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https://github.com/imjasonh/nescript
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Pulse-channel sfx with a multi-byte `pitch:` array used to silently ignore everything past the first byte — the runtime audio tick latched the period at trigger time and never updated it. Programs that wanted a frequency sweep had no way to express it. The compiler now compiles a per-frame pitch envelope blob alongside the existing volume envelope when `decl.pitch` has more than one distinct value. The blob is padded (or truncated) to the volume envelope's length and ends in a zero sentinel so the runtime walker stops both pointers on the same NMI. Sfx with a single scalar pitch (or an array where every byte is the same) keep their historical "no pitch blob, latch once" path and emit byte-identical ROM bytes. The runtime gains two new pieces, both gated on a new `__sfx_pitch_used` codegen marker so programs without varying-pitch sfx pay zero bytes: 1. `gen_audio_tick` emits a per-frame pitch update block inside the SFX tick: read a byte through `(AUDIO_SFX_PITCH_PTR),Y`, write it to `$4002` (pulse-1 period low), advance the pointer. The block bails on a zero high-byte pointer so a single program can mix scalar-pitch and varying-pitch sfx without one clobbering the other. 2. `emit_play_pulse` seeds `AUDIO_SFX_PITCH_PTR_LO/HI` with the pitch-blob label for varying-pitch sfx and zeros it for scalar-pitch sfx. The per-call branch is skipped entirely when the program has no varying-pitch sfx anywhere. The new `examples/sfx_pitch_envelope.ne` exercises the path with a 16-frame siren sweep. Triangle and noise per-frame pitch are deferred — they share the same data shape but the runtime ticks for those channels still write only their volume registers, see docs/future-work.md for the gap. https://claude.ai/code/session_01KEczoNUX3WmcFLfq6iAQxB |
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| .. | ||
| arrays_and_functions.audio.hash | ||
| arrays_and_functions.png | ||
| audio_demo.audio.hash | ||
| audio_demo.png | ||
| bitwise_ops.audio.hash | ||
| bitwise_ops.png | ||
| bouncing_ball.audio.hash | ||
| bouncing_ball.png | ||
| coin_cavern.audio.hash | ||
| coin_cavern.png | ||
| comparisons.audio.hash | ||
| comparisons.png | ||
| friendly_assets.audio.hash | ||
| friendly_assets.png | ||
| function_chain.audio.hash | ||
| function_chain.png | ||
| hello_sprite.audio.hash | ||
| hello_sprite.png | ||
| inline_asm_demo.audio.hash | ||
| inline_asm_demo.png | ||
| logic_ops.audio.hash | ||
| logic_ops.png | ||
| loop_break_continue.audio.hash | ||
| loop_break_continue.png | ||
| match_demo.audio.hash | ||
| match_demo.png | ||
| mmc1_banked.audio.hash | ||
| mmc1_banked.png | ||
| mmc3_per_state_split.audio.hash | ||
| mmc3_per_state_split.png | ||
| nested_structs.audio.hash | ||
| nested_structs.png | ||
| noise_triangle_sfx.audio.hash | ||
| noise_triangle_sfx.png | ||
| palette_and_background.audio.hash | ||
| palette_and_background.png | ||
| platformer.audio.hash | ||
| platformer.png | ||
| scanline_split.audio.hash | ||
| scanline_split.png | ||
| sfx_pitch_envelope.audio.hash | ||
| sfx_pitch_envelope.png | ||
| sprites_and_palettes.audio.hash | ||
| sprites_and_palettes.png | ||
| state_machine.audio.hash | ||
| state_machine.png | ||
| structs_enums_for.audio.hash | ||
| structs_enums_for.png | ||
| two_player.audio.hash | ||
| two_player.png | ||
| uxrom_banked.audio.hash | ||
| uxrom_banked.png | ||
| uxrom_banked_to_banked.audio.hash | ||
| uxrom_banked_to_banked.png | ||
| uxrom_user_banked.audio.hash | ||
| uxrom_user_banked.png | ||
