1 files changed, 13 insertions, 16 deletions

diff --git a/tools/spectral_editor/script.js b/tools/spectral_editor/script.js
index 024005e..7c424f9 100644
--- a/tools/spectral_editor/script.js
+++ b/tools/spectral_editor/script.js
@@ -867,28 +867,20 @@ function onCanvasWheel(e) {
 
     // Zoom mode: Ctrl/Cmd + wheel
     if (e.ctrlKey || e.metaKey) {
-        // Calculate frame and frequency under cursor BEFORE zoom
+        // Calculate frame under cursor BEFORE zoom
         const frameUnderCursor = (mouseX + state.viewportOffsetX) / state.pixelsPerFrame;
-        const freqUnderCursor = (mouseY + state.viewportOffsetY) / state.pixelsPerBin;
 
-        // Calculate new zoom level
+        // Calculate new zoom level (horizontal only - logarithmic frequency axis doesn't zoom)
         const zoomFactor = e.deltaY > 0 ? 0.9 : 1.1;  // Wheel down = zoom out, wheel up = zoom in
-        const oldPixelsPerFrame = state.pixelsPerFrame;
-        const oldPixelsPerBin = state.pixelsPerBin;
-
         state.pixelsPerFrame = Math.max(0.5, Math.min(20.0, state.pixelsPerFrame * zoomFactor));
-        state.pixelsPerBin = Math.max(0.1, Math.min(5.0, state.pixelsPerBin * zoomFactor));
 
-        // Adjust viewport offset so frame/freq under cursor stays in same screen position
+        // Adjust viewport offset so frame under cursor stays in same screen position
         // After zoom: new_offset = frame * newPixelsPerFrame - mouseX
         state.viewportOffsetX = frameUnderCursor * state.pixelsPerFrame - mouseX;
-        state.viewportOffsetY = freqUnderCursor * state.pixelsPerBin - mouseY;
 
         // Clamp viewport offset to valid range
         const maxOffsetX = Math.max(0, state.referenceNumFrames * state.pixelsPerFrame - state.canvasWidth);
-        const maxOffsetY = Math.max(0, DCT_SIZE * state.pixelsPerBin - state.canvasHeight);
         state.viewportOffsetX = Math.max(0, Math.min(maxOffsetX, state.viewportOffsetX));
-        state.viewportOffsetY = Math.max(0, Math.min(maxOffsetY, state.viewportOffsetY));
 
         render();
         return;
@@ -903,11 +895,16 @@ function onCanvasWheel(e) {
         return;
     }
 
-    // Normal mode: pan vertically
-    state.viewportOffsetY += e.deltaY;
-    const maxOffsetY = Math.max(0, DCT_SIZE * state.pixelsPerBin - state.canvasHeight);
-    state.viewportOffsetY = Math.max(0, Math.min(maxOffsetY, state.viewportOffsetY));
-    render();
+    // Normal mode: pan vertically (disabled for logarithmic frequency axis)
+    // Note: With logarithmic frequency scale, vertical pan doesn't make sense
+    // because the frequency range (FREQ_MIN to FREQ_MAX) is always scaled to fit canvas height.
+    // Vertical pan only works in linear frequency mode.
+    if (!USE_LOG_SCALE) {
+        state.viewportOffsetY += e.deltaY;
+        const maxOffsetY = Math.max(0, DCT_SIZE * state.pixelsPerBin - state.canvasHeight);
+        state.viewportOffsetY = Math.max(0, Math.min(maxOffsetY, state.viewportOffsetY));
+        render();
+    }
 }
 
 // ============================================================================