1 files changed, 45 insertions, 3 deletions

diff --git a/src/draw.zig b/src/draw.zig
index 1f30a40b..9df76cfd 100644
--- a/src/draw.zig
+++ b/src/draw.zig
@@ -134,11 +134,12 @@ pub fn place(p: *Pardes, s: *Surface) void {
         // snaps (it has no in-between), and so does nothing that shows it.
         const shown = lift != .off or inactiveDim(p) != 0;
         const motion = animation.Motion.of(if (shown and builtins.capabilities.lift) p.settings.motion else .off);
-        spring.retarget(if (id == p.active) 1 else 0, p.now_ns, motion);
+        // A flavour exaggerates what is only a few pixels (Motion.gain).
+        spring.retarget(if (id == p.active) animation.Motion.of(p.settings.motion).gain else 0, p.now_ns, motion);
         _ = spring.step(p.now_ns);
     }
     for (s.regions[0..s.nregions]) |*region| switch (region.kind) {
-        .grip, .tag, .body, .rail => region.lift = if (lift != .off) p.lifts[region.owner].value(p.now_ns) else 0,
+        .grip, .tag, .body, .rail => region.lift = if (lift != .off) std.math.clamp(p.lifts[region.owner].value(p.now_ns), -1, 2) else 0,
         .notice => region.lift = if (lift != .off) 1 else 0,
         else => {},
     };
@@ -416,7 +417,8 @@ pub fn render(p: *Pardes, arena: std.mem.Allocator) !*Surface {
 
     for (p.panes, p.lifts, 0..) |slot, spring, id| {
         if (slot == null or id == p.active) continue;
-        const amount = @as(f32, @floatFromInt(inactiveDim(p))) / 100 * std.math.clamp(1 - spring.value(p.now_ns), 0, 1);
+        const focus = spring.value(p.now_ns) / animation.Motion.of(p.settings.motion).gain;
+        const amount = @as(f32, @floatFromInt(inactiveDim(p))) / 100 * std.math.clamp(1 - focus, 0, 1);
         if (amount > 0.001) recede(p, s, id, amount);
     }
 
@@ -1604,6 +1606,46 @@ test "with no lift and no dim a focus switch asks for no frames" {
     try std.testing.expect(!p.continuous());
 }
 
+test "each Motion flavour reaches the lift as its own trajectory" {
+    // A grid snaps; the flavours are a pixel shell's.
+    if (!builtins.capabilities.lift) return error.SkipZigTest;
+    const p = try Pardes.init(std.testing.allocator, .{ .cols = 80, .rows = 24 });
+    defer p.deinit();
+    _ = try p.setTestFile("text\n");
+    p.newScratchBelow(0);
+    var arena: std.heap.ArenaAllocator = .init(std.testing.allocator);
+    defer arena.deinit();
+    p.settings.lift = .shadow;
+    var peaks: [5]f32 = undefined;
+    const ms = std.time.ns_per_ms;
+    var start: u64 = std.time.ns_per_s;
+    for (std.enums.values(animation.Motion.Flavour), &peaks) |flavour, *peak| {
+        p.settings.motion = flavour;
+        p.active = 1;
+        p.advance(start);
+        _ = arena.reset(.retain_capacity);
+        _ = try p.render(arena.allocator());
+        start += 3 * std.time.ns_per_s;
+        p.advance(start);
+        _ = try p.render(arena.allocator());
+        p.active = 0;
+        peak.* = 0;
+        var t: u64 = 0;
+        while (t <= 1500 * ms) : (t += 4 * ms) {
+            p.advance(start + t);
+            _ = arena.reset(.retain_capacity);
+            const s = try p.render(arena.allocator());
+            const lift = for (s.regionList()) |region| {
+                if (region.kind == .grip and region.owner == 0) break region.lift;
+            } else unreachable;
+            peak.* = @max(peak.*, lift);
+        }
+        start += 3 * std.time.ns_per_s;
+    }
+    // Bouncy and playful pass their (exaggerated) mark; smooth never does.
+    try std.testing.expect(peaks[2] <= 1.001 and peaks[3] > 1.25 and peaks[4] > peaks[3]);
+}
+
 test "a monkey over notices, prompts, tags and tiny panes at a gui's metrics never panics" {
     // The snapshot harness runs the tty, whose tagline pitch is the body's,
     // so it never reaches what a narrower tagline does to a notice's band: