L1: shared LICE drawing kit — theme/palette + component geometry + draw kit; retire GDI text in bank_panel

src/draw_kit.h

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+#pragma once
+// draw_kit — the LICE-facing SHELL half of the shared drawing kit (Phase L, L1). This is
+// the ONE source of drawing for the whole system: every surface (bank_panel now; the VST
+// editor + embed strip at L3) fills, buttons, rows, sliders, waveforms, and — above all —
+// draws TEXT through this kit, so a control looks identical everywhere because it is the
+// same kit function. It replaces the flat LICE_FillRect blocks and raw-GDI DrawTextA with
+// gradient/AA surfaces (the vwnd micro-gradient + inner highlight/shadow trick) and cached
+// anti-aliased text (LICE_CachedFont), honoring the interaction-state model.
+//
+// PURE/SHELL SPLIT (CLAUDE.md §load-bearing): this file is SHELL — it touches LICE and
+// SWELL (HFONT). All palette decisions come from the pure `theme` module (role -> KitColor);
+// all layout/hit-test from the pure `component_geometry` / mode_switch / etc. modules. This
+// file only turns those pure answers into LICE calls. It is DAW-verified, not unit-tested.
+//
+// FONT LIFECYCLE (owned here): the kit holds a small set of LICE_CachedFonts (title / label
+// / value-mono / micro). kitFontsInit() creates them once (from HFONTs handed off with
+// LICE_FONT_FLAG_OWNS_HFONT, so the cached font frees the HFONT itself — verified in
+// lice_text.h §SetFromHFont doc: "OWNS means LICE_IFont will clean up hfont on font change
+// or exit"). kitFontsShutdown() deletes the cached fonts. The consumer calls init on panel
+// open and shutdown on close/teardown. text() no-ops safely before init (defensive), so a
+// draw that races construction never crashes.
+//
+// DOUBLE-BUFFER DISCIPLINE (§3.5 "zero-jank"): every function here draws into the caller's
+// offscreen LICE_IBitmap; the caller BitBlt's once. Nothing here draws direct-to-DC.
+
+#include "component_geometry.h"  // KitBox / SliderGeometry — the pure geometry the shell draws
+#include "peaks.h"               // Envelope — the waveform primitive's input
+#include "theme.h"               // Role / InteractionState / KitColor / TextClass
+
+// LICE + SWELL types at the boundary (this is the shell half). Forward-declared where
+// possible to keep the header light; the .cpp includes the full LICE/SWELL headers.
+class LICE_IBitmap;
+
+namespace reasampler {
+
+// The kit's four cached fonts (§3.1 type scale). Consumers pass a Font to text() to pick
+// the size/weight; the kit maps it to the matching LICE_CachedFont.
+enum class Font {
+    Title,      // ~15px semibold — region titles, headings
+    Label,      // ~12px regular — labels, body
+    ValueMono,  // ~12px tabular/mono — numbers (dB/ms/notes) that must not jitter
+    Micro,      // ~10px dim — units, counts, keybinding sub-labels
+};
+
+// Horizontal text alignment for text(). Vertical is always centered in the rect (the kit's
+// single-line convention); a caller wanting multi-line composes rows itself.
+enum class Align { Left, Center, Right };
+
+// --- Font lifecycle (owned by the kit) ---------------------------------------
+
+// Creates the four cached fonts once. Idempotent: a second call before shutdown is a no-op
+// (the kit already holds live fonts). Safe to call on every panel open. Uses the platform
+// UI sans (Segoe UI) for title/label/micro and a tabular mono (Consolas) for value-mono;
+// the exact HFONT is created here, so a face change is a one-line edit. NO-OP-SAFE: if font
+// creation fails, text() degrades to drawing nothing rather than crashing.
+void kitFontsInit();
+
+// Deletes the cached fonts (which free their owned HFONTs — LICE_FONT_FLAG_OWNS_HFONT).
+// Idempotent. The consumer calls this on panel close / extension shutdown.
+void kitFontsShutdown();
+
+// --- Text (the single biggest "temple os -> modern" lever) -------------------
+
+// Draws a single line of AA cached-font text in `color` inside `box`, horizontally aligned
+// per `align` and vertically centered, clipped with an end-ellipsis. This REPLACES the
+// GDI SetTextColor + DrawText path. No-op (safe) before kitFontsInit() or on a null bitmap.
+void text(LICE_IBitmap* bmp, const KitBox& box, const char* str,
+          Font font, const KitColor& color, Align align);
+
+// Convenience overload: text in a palette ROLE's color (the common case — the shell almost
+// always wants text/primary or text/dim, not a raw color).
+void text(LICE_IBitmap* bmp, const KitBox& box, const char* str,
+          Font font, Role role, Align align);
+
+// --- Surfaces + components ----------------------------------------------------
+
+// The kit's foundational fill: a micro-gradient (a few percent lighter at the top, via
+// LICE_GradRect) plus a 1px inner top-highlight and bottom-shadow — the vwnd trick that
+// kills the flat look (§2.2). Every button/row/cell fills through this so elevation reads
+// without a border. `role` picks the surface color; `state` transforms it per the
+// interaction model (hover lightens, pressed darkens, disabled desaturates, etc.).
+void fillSurface(LICE_IBitmap* bmp, const KitBox& box, Role role, InteractionState state);
+
+// A rounded, gradient-filled button with the inner highlight/shadow and a centered label,
+// honoring the interaction state. `warn == true` swaps the surface to the warn role (for
+// byte-deleting verbs like prune/delete) — the only place warn is drawn. A degenerate box
+// is a no-op.
+void drawButton(LICE_IBitmap* bmp, const KitButtonBox& button, const char* label,
+                InteractionState state, bool warn);
+
+// A horizontal slider: the track groove, the accent-filled portion up to the handle, and
+// the handle (a raised knob honoring state — hover/dragging brighten it). `geom` is the
+// pure SliderGeometry the caller computed; the kit only draws it. Degenerate geom is a no-op.
+void drawSlider(LICE_IBitmap* bmp, const SliderGeometry& geom, InteractionState state);
+
+// A selectable list row: the row surface (rest/hover/active/focus via state), an optional
+// leading thumbnail area reserved at `thumbWidth` px (0 for none — the caller draws the
+// thumbnail into the returned-by-convention left inset), and a left-aligned label in the
+// remaining width. Focus draws a 1px text/primary ring distinct from the accent selection
+// fill. A degenerate row is a no-op.
+void drawListRow(LICE_IBitmap* bmp, const ListRowBox& row, const char* label,
+                 int thumbWidth, InteractionState state);
+
+// A waveform envelope drawn as a min/max column plot over the bg/panel surface: a midline
+// per channel and an accent vertical line per bin (the same shape the panel thumbnail
+// draws, lifted into the kit so the panel and the L3 editor waveform share it). `box` is
+// the draw region; `env` is the per-channel min/max envelope from peaks::computeEnvelope.
+// An empty env draws just the midline. The caller fills the surface first (or passes a box
+// already filled); this draws only the wave + midline.
+void drawWaveform(LICE_IBitmap* bmp, const KitBox& box, const Envelope& env);
+
+} // namespace reasampler