backend: the viewports API is the backend package's, with a stand-in

backend/build.zig

@@ -156,6 +156,16 @@ pub fn objcModule(dep: *std.Build.Dependency, opts: Options) ?*std.Build.Module
     return objc.module("objc");
 }
 
+/// `viewports` for a backend without OS windows besides the main one (`src/viewports_none.zig`):
+/// dvui's own, its testing backend, the web. An app that builds on either kind imports it as
+/// `viewports_none` and takes the backend's own `viewports` where it has one. Needs only dvui,
+/// so nothing of SDL is fetched for it.
+pub fn viewportsNoneModule(dep: *std.Build.Dependency, dvui_mod: *std.Build.Module) *std.Build.Module {
+    const m = dep.builder.createModule(.{ .root_source_file = dep.builder.path("src/viewports_none.zig") });
+    m.addImport("dvui", dvui_mod);
+    return m;
+}
+
 /// zigwin32, from this package's pin, for an app's own Windows code. Null on the configure pass
 /// that fetches it.
 pub fn win32Module(dep: *std.Build.Dependency) ?*std.Build.Module {

backend/src/SDLBackend.zig

@@ -16,6 +16,8 @@ const dvui = @import("dvui");
 
 const GpuRenderer = @import("GpuRenderer.zig");
 pub const viewport_map = @import("viewport_map.zig");
+/// The OS windows besides the main one an app draws with (`Viewport`).
+pub const viewports = @import("viewports.zig");
 /// What this backend keeps count of as it runs (`health`).
 pub const Health = @import("Health.zig");
 
@@ -94,7 +96,7 @@ window_geometry: WindowGeometry = .{},
 // Set by `initWindow` and `initWindowSecondary` for use by eventual child window.
 init_opts_save: ?InitOptions = null,
 /// The OS windows besides this one that show part of its frame (`Viewport`).
-viewports: [max_viewports]?Viewport = @splat(null),
+viewport_slots: [max_viewports]?Viewport = @splat(null),
 /// Where a held pointer is read while one is held (`PointerPin`, `heldPoint`).
 pointer_pin: PointerPin = .none,
 /// macOS: the main window may have come in front of a viewport's window — it took focus, was
@@ -915,7 +917,7 @@ fn noteMainForward(self: *SDLBackend, target: ?*c.SDL_Window, event_type: u32) v
     };
     if (event_type == c.SDL_EVENT_WINDOW_FOCUS_GAINED) self.main_focused_once = true;
     if (!over) return;
-    for (&self.viewports) |*slot| if (slot.*) |*v| {
+    for (&self.viewport_slots) |*slot| if (slot.*) |*v| {
         v.over_main = true;
     };
 }
@@ -1172,7 +1174,7 @@ fn openViewport(self: *SDLBackend, at: viewport_map.Rect, title_text: [:0]const
     const carry = role != .window;
     const menu = role == .menu;
     if (!viewportsAvailable()) return null;
-    const slot = for (self.viewports, 0..) |v, i| {
+    const slot = for (self.viewport_slots, 0..) |v, i| {
         if (v == null) break i;
     } else return null;
     const b = viewport_map.band(slot);
@@ -1220,8 +1222,8 @@ fn openViewport(self: *SDLBackend, at: viewport_map.Rect, title_text: [:0]const
     // where SDL makes it a child window that moves with its parent, and the windows that left
     // the main one stay where they are when it moves (`plans/POPOUT_WINDOWS_PLAN.md`, decision 2).
     if (comptime builtin.os.tag != .macos) _ = c.SDL_SetWindowParent(window, self.window);
-    self.viewports[slot] = .{ .window = window, .band = b, .anchor = anchor, .density = d, .screen = placed.screen, .frame = placed.frame, .passive = carry and !menu, .overlay = role == .overlay, .menu = menu };
-    const vp = &self.viewports[slot].?;
+    self.viewport_slots[slot] = .{ .window = window, .band = b, .anchor = anchor, .density = d, .screen = placed.screen, .frame = placed.frame, .passive = carry and !menu, .overlay = role == .overlay, .menu = menu };
+    const vp = &self.viewport_slots[slot].?;
     // Dressed by `viewportOpenMenu`, and no hit test: nothing in it moves or resizes it.
     if (menu) return vp;
     if (role == .overlay) {
@@ -1325,13 +1327,13 @@ pub fn viewportClose(self: *SDLBackend, vp: *Viewport) void {
     // What rides on it lets go first (`Viewport.ride`): SDL destroys a window's children with it,
     // and the slot of each still holds its window. The app moves a dialog left behind back over
     // the main window (`Popout`).
-    for (&self.viewports) |*slot| {
+    for (&self.viewport_slots) |*slot| {
         if (slot.*) |*other| if (other != vp and other.ride != null and other.ride == vp.window) {
             _ = c.SDL_SetWindowParent(other.window, null);
             other.ride = null;
         };
     }
-    for (&self.viewports) |*slot| {
+    for (&self.viewport_slots) |*slot| {
         if (slot.*) |*v| if (v == vp) {
             // Holding the keyboard as it goes — a float that merged back into the main window, or
             // came back on a command, while its window was the one in front — it hands it back to
@@ -1352,7 +1354,7 @@ pub fn viewportClose(self: *SDLBackend, vp: *Viewport) void {
             break;
         };
     }
-    for (self.viewports) |v| if (v != null) return;
+    for (self.viewport_slots) |v| if (v != null) return;
     _ = c.SDL_ResetHint(c.SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH);
 }
 
@@ -1623,7 +1625,7 @@ pub fn viewportPresent(_: *SDLBackend, vp: *Viewport, target: ?dvui.TextureTarge
 }
 
 fn viewportOf(self: *SDLBackend, window: *c.SDL_Window) ?*Viewport {
-    for (&self.viewports) |*slot| {
+    for (&self.viewport_slots) |*slot| {
         if (slot.*) |*v| if (v.window == window) return v;
     }
     return null;
@@ -1666,7 +1668,7 @@ fn heldAcrossWindows(self: *SDLBackend, event: c.SDL_Event) bool {
         c.SDL_EVENT_MOUSE_BUTTON_DOWN, c.SDL_EVENT_MOUSE_BUTTON_UP => if (event.button.which == c.SDL_TOUCH_MOUSEID) return false,
         else => return false,
     }
-    const any = for (self.viewports) |v| {
+    const any = for (self.viewport_slots) |v| {
         if (v != null) break true;
     } else false;
     if (!any) return false;
@@ -1700,7 +1702,7 @@ fn heldPoint(self: *SDLBackend) dvui.Point.Physical {
     var mh: c_int = 0;
     _ = c.SDL_GetWindowSize(self.window, &mw, &mh);
     const over_main = gx >= origin.x and gy >= origin.y and gx < origin.x + @as(f32, @floatFromInt(mw)) and gy < origin.y + @as(f32, @floatFromInt(mh));
-    for (&self.viewports) |*slot| {
+    for (&self.viewport_slots) |*slot| {
         const vp = if (slot.*) |*v| v else continue;
         if (vp.passive or vp.see_through) continue;
         // In a fullscreen Space of its own, a window is where the OS put it, and under nothing:
@@ -1964,7 +1966,7 @@ pub fn deinit(self: *SDLBackend) void {
             WindowGeometry.save(self);
         }
         // Viewports are claimed on this window's device: given back before it goes.
-        for (&self.viewports) |*slot| {
+        for (&self.viewport_slots) |*slot| {
             if (slot.*) |*v| self.viewportClose(v);
         }
         self.gpu.destroy();
@@ -1988,7 +1990,7 @@ pub fn renderPresent(self: *SDLBackend) void {
     var transacted: [max_viewports]bool = @splat(false);
     var any = false;
     if (comptime builtin.os.tag == .macos) {
-        for (&self.viewports, 0..) |*slot, i| {
+        for (&self.viewport_slots, 0..) |*slot, i| {
             const vp = if (slot.*) |*v| v else continue;
             const first = !vp.shown and vp.pending != null;
             const reshaped = vp.passive and !vp.overlay and (vp.carry_radius != vp.carry_radius_shown or vp.carry_alpha != vp.carry_alpha_shown or vp.carry_size_shown[0] != vp.screen.w or vp.carry_size_shown[1] != vp.screen.h);
@@ -2018,7 +2020,7 @@ pub fn renderPresent(self: *SDLBackend) void {
         }
     }
     defer if (comptime builtin.os.tag == .macos) if (any) {
-        for (&self.viewports, transacted) |*slot, t| {
+        for (&self.viewport_slots, transacted) |*slot, t| {
             if (!t) continue;
             const vp = if (slot.*) |*v| v else continue;
             fizzy_native_viewport_presented(cocoaWindow(vp.window));
@@ -2033,7 +2035,7 @@ pub fn renderPresent(self: *SDLBackend) void {
     // drawables back slowly while the main window goes through a Space transition, and waiting on
     // them every frame halved the move's rate with one open.
     const main_moving = platform.window.windowMovingItself(self.window);
-    for (&self.viewports, 0..) |*slot, i| {
+    for (&self.viewport_slots, 0..) |*slot, i| {
         const vp = if (slot.*) |*v| v else continue;
         const target = vp.pending orelse continue;
         vp.pending = null;
@@ -2058,7 +2060,7 @@ pub fn renderPresent(self: *SDLBackend) void {
     self.gpu.present(self.clear_window_on_begin, builtin.os.tag == .windows and self.inLiveResize());
     // Shown once there is a frame in it (or empty, above). Not made key: the window it came out of
     // keeps the keyboard until the viewport is clicked.
-    for (&self.viewports, first_frame, map_empty) |*slot, show, empty| {
+    for (&self.viewport_slots, first_frame, map_empty) |*slot, show, empty| {
         if (!show and !empty) continue;
         const vp = if (slot.*) |*v| v else continue;
         if (!vp.mapped) {
@@ -2081,11 +2083,11 @@ pub fn renderPresent(self: *SDLBackend) void {
     // activates, which brings the main window in front of them (`fizzy_macos_watch_first_activation`).
     if (comptime builtin.os.tag == .macos) {
         fizzy_macos_watch_first_activation();
-        if (fizzy_macos_took_first_activation() != 0) for (&self.viewports) |*slot| if (slot.*) |*v| {
+        if (fizzy_macos_took_first_activation() != 0) for (&self.viewport_slots) |*slot| if (slot.*) |*v| {
             v.over_main = true;
         };
         const main_ns = cocoaWindow(self.window);
-        for (&self.viewports) |*slot| {
+        for (&self.viewport_slots) |*slot| {
             const vp = if (slot.*) |*v| v else continue;
             if (!vp.over_main) continue;
             vp.over_main = false;
@@ -2098,7 +2100,7 @@ pub fn renderPresent(self: *SDLBackend) void {
         // when the stacking may have changed.
         if (self.stack_stale) {
             self.stack_stale = false;
-            for (&self.viewports) |*slot| {
+            for (&self.viewport_slots) |*slot| {
                 const vp = if (slot.*) |*v| v else continue;
                 vp.under_main = vp.mapped and !vp.passive and !vp.menu and fizzy_macos_viewport_under_main(cocoaWindow(vp.window), main_ns) != 0;
             }
@@ -2176,7 +2178,7 @@ pub fn begin(self: *SDLBackend, arena: std.mem.Allocator) !void {
     // A float's window standing still on its way into or out of full screen: its picture has
     // taken this frame's step (`begin_hook`), and the float follows it there — as it did the
     // window's moves — and back to the window as the way ends.
-    if (comptime builtin.os.tag == .macos) for (&self.viewports) |*slot| {
+    if (comptime builtin.os.tag == .macos) for (&self.viewport_slots) |*slot| {
         const vp = if (slot.*) |*v| v else continue;
         if (vp.picture_at[0] != 0 or vp.picture_at[1] != 0 or platform.window.windowSpacePicture(vp.window) != null)
             viewportFollowWindow(vp);
@@ -2227,7 +2229,7 @@ fn mainHeld(self: *SDLBackend) bool {
     // Its own way into or out of full screen is drawn whatever AppKit says of it on the way.
     if (platform.window.windowMovingItself(self.window)) return false;
     if (c.SDL_GetWindowFlags(self.window) & c.SDL_WINDOW_OCCLUDED != 0) return true;
-    for (&self.viewports) |*slot| {
+    for (&self.viewport_slots) |*slot| {
         const vp = if (slot.*) |*v| v else continue;
         if (vp.shown and platform.window.windowMovingItself(vp.window)) return true;
     }

backend/src/platform/window.zig

@@ -53,6 +53,46 @@ pub const WindowGlass = extern struct {
     feather: f64,
 };
 
+/// A window's Liquid Glass this frame (`liquidGlassLook`, `viewports.windowGlass`), as an app
+/// says it: what `core.glass_look.window` says at the window's opacity, the window's colour, and the clearing
+/// bevel `core.glass_look.band` gives its size.
+pub const WindowGlassLook = struct {
+    under_variant: i32,
+    under_style: i32,
+    over_variant: i32,
+    over_style: i32,
+    frost: f32,
+    blur: f32,
+    glass: f32,
+    fill: dvui.Color,
+    /// The colour's opacity in the body…
+    fill_opacity: f32,
+    /// …and over all of it, the bevel too.
+    top_fill: f32,
+    /// Points, each.
+    radius: f32,
+    clear: f32,
+    feather: f32,
+
+    /// As `fizzy_macos_window_liquid_glass_look` reads it.
+    pub fn native(self: WindowGlassLook) WindowGlass {
+        return .{
+            .under_variant = self.under_variant,
+            .under_style = self.under_style,
+            .over_variant = self.over_variant,
+            .over_style = self.over_style,
+            .frost = self.frost,
+            .blur = self.blur,
+            .glass = self.glass,
+            .fill = .{ @as(f64, @floatFromInt(self.fill.r)) / 255, @as(f64, @floatFromInt(self.fill.g)) / 255, @as(f64, @floatFromInt(self.fill.b)) / 255, self.fill_opacity },
+            .top_fill = self.top_fill,
+            .radius = self.radius,
+            .clear = self.clear,
+            .feather = self.feather,
+        };
+    }
+};
+
 /// Make one of fizzy's titled windows (`raw_ptr`, its `NSWindow`) a window of Liquid Glass — over
 /// the clear lens a body of frost, the plain blur (the vibrancy it wore before,
 /// `ns_visual_effect_material`) and the window's colour, fading out across a clearing bevel along
@@ -259,7 +299,7 @@ pub fn setStyle(win: *dvui.Window) void {
         // Not a menu's or a dialog's: dressed once as it opens (`fizzy_macos_viewport_menu`), it
         // never goes full screen, and this made it a full-screen primary window over the
         // auxiliary one it was opened as, every frame.
-        for (&win.backend.impl.viewports) |*slot| {
+        for (&win.backend.impl.viewport_slots) |*slot| {
             const vp = if (slot.*) |*v| v else continue;
             if (vp.passive or vp.menu) continue;
             const ns = c.SDL_GetPointerProperty(c.SDL_GetWindowProperties(vp.window), c.SDL_PROP_WINDOW_COCOA_WINDOW_POINTER, null) orelse continue;
@@ -383,7 +423,7 @@ pub fn setBackground(win: *dvui.Window, color: dvui.Color) void {
             // Every float's own window too, and each opened from now on (`SDLBackend.viewportGlass`):
             // side by side, and each in a Space of its own, they are one app's windows.
             win.backend.impl.window_skin = color;
-            for (&win.backend.impl.viewports) |*slot| {
+            for (&win.backend.impl.viewport_slots) |*slot| {
                 const vp = if (slot.*) |*v| v else continue;
                 if (vp.passive) continue;
                 const ns = c.SDL_GetPointerProperty(c.SDL_GetWindowProperties(vp.window), c.SDL_PROP_WINDOW_COCOA_WINDOW_POINTER, null) orelse continue;