix_16bit_mono_left_done
jnc mix_16bit_mono_left_positive
mov ax, 8000h
jmp mix_16bit_mono_left_done
mix_16bit_mono_left_positive:
mov ax, 7FFFh
mix_16bit_mono_left_done:
ror eax, 10h
ror edx, 10h
add ax, dx
jno mix_16bit_mono_right_done
jnc mix_16bit_mono_right_positive
mov ax, 8000h
jmp mix_16bit_mono_right_done
mix_16bit_mono_right_positive:
mov ax, 7FFFh
mix_16bit_mono_right_done:
rol eax, 10h
mov dword ptr [edi], eax
add edi, 4
dec ecx
jz voice_done
mov edx, 0
mov dx, word ptr [ebx + 10h]
add dx, word ptr [ebx + 12h]
mov word ptr [ebx + 10h], dx
and word ptr [ebx + 10h], 0FFh
shr dx, 8
jz mix_16bit_mono_accumulate
shl dx, 1
add esi, edx
jmp mix_16bit_mono
mix_16bit_mono_at_end:
test dword ptr [ebx], 4
jz stop_voice
mov esi, dword ptr [ebx + 8]
jmp mix_16bit_mono_sample
mix_16bit_stereo:
cmp esi, dword ptr [ebx + 0Ch]
jge mix_16bit_stereo_at_end
mix_16bit_stereo_sample:
mov ax, word ptr [esi + 2]
imul word ptr [ebx + 1Ah]
mov ax, dx
rol eax, 10h
mov ax, word ptr [esi]
imul word ptr [ebx + 18h]
mov ax, dx
mix_16bit_stereo_accumulate:
mov edx, dword ptr [edi]
add ax, dx
jno mix_16bit_stereo_left_done
jnc mix_16bit_stereo_left_positive
mov ax, 8000h
jmp mix_16bit_stereo_left_done
mix_16bit_stereo_left_positive:
mov ax, 7FFFh
mix_16bit_stereo_left_done:
ror eax, 10h
ror edx, 10h
add ax, dx
jno mix_16bit_stereo_right_done
jnc mix_16bit_stereo_right_positive
mov ax, 8000h
jmp mix_16bit_stereo_right_done
mix_16bit_stereo_right_positive:
mov ax, 7FFFh
mix_16bit_stereo_right_done:
rol eax, 10h
mov dword ptr [edi], eax
add edi, 4
dec ecx
jz voice_done
mov edx, 0
mov dx, word ptr [ebx + 10h]
add dx, word ptr [ebx + 12h]
mov word ptr [ebx + 10h], dx
and word ptr [ebx + 10h], 0FFh
shr dx, 8
jz mix_16bit_stereo_accumulate
shl dx, 2
add esi, edx
jmp mix_16bit_stereo
mix_16bit_stereo_at_end:
test dword ptr [ebx], 4
jz stop_voice
mov esi, dword ptr [ebx + 8]
jmp mix_16bit_stereo_sample
stop_voice:
and dword ptr [ebx], 0FFFFFFFDh
voice_done:
mov dword ptr [ebx + 4], esi
pop ecx
next_voice:
dec ecx
jz mix_done
lea ebx, [ebx + 20h]
jmp voice_loop
mix_done:
pop edi
pop esi
pop edx
pop ecx
pop ebx
pop eax
leave
ret
ix_dspv_mix endp
end
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