sdk: release 0.2.18, a plugin's glass over its picture and native

core/gfx/LiquidField.zig

@@ -20,7 +20,8 @@
 //!
 //! **Drawing.** Inside a layer's `dvui.deferRender` job, after its capture: `draw` with the
 //! frost and what it covers. False where the backend has no programs (`core.gfx.programs`) or the
-//! program is not ready yet, and the caller draws its meshes instead, without the joins.
+//! program is not ready yet, and the caller draws its meshes instead, without the joins. A lens
+//! over a picture of the caller's own (a magnifier) needs no capture: `drawPicture` queues itself.
 //!
 //! Layers do not join each other: a dialog over a drop is two layers, the dialog's capture taken
 //! with the drop already on the frame.
@@ -75,6 +76,9 @@ refraction: f32 = 1,
 /// It carries text — a dialog, a menu — and keeps some frost over a clear lens to read
 /// (`glass_look.forText`).
 text: bool = false,
+/// It is a lens over a picture of the caller's own (`drawPicture`): its middle the picture as it
+/// is, only the band along its edge glass (`glass_look.forLens`).
+lens: bool = false,
 
 pub fn add(self: *LiquidField, shape: Shape) void {
     if (self.len >= max_shapes) return;
@@ -325,7 +329,7 @@ pub fn draw(self: *const LiquidField, frost: dvui.Texture, covered: dvui.Rect.Ph
     // The window behind the glass, published for this frame.
     u.backdrop[0] = if (opaqueWindow()) 1 else 0;
     // And the glass the slider makes of it this frame (`publishLook`).
-    if (publishedLook()) |l| self.applyLook(&u, if (self.text) glass_look.forText(l) else glass_look.forDrops(l));
+    if (publishedLook()) |l| self.applyLook(&u, if (self.lens) glass_look.forLens(l) else if (self.text) glass_look.forText(l) else glass_look.forDrops(l));
     const textures = [_]?*anyopaque{programs.handle(sharp)};
     if (!h.begin(id, &textures, textures.len, u.vec4s(), uniform_vec4s)) return false;
     defer h.end();
@@ -336,6 +340,56 @@ pub fn draw(self: *const LiquidField, frost: dvui.Texture, covered: dvui.Rect.Ph
     return true;
 }
 
+/// The shapes as a lens over a picture of the caller's own — a magnifier's zoom, a loupe — rather
+/// than over what is behind them. `picture` is a picture of `covered` (physical pixels, window
+/// coordinates), reaching `pictureMargin` past the shapes. Its middle is the picture as it is,
+/// unblurred, untinted and unlit, so a colour picked through it is the colour under it; only the
+/// band along its edge is glass (`lens`, `glass_look.forLens`). Where the app publishes no look
+/// (the web), it is the earlier glass, its rim pulling from just outside the shape, which is what
+/// the margin is for. Nothing under it is read, so it costs no capture.
+///
+/// Queued in order with the frame (`dvui.deferRender`), as every glass is, and drawn at full
+/// alpha: glass replaces what it covers, and at part alpha it left a hole. `picture` must live
+/// until the frame ends. False, having queued nothing, where there is no glass program (`ready`):
+/// draw the picture some other way.
+pub fn drawPicture(self: *const LiquidField, picture: dvui.Texture, covered: dvui.Rect.Physical) bool {
+    if (self.len == 0) return true;
+    if (!ready()) return false;
+    const job = dvui.currentWindow().arena().create(PictureJob) catch return false;
+    job.* = .{ .field = self.*, .picture = picture, .covered = covered };
+    job.field.lens = true;
+    job.field.tint = null;
+    job.field.mix = 0;
+    job.field.lift = 0;
+    for (job.field.shapes[0..job.field.len]) |*sh| sh.blur = 0;
+    dvui.deferRender(job, PictureJob.run);
+    return true;
+}
+
+/// Physical pixels the picture `drawPicture` lays the glass over should reach past the shapes: as
+/// far as the earlier glass's rim reaches out (`liquid_glass.margin`), at the strongest of its
+/// shapes' lenses. Apple's lens pulls only from inside the shape and needs none of it.
+pub fn pictureMargin(self: *const LiquidField) f32 {
+    var lens: f32 = 0;
+    for (self.shapes[0..self.len]) |sh| lens = @max(lens, sh.lens);
+    return liquid_glass.margin(.{ .lens = lens, .refraction = self.refraction }, self.scale);
+}
+
+/// What `drawPicture` hands to the replay, in the frame's arena.
+const PictureJob = struct {
+    field: LiquidField,
+    picture: dvui.Texture,
+    covered: dvui.Rect.Physical,
+
+    fn run(ctx: ?*anyopaque) void {
+        const self: *PictureJob = @ptrCast(@alignCast(ctx orelse return));
+        const prev_alpha = dvui.currentWindow().alpha;
+        dvui.alphaSet(1);
+        defer dvui.alphaSet(prev_alpha);
+        _ = self.field.draw(self.picture, self.covered, null);
+    }
+};
+
 /// One quad per group, its vertex colour telling the program which pass and which shapes.
 fn quads(self: *const LiquidField, groups: Clusters, glass: bool, frost: dvui.Texture) void {
     const arena = dvui.currentWindow().arena();

core/gfx/glass_look.zig

@@ -261,6 +261,21 @@ pub fn forText(look: InApp) InApp {
     return l;
 }
 
+/// `look` for a lens over a picture of the caller's own — a magnifier's zoom, a loupe — rather than
+/// over what is behind it (`LiquidField.drawPicture`): the picture is what it shows, as it is, so
+/// its middle takes no frost, none of the window's colour and no lift, at any point on the slider
+/// — a colour picked through it is the colour under it. Only the band along its edge is glass,
+/// bending the picture toward its rim and lit there, and that follows the slider as every glass
+/// does: a clear lens at the bottom, its shine going at the top.
+pub fn forLens(look: InApp) InApp {
+    var l = look;
+    l.frost = 0;
+    l.mix = 0;
+    l.text_mix = 0;
+    l.lift = 0;
+    return l;
+}
+
 fn smoothstep(x: f32) f32 {
     return x * x * (3 - 2 * x);
 }
@@ -325,6 +340,22 @@ test "a surface carrying text keeps some frost over a clear lens, none once it i
     try std.testing.expectEqual(inApp(1).frost, forText(inApp(1)).frost);
 }
 
+test "a lens over a picture leaves its middle as it is, everywhere on the slider" {
+    var i: usize = 0;
+    while (i <= 20) : (i += 1) {
+        const t = @as(f32, @floatFromInt(i)) / 20;
+        const l = forLens(inApp(t));
+        try std.testing.expectEqual(@as(f32, 0), l.frost);
+        try std.testing.expectEqual(@as(f32, 0), l.mix);
+        try std.testing.expectEqual(@as(f32, 0), l.lift);
+        // Its edge is the slider's glass all the same.
+        try std.testing.expectEqual(inApp(t).bend, l.bend);
+        try std.testing.expectEqual(inApp(t).rim, l.rim);
+    }
+    // A clear lens at the bottom, folding at its rim as Apple's does.
+    try std.testing.expect(forLens(inApp(0)).bend > 1);
+}
+
 test "a drop's plain blur is light, growing with the glass's roughness" {
     try std.testing.expectApproxEqAbs(drop_blur_min, native(0).blur, 1e-6);
     try std.testing.expectApproxEqAbs(drop_blur, native(1).blur, 1e-6);

core/native_glass.zig

@@ -5,7 +5,8 @@
 //! app reconciles the OS's glass with it at the end of the frame; nothing of it is drawn by the app.
 //!
 //! In dvui's data, as `screens` is, so whatever draws the glass — fizzy, a plugin's drop zones —
-//! declares it the same way, with no SDK between them.
+//! declares it the same way, with no SDK between them. Outside a drag, glass a plugin declares
+//! shows in the same overlay wherever the OS offers it (`offered`).
 const std = @import("std");
 const dvui = @import("dvui");
 
@@ -52,6 +53,21 @@ pub fn publishOn(on_: bool) void {
     current().on = on_;
 }
 
+/// Whether the OS can draw glass declared outside a view drag this frame (a plugin's own, such as
+/// pixi's dropper magnifier), set by the app before anything draws. While it can, glass declared
+/// with `add` shows in the app's overlay of the OS's glass whatever else is on, and the layers
+/// marked to go over it (`core.screens.markCarried`) are taken into the overlay's picture. The
+/// app's own windows draw none of either. Where it cannot, draw the app's own glass.
+pub fn publishOffered(on_: bool) void {
+    dvui.dataSet(null, key_id, "_offered", on_);
+}
+
+/// Whether the OS draws glass declared this frame outside a view drag (`publishOffered`): declare
+/// it (`add`) and draw none.
+pub fn offered() bool {
+    return dvui.dataGet(null, key_id, "_offered", bool) orelse false;
+}
+
 /// Whether the carried view's picture goes under the OS's glass this frame, in a window of its own
 /// beneath the drag's (the app's, each frame): the glass then bends it, a lens over what is carried.
 /// The drag hands it over rather than drawing it over the glass.

sdk/sdk_version.zig

@@ -23,5 +23,5 @@ const std = @import("std");
 pub const sdk_version = std.SemanticVersion{
     .major = 0,
     .minor = 2,
-    .patch = 17,
+    .patch = 18,
 };

src/editor/Popout.zig

@@ -173,6 +173,10 @@ pub fn beginFrame(state: *State) void {
     // is on, and after it while its drops are still running back together (`ViewDrag.last_pending`)
     // — their going, as their coming, is the OS's glass too.
     fizzy.core.native_glass.publishOn(nativeGlass() and (state.view_drag.active() or state.view_drag.last_pending_count > 0));
+    // And glass declared outside a drag, such as a plugin's (pixi's dropper magnifier): the OS's
+    // wherever it has it, in the same overlay, which stays while any glass is declared
+    // (`overlayFrame`).
+    fizzy.core.native_glass.publishOffered(nativeGlass());
     // And the carried view's picture under that glass, in a window of its own (`photoFrame`).
     fizzy.core.native_glass.publishUnder(nativeGlass() and viewports.carries);
     fizzy.core.screens.publishBeyond(viewports.carries and state.view_drag.active());
@@ -462,7 +466,9 @@ fn overlaySpacing(s: f32) f32 {
 /// what is under them. The carried view's photograph lies under its drop's glass (`overlayPhoto`);
 /// what goes over the glass — the drop's name, the bubbles' icons (`core.screens.markCarried`) — is
 /// taken into the overlay's picture. Glass and pictures change in one transaction. It goes when the
-/// drag does; a float the drop opens grows out of a carry window of its own (`growFrame`).
+/// drag does; a float the drop opens grows out of a carry window of its own (`growFrame`). Glass
+/// declared outside a drag (`core.native_glass.offered`: pixi's dropper magnifier) keeps it up the
+/// same way, with what is marked to go over it.
 fn overlayFrame(state: *State) void {
     const d = &state.view_drag;
     // Kept past the drag while its drops still go, and gone once there is no glass left.

tests/integration.zig

@@ -4454,6 +4454,25 @@ test "liquid field: groups are the shapes that touch, each drawn as its own quad
     try std.testing.expectEqual(@as(f32, 22), u.shapes[1][0][0]);
 }
 
+test "liquid field: a lens's picture reaches as far past its shapes as the earlier glass's rim pulls from" {
+    const LF = fizzy.core.LiquidField;
+    var f: LF = .{ .scale = 2, .refraction = 1 };
+    f.add(LF.Shape.circle(.{ .x = 100, .y = 100 }, 60));
+    // The earlier glass (the web's) pulls its rim from `liquid_glass.refraction` points out at full
+    // strength: a picture reaching that far past the shape has something there to show.
+    try std.testing.expect(f.pictureMargin() >= fizzy.core.liquid_glass.refraction * 2);
+    // Further at the strongest refraction setting.
+    var strong = f;
+    strong.refraction = 2;
+    try std.testing.expect(strong.pictureMargin() > f.pictureMargin());
+    // And further for a stronger lens on its shape.
+    var bent = f;
+    bent.shapes[0].lens = 1.5;
+    try std.testing.expect(bent.pictureMargin() > f.pictureMargin());
+    // Nothing in fizzy draws one (pixi's dropper magnifier does): compiled here all the same.
+    _ = &LF.drawPicture;
+}
+
 test "liquid glass: the rings of a pane run the way dvui's paths do" {
     const r: dvui.Rect.Physical = .{ .x = 0, .y = 0, .w = 200, .h = 100 };
     var pts: [4 * 7 + 2 * (8 - 1) + 2 * (4 - 1)]dvui.Point.Physical = undefined;