The span-selector panel was rendered directly onto the spectrum canvas
every frame via DrawSelf, doing ~30 TextWidth + ~11 TextOut Canvas calls.
On Cocoa these text ops are very expensive (~10.6 ms/frame, ~30% of a
core) and dominated DrawSpectrum.
Render the panel once into a per-pixel-alpha cache bitmap and only
composite it over the spectrum each frame; rebuild only when state
changes (rate, hover, hidden, bounds). The cache is built with the
two-background method (render over black and white, derive straight
alpha + color) so layered semi-transparent button fills and antialiased
text composite over the live spectrum exactly as before.
Cuts the overlay phase from ~10.6 ms to ~0.2 ms per frame; DrawSpectrum
drops ~13.8 ms -> ~2.7 ms. Mirrors the caching VfoOverlay already uses.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
On Cocoa the full-bitmap alpha-restore pass is unnecessary: Canvas
operations keep alpha at $FF and the cached grid background is opaque,
so removing it cuts a full-frame O(W*H) pass per spectrum frame with no
visual change (verified on macOS).
Kept under {$IFNDEF DARWIN} for Qt6/win32 (different drawing backends
may zero alpha on antialiased edges) until visually verified there.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
WaterfallView: drop per-frame TLazIntfImage + LoadFromIntfImage (device
bitmap recreation + full pixel-format conversion every frame). Write
pixels directly into the bitmap via BeginUpdate/ScanLine like
SpectrumView already does, with platform-native byte order (ARGB on
Cocoa, BGRA elsewhere).
Replace per-pixel float colorization with a 512-entry dB->color LUT
rebuilt only when WfLow/WfHigh/theme change beyond a small threshold.
Turn the bitmap itself into a ring buffer: each frame builds a single
new row and writes one ScanLine; scrolling is done at paint time via two
CopyRect calls. Removes both full-frame passes per frame (image memmove
+ buffer->bitmap copy), cutting per-frame cost from O(W*H) to O(W). TX
mode preserved by leaving out-of-span columns untouched in the row buf.
SpectrumView: rewrite the per-frame alpha-restore pass from a strided
per-byte loop to a sequential per-dword OR with the alpha mask
(bit-identical output, sequential memory access).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
On macOS Cocoa, TBitmap.pf32bit stores pixels in ARGB order
(byte0=A, byte1=R, byte2=G, byte3=B) rather than BGRA used on
Linux/Windows. All raw ScanLine pixel blending and channel mapping
is now guarded with { DARWIN} to use the correct offsets.
Also fix PortAudio library discovery on macOS: probe .dylib names
(including Homebrew paths) before falling through to .so/.dll.
