The 28/48/5 Rectangle delegates cost one dirty node + batch churn each
per frame on Qt's Metal path (QRhiMetal::setShaderResources per batch
is where the ~6x vs Linux lives). Each mode's Loader now instantiates
ONE ShaderEffect — one node, one draw call: heights go to scalar
uniforms (b0..bN) pushed in one JS pass per settle tick, bar/gap/
gradient geometry is computed in the fragment shader with the same
colors and 1px rounding as the Rectangle version. The pre-existing
Repeater delegates are kept verbatim as the fallback arm (software
renderer or shader-compile error — the renderer preference added in
#104 makes that arm user-reachable).
Runtime findings on Qt 6.11 (documented in the file header): inline
GLSL strings are dead (fragmentShader is a URL property), so shaders
are baked with qsb --glsl 440 --msl 12 and shipped under
qml/assets/shaders/ (auto-qrc); and the built-in default vertex stage
emits no qt_TexCoord0, so one explicit shared vertex shader is baked
alongside.
Verified: build + 204/204 tests + both QML audits; RFB (fallback arm,
all three modes live during playback); Xvfb/GL (shader arm, all three
modes, zero shader errors; QSG_VISUALIZE=batches shows one uniform
batch block for the strip).
km
vicrodh
9ce7ef4ca0