fix(waveform): 4x-oversampled min/max envelope, columnMinMax homed in peaks, panel routed through shared drawWaveform — one gap-free algorithm on all surfaces

tests/test_waveform_view.cpp

@@ -7,8 +7,7 @@
 // markerAtPoint (grab band, first-match on overlap, off-area + null-array rejection);
 // resolveDragFrame (round-to-nearest-frame, clamp to [0,frameCount], zero-delta/zero-width
 // no-ops); nearestZeroCrossing (nearest sign-change, sample-on-zero, equidistant-tie-to-lower,
-// no-crossing keeps target, target clamp, degenerate buffers);
-// columnMinMax (per-pixel-column bin merge: 1:1, upsample, downsample, degenerate).
+// no-crossing keeps target, target clamp, degenerate buffers).
 
 #include "../src/vst/waveform_view.h"
 
@@ -17,8 +16,6 @@
 
 using namespace reasampler::vst;
 using reasampler::AudioSample;
-using reasampler::MinMax;
-using reasampler::ChannelEnvelope;
 
 static int g_fail = 0;
 #define CHECK(cond) do { if(!(cond)) { \
@@ -195,86 +192,6 @@ static void testZeroCrossingDegenerate() {
     CHECK(nearestZeroCrossing(one.data(), 1, 0) == 0);  // <2 frames -> clamped target
 }
 
-// --- columnMinMax -------------------------------------------------------------
-// Helpers: build a ChannelEnvelope from parallel min/max arrays.
-static ChannelEnvelope makeEnvelope(const std::vector<float>& mins,
-                                     const std::vector<float>& maxs) {
-    ChannelEnvelope env(mins.size());
-    for (std::size_t i = 0; i < mins.size(); ++i) {
-        env[i] = MinMax{mins[i], maxs[i]};
-    }
-    return env;
-}
-
-static void testColumnMinMaxOneToOne() {
-    // 4 bins, 4 pixel columns: each column maps exactly one bin.
-    ChannelEnvelope env = makeEnvelope({-1.0f, -0.5f, 0.0f, 0.5f},
-                                       { 0.5f,  0.0f, 0.5f, 1.0f});
-    // col 0 → bin 0, col 1 → bin 1, etc.
-    CHECK(columnMinMax(env, 4, 0).min == -1.0f && columnMinMax(env, 4, 0).max == 0.5f);
-    CHECK(columnMinMax(env, 4, 1).min == -0.5f && columnMinMax(env, 4, 1).max == 0.0f);
-    CHECK(columnMinMax(env, 4, 2).min ==  0.0f && columnMinMax(env, 4, 2).max == 0.5f);
-    CHECK(columnMinMax(env, 4, 3).min ==  0.5f && columnMinMax(env, 4, 3).max == 1.0f);
-}
-
-static void testColumnMinMaxUpsample() {
-    // 2 bins, 4 pixel columns: columns 0,1 map to bin 0; columns 2,3 map to bin 1.
-    // Verifies that upsampling (more columns than bins) returns the enclosing bin
-    // and does not leave any column empty.
-    ChannelEnvelope env = makeEnvelope({-1.0f, 0.5f}, {0.0f, 1.0f});
-    // col 0: (0*2)/4=0, (1*2)/4=0 -> empty range -> fallback bin 0.
-    CHECK(columnMinMax(env, 4, 0).min == -1.0f && columnMinMax(env, 4, 0).max == 0.0f);
-    CHECK(columnMinMax(env, 4, 1).min == -1.0f && columnMinMax(env, 4, 1).max == 0.0f);
-    CHECK(columnMinMax(env, 4, 2).min ==  0.5f && columnMinMax(env, 4, 2).max == 1.0f);
-    CHECK(columnMinMax(env, 4, 3).min ==  0.5f && columnMinMax(env, 4, 3).max == 1.0f);
-}
-
-static void testColumnMinMaxDownsample() {
-    // 4 bins, 2 pixel columns: each column merges 2 bins.
-    // col 0: bins [0,2) → min(-1,-0.5)=-1, max(0.5,0.0)=0.5.
-    // col 1: bins [2,4) → min(0.0,0.5)=0.0, max(0.5,1.0)=1.0.
-    ChannelEnvelope env = makeEnvelope({-1.0f, -0.5f, 0.0f, 0.5f},
-                                       { 0.5f,  0.0f, 0.5f, 1.0f});
-    CHECK(columnMinMax(env, 2, 0).min == -1.0f && columnMinMax(env, 2, 0).max == 0.5f);
-    CHECK(columnMinMax(env, 2, 1).min ==  0.0f && columnMinMax(env, 2, 1).max == 1.0f);
-}
-
-static void testColumnMinMaxColClamp() {
-    // col out of [0, innerW-1] is clamped: negative clamps to 0, >= innerW clamps to last.
-    ChannelEnvelope env = makeEnvelope({-0.5f, 0.5f}, {-0.1f, 0.9f});
-    CHECK(columnMinMax(env, 2, -5).min == -0.5f);   // clamps to col 0
-    CHECK(columnMinMax(env, 2, 999).max == 0.9f);   // clamps to col 1
-}
-
-static void testColumnMinMaxDegenerate() {
-    ChannelEnvelope empty;
-    // Empty envelope → {0, 0}.
-    MinMax z = columnMinMax(empty, 4, 0);
-    CHECK(z.min == 0.0f && z.max == 0.0f);
-
-    // innerW <= 0 → {0, 0}.
-    ChannelEnvelope env = makeEnvelope({0.3f}, {0.7f});
-    MinMax z2 = columnMinMax(env, 0, 0);
-    CHECK(z2.min == 0.0f && z2.max == 0.0f);
-    MinMax z3 = columnMinMax(env, -1, 0);
-    CHECK(z3.min == 0.0f && z3.max == 0.0f);
-}
-
-static void testColumnMinMaxFullCoverageNoBlanks() {
-    // The critical gap-free property: for any bins/innerW ratio, every pixel column
-    // in [0, innerW) returns a non-zero-width or valid result (no column is skipped).
-    // Use 6 bins over 10 pixel columns (non-integer ratio). Every column must return
-    // the min/max of at least one bin (not the default {0,0} that would indicate a gap).
-    ChannelEnvelope env = makeEnvelope({0.1f, 0.2f, 0.3f, 0.4f, 0.5f, 0.6f},
-                                       {0.2f, 0.3f, 0.4f, 0.5f, 0.6f, 0.7f});
-    for (int col = 0; col < 10; ++col) {
-        MinMax mm = columnMinMax(env, 10, col);
-        // Every column must have a real bin value, not zero (all bins have positive values).
-        CHECK(mm.min >= 0.1f && mm.max <= 0.7f);
-        CHECK(mm.min <= mm.max);
-    }
-}
-
 int main() {
     testFrameToXEndpoints();
     testFrameToXClampsOutOfRange();
@@ -300,13 +217,6 @@ int main() {
     testZeroCrossingClampsTarget();
     testZeroCrossingDegenerate();
 
-    testColumnMinMaxOneToOne();
-    testColumnMinMaxUpsample();
-    testColumnMinMaxDownsample();
-    testColumnMinMaxColClamp();
-    testColumnMinMaxDegenerate();
-    testColumnMinMaxFullCoverageNoBlanks();
-
     if (g_fail == 0) std::printf("waveform_view: all tests passed\n");
     else std::printf("waveform_view: %d FAILED\n", g_fail);
     return g_fail == 0 ? 0 : 1;