rename and simplification

1 files changed, 2227 insertions, 0 deletions

diff --git a/src/platform/cocoa/window.m b/src/platform/cocoa/window.m
new file mode 100644
index 0000000..3c8519a
--- /dev/null
+++ b/src/platform/cocoa/window.m
@@ -0,0 +1,2227 @@
+#import <AppKit/AppKit.h>
+#import <Metal/Metal.h>
+#import <QuartzCore/QuartzCore.h>
+
+#include "platform/cocoa/api.h"
+#include "yasl/native/cocoa.h"
+#include "common/timing.h"
+#include "common/loop.h"
+#include "platform/cocoa/keycodes.h"
+#include "common/keyboard.h"
+#include "keymap.h"
+
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define LINK_IDLE_FRAMES 8
+#define SCROLL_POINTS_PER_LINE 10.0
+
+enum {
+    DEVICE_LCTL   = 0x0001,
+    DEVICE_LSHIFT = 0x0002,
+    DEVICE_RSHIFT = 0x0004,
+    DEVICE_LCMD   = 0x0008,
+    DEVICE_RCMD   = 0x0010,
+    DEVICE_LALT   = 0x0020,
+    DEVICE_RALT   = 0x0040,
+    DEVICE_RCTL   = 0x2000,
+};
+
+@interface YaslView : NSView <NSTextInputClient>
+@property (nonatomic, assign) struct cocoa_surface *surface;
+@end
+
+@interface YaslAppDelegate : NSObject <NSApplicationDelegate>
+@end
+
+@interface YaslWindow : NSWindow
+@property (nonatomic, assign) struct cocoa_surface *surface;
+@end
+
+@interface YaslWindowController : NSWindowController <NSWindowDelegate>
+@property (nonatomic, assign) struct cocoa_surface *surface;
+@property (nonatomic, assign) BOOL fullscreenTransition;
+@end
+
+#include "common/input.h"
+
+struct cocoa_surface {
+    struct yasl_surface base;
+    YaslWindow *window;
+    YaslWindowController *controller;
+    YaslView *view;
+    CAMetalLayer *layer;
+    id<MTLCommandQueue> software_queue;
+    id<MTLBuffer> software_buffer;
+    NSUInteger software_buffer_capacity;
+    CADisplayLink *link;
+
+    struct cocoa_surface *parent;
+    bool is_popup;
+    struct yasl_vector2i content_offset;
+
+    const struct yasl_window_cbs *cbs;
+    void *ud;
+    uint64_t frames_skipped;
+
+    char *preedit;
+    struct yasl_rect2i ime_caret;
+
+    struct yasl_vector2i size;
+    uint32_t scale_120;
+    uint32_t bg_color;
+    uint32_t *pixels;
+    size_t pixel_capacity;
+
+    id<CAMetalDrawable> drawable;
+    bool transaction;
+    struct yasl_frame frame;
+    struct yasl_damage_list damage;
+    bool did_present;
+    unsigned idle_frames;
+    bool want_draw;
+    bool frame_due;
+    bool unpaced;
+    bool rendering;
+    bool closed;
+    bool destroyed;
+    struct cocoa_surface *dead_next;
+
+    struct input_queue input;
+    struct yasl_vector2i pointer;
+    double scroll_x;
+    uint32_t state;
+    uint32_t mods;
+    uint32_t buttons;
+    enum yasl_cursor cursor;
+    enum yasl_pointer_device tablet_device;
+    bool tablet_down;
+
+    char title[160];
+    struct yasl_frame_clock clock;
+};
+
+struct cocoa_display {
+    struct yasl_display base;
+    struct cocoa_surface **windows;
+    int count;
+    int capacity;
+    const struct yasl_display_cbs *cbs;
+    void *ud;
+    char *app_id;
+    struct yasl_loop *loop;
+    id key_up_monitor;
+    NSCursor *hidden_cursor;
+    YaslAppDelegate *delegate;
+    NSPoint cascade;
+    struct cocoa_surface *dead;
+    struct {
+        bool active;
+        struct cocoa_surface *origin;
+        struct cocoa_surface *carried;
+        struct yasl_vector2i carry_offset;
+        struct cocoa_surface *hover;
+        struct yasl_vector2i hover_pos;
+        struct yasl_drag_listener listener;
+        void *ud;
+        NSImage *image;
+        NSWindow *image_window;
+        struct yasl_vector2i image_size;
+        struct yasl_vector2i image_hotspot;
+    } drag;
+    int depth;
+    bool open;
+    bool launched;
+    bool pumping;
+    bool owns_loop;
+};
+
+static struct cocoa_display darwin_ctx;
+
+static void drag_end(struct cocoa_display *d, enum yasl_drag_end how)
+{
+    if (!d || !d->drag.active) return;
+    struct yasl_drag_listener l = d->drag.listener;
+    void *ud = d->drag.ud;
+    struct cocoa_surface *hover = d->drag.hover;
+    struct yasl_vector2i pos = d->drag.hover_pos;
+
+    d->drag.active = false;
+    d->drag.listener = (struct yasl_drag_listener){0};
+    d->drag.hover = NULL;
+    d->drag.origin = NULL;
+    d->drag.carried = NULL;
+
+    if (d->drag.image_window) {
+        [d->drag.image_window close];
+        [d->drag.image_window release];
+        d->drag.image_window = nil;
+    }
+    [d->drag.image release];
+    d->drag.image = nil;
+
+    if (hover && !hover->destroyed && hover->cbs && hover->cbs->drag) {
+        if (how == YASL_DRAG_DROPPED)
+            hover->cbs->drag(&hover->base, YASL_DRAG_DROP, pos, hover->ud);
+        else
+            hover->cbs->drag(&hover->base, YASL_DRAG_LEAVE, pos, hover->ud);
+    }
+    if (l.end)
+        l.end(ud, how);
+}
+
+static void render_and_commit(struct cocoa_surface *w);
+static void reap_dead(struct cocoa_display *d);
+
+static void set_state(struct cocoa_surface *w, uint32_t bit, bool on)
+{
+    if (!w || w->closed)
+        return;
+    uint32_t next = on ? (w->state | bit) : (w->state & ~bit);
+    if (next == w->state)
+        return;
+    w->state = next;
+    darwin_ctx.depth++;
+    if (w->cbs->state)
+        w->cbs->state(&w->base, w->state, w->ud);
+    darwin_ctx.depth--;
+}
+
+static void check_pointer_reset(struct cocoa_surface *w)
+{
+    if (!w || w->closed) return;
+    if (w->buttons != 0 || w->tablet_down) {
+        struct yasl_input_event ev = {
+            .kind = YASL_INPUT_RESET,
+            .surface = &w->base,
+        };
+        input_queue_push(&w->input, &ev);
+        w->buttons = 0;
+        w->tablet_down = false;
+    }
+}
+
+static void push_focus(struct cocoa_surface *w, bool focused)
+{
+    if (!w || w->closed)
+        return;
+    if (!focused)
+        check_pointer_reset(w);
+    struct yasl_input_event ev = {
+        .kind = YASL_INPUT_FOCUS,
+        .surface = &w->base,
+        .focus = { .focused = focused },
+    };
+    input_queue_push(&w->input, &ev);
+    darwin_ctx.depth++;
+    set_state(w, YASL_STATE_ACTIVATED, focused);
+    cocoa_surface_schedule_redraw(w);
+    darwin_ctx.depth--;
+}
+
+static void sync_size(struct cocoa_surface *w, bool force)
+{
+    if (!w || !w->layer || w->closed)
+        return;
+    uint64_t start = yasl_loop_now_ns();
+    NSRect bounds = w->view.bounds;
+    CGFloat scale = w->window.backingScaleFactor;
+    if (scale < 1.0)
+        scale = 1.0;
+    struct yasl_vector2i size = {
+        .x = (int)lround(bounds.size.width * scale),
+        .y = (int)lround(bounds.size.height * scale),
+    };
+    uint32_t scale_120 = (uint32_t)lround(scale * YASL_SCALE_UNIT);
+    bool rescaled = force || scale_120 != w->scale_120;
+    bool resized = force || (size.x != w->size.x || size.y != w->size.y);
+    if (!rescaled && !resized)
+        return;
+    darwin_ctx.depth++;
+    w->size = size;
+    w->scale_120 = scale_120;
+    w->layer.contentsScale = scale;
+    w->layer.drawableSize = CGSizeMake(size.x, size.y);
+    if (w->cbs->configure)
+        w->cbs->configure(&w->base, (struct yasl_geometry){
+            .size = size, .scale_120 = scale_120,
+        }, w->ud);
+    cocoa_surface_schedule_redraw(w);
+    if (w->view.inLiveResize)
+        render_and_commit(w);
+    yasl_clock_note_resize(&w->clock, yasl_loop_now_ns() - start);
+    darwin_ctx.depth--;
+}
+
+static unsigned cocoa_mods(NSEventModifierFlags m)
+{
+    unsigned mods = 0;
+    if (m & NSEventModifierFlagShift) mods |= YASL_MOD_SHIFT;
+    if (m & NSEventModifierFlagOption) mods |= YASL_MOD_ALT;
+    if (m & NSEventModifierFlagControl) mods |= YASL_MOD_CTRL;
+    if (m & NSEventModifierFlagCommand) mods |= YASL_MOD_SUPER;
+    if (m & NSEventModifierFlagCapsLock) mods |= YASL_MOD_CAPS;
+    return mods;
+}
+
+/* Decode a single Unicode scalar, never a lone UTF-16 surrogate. Layout labels
+ * are optional: multi-scalar mappings and native function-key characters are 0. */
+static uint32_t cocoa_key_label(NSString *characters)
+{
+    if (!characters.length) return 0;
+    unichar first = [characters characterAtIndex:0];
+    if (characters.length == 1)
+        return yasl_key_label(first);
+    if (characters.length == 2 && first >= 0xd800 && first <= 0xdbff) {
+        unichar second = [characters characterAtIndex:1];
+        if (second >= 0xdc00 && second <= 0xdfff)
+            return yasl_key_label(0x10000 + ((first - 0xd800) << 10) + second - 0xdc00);
+    }
+    return 0;
+}
+
+static struct yasl_key_event cocoa_key_event(NSEvent *ev, enum yasl_key_action action)
+{
+    struct yasl_key_event k = {
+        .key = yasl_key_from_cocoa(ev.keyCode),
+        .action = action,
+        .mods = cocoa_mods(ev.modifierFlags),
+        .native_code = ev.keyCode,
+    };
+    /* characters properties are invalid on flagsChanged events. */
+    if (ev.type == NSEventTypeKeyDown || ev.type == NSEventTypeKeyUp) {
+        k.codepoint = cocoa_key_label([ev charactersByApplyingModifiers:0]);
+        k.shifted = cocoa_key_label([ev charactersByApplyingModifiers:NSEventModifierFlagShift]);
+    }
+    return k;
+}
+
+static void on_key_event(struct cocoa_surface *w, NSEvent *ev, enum yasl_key_action action)
+{
+    w->mods = cocoa_mods(ev.modifierFlags);
+    struct yasl_key_event k = cocoa_key_event(ev, action);
+    struct yasl_input_event input_ev = {
+        .kind = YASL_INPUT_KEY,
+        .surface = &w->base,
+        .key = k,
+    };
+    input_queue_push(&w->input, &input_ev);
+}
+
+static void on_text_input(struct cocoa_surface *w, const char *text, size_t len)
+{
+    if (len) {
+        struct yasl_input_event ev = {
+            .kind = YASL_INPUT_TEXT,
+            .surface = &w->base,
+            .text = { .text = text, .len = len },
+        };
+        input_queue_push(&w->input, &ev);
+    }
+}
+
+static bool modifier_down(NSEvent *ev)
+{
+    NSEventModifierFlags f = ev.modifierFlags;
+    switch (ev.keyCode) {
+    case kVK_Shift: return f & DEVICE_LSHIFT;
+    case kVK_RightShift: return f & DEVICE_RSHIFT;
+    case kVK_Control: return f & DEVICE_LCTL;
+    case kVK_RightControl: return f & DEVICE_RCTL;
+    case kVK_Option: return f & DEVICE_LALT;
+    case kVK_RightOption: return f & DEVICE_RALT;
+    case kVK_Command: return f & DEVICE_LCMD;
+    case kVK_RightCommand: return f & DEVICE_RCMD;
+    case kVK_CapsLock: return f & NSEventModifierFlagCapsLock;
+    default: return false;
+    }
+}
+
+static int cocoa_button(NSInteger number)
+{
+    switch (number) {
+    case 0: return 0;
+    case 1: return 2;
+    case 2: return 1;
+    default: return -1;
+    }
+}
+
+static struct yasl_vector2i event_pos(struct cocoa_surface *w, NSEvent *ev)
+{
+    NSPoint p = [w->view convertPoint:ev.locationInWindow fromView:nil];
+    CGFloat scale = w->window.backingScaleFactor;
+    if (scale < 1.0)
+        scale = 1.0;
+    return (struct yasl_vector2i){
+        .x = (int)floor(p.x * scale),
+        .y = (int)floor((w->view.bounds.size.height - p.y) * scale),
+    };
+}
+
+static void update_drag_hover(struct cocoa_display *d, NSPoint screenPoint)
+{
+    if (!d || !d->drag.active) return;
+
+    NSInteger excludeNum = 0;
+    if (d->drag.carried && d->drag.carried->window)
+        excludeNum = d->drag.carried->window.windowNumber;
+    else if (d->drag.image_window)
+        excludeNum = d->drag.image_window.windowNumber;
+
+    NSInteger winNum = [NSWindow windowNumberAtPoint:screenPoint belowWindowWithWindowNumber:excludeNum];
+    struct cocoa_surface *target = NULL;
+    struct yasl_vector2i pos = {0};
+
+    if (winNum > 0) {
+        NSWindow *nswin = [NSApp windowWithWindowNumber:winNum];
+        if (nswin && [nswin isKindOfClass:[YaslWindow class]]) {
+            struct cocoa_surface *candidate = ((YaslWindow *)nswin).surface;
+            if (candidate && candidate != d->drag.carried && !candidate->closed && candidate->view) {
+                NSPoint winPoint = [candidate->window convertPointFromScreen:screenPoint];
+                NSPoint viewPoint = [candidate->view convertPoint:winPoint fromView:nil];
+                if (NSPointInRect(viewPoint, candidate->view.bounds)) {
+                    CGFloat scale = candidate->window.backingScaleFactor;
+                    if (scale < 1.0) scale = 1.0;
+                    pos.x = (int)floor(viewPoint.x * scale);
+                    pos.y = (int)floor((candidate->view.bounds.size.height - viewPoint.y) * scale);
+                    target = candidate;
+                }
+            }
+        }
+        if (!target) {
+            for (int i = 0; i < d->count; i++) {
+                struct cocoa_surface *s = d->windows[i];
+                if (s != d->drag.carried && !s->closed && s->window && s->window.windowNumber == winNum && s->view) {
+                    NSPoint winPoint = [s->window convertPointFromScreen:screenPoint];
+                    NSPoint viewPoint = [s->view convertPoint:winPoint fromView:nil];
+                    if (NSPointInRect(viewPoint, s->view.bounds)) {
+                        CGFloat scale = s->window.backingScaleFactor;
+                        if (scale < 1.0) scale = 1.0;
+                        pos.x = (int)floor(viewPoint.x * scale);
+                        pos.y = (int)floor((s->view.bounds.size.height - viewPoint.y) * scale);
+                        target = s;
+                    }
+                    break;
+                }
+            }
+        }
+    }
+
+    if (target != d->drag.hover) {
+        if (d->drag.hover) {
+            struct cocoa_surface *old = d->drag.hover;
+            struct yasl_vector2i old_pos = d->drag.hover_pos;
+            d->drag.hover = NULL;
+            if (old->cbs && old->cbs->drag && !old->destroyed)
+                old->cbs->drag(&old->base, YASL_DRAG_LEAVE, old_pos, old->ud);
+            if (!d->drag.active) return;
+        }
+        if (target && target->destroyed) target = NULL;
+        d->drag.hover = target;
+        d->drag.hover_pos = pos;
+        if (target && !target->destroyed && target->cbs && target->cbs->drag)
+            target->cbs->drag(&target->base, YASL_DRAG_OVER, pos, target->ud);
+    } else if (target && !target->destroyed) {
+        d->drag.hover_pos = pos;
+        if (target->cbs && target->cbs->drag)
+            target->cbs->drag(&target->base, YASL_DRAG_OVER, pos, target->ud);
+    }
+}
+
+static void push_pointer(struct cocoa_surface *w, NSEvent *ev, enum yasl_pointer_kind kind,
+                         int button)
+{
+    if (!w || w->closed || button < 0)
+        return;
+    bool proximity = ev.type == NSEventTypeTabletProximity ||
+                     ev.subtype == NSEventSubtypeTabletProximity;
+    if (proximity) {
+        if (ev.isEnteringProximity) {
+            w->tablet_device = ev.pointingDeviceType == NSPointingDeviceTypeEraser ?
+                YASL_PTR_DEV_ERASER : ev.pointingDeviceType == NSPointingDeviceTypePen ?
+                YASL_PTR_DEV_PEN : YASL_PTR_DEV_MOUSE;
+            return;
+        }
+        kind = YASL_PTR_LEAVE;
+        button = 3;
+    }
+    w->mods = cocoa_mods(ev.modifierFlags);
+    if (kind != YASL_PTR_LEAVE)
+        w->pointer = event_pos(w, ev);
+
+    enum yasl_pointer_device device = YASL_PTR_DEV_MOUSE;
+    struct yasl_pointer_pen pen = {0};
+
+    if (kind == YASL_PTR_LEAVE && w->tablet_device != YASL_PTR_DEV_MOUSE) {
+        device = w->tablet_device;
+        w->tablet_down = false;
+    } else if (ev.type == NSEventTypeTabletPoint || ev.subtype == NSEventSubtypeTabletPoint) {
+        /* pointingDeviceType belongs to proximity events. Remember that
+         * event's tool so erasers and zero-pressure hover stay classified. */
+        device = w->tablet_device == YASL_PTR_DEV_ERASER ? YASL_PTR_DEV_ERASER : YASL_PTR_DEV_PEN;
+        float press = (float)ev.pressure;
+        if (press > 1.0f) press = 1.0f;
+        if (press > 0.0f)
+            pen.pressure = (uint16_t)(press * 65535.0f);
+
+        NSPoint tilt = ev.tilt;
+        pen.tilt_x = (int8_t)lround(fmax(-1, fmin(1, tilt.x)) * 90.0);
+        pen.tilt_y = (int8_t)lround(fmax(-1, fmin(1, -tilt.y)) * 90.0);
+        if (button == 0 && kind == YASL_PTR_PRESS) w->tablet_down = true;
+        if (button == 0 && kind == YASL_PTR_RELEASE) {
+            w->tablet_down = false;
+            pen.pressure = 0;
+        }
+    }
+
+    if (kind == YASL_PTR_PRESS && button >= 0 && button < 32)
+        w->buttons |= (1u << button);
+    else if (kind == YASL_PTR_RELEASE && button >= 0 && button < 32)
+        w->buttons &= ~(1u << button);
+
+    struct yasl_input_event input_ev = {
+        .surface = &w->base,
+        .kind = YASL_INPUT_MOUSE,
+        .mouse = {
+            .pos = w->pointer,
+            .button = (int16_t)button,
+            .kind = kind,
+            .device = device,
+            .mods = w->mods,
+            .pen = pen,
+        },
+    };
+    input_queue_push(&w->input, &input_ev);
+    if (kind == YASL_PTR_MOTION && darwin_ctx.drag.active) {
+        if (darwin_ctx.drag.carried) {
+            cocoa_surface_place_under_pointer(darwin_ctx.drag.carried, darwin_ctx.drag.carry_offset);
+        } else if (darwin_ctx.drag.image_window) {
+            CGFloat scale = darwin_ctx.drag.origin && darwin_ctx.drag.origin->window
+                ? darwin_ctx.drag.origin->window.backingScaleFactor : 1.0;
+            if (scale < 1.0) scale = 1.0;
+            NSPoint mouse = [NSEvent mouseLocation];
+            CGFloat pt_h = darwin_ctx.drag.image_size.y / scale;
+            [darwin_ctx.drag.image_window setFrameOrigin:NSMakePoint(
+                mouse.x - darwin_ctx.drag.image_hotspot.x / scale,
+                mouse.y - pt_h + darwin_ctx.drag.image_hotspot.y / scale)];
+        }
+        update_drag_hover(&darwin_ctx, [NSEvent mouseLocation]);
+    } else if (kind == YASL_PTR_RELEASE && darwin_ctx.drag.active) {
+        update_drag_hover(&darwin_ctx, [NSEvent mouseLocation]);
+        drag_end(&darwin_ctx, YASL_DRAG_DROPPED);
+    }
+    if (proximity) {
+        w->tablet_device = YASL_PTR_DEV_MOUSE;
+        w->tablet_down = false;
+    }
+}
+
+static NSCursor *cocoa_cursor(enum yasl_cursor cursor)
+{
+    switch (cursor) {
+    case YASL_CURSOR_TEXT: return [NSCursor IBeamCursor];
+    case YASL_CURSOR_LINK: return [NSCursor pointingHandCursor];
+    case YASL_CURSOR_CROSSHAIR: return [NSCursor crosshairCursor];
+    case YASL_CURSOR_HIDDEN:
+        if (!darwin_ctx.hidden_cursor) {
+            NSImage *image = [[NSImage alloc] initWithSize:NSMakeSize(1, 1)];
+            [image lockFocus];
+            [[NSColor clearColor] set];
+            NSRectFillUsingOperation(NSMakeRect(0, 0, 1, 1), NSCompositingOperationCopy);
+            [image unlockFocus];
+            darwin_ctx.hidden_cursor = [[NSCursor alloc] initWithImage:image hotSpot:NSZeroPoint];
+            [image release];
+        }
+        return darwin_ctx.hidden_cursor;
+    case YASL_CURSOR_ARROW:
+    default: return [NSCursor arrowCursor];
+    }
+}
+
+@implementation YaslAppDelegate
+- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
+{
+    (void)sender;
+    if (darwin_ctx.cbs && darwin_ctx.cbs->quit)
+        darwin_ctx.cbs->quit(darwin_ctx.ud);
+    return NSTerminateCancel;
+}
+- (BOOL)applicationShouldHandleReopen:(NSApplication *)sender hasVisibleWindows:(BOOL)visible
+{
+    (void)sender;
+    if (!visible && darwin_ctx.cbs && darwin_ctx.cbs->reopen)
+        darwin_ctx.cbs->reopen(darwin_ctx.ud);
+    return YES;
+}
+- (BOOL)applicationShouldTerminateAfterLastWindowClosed:(NSApplication *)sender
+{
+    (void)sender;
+    return NO;
+}
+@end
+
+static struct yasl_vector2i dragging_pos(YaslView *view, id<NSDraggingInfo> sender)
+{
+    NSPoint p = [view convertPoint:[sender draggingLocation] fromView:nil];
+    NSWindow *win = view.window;
+    CGFloat scale = win ? win.backingScaleFactor : 1.0;
+    if (scale < 1.0) scale = 1.0;
+    return (struct yasl_vector2i){
+        .x = (int)floor(p.x * scale),
+        .y = (int)floor((view.bounds.size.height - p.y) * scale),
+    };
+}
+
+@implementation YaslView
+
+- (instancetype)initWithFrame:(NSRect)frameRect
+{
+    self = [super initWithFrame:frameRect];
+    if (self) {
+        self.wantsLayer = YES;
+        self.layerContentsRedrawPolicy = NSViewLayerContentsRedrawNever;
+        self.layerContentsPlacement = NSViewLayerContentsPlacementTopLeft;
+        [self registerForDraggedTypes:@[NSPasteboardTypeFileURL]];
+    }
+    return self;
+}
+
+- (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender
+{
+    NSPasteboard *pb = [sender draggingPasteboard];
+    if ([pb canReadItemWithDataConformingToTypes:@[NSPasteboardTypeFileURL]]) {
+        struct cocoa_surface *w = self.surface;
+        if (w && w->cbs && w->cbs->drop) {
+            struct yasl_vector2i pos = dragging_pos(self, sender);
+            w->cbs->drop(&w->base, YASL_DROP_OVER, pos, w->ud);
+        }
+        return NSDragOperationCopy;
+    }
+    return NSDragOperationNone;
+}
+
+- (NSDragOperation)draggingUpdated:(id<NSDraggingInfo>)sender
+{
+    return [self draggingEntered:sender];
+}
+
+- (void)draggingExited:(id<NSDraggingInfo>)sender
+{
+    NSPasteboard *pb = [sender draggingPasteboard];
+    if ([pb canReadItemWithDataConformingToTypes:@[NSPasteboardTypeFileURL]]) {
+        struct cocoa_surface *w = self.surface;
+        if (w && w->cbs && w->cbs->drop) {
+            struct yasl_vector2i pos = dragging_pos(self, sender);
+            w->cbs->drop(&w->base, YASL_DROP_LEAVE, pos, w->ud);
+        }
+    }
+}
+
+- (BOOL)performDragOperation:(id<NSDraggingInfo>)sender
+{
+    struct cocoa_surface *w = self.surface;
+    if (!w) return NO;
+    struct yasl_vector2i pos = dragging_pos(self, sender);
+    BOOL ok = NO;
+
+    NSPasteboard *pb = [sender draggingPasteboard];
+    NSArray<NSURL *> *urls = [pb readObjectsForClasses:@[[NSURL class]]
+        options:@{NSPasteboardURLReadingFileURLsOnlyKey: @YES}];
+    if (urls.count) {
+        NSMutableString *result = [NSMutableString string];
+        for (NSURL *url in urls) {
+            [result appendString:url.absoluteString];
+            [result appendString:@"\r\n"];
+        }
+        const char *utf8 = result.UTF8String;
+        if (utf8 && strlen(utf8)) {
+            struct yasl_input_event ev = {
+                .kind = YASL_INPUT_DROP_FILES,
+                .surface = &w->base,
+                .drop_files = { .files = utf8, .len = strlen(utf8) },
+            };
+            input_queue_push(&w->input, &ev);
+            cocoa_surface_schedule_redraw(w);
+            ok = YES;
+        }
+    }
+    if (w->cbs && w->cbs->drop)
+        w->cbs->drop(&w->base, YASL_DROP_LEAVE, pos, w->ud);
+    return ok;
+}
+
+- (CALayer *)makeBackingLayer
+{
+    CAMetalLayer *layer = [CAMetalLayer layer];
+    layer.pixelFormat = MTLPixelFormatBGRA8Unorm;
+    layer.framebufferOnly = YES;
+    layer.allowsNextDrawableTimeout = YES;
+    layer.opaque = YES;
+    layer.contentsGravity = kCAGravityTopLeft;
+    CGColorSpaceRef srgb = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
+    layer.colorspace = srgb;
+    CGColorSpaceRelease(srgb);
+    return layer;
+}
+
+- (BOOL)isOpaque { return !self.surface || !self.surface->is_popup; }
+- (BOOL)acceptsFirstResponder { return YES; }
+- (BOOL)becomeFirstResponder { return YES; }
+- (BOOL)canBecomeKeyView { return YES; }
+- (BOOL)wantsUpdateLayer { return YES; }
+
+- (void)setFrameSize:(NSSize)size
+{
+    [super setFrameSize:size];
+    sync_size(self.surface, false);
+}
+
+- (void)viewDidChangeBackingProperties
+{
+    [super viewDidChangeBackingProperties];
+    sync_size(self.surface, false);
+}
+
+- (void)viewWillStartLiveResize
+{
+    [super viewWillStartLiveResize];
+    struct cocoa_surface *w = self.surface;
+    if (w)
+        w->layer.presentsWithTransaction = YES;
+}
+
+- (void)viewDidEndLiveResize
+{
+    [super viewDidEndLiveResize];
+    struct cocoa_surface *w = self.surface;
+    if (!w)
+        return;
+    w->layer.presentsWithTransaction = NO;
+    cocoa_surface_schedule_redraw(w);
+}
+
+- (void)displayLinkFired:(CADisplayLink *)link
+{
+    struct cocoa_surface *w = self.surface;
+    if (!w || w->closed)
+        return;
+    CFTimeInterval period = link.targetTimestamp - link.timestamp;
+    if (period > 0.0 && period < 0.25)
+        w->clock.refresh_ns = period * 1e9;
+    w->frame_due = true;
+    if (!w->want_draw || (w->state & YASL_STATE_SUSPENDED)) {
+        if (++w->idle_frames >= LINK_IDLE_FRAMES)
+            link.paused = YES;
+        return;
+    }
+    w->idle_frames = 0;
+    if (darwin_ctx.loop)
+        yasl_loop_kick(darwin_ctx.loop);
+}
+
+- (void)updateTrackingAreas
+{
+    [super updateTrackingAreas];
+    if (self.trackingAreas.count > 0)
+        return;
+    NSTrackingArea *area = [[NSTrackingArea alloc]
+        initWithRect:NSZeroRect
+             options:NSTrackingMouseMoved | NSTrackingMouseEnteredAndExited |
+                     NSTrackingCursorUpdate | NSTrackingActiveAlways |
+                     NSTrackingInVisibleRect
+               owner:self
+            userInfo:nil];
+    [self addTrackingArea:area];
+    [area release];
+}
+
+- (void)cursorUpdate:(NSEvent *)event
+{
+    (void)event;
+    struct cocoa_surface *w = self.surface;
+    [cocoa_cursor(w ? w->cursor : YASL_CURSOR_ARROW) set];
+}
+
+- (void)keyDown:(NSEvent *)event
+{
+    struct cocoa_surface *w = self.surface;
+    if (!w) return;
+    on_key_event(w, event, event.isARepeat ? YASL_KEY_REPEAT : YASL_KEY_PRESS);
+    [self interpretKeyEvents:@[event]];
+}
+
+- (void)keyUp:(NSEvent *)event
+{
+    struct cocoa_surface *w = self.surface;
+    if (w)
+        on_key_event(w, event, YASL_KEY_RELEASE);
+}
+
+- (void)flagsChanged:(NSEvent *)event
+{
+    struct cocoa_surface *w = self.surface;
+    if (!w) return;
+    w->mods = cocoa_mods(event.modifierFlags);
+    on_key_event(w, event, modifier_down(event) ? YASL_KEY_PRESS : YASL_KEY_RELEASE);
+}
+
+- (void)mouseDown:(NSEvent *)event
+{
+    [self.window makeFirstResponder:self];
+    push_pointer(self.surface, event, YASL_PTR_PRESS, cocoa_button(event.buttonNumber));
+}
+- (void)rightMouseDown:(NSEvent *)event { [self mouseDown:event]; }
+- (void)otherMouseDown:(NSEvent *)event { [self mouseDown:event]; }
+
+- (void)mouseUp:(NSEvent *)event
+{
+    push_pointer(self.surface, event, YASL_PTR_RELEASE, cocoa_button(event.buttonNumber));
+}
+- (void)rightMouseUp:(NSEvent *)event { [self mouseUp:event]; }
+- (void)otherMouseUp:(NSEvent *)event { [self mouseUp:event]; }
+
+- (void)mouseMoved:(NSEvent *)event
+{
+    push_pointer(self.surface, event, YASL_PTR_MOTION, 3);
+}
+
+- (void)mouseDragged:(NSEvent *)event
+{
+    push_pointer(self.surface, event, YASL_PTR_MOTION, 0);
+}
+- (void)rightMouseDragged:(NSEvent *)event
+{
+    push_pointer(self.surface, event, YASL_PTR_MOTION, 2);
+}
+- (void)otherMouseDragged:(NSEvent *)event
+{
+    push_pointer(self.surface, event, YASL_PTR_MOTION, cocoa_button(event.buttonNumber));
+}
+
+- (void)mouseExited:(NSEvent *)event
+{
+    push_pointer(self.surface, event, YASL_PTR_LEAVE, 3);
+}
+
+- (void)tabletProximity:(NSEvent *)event
+{
+    push_pointer(self.surface, event, YASL_PTR_MOTION, 3);
+}
+
+- (void)tabletPoint:(NSEvent *)event
+{
+    struct cocoa_surface *w = self.surface;
+    if (!w) return;
+    bool down = (event.buttonMask & NSEventButtonMaskPenTip) != 0;
+    enum yasl_pointer_kind kind = down == w->tablet_down ? YASL_PTR_MOTION :
+        down ? YASL_PTR_PRESS : YASL_PTR_RELEASE;
+    push_pointer(w, event, kind, 0);
+}
+
+- (void)scrollWheel:(NSEvent *)event
+{
+    struct cocoa_surface *w = self.surface;
+    if (!w) return;
+    double dx = -event.scrollingDeltaX, dy = -event.scrollingDeltaY;
+    if (event.hasPreciseScrollingDeltas) {
+        dx /= SCROLL_POINTS_PER_LINE;
+        dy /= SCROLL_POINTS_PER_LINE;
+    }
+    if (!isfinite(dx) || !isfinite(dy) || (dx == 0 && dy == 0)) return;
+    w->mods = cocoa_mods(event.modifierFlags);
+    w->pointer = event_pos(w, event);
+    struct yasl_input_event input_ev = {
+        .kind = YASL_INPUT_MOUSE,
+        .surface = &w->base,
+        .mouse = {
+            .pos = w->pointer,
+            .kind = YASL_PTR_SCROLL,
+            .mods = w->mods,
+            .scroll = {dx, dy},
+        },
+    };
+    input_queue_push(&w->input, &input_ev);
+}
+
+static NSString *plain_string(id string)
+{
+    return [string isKindOfClass:[NSAttributedString class]]
+        ? [(NSAttributedString *)string string] : (NSString *)string;
+}
+
+- (void)insertText:(id)string replacementRange:(NSRange)replacementRange
+{
+    (void)replacementRange;
+    struct cocoa_surface *w = self.surface;
+    if (!w) return;
+    const char *utf8 = plain_string(string).UTF8String;
+    size_t len = utf8 ? strlen(utf8) : 0;
+    free(w->preedit);
+    w->preedit = NULL;
+    on_text_input(w, utf8, len);
+    cocoa_surface_schedule_redraw(w);
+}
+
+- (void)doCommandBySelector:(SEL)selector { (void)selector; }
+
+- (void)setMarkedText:(id)string selectedRange:(NSRange)selectedRange
+     replacementRange:(NSRange)replacementRange
+{
+    (void)selectedRange;
+    (void)replacementRange;
+    struct cocoa_surface *w = self.surface;
+    if (!w) return;
+    NSString *str = plain_string(string);
+    const char *utf8 = str.length ? str.UTF8String : NULL;
+    free(w->preedit);
+    w->preedit = utf8 ? strdup(utf8) : NULL;
+    cocoa_surface_schedule_redraw(w);
+}
+
+- (void)unmarkText
+{
+    struct cocoa_surface *w = self.surface;
+    if (!w || !w->preedit) return;
+    free(w->preedit);
+    w->preedit = NULL;
+    cocoa_surface_schedule_redraw(w);
+}
+
+- (NSRange)selectedRange { return NSMakeRange(NSNotFound, 0); }
+- (NSRange)markedRange
+{
+    struct cocoa_surface *w = self.surface;
+    if (!w || !w->preedit)
+        return NSMakeRange(NSNotFound, 0);
+    return NSMakeRange(0, [NSString stringWithUTF8String:w->preedit].length);
+}
+- (BOOL)hasMarkedText { return self.surface && self.surface->preedit != NULL; }
+- (nullable NSAttributedString *)attributedSubstringForProposedRange:(NSRange)range
+                                                         actualRange:(nullable NSRangePointer)actualRange
+{
+    (void)range; (void)actualRange;
+    return nil;
+}
+- (NSArray<NSAttributedStringKey> *)validAttributesForMarkedText { return @[]; }
+- (NSRect)firstRectForCharacterRange:(NSRange)range actualRange:(nullable NSRangePointer)actualRange
+{
+    (void)range; (void)actualRange;
+    struct cocoa_surface *w = self.surface;
+    if (!w || !w->window) return NSZeroRect;
+    CGFloat scale = w->window.backingScaleFactor;
+    if (scale < 1.0) scale = 1.0;
+    NSRect r = NSMakeRect(w->ime_caret.x / scale,
+        self.bounds.size.height - (w->ime_caret.y + w->ime_caret.height) / scale,
+        w->ime_caret.width / scale, w->ime_caret.height / scale);
+    return [w->window convertRectToScreen:[self convertRect:r toView:nil]];
+}
+- (NSUInteger)characterIndexForPoint:(NSPoint)point { (void)point; return 0; }
+
+@end
+
+@implementation YaslWindow
+
+- (void)sendEvent:(NSEvent *)event
+{
+    darwin_ctx.depth++;
+    @try {
+        [super sendEvent:event];
+    } @finally {
+        darwin_ctx.depth--;
+    }
+}
+
+@end
+
+@implementation YaslWindowController
+
+- (void)windowDidBecomeKey:(NSNotification *)notification
+{
+    (void)notification;
+    if (self.surface) push_focus(self.surface, true);
+}
+
+- (void)windowDidResignKey:(NSNotification *)notification
+{
+    (void)notification;
+    if (self.surface) push_focus(self.surface, false);
+}
+
+- (void)windowDidChangeOcclusionState:(NSNotification *)notification
+{
+    (void)notification;
+    struct cocoa_surface *w = self.surface;
+    if (!w) return;
+    bool visible = (self.window.occlusionState & NSWindowOcclusionStateVisible) != 0;
+    darwin_ctx.depth++;
+    set_state(w, YASL_STATE_SUSPENDED, !visible);
+    if (visible)
+        cocoa_surface_schedule_redraw(w);
+    else
+        w->link.paused = YES;
+    darwin_ctx.depth--;
+}
+
+- (void)windowWillEnterFullScreen:(NSNotification *)notification
+{
+    (void)notification;
+    self.fullscreenTransition = YES;
+}
+
+- (void)windowWillExitFullScreen:(NSNotification *)notification
+{
+    (void)notification;
+    self.fullscreenTransition = YES;
+}
+
+- (void)syncWindowState
+{
+    self.fullscreenTransition = NO;
+    struct cocoa_surface *w = self.surface;
+    if (!w || w->closed)
+        return;
+    darwin_ctx.depth++;
+    bool fullscreen = (self.window.styleMask & NSWindowStyleMaskFullScreen) != 0;
+    set_state(w, YASL_STATE_FULLSCREEN, fullscreen);
+    set_state(w, YASL_STATE_MAXIMIZED, !fullscreen && self.window.isZoomed);
+    sync_size(w, false);
+    darwin_ctx.depth--;
+}
+
+- (void)windowDidEnterFullScreen:(NSNotification *)notification { [self syncWindowState]; }
+- (void)windowDidExitFullScreen:(NSNotification *)notification { [self syncWindowState]; }
+- (void)windowDidFailToEnterFullScreen:(NSWindow *)window { (void)window; [self syncWindowState]; }
+- (void)windowDidFailToExitFullScreen:(NSWindow *)window { (void)window; [self syncWindowState]; }
+
+- (void)windowDidResize:(NSNotification *)notification
+{
+    (void)notification;
+    if (!self.fullscreenTransition)
+        [self syncWindowState];
+}
+
+- (void)windowDidChangeScreen:(NSNotification *)notification
+{
+    (void)notification;
+    sync_size(self.surface, false);
+}
+
+- (void)windowWillClose:(NSNotification *)notification
+{
+    (void)notification;
+    struct cocoa_surface *w = self.surface;
+    if (!w || w->closed)
+        return;
+    darwin_ctx.depth++;
+    w->closed = true;
+    [w->link invalidate];
+    if (w->cbs->close)
+        w->cbs->close(&w->base, w->ud);
+    darwin_ctx.depth--;
+}
+
+@end
+
+bool cocoa_surface_present(struct cocoa_surface *w, const struct yasl_framebuffer *fb,
+                          const struct yasl_damage_list *damage)
+{
+    if (!w || w->closed || !w->rendering || w->did_present || !fb || !damage ||
+        fb->pixels != w->frame.target.pixels || fb->size.x != w->size.x ||
+        fb->size.y != w->size.y || !w->drawable)
+        return false;
+    if (w->software_queue) {
+        if (fb->pixels != w->pixels || fb->size.x != w->size.x || fb->size.y != w->size.y)
+            return false;
+        NSUInteger row_bytes = ((NSUInteger)w->size.x * 4 + 255) & ~(NSUInteger)255;
+        NSUInteger length = row_bytes * (NSUInteger)w->size.y;
+        if (!w->software_buffer || w->software_buffer_capacity < length) {
+            [w->software_buffer release];
+            w->software_buffer = [w->layer.device newBufferWithLength:length
+                                                    options:MTLResourceStorageModeShared];
+            w->software_buffer_capacity = w->software_buffer ? length : 0;
+        }
+        id<MTLBuffer> buffer = w->software_buffer;
+        if (!buffer) return false;
+        for (int y = 0; y < w->size.y; y++)
+            memcpy((char *)buffer.contents + (NSUInteger)y * row_bytes,
+                   w->pixels + (size_t)y * w->size.x, (size_t)w->size.x * 4);
+        id<MTLCommandBuffer> command = [w->software_queue commandBuffer];
+        id<MTLBlitCommandEncoder> blit = [command blitCommandEncoder];
+        if (!blit) return false;
+        id<CAMetalDrawable> drawable = w->drawable;
+        [blit copyFromBuffer:buffer sourceOffset:0 sourceBytesPerRow:row_bytes
+           sourceBytesPerImage:length sourceSize:MTLSizeMake(w->size.x, w->size.y, 1)
+                    toTexture:drawable.texture destinationSlice:0 destinationLevel:0
+            destinationOrigin:MTLOriginMake(0, 0, 0)];
+        [blit endEncoding];
+        [command presentDrawable:drawable];
+        [command commit];
+    }
+    yasl_clock_presented(&w->clock, yasl_loop_now_ns(), false);
+    w->did_present = true;
+    return true;
+}
+
+static void render_and_commit(struct cocoa_surface *w)
+{
+    if (w->closed || !w->cbs->draw || w->rendering || w->size.x <= 0 || w->size.y <= 0 ||
+        (w->state & YASL_STATE_SUSPENDED))
+        return;
+
+    size_t count = (size_t)w->size.x * (size_t)w->size.y;
+    if (w->software_queue && count > w->pixel_capacity) {
+        uint32_t *pixels = realloc(w->pixels, count * sizeof(*pixels));
+        if (!pixels) return;
+        w->pixels = pixels;
+        w->pixel_capacity = count;
+    }
+    darwin_ctx.depth++;
+    w->rendering = true;
+    w->want_draw = false;
+    w->frame_due = false;
+    w->did_present = false;
+    id<CAMetalDrawable> drawable = [w->layer nextDrawable];
+    w->drawable = drawable;
+    w->transaction = w->layer.presentsWithTransaction;
+    w->damage = (struct yasl_damage_list){0};
+    w->frame = (struct yasl_frame){
+        .surface = &w->base,
+        .target = {
+            .generation = yasl_frame_begin(&w->base),
+            .pixels = w->software_queue ? w->pixels : NULL,
+            .size = w->size,
+        },
+    };
+    if (drawable)
+        w->cbs->draw(&w->base, &w->frame, w->ud);
+    if (!w->closed && !w->did_present) {
+        w->want_draw = true;
+        w->frames_skipped++;
+    }
+    w->drawable = nil;
+    w->rendering = false;
+    darwin_ctx.depth--;
+}
+
+static void pump_window(struct cocoa_surface *w)
+{
+    if (!w || w->closed || !w->want_draw || !w->cbs->draw)
+        return;
+    if (w->link && !w->frame_due && !w->unpaced)
+        return;
+    @autoreleasepool { render_and_commit(w); }
+}
+
+int cocoa_display_dispatch_timeout(struct cocoa_display *d, int timeout_ms)
+{
+    assert([NSThread isMainThread]);
+    if (!d || d->pumping)
+        return -1;
+    for (int i = 0; i < d->count; i++) {
+        struct cocoa_surface *w = d->windows[i];
+        if (w->input.count || w->input.reset_pending ||
+            (w->want_draw && (!w->link || w->frame_due || w->unpaced))) {
+            timeout_ms = 0;
+            break;
+        }
+    }
+    d->pumping = true;
+    d->depth++;
+    int count = 0;
+    @try {
+        if (d->loop) {
+            int timer_to = yasl_loop_next_timeout_ms(d->loop);
+            if (timer_to >= 0 && (timeout_ms < 0 || timer_to < timeout_ms)) {
+                timeout_ms = timer_to;
+            }
+        }
+
+        NSDate *limitDate;
+        if (timeout_ms == 0)
+            limitDate = [NSDate distantPast];
+        else if (timeout_ms < 0)
+            limitDate = [NSDate distantFuture];
+        else
+            limitDate = [NSDate dateWithTimeIntervalSinceNow:(double)timeout_ms / 1000.0];
+
+        @autoreleasepool {
+            NSEvent *ev = [NSApp nextEventMatchingMask:NSEventMaskAny
+                                            untilDate:limitDate
+                                               inMode:NSDefaultRunLoopMode
+                                              dequeue:YES];
+            if (ev) {
+                count++;
+                [NSApp sendEvent:ev];
+                [NSApp updateWindows];
+
+                while ((ev = [NSApp nextEventMatchingMask:NSEventMaskAny
+                                                untilDate:[NSDate distantPast]
+                                                   inMode:NSDefaultRunLoopMode
+                                                  dequeue:YES])) {
+                    count++;
+                    [NSApp sendEvent:ev];
+                    [NSApp updateWindows];
+                }
+            }
+        }
+
+        if (d->loop) {
+            yasl_loop_step(d->loop, 0);
+        }
+    } @finally {
+        d->depth--;
+        d->pumping = false;
+    }
+    return count;
+}
+
+void cocoa_display_flush(struct cocoa_display *d)
+{
+    assert([NSThread isMainThread]);
+    if (!d) return;
+    d->depth++;
+    for (int i = d->count - 1; i >= 0; i--) {
+        if (i < d->count)
+            pump_window(d->windows[i]);
+    }
+    @autoreleasepool {
+        [NSApp updateWindows];
+    }
+    if (--d->depth == 0)
+        reap_dead(d);
+}
+
+void cocoa_surface_schedule_redraw(struct cocoa_surface *w)
+{
+    if (!w || w->closed) return;
+    w->want_draw = true;
+    w->idle_frames = 0;
+    if (w->link.paused) {
+        w->frame_due = true;
+        w->link.paused = NO;
+    }
+    if (darwin_ctx.loop)
+        yasl_loop_kick(darwin_ctx.loop);
+}
+
+static void app_init(const char *app_name)
+{
+    if (darwin_ctx.launched) return;
+    [NSApplication sharedApplication];
+    [NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
+    NSWindow.allowsAutomaticWindowTabbing = NO;
+    darwin_ctx.delegate = [[YaslAppDelegate alloc] init];
+    NSApp.delegate = darwin_ctx.delegate;
+
+    NSString *ns_name = app_name ? [NSString stringWithUTF8String:app_name] : @"YASL";
+    NSMenu *menu = [[NSMenu alloc] init];
+    NSMenuItem *app_item = [[NSMenuItem alloc] init];
+    NSMenu *app_menu = [[NSMenu alloc] initWithTitle:ns_name];
+    [app_menu addItemWithTitle:[NSString stringWithFormat:@"About %@", ns_name]
+                        action:@selector(orderFrontStandardAboutPanel:)
+                 keyEquivalent:@""];
+    [app_menu addItem:[NSMenuItem separatorItem]];
+    [app_menu addItemWithTitle:[NSString stringWithFormat:@"Quit %@", ns_name]
+                        action:@selector(terminate:)
+                 keyEquivalent:@"q"];
+    app_item.submenu = app_menu;
+    [menu addItem:app_item];
+    [app_menu release];
+    [app_item release];
+    NSApp.mainMenu = menu;
+    [menu release];
+
+    darwin_ctx.key_up_monitor = [NSEvent addLocalMonitorForEventsMatchingMask:NSEventMaskKeyUp
+        handler:^NSEvent *(NSEvent *event) {
+            if (!(event.modifierFlags & NSEventModifierFlagCommand) || !event.window)
+                return event;
+            [event.window sendEvent:event];
+            return nil;
+        }];
+    [NSApp finishLaunching];
+    darwin_ctx.launched = true;
+}
+
+static void place_window(NSWindow *window)
+{
+    if (!darwin_ctx.count) {
+        [window center];
+        NSRect frame = window.frame;
+        darwin_ctx.cascade = NSMakePoint(frame.origin.x, frame.origin.y + frame.size.height);
+        return;
+    }
+    darwin_ctx.cascade = [window cascadeTopLeftFromPoint:darwin_ctx.cascade];
+}
+
+struct cocoa_display *cocoa_display_open(struct yasl_loop *loop, const struct yasl_display_spec *spec)
+{
+    assert([NSThread isMainThread]);
+    if (darwin_ctx.open) return NULL;
+    const char *name = spec && spec->app_id ? spec->app_id : "YASL";
+    @autoreleasepool { app_init(name); }
+    darwin_ctx.base.ops = &yasl_cocoa_backend;
+    darwin_ctx.base.native_handle = (__bridge void *)[NSApplication sharedApplication];
+    darwin_ctx.open = true;
+    if (!loop) {
+        darwin_ctx.loop = yasl_loop_create();
+        darwin_ctx.owns_loop = true;
+    } else {
+        darwin_ctx.loop = loop;
+        darwin_ctx.owns_loop = false;
+    }
+    darwin_ctx.base.loop = darwin_ctx.loop;
+    if (spec) {
+        darwin_ctx.base.callbacks = spec->cbs ? *spec->cbs : (struct yasl_display_cbs){0};
+        darwin_ctx.cbs = &darwin_ctx.base.callbacks;
+        darwin_ctx.ud = spec->ud;
+        if (spec->app_id) darwin_ctx.app_id = strdup(spec->app_id);
+    }
+    return &darwin_ctx;
+}
+
+void cocoa_display_close(struct cocoa_display *d)
+{
+    if (!d) return;
+    drag_end(d, YASL_DRAG_CANCELLED);
+    assert(!d->count && "destroy every surface before its display");
+    reap_dead(d);
+    if (d->key_up_monitor) {
+        [NSEvent removeMonitor:d->key_up_monitor];
+        d->key_up_monitor = nil;
+    }
+    if (d->owns_loop && d->loop) {
+        yasl_loop_destroy(d->loop);
+        d->loop = NULL;
+        d->base.loop = NULL;
+    }
+    NSApp.delegate = nil;
+    [d->delegate release];
+    d->delegate = nil;
+    [d->hidden_cursor release];
+    free(d->app_id);
+    free(d->windows);
+    *d = (struct cocoa_display){0};
+}
+
+uint32_t cocoa_display_caps(const struct cocoa_display *d)
+{
+    return d ? (YASL_CAP_POPUPS | YASL_CAP_DRAG | YASL_CAP_DRAG_CARRY |
+                YASL_CAP_PLACE_WINDOW | YASL_CAP_PRIMARY_SELECTION |
+                YASL_CAP_CSD | YASL_CAP_NATIVE_GRAPHICS |
+                YASL_CAP_FRAME_PACING | YASL_CAP_TABLET) : 0;
+}
+
+struct cocoa_surface *cocoa_surface_create_toplevel(struct cocoa_display *d,
+                                                  const struct yasl_window_spec *spec, void *graphics_device)
+{
+    assert([NSThread isMainThread]);
+    if (!d || !d->open || !spec)
+        return NULL;
+    @autoreleasepool {
+        if (darwin_ctx.count >= darwin_ctx.capacity) {
+            int cap = darwin_ctx.capacity ? darwin_ctx.capacity * 2 : 16;
+            struct cocoa_surface **wins = realloc(darwin_ctx.windows, (size_t)cap * sizeof(*wins));
+            if (!wins) return NULL;
+            darwin_ctx.windows = wins;
+            darwin_ctx.capacity = cap;
+        }
+
+        struct cocoa_surface *w = calloc(1, sizeof(*w));
+        if (!w) return NULL;
+        w->base.display = &d->base;
+        cocoa_surface_set_callbacks(w, NULL, NULL);
+        w->clock.refresh_ns = YASL_REFRESH_DEFAULT_NS;
+        const char *t = spec->title ? spec->title : "YASL";
+        strncpy(w->title, t, sizeof(w->title) - 1);
+
+        int win_w = spec->size.x > 0 ? spec->size.x : 800;
+        int win_h = spec->size.y > 0 ? spec->size.y : 480;
+        NSWindowStyleMask style = NSWindowStyleMaskTitled | NSWindowStyleMaskClosable |
+                                  NSWindowStyleMaskMiniaturizable | NSWindowStyleMaskResizable;
+        w->window = [[YaslWindow alloc] initWithContentRect:NSMakeRect(0, 0, win_w, win_h)
+                                                  styleMask:style
+                                                    backing:NSBackingStoreBuffered
+                                                      defer:NO];
+        w->window.releasedWhenClosed = NO;
+        w->base.native_handle = (__bridge void *)w->window;
+        w->base.size = w->size;
+        w->base.scale_120 = w->scale_120;
+        w->controller = [[YaslWindowController alloc] initWithWindow:w->window];
+        w->controller.surface = w;
+        w->window.delegate = w->controller;
+        w->window.acceptsMouseMovedEvents = YES;
+        w->window.collectionBehavior = NSWindowCollectionBehaviorFullScreenPrimary;
+        w->window.titlebarAppearsTransparent = YES;
+        w->window.title = [NSString stringWithUTF8String:w->title] ?: @"YASL";
+        w->window.colorSpace = [NSColorSpace sRGBColorSpace];
+
+        w->view = [[YaslView alloc] initWithFrame:w->window.contentView.bounds];
+        w->window.contentView = w->view;
+        w->layer = (CAMetalLayer *)w->view.layer;
+        if (graphics_device) {
+            w->layer.device = (id<MTLDevice>)graphics_device;
+        } else {
+            id<MTLDevice> device = MTLCreateSystemDefaultDevice();
+            w->layer.device = device;
+            w->software_queue = [device newCommandQueue];
+            [device release];
+            if (!w->software_queue) {
+                w->window.delegate = nil;
+                w->controller.surface = NULL;
+                [w->window close];
+                [w->view release];
+                [w->controller release];
+                [w->window release];
+                free(w);
+                return NULL;
+            }
+            w->layer.framebufferOnly = NO;
+        }
+
+        w->link = [[w->view displayLinkWithTarget:w->view
+                                         selector:@selector(displayLinkFired:)] retain];
+        [w->link addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
+
+        place_window(w->window);
+        w->window.surface = w;
+        w->view.surface = w;
+        darwin_ctx.windows[darwin_ctx.count++] = w;
+
+        [w->window makeKeyAndOrderFront:nil];
+        [w->window makeFirstResponder:w->view];
+        [NSApp activate];
+
+        sync_size(w, true);
+        if (spec->tearing) {
+            w->layer.displaySyncEnabled = NO;
+            w->unpaced = true;
+        }
+        if (spec->fullscreen)
+            [w->window toggleFullScreen:nil];
+        return w;
+    }
+}
+
+static void surface_free(struct cocoa_surface *w)
+{
+    [w->link release];
+    [w->software_buffer release];
+    [w->software_queue release];
+    [w->view release];
+    [w->controller release];
+    [w->window release];
+    free(w->preedit);
+    free(w->pixels);
+    free(w);
+}
+
+static void reap_dead(struct cocoa_display *d)
+{
+    assert(d->depth == 0);
+    while (d->dead) {
+        struct cocoa_surface *w = d->dead;
+        d->dead = w->dead_next;
+        surface_free(w);
+    }
+}
+
+void cocoa_surface_destroy(struct cocoa_surface *w)
+{
+    assert([NSThread isMainThread]);
+    if (!w || w->destroyed) return;
+    if (darwin_ctx.drag.active) {
+        if (darwin_ctx.drag.origin == w || darwin_ctx.drag.carried == w)
+            drag_end(&darwin_ctx, YASL_DRAG_CANCELLED);
+        else if (darwin_ctx.drag.hover == w)
+            darwin_ctx.drag.hover = NULL;
+    }
+    if (w->is_popup && w->parent && w->parent->window) {
+        [w->parent->window removeChildWindow:w->window];
+        w->parent = NULL;
+    }
+    for (int i = 0; i < darwin_ctx.count; i++) {
+        if (darwin_ctx.windows[i]->parent == w) {
+            if (w->window && darwin_ctx.windows[i]->window)
+                [w->window removeChildWindow:darwin_ctx.windows[i]->window];
+            darwin_ctx.windows[i]->parent = NULL;
+        }
+    }
+    w->buttons = 0;
+    w->tablet_down = false;
+    darwin_ctx.depth++;
+    bool native_closed = w->closed;
+    static const struct yasl_window_cbs no_callbacks = {0};
+    w->destroyed = true;
+    w->closed = true;
+    w->cbs = &no_callbacks;
+    w->ud = NULL;
+    [w->link invalidate];
+    w->window.delegate = nil;
+    w->controller.surface = NULL;
+    w->window.surface = NULL;
+    w->view.surface = NULL;
+    if (!native_closed)
+        [w->window close];
+    input_queue_clear(&w->input);
+    w->dead_next = darwin_ctx.dead;
+    darwin_ctx.dead = w;
+
+    for (int i = 0; i < darwin_ctx.count; i++) {
+        if (darwin_ctx.windows[i] == w) {
+            darwin_ctx.windows[i] = darwin_ctx.windows[--darwin_ctx.count];
+            break;
+        }
+    }
+    if (!darwin_ctx.count) {
+        free(darwin_ctx.windows);
+        darwin_ctx.windows = NULL;
+        darwin_ctx.capacity = 0;
+        darwin_ctx.cascade = NSZeroPoint;
+    }
+    darwin_ctx.depth--;
+    if (darwin_ctx.loop)
+        yasl_loop_kick(darwin_ctx.loop);
+}
+
+struct cocoa_display *cocoa_surface_display(const struct cocoa_surface *w)
+{
+    return w ? &darwin_ctx : NULL;
+}
+
+void cocoa_surface_set_title(struct cocoa_surface *w, const char *title)
+{
+    if (!w || w->closed || !title) return;
+    strncpy(w->title, title, sizeof(w->title) - 1);
+    w->window.title = [NSString stringWithUTF8String:w->title] ?: @"YASL";
+}
+
+void cocoa_surface_set_background_color(struct cocoa_surface *w, uint32_t bg)
+{
+    if (!w || w->closed) return;
+    w->bg_color = bg;
+    double r = ((bg >> 16) & 0xff) / 255.0;
+    double g = ((bg >> 8) & 0xff) / 255.0;
+    double b = (bg & 0xff) / 255.0;
+    w->window.backgroundColor = [NSColor colorWithSRGBRed:r green:g blue:b alpha:1.0];
+    bool dark = 0.299 * r + 0.587 * g + 0.114 * b < 0.5;
+    w->window.appearance = [NSAppearance appearanceNamed:
+        dark ? NSAppearanceNameDarkAqua : NSAppearanceNameAqua];
+}
+
+void cocoa_surface_set_cursor(struct cocoa_surface *w, enum yasl_cursor cursor)
+{
+    if (!w || w->closed || cursor == w->cursor || (unsigned)cursor > YASL_CURSOR_HIDDEN) return;
+    w->cursor = cursor;
+    NSPoint p = [w->view convertPoint:w->window.mouseLocationOutsideOfEventStream fromView:nil];
+    if (w->window.isKeyWindow && NSPointInRect(p, w->view.bounds))
+        [cocoa_cursor(cursor) set];
+}
+
+bool cocoa_surface_place_under_pointer(struct cocoa_surface *w, struct yasl_vector2i at)
+{
+    if (!w || w->closed || !w->window) return false;
+    CGFloat scale = w->window.backingScaleFactor;
+    if (scale < 1.0) scale = 1.0;
+    NSPoint mouse = [NSEvent mouseLocation];
+    NSRect content = [w->window contentRectForFrameRect:w->window.frame];
+    NSPoint origin = NSMakePoint(mouse.x - at.x / scale,
+                                 mouse.y - content.size.height + at.y / scale);
+    [w->window setFrameOrigin:[w->window frameRectForContentRect:
+        (NSRect){ .origin = origin, .size = content.size }].origin];
+    return true;
+}
+
+void cocoa_surface_set_ime_caret(struct cocoa_surface *w, struct yasl_rect2i caret)
+{
+    if (w) w->ime_caret = caret;
+}
+
+const char *cocoa_surface_ime_preedit(const struct cocoa_surface *w)
+{
+    return w ? w->preedit : NULL;
+}
+
+bool cocoa_surface_ime_preedit_cursor(const struct cocoa_surface *w, int *begin, int *end)
+{
+    (void)w; (void)begin; (void)end;
+    return false;
+}
+
+static NSPasteboard *pasteboard_for_selection(enum yasl_selection sel)
+{
+    switch (sel) {
+    case YASL_CLIPBOARD:
+        return [NSPasteboard generalPasteboard];
+    case YASL_PRIMARY:
+        return [NSPasteboard pasteboardWithName:@"dev.wsap.yasl.primary"];
+    default:
+        return nil;
+    }
+}
+
+void cocoa_display_copy(struct cocoa_display *d, enum yasl_selection sel, const char *text)
+{
+    (void)d;
+    if (!text) return;
+    NSPasteboard *pb = pasteboard_for_selection(sel);
+    if (!pb) return;
+    NSString *s = [NSString stringWithUTF8String:text];
+    if (!s) return;
+    [pb clearContents];
+    [pb setString:s forType:NSPasteboardTypeString];
+}
+
+void cocoa_display_paste(struct cocoa_display *d, enum yasl_selection sel, struct cocoa_surface *target)
+{
+    (void)d;
+    if (!target) return;
+    NSPasteboard *pb = pasteboard_for_selection(sel);
+    if (!pb) return;
+    NSString *s = [pb stringForType:NSPasteboardTypeString];
+    const char *utf8 = s ? s.UTF8String : NULL;
+    if (utf8) {
+        struct yasl_input_event ev = {
+            .kind = YASL_INPUT_PASTE,
+            .surface = &target->base,
+            .paste = { .text = utf8, .len = strlen(utf8) },
+        };
+        input_queue_push(&target->input, &ev);
+    }
+}
+
+int cocoa_display_modifiers(const struct cocoa_display *d)
+{
+    (void)d;
+    return (int)cocoa_mods(NSEvent.modifierFlags);
+}
+
+struct yasl_geometry cocoa_surface_geometry(const struct cocoa_surface *w)
+{
+    return (struct yasl_geometry){
+        .size = w ? w->size : (struct yasl_vector2i){0},
+        .scale_120 = w ? w->scale_120 : YASL_SCALE_UNIT,
+    };
+}
+
+static bool popup_spec_valid(const struct cocoa_surface *parent,
+                             const struct yasl_popup_spec *spec)
+{
+    if (!parent || !spec) return false;
+    int parent_cx = parent->is_popup ? parent->content_offset.x : 0;
+    int parent_cy = parent->is_popup ? parent->content_offset.y : 0;
+    int64_t x = (int64_t)spec->anchor.x - parent_cx;
+    int64_t y = (int64_t)spec->anchor.y - parent_cy;
+    return x >= -32768 && x <= 32767 && y >= -32768 && y <= 32767 &&
+           spec->anchor.width >= 0 && spec->anchor.height >= 0 &&
+           spec->size.x > 0 && spec->size.y > 0 &&
+           spec->size.x <= 32767 && spec->size.y <= 32767 &&
+           spec->content_offset.x >= 0 && spec->content_offset.y >= 0 &&
+           spec->content_size.x >= 0 && spec->content_size.y >= 0 &&
+           (int64_t)spec->content_offset.x + spec->content_size.x <= spec->size.x &&
+           (int64_t)spec->content_offset.y + spec->content_size.y <= spec->size.y;
+}
+
+static NSRect popup_calc_frame(struct cocoa_surface *parent, const struct yasl_popup_spec *spec)
+{
+    CGFloat scale = parent->window ? parent->window.backingScaleFactor : 1.0;
+    if (scale < 1.0) scale = 1.0;
+
+    CGFloat pcx = (parent->is_popup ? parent->content_offset.x : 0) / scale;
+    CGFloat pcy = (parent->is_popup ? parent->content_offset.y : 0) / scale;
+
+    CGFloat pw = spec->size.x / scale;
+    CGFloat ph = spec->size.y / scale;
+    CGFloat ax = (spec->anchor.x / scale) - pcx;
+    CGFloat ay = (spec->anchor.y / scale) - pcy;
+    CGFloat aw = spec->anchor.width / scale;
+    CGFloat ah = spec->anchor.height / scale;
+    CGFloat ox = spec->content_offset.x / scale;
+    CGFloat oy = spec->content_offset.y / scale;
+
+    CGFloat top_left_x = spec->beside ? (ax + aw - ox) : (ax - ox);
+    CGFloat top_left_y = spec->beside ? (ay - oy) : (ay + ah - oy);
+
+    CGFloat view_h = parent->view.bounds.size.height;
+    CGFloat view_y = view_h - top_left_y;
+
+    NSPoint ptInView = NSMakePoint(top_left_x, view_y);
+    NSPoint ptInWin = [parent->view convertPoint:ptInView toView:nil];
+    NSPoint screen_tl = [parent->window convertPointToScreen:ptInWin];
+
+    NSRect frame = NSMakeRect(screen_tl.x, screen_tl.y - ph, pw, ph);
+
+    NSScreen *screen = parent->window.screen ?: [NSScreen mainScreen];
+    if (screen) {
+        NSRect visible = screen.visibleFrame;
+        if (NSMaxX(frame) > NSMaxX(visible)) {
+            if (spec->beside) {
+                CGFloat flip_tl_x = ax - pw + ox;
+                NSPoint flip_v = NSMakePoint(flip_tl_x, view_y);
+                NSPoint flip_w = [parent->view convertPoint:flip_v toView:nil];
+                NSPoint flip_s = [parent->window convertPointToScreen:flip_w];
+                frame.origin.x = flip_s.x;
+            }
+            if (NSMaxX(frame) > NSMaxX(visible))
+                frame.origin.x = NSMaxX(visible) - frame.size.width;
+        }
+        if (NSMinX(frame) < NSMinX(visible))
+            frame.origin.x = NSMinX(visible);
+
+        if (NSMinY(frame) < NSMinY(visible)) {
+            if (!spec->beside) {
+                CGFloat flip_top_y = ay - ph + oy;
+                CGFloat flip_vy = view_h - flip_top_y;
+                NSPoint flip_v = NSMakePoint(top_left_x, flip_vy);
+                NSPoint flip_w = [parent->view convertPoint:flip_v toView:nil];
+                NSPoint flip_s = [parent->window convertPointToScreen:flip_w];
+                frame.origin.y = flip_s.y - ph;
+            }
+            if (NSMinY(frame) < NSMinY(visible))
+                frame.origin.y = NSMinY(visible);
+        }
+        if (NSMaxY(frame) > NSMaxY(visible))
+            frame.origin.y = NSMaxY(visible) - frame.size.height;
+    }
+    return frame;
+}
+
+struct cocoa_surface *cocoa_surface_create_popup(struct cocoa_surface *parent,
+        const struct yasl_popup_spec *spec)
+{
+    assert([NSThread isMainThread]);
+    if (!parent || parent->closed || !parent->window || !parent->view ||
+        !popup_spec_valid(parent, spec))
+        return NULL;
+
+    @autoreleasepool {
+        if (darwin_ctx.count >= darwin_ctx.capacity) {
+            int cap = darwin_ctx.capacity ? darwin_ctx.capacity * 2 : 16;
+            struct cocoa_surface **wins = realloc(darwin_ctx.windows, (size_t)cap * sizeof(*wins));
+            if (!wins) return NULL;
+            darwin_ctx.windows = wins;
+            darwin_ctx.capacity = cap;
+        }
+
+        struct cocoa_surface *w = calloc(1, sizeof(*w));
+        if (!w) return NULL;
+        w->base.display = parent->base.display;
+        cocoa_surface_set_callbacks(w, NULL, NULL);
+        w->clock.refresh_ns = parent->clock.refresh_ns ? parent->clock.refresh_ns : YASL_REFRESH_DEFAULT_NS;
+        w->parent = parent;
+        w->is_popup = true;
+        w->content_offset = spec->content_offset;
+
+        NSRect frame = popup_calc_frame(parent, spec);
+        NSWindowStyleMask style = NSWindowStyleMaskBorderless;
+        w->window = [[YaslWindow alloc] initWithContentRect:frame
+                                                  styleMask:style
+                                                    backing:NSBackingStoreBuffered
+                                                      defer:NO];
+        w->window.releasedWhenClosed = NO;
+        w->base.native_handle = (__bridge void *)w->window;
+        w->base.size = w->size;
+        w->base.scale_120 = w->scale_120;
+        w->window.opaque = NO;
+        w->window.backgroundColor = [NSColor clearColor];
+        w->window.hasShadow = NO;
+        w->controller = [[YaslWindowController alloc] initWithWindow:w->window];
+        w->controller.surface = w;
+        w->window.delegate = w->controller;
+        w->window.acceptsMouseMovedEvents = YES;
+        w->window.colorSpace = [NSColorSpace sRGBColorSpace];
+
+        w->view = [[YaslView alloc] initWithFrame:w->window.contentView.bounds];
+        w->window.contentView = w->view;
+        w->layer = (CAMetalLayer *)w->view.layer;
+        w->layer.opaque = NO;
+        w->layer.device = parent->layer.device;
+        if (parent->software_queue) {
+            w->software_queue = [w->layer.device newCommandQueue];
+            if (!w->software_queue) {
+                w->window.delegate = nil;
+                w->controller.surface = NULL;
+                [w->view release];
+                [w->controller release];
+                [w->window release];
+                free(w);
+                return NULL;
+            }
+            w->layer.framebufferOnly = NO;
+        } else {
+            w->layer.framebufferOnly = parent->layer.framebufferOnly;
+        }
+
+        w->link = [[w->view displayLinkWithTarget:w->view
+                                         selector:@selector(displayLinkFired:)] retain];
+        [w->link addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
+
+        w->window.surface = w;
+        w->view.surface = w;
+        darwin_ctx.windows[darwin_ctx.count++] = w;
+
+        [parent->window addChildWindow:w->window ordered:NSWindowAbove];
+        [w->window orderFront:nil];
+
+        sync_size(w, true);
+        return w;
+    }
+}
+
+bool cocoa_surface_popup_reposition(struct cocoa_surface *popup,
+        const struct yasl_popup_spec *spec)
+{
+    if (!popup || popup->closed || !popup->is_popup || !popup->parent ||
+        !popup->parent->window || !popup->parent->view ||
+        !popup_spec_valid(popup->parent, spec))
+        return false;
+
+    @autoreleasepool {
+        popup->content_offset = spec->content_offset;
+        NSRect frame = popup_calc_frame(popup->parent, spec);
+        [popup->window setFrame:frame display:YES];
+        sync_size(popup, false);
+        return true;
+    }
+}
+
+bool cocoa_surface_start_interactive_move(struct cocoa_surface *s)
+{
+    if (!s || !s->window) return false;
+    [s->window performWindowDragWithEvent:[NSApp currentEvent]];
+    return true;
+}
+
+static NSImage *image_from_pixels(const uint32_t *pixels, int width, int height)
+{
+    if (!pixels || width <= 0 || height <= 0)
+        return nil;
+    CGColorSpaceRef cs = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
+    if (!cs) return nil;
+    size_t bytes = (size_t)width * (size_t)height * 4;
+    CFDataRef data = CFDataCreate(kCFAllocatorDefault, (const UInt8 *)pixels, (CFIndex)bytes);
+    CGDataProviderRef provider = data ? CGDataProviderCreateWithCFData(data) : NULL;
+    if (data)
+        CFRelease(data);
+    if (!provider) {
+        CGColorSpaceRelease(cs);
+        return nil;
+    }
+    CGImageRef cgImage = CGImageCreate((size_t)width, (size_t)height,
+                                       8, 32, (size_t)width * 4, cs,
+                                       kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little,
+                                       provider, NULL, NO, kCGRenderingIntentDefault);
+    CGDataProviderRelease(provider);
+    CGColorSpaceRelease(cs);
+    if (!cgImage)
+        return nil;
+    NSImage *image = [[NSImage alloc] initWithCGImage:cgImage size:NSMakeSize(width, height)];
+    CGImageRelease(cgImage);
+    return image;
+}
+
+bool cocoa_display_drag_start(struct cocoa_display *d, struct cocoa_surface *origin,
+                             const struct yasl_drag_image *image,
+                             const struct yasl_drag_listener *l, void *ud)
+{
+    if (!d || !origin || d->drag.active || !l)
+        return false;
+    d->drag.active = true;
+    d->drag.origin = origin;
+    d->drag.carried = NULL;
+    d->drag.hover = NULL;
+    d->drag.hover_pos = (struct yasl_vector2i){0};
+    d->drag.listener = *l;
+    d->drag.ud = ud;
+    [d->drag.image release];
+    d->drag.image = nil;
+    if (d->drag.image_window) {
+        [d->drag.image_window close];
+        [d->drag.image_window release];
+        d->drag.image_window = nil;
+    }
+    if (image && image->pixels && image->size.x > 0 && image->size.y > 0) {
+        d->drag.image = image_from_pixels(image->pixels, image->size.x, image->size.y);
+        d->drag.image_size = image->size;
+        d->drag.image_hotspot = image->hotspot;
+        if (d->drag.image) {
+            CGFloat scale = origin->window ? origin->window.backingScaleFactor : 1.0;
+            if (scale < 1.0) scale = 1.0;
+            CGFloat pt_w = image->size.x / scale;
+            CGFloat pt_h = image->size.y / scale;
+            NSWindow *win = [[NSWindow alloc] initWithContentRect:NSMakeRect(0, 0, pt_w, pt_h)
+                                                        styleMask:NSWindowStyleMaskBorderless
+                                                          backing:NSBackingStoreBuffered
+                                                            defer:NO];
+            win.releasedWhenClosed = NO;
+            win.opaque = NO;
+            win.backgroundColor = [NSColor clearColor];
+            win.ignoresMouseEvents = YES;
+            win.level = NSFloatingWindowLevel;
+            win.hasShadow = YES;
+            NSImageView *iv = [[NSImageView alloc] initWithFrame:NSMakeRect(0, 0, pt_w, pt_h)];
+            iv.image = d->drag.image;
+            iv.imageScaling = NSImageScaleAxesIndependently;
+            win.contentView = iv;
+            [iv release];
+            d->drag.image_window = win;
+            NSPoint mouse = [NSEvent mouseLocation];
+            [win setFrameOrigin:NSMakePoint(mouse.x - image->hotspot.x / scale,
+                                            mouse.y - pt_h + image->hotspot.y / scale)];
+            [win orderFront:nil];
+        }
+    }
+    update_drag_hover(d, [NSEvent mouseLocation]);
+    return true;
+}
+
+void cocoa_display_drag_cancel(struct cocoa_display *d)
+{
+    drag_end(d, YASL_DRAG_CANCELLED);
+}
+
+bool cocoa_surface_drag_carry(struct cocoa_surface *w, struct yasl_vector2i offset)
+{
+    if (!w || w->closed || !darwin_ctx.drag.active)
+        return false;
+    if (darwin_ctx.drag.image_window) {
+        [darwin_ctx.drag.image_window close];
+        [darwin_ctx.drag.image_window release];
+        darwin_ctx.drag.image_window = nil;
+    }
+    darwin_ctx.drag.carried = w;
+    darwin_ctx.drag.carry_offset = offset;
+    return cocoa_surface_place_under_pointer(w, offset);
+}
+
+bool cocoa_surface_start_interactive_resize(struct cocoa_surface *s, enum yasl_resize_edge edge)
+{
+    (void)s; (void)edge;
+    return false;
+}
+
+bool cocoa_surface_show_window_menu(struct cocoa_surface *s, struct yasl_vector2i pos)
+{
+    (void)s; (void)pos;
+    return false;
+}
+
+void *cocoa_display_get_native_handle(struct cocoa_display *d)
+{
+    return d ? (void *)NSApp : NULL;
+}
+
+void *cocoa_surface_get_native_handle(struct cocoa_surface *s)
+{
+    return s ? (void *)s->window : NULL;
+}
+
+
+
+void cocoa_surface_set_callbacks(struct cocoa_surface *w,
+        const struct yasl_window_cbs *cbs, void *ud)
+{
+    if (!w || w->closed) return;
+    w->base.callbacks = cbs ? *cbs : (struct yasl_window_cbs){0};
+    w->cbs = &w->base.callbacks;
+    w->ud = ud;
+}
+
+bool cocoa_surface_input_poll(struct cocoa_surface *w, struct yasl_input_event *ev)
+{
+    if (!w || !ev || !input_queue_pop(&w->input, ev))
+        return false;
+    if (ev->kind == YASL_INPUT_RESET) {
+        w->buttons = 0;
+        w->tablet_down = false;
+        w->mods = 0;
+        if (w->preedit) {
+            free(w->preedit);
+            w->preedit = NULL;
+        }
+    }
+    return true;
+}
+
+uint32_t cocoa_surface_state(const struct cocoa_surface *w)
+{
+    return w ? w->state : 0;
+}
+
+struct yasl_timing cocoa_surface_timing(const struct cocoa_surface *w)
+{
+    struct yasl_timing timing = {0};
+    if (w) {
+        timing.refresh_ns = w->clock.refresh_ns;
+        timing.last_present_ns = w->clock.last_present_ns;
+        timing.next_present_ns = yasl_clock_next_present_ns(&w->clock);
+        timing.frames_skipped = w->frames_skipped;
+        timing.source = w->clock.source;
+        yasl_clock_resize_stats(&w->clock, &timing.resize);
+    }
+    return timing;
+}
+
+uint64_t cocoa_surface_frame_time_ns(struct cocoa_surface *w, uint64_t now)
+{
+    return w ? yasl_clock_frame_timestamp_ns(&w->clock, now) : now;
+}
+
+static struct yasl_display *impl_display_open(struct yasl_loop *loop, const struct yasl_display_spec *spec)
+{
+    struct cocoa_display *result = cocoa_display_open(loop, spec);
+    return result ? &result->base : NULL;
+}
+
+static void impl_display_close(struct yasl_display *d)
+{
+    cocoa_display_close((struct cocoa_display *)d);
+}
+
+static uint32_t impl_display_caps(const struct yasl_display *d)
+{
+    return cocoa_display_caps((const struct cocoa_display *)d);
+}
+
+static int impl_display_dispatch_timeout(struct yasl_display *d, int timeout_ms)
+{
+    return cocoa_display_dispatch_timeout((struct cocoa_display *)d, timeout_ms);
+}
+
+static void impl_display_flush(struct yasl_display *d)
+{
+    cocoa_display_flush((struct cocoa_display *)d);
+}
+
+static int impl_display_modifiers(const struct yasl_display *d)
+{
+    return cocoa_display_modifiers((const struct cocoa_display *)d);
+}
+
+static void impl_display_copy(struct yasl_display *d, enum yasl_selection sel, const char *text)
+{
+    cocoa_display_copy((struct cocoa_display *)d, sel, text);
+}
+
+static void impl_display_paste(struct yasl_display *d, enum yasl_selection sel, struct yasl_surface *target)
+{
+    cocoa_display_paste((struct cocoa_display *)d, sel, (struct cocoa_surface *)target);
+}
+
+static bool impl_display_drag_start(struct yasl_display *d, struct yasl_surface *origin, const struct yasl_drag_image *image, const struct yasl_drag_listener *l, void *ud)
+{
+    return cocoa_display_drag_start((struct cocoa_display *)d, (struct cocoa_surface *)origin, image, l, ud);
+}
+
+static void impl_display_drag_cancel(struct yasl_display *d)
+{
+    cocoa_display_drag_cancel((struct cocoa_display *)d);
+}
+
+static struct yasl_surface *impl_surface_create_toplevel(struct yasl_display *d,
+        const struct yasl_window_spec *spec, void *graphics_device)
+{
+    struct cocoa_surface *result = cocoa_surface_create_toplevel((struct cocoa_display *)d, spec, graphics_device);
+    return result ? &result->base : NULL;
+}
+
+static struct yasl_surface *impl_surface_create_popup(struct yasl_surface *parent, const struct yasl_popup_spec *spec)
+{
+    struct cocoa_surface *result = cocoa_surface_create_popup((struct cocoa_surface *)parent, spec);
+    return result ? &result->base : NULL;
+}
+
+static bool impl_surface_popup_reposition(struct yasl_surface *popup, const struct yasl_popup_spec *spec)
+{
+    return cocoa_surface_popup_reposition((struct cocoa_surface *)popup, spec);
+}
+
+static void impl_surface_destroy(struct yasl_surface *s)
+{
+    cocoa_surface_destroy((struct cocoa_surface *)s);
+}
+
+static struct yasl_display *impl_surface_display(const struct yasl_surface *s)
+{
+    struct cocoa_display *result = cocoa_surface_display((const struct cocoa_surface *)s);
+    return result ? &result->base : NULL;
+}
+
+static void impl_surface_set_callbacks(struct yasl_surface *s, const struct yasl_window_cbs *cbs, void *ud)
+{
+    cocoa_surface_set_callbacks((struct cocoa_surface *)s, cbs, ud);
+}
+
+static void impl_surface_set_title(struct yasl_surface *s, const char *title)
+{
+    cocoa_surface_set_title((struct cocoa_surface *)s, title);
+}
+
+static void impl_surface_schedule_redraw(struct yasl_surface *s)
+{
+    cocoa_surface_schedule_redraw((struct cocoa_surface *)s);
+}
+
+static bool impl_surface_present(struct yasl_surface *s, const struct yasl_framebuffer *fb, const struct yasl_damage_list *damage)
+{
+    return cocoa_surface_present((struct cocoa_surface *)s, fb, damage);
+}
+
+static bool impl_surface_input_poll(struct yasl_surface *s, struct yasl_input_event *ev)
+{
+    return cocoa_surface_input_poll((struct cocoa_surface *)s, ev);
+}
+
+static struct yasl_geometry impl_surface_geometry(const struct yasl_surface *s)
+{
+    return cocoa_surface_geometry((const struct cocoa_surface *)s);
+}
+
+static uint32_t impl_surface_state(const struct yasl_surface *s)
+{
+    return cocoa_surface_state((const struct cocoa_surface *)s);
+}
+
+static struct yasl_timing impl_surface_timing(const struct yasl_surface *s)
+{
+    return cocoa_surface_timing((const struct cocoa_surface *)s);
+}
+
+static uint64_t impl_surface_frame_time_ns(struct yasl_surface *s, uint64_t now)
+{
+    return cocoa_surface_frame_time_ns((struct cocoa_surface *)s, now);
+}
+
+static void impl_surface_set_cursor(struct yasl_surface *s, enum yasl_cursor cursor)
+{
+    cocoa_surface_set_cursor((struct cocoa_surface *)s, cursor);
+}
+
+static void impl_surface_set_background_color(struct yasl_surface *s, uint32_t bg)
+{
+    cocoa_surface_set_background_color((struct cocoa_surface *)s, bg);
+}
+
+static const char *impl_surface_ime_preedit(const struct yasl_surface *s)
+{
+    return cocoa_surface_ime_preedit((const struct cocoa_surface *)s);
+}
+
+static bool impl_surface_ime_preedit_cursor(const struct yasl_surface *s, int *begin, int *end)
+{
+    return cocoa_surface_ime_preedit_cursor((const struct cocoa_surface *)s, begin, end);
+}
+
+static void impl_surface_set_ime_caret(struct yasl_surface *s, struct yasl_rect2i caret)
+{
+    cocoa_surface_set_ime_caret((struct cocoa_surface *)s, caret);
+}
+
+static bool impl_surface_start_interactive_move(struct yasl_surface *s)
+{
+    return cocoa_surface_start_interactive_move((struct cocoa_surface *)s);
+}
+
+static bool impl_surface_start_interactive_resize(struct yasl_surface *s, enum yasl_resize_edge edge)
+{
+    return cocoa_surface_start_interactive_resize((struct cocoa_surface *)s, edge);
+}
+
+static bool impl_surface_show_window_menu(struct yasl_surface *s, struct yasl_vector2i pos)
+{
+    return cocoa_surface_show_window_menu((struct cocoa_surface *)s, pos);
+}
+
+static bool impl_surface_drag_carry(struct yasl_surface *s, struct yasl_vector2i offset)
+{
+    return cocoa_surface_drag_carry((struct cocoa_surface *)s, offset);
+}
+
+static bool impl_surface_place_under_pointer(struct yasl_surface *s, struct yasl_vector2i at)
+{
+    return cocoa_surface_place_under_pointer((struct cocoa_surface *)s, at);
+}
+
+static void *impl_display_get_native_handle(struct yasl_display *d)
+{
+    return cocoa_display_get_native_handle((struct cocoa_display *)d);
+}
+
+static void *impl_surface_get_native_handle(struct yasl_surface *s)
+{
+    return cocoa_surface_get_native_handle((struct cocoa_surface *)s);
+}
+
+static bool impl_surface_get_native_frame(struct yasl_surface *s,
+        const struct yasl_framebuffer *target, struct yasl_native_frame *out)
+{
+    struct cocoa_surface *w = (struct cocoa_surface *)s;
+    if (w->closed || !w->rendering || w->did_present || !w->drawable ||
+        target->pixels != w->frame.target.pixels ||
+        target->size.x != w->size.x || target->size.y != w->size.y)
+        return false;
+    *out = (struct yasl_native_frame){(void *)w->drawable, w->transaction};
+    return true;
+}
+
+const struct yasl_backend_ops yasl_cocoa_backend = {
+    .type = YASL_BACKEND_COCOA,
+    .display_open = impl_display_open,
+    .display_close = impl_display_close,
+    .display_caps = impl_display_caps,
+    .display_dispatch_timeout = impl_display_dispatch_timeout,
+    .display_flush = impl_display_flush,
+    .display_modifiers = impl_display_modifiers,
+    .display_copy = impl_display_copy,
+    .display_paste = impl_display_paste,
+    .display_drag_start = impl_display_drag_start,
+    .display_drag_cancel = impl_display_drag_cancel,
+    .surface_create_toplevel = impl_surface_create_toplevel,
+    .surface_create_popup = impl_surface_create_popup,
+    .surface_popup_reposition = impl_surface_popup_reposition,
+    .surface_destroy = impl_surface_destroy,
+    .surface_display = impl_surface_display,
+    .surface_set_callbacks = impl_surface_set_callbacks,
+    .surface_set_title = impl_surface_set_title,
+    .surface_schedule_redraw = impl_surface_schedule_redraw,
+    .surface_present = impl_surface_present,
+    .surface_input_poll = impl_surface_input_poll,
+    .surface_geometry = impl_surface_geometry,
+    .surface_state = impl_surface_state,
+    .surface_timing = impl_surface_timing,
+    .surface_frame_time_ns = impl_surface_frame_time_ns,
+    .surface_set_cursor = impl_surface_set_cursor,
+    .surface_set_background_color = impl_surface_set_background_color,
+    .surface_ime_preedit = impl_surface_ime_preedit,
+    .surface_ime_preedit_cursor = impl_surface_ime_preedit_cursor,
+    .surface_set_ime_caret = impl_surface_set_ime_caret,
+    .surface_start_interactive_move = impl_surface_start_interactive_move,
+    .surface_start_interactive_resize = impl_surface_start_interactive_resize,
+    .surface_show_window_menu = impl_surface_show_window_menu,
+    .surface_drag_carry = impl_surface_drag_carry,
+    .surface_place_under_pointer = impl_surface_place_under_pointer,
+    .display_get_native_handle = impl_display_get_native_handle,
+    .surface_get_native_handle = impl_surface_get_native_handle,
+    .surface_get_native_frame = impl_surface_get_native_frame,
+};
+
+NSApplication *yasl_cocoa_display_get_application(struct yasl_display *d)
+{
+    return (d && yasl_display_backend(d) == YASL_BACKEND_COCOA) ?
+        (NSApplication *)yasl_display_get_native_handle(d) : nil;
+}
+
+NSWindow *yasl_cocoa_surface_get_window(struct yasl_surface *s)
+{
+    return (s && s->display && yasl_display_backend(s->display) == YASL_BACKEND_COCOA) ?
+        (NSWindow *)yasl_surface_get_native_handle(s) : nil;
+}
+
+NSView *yasl_cocoa_surface_get_view(struct yasl_surface *s)
+{
+    NSWindow *w = yasl_cocoa_surface_get_window(s);
+    return w ? w.contentView : nil;
+}