mirror of
https://github.com/irmen/prog8.git
synced 2024-11-23 07:32:10 +00:00
81 lines
3.1 KiB
Plaintext
81 lines
3.1 KiB
Plaintext
;...........
|
|
; init_pcm :
|
|
; ===========================================================================
|
|
; Arguments: (none)
|
|
; Returns: (none)
|
|
; Affects: A
|
|
; ---------------------------------------------------------------------------
|
|
; Call this before using any of the other routines.
|
|
;
|
|
; Initializes the memory locations used by PCMM player to a stopped playback
|
|
; state, sets VERA playback rate to 0 (disabled) and clears the PCM FIFO
|
|
; also sets the volume to 15 (F).
|
|
|
|
|
|
;...........
|
|
; play_pcm :
|
|
; ===========================================================================
|
|
; Arguments: (none)
|
|
; Returns: (none)
|
|
; Affects: A,X,Y
|
|
; ---------------------------------------------------------------------------
|
|
; Call this once per frame to ensure that the PCM samples are being fed
|
|
; into VERA's PCM FIFO. While this routine is technically IRQ-safe, it is
|
|
; recommended that it not be executed during the VSYNC IRQ, as higher
|
|
; quality sample streams can consume up to ~30k CPU cycles to process.
|
|
;
|
|
; Consistent, jitter-free low-latency playback can be assured using a line IRQ
|
|
;
|
|
; If using ZSM player module, it is recommended that this call happen after
|
|
; the ZSM player's update function (playmusic) so that any PCM events will
|
|
; be processed on the same frame.
|
|
|
|
;...........
|
|
; stop_pcm :
|
|
; ===========================================================================
|
|
; Arguments: (none)
|
|
; Returns: (none)
|
|
; Affects: A
|
|
; ---------------------------------------------------------------------------
|
|
; Disables PCM playback in VERA_audio_rate register, clears the FIFO, and
|
|
; sets the PCM player module's status to clear.
|
|
|
|
;.............
|
|
; start_digi :
|
|
; ===========================================================================
|
|
; Arguments: Pointer to digi parameter table in memory.
|
|
; .A = RAM bank
|
|
; .XY = Memory address
|
|
; Returns: none
|
|
; Affects: none
|
|
; ---------------------------------------------------------------------------
|
|
; Documentation and terminology in Zsound uses the term "digi" to refer to
|
|
; a digital audio clip, as the term "sample" also refers to an individual
|
|
; PCM sample. Thus "digi" disambiguates between the two.
|
|
;
|
|
; start_digi expects a pointer to a digi parameter table in memory (low or
|
|
; high memory are both acceptable locations. If in Hi memory, the table
|
|
; must exist entirely within the same bank.
|
|
;
|
|
; The table's contents are the same as the DIGITAB struct at the
|
|
; beginning of this inc file.
|
|
;
|
|
; note that start_digi is a one-shot call to trigger a digi. There is
|
|
; currently no infrastructure to make callbacks at the end of a digi's
|
|
; playback, or any granular controls to modify a playback in progress
|
|
; such as volume changes, etc.
|
|
;
|
|
; In the future, more granular controls are planned, but the exact
|
|
; nature and functionality are as yet to be determined.
|
|
|
|
;.................
|
|
; set_pcm_volume :
|
|
; ===========================================================================
|
|
; Arguments: Pointer to digi parameter table in memory.
|
|
; .A = new volume level (only the 4 LSB are used)
|
|
;
|
|
; Returns: none
|
|
; Affects: none
|
|
; ---------------------------------------------------------------------------
|
|
; Sets the PCM volume level 0..F
|