Simplify the public event and CPU API

Applications now need far less ceremony: hello.c is a 20-line loop that
handles REFRESH, CLOSE and QUIT and draws into the surface's own pixels.

- Fold GEOMETRY, STATE and FOCUS into one WINDOW event carrying size,
  scale and state; unchanged values send nothing.
- Guarantee REFRESH once a window has a size and after every resize,
  never at size zero.
- Merge DROP_HOVER into DROP with over/leave/data actions and give drag
  and drop actions enums.
- Keep event strings valid until the next wait and drop
  yasl_event_release; empty or failed waits report NONE.
- Replace copy-in presentation with a lent pixel buffer:
  yasl_cpu_pixels and yasl_cpu_present.
- Remove yasl_poll_event, yasl_cpu_read_pixels, unused event fields and
  comments that restated names.
- Wayland: resize floating windows in request_size instead of reporting
  it unsupported, and stop marking new GPU surfaces as Vulkan so
  yasl_vulkan_create_surface no longer fails with NATIVE_WINDOW_IN_USE.

Also includes the in-progress public API refactor that was uncommitted
in the tree (removal of the app/loop layer, new surface, GL and Vulkan
entry points).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 47 insertions, 32 deletions

diff --git a/src/platform/wayland/popup.c b/src/platform/wayland/popup.c
index 44c7206..c563eb4 100644
--- a/src/platform/wayland/popup.c
+++ b/src/platform/wayland/popup.c
@@ -24,9 +24,19 @@ static const struct xdg_popup_listener popup_listener = {
 };
 
 static bool popup_spec_valid(const struct wayland_surface *parent,
-                             const struct yasl_popup_spec *spec)
+                             const struct yasl_private_popup_spec *spec)
 {
     if (!parent || !spec) return false;
+    if (spec->positioner_explicit &&
+        (spec->anchor_edges > XDG_POSITIONER_ANCHOR_BOTTOM_RIGHT ||
+         spec->gravity > XDG_POSITIONER_GRAVITY_BOTTOM_RIGHT ||
+         (spec->constraints & ~(unsigned)(XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_SLIDE_X |
+             XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_SLIDE_Y |
+             XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_FLIP_X |
+             XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_FLIP_Y |
+             XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_RESIZE_X |
+             XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_RESIZE_Y))))
+        return false;
     int64_t x = (int64_t)spec->anchor.x - parent->content.x;
     int64_t y = (int64_t)spec->anchor.y - parent->content.y;
     return x >= INT_MIN && x <= INT_MAX && y >= INT_MIN && y <= INT_MAX &&
@@ -37,29 +47,29 @@ static bool popup_spec_valid(const struct wayland_surface *parent,
            (int64_t)spec->content_offset.y + spec->content_size.y <= spec->size.y;
 }
 
-static bool popup_apply_spec(struct wayland_surface *w, const struct yasl_popup_spec *spec)
+static bool popup_apply_spec(struct wayland_surface *w, const struct yasl_private_popup_spec *spec)
 {
     uint32_t scale = w->parent->scale_120;
-    struct yasl_vector2i logical = {
-        .x = (int)(((int64_t)spec->size.x * YASL_SCALE_UNIT + scale - 1) / scale),
-        .y = (int)(((int64_t)spec->size.y * YASL_SCALE_UNIT + scale - 1) / scale),
+    struct yasl_private_vector2i logical = {
+        .x = (int)(((int64_t)spec->size.x * YASL_PRIVATE_SCALE_UNIT + scale - 1) / scale),
+        .y = (int)(((int64_t)spec->size.y * YASL_PRIVATE_SCALE_UNIT + scale - 1) / scale),
     };
     int width = device_px(logical.x, scale);
     int height = device_px(logical.y, scale);
     size_t bytes;
     if (logical.x <= 0 || logical.y <= 0 || !buffer_size(width, height, &bytes))
         return false;
-    struct yasl_vector2i content = spec->content_size;
+    struct yasl_private_vector2i content = spec->content_size;
     if (!content.x) content.x = spec->size.x - spec->content_offset.x;
     if (!content.y) content.y = spec->size.y - spec->content_offset.y;
     bool rescaled = scale != w->scale_120;
     w->scale_120 = w->pending_scale_120 = scale;
-    w->scale_factor = (double)scale / YASL_SCALE_UNIT;
+    w->scale_factor = (double)scale / YASL_PRIVATE_SCALE_UNIT;
     w->width = width;
     w->height = height;
     w->logical_width = logical.x;
     w->logical_height = logical.y;
-    w->content = (struct yasl_rect2i){
+    w->content = (struct yasl_private_rect2i){
         .x = spec->content_offset.x, .y = spec->content_offset.y,
         .width = content.x, .height = content.y
     };
@@ -67,20 +77,20 @@ static bool popup_apply_spec(struct wayland_surface *w, const struct yasl_popup_
         w->buffers[i].presented = false;
     if (w->viewport)
         wp_viewport_set_destination(w->viewport, logical.x, logical.y);
-    else if ((rescaled || !w->configured) && scale % YASL_SCALE_UNIT == 0 &&
+    else if ((rescaled || !w->configured) && scale % YASL_PRIVATE_SCALE_UNIT == 0 &&
              wl_proxy_get_version((struct wl_proxy *)w->surface) >=
              WL_SURFACE_SET_BUFFER_SCALE_SINCE_VERSION)
-        wl_surface_set_buffer_scale(w->surface, (int32_t)(scale / YASL_SCALE_UNIT));
+        wl_surface_set_buffer_scale(w->surface, (int32_t)(scale / YASL_PRIVATE_SCALE_UNIT));
     return true;
 }
 
 static void popup_set_geometry(struct wayland_surface *w)
 {
     uint32_t scale = w->scale_120;
-    int gx = yasl_scale_to_logical(w->content.x, scale);
-    int gy = yasl_scale_to_logical(w->content.y, scale);
-    int gw = yasl_scale_to_logical(w->content.width, scale);
-    int gh = yasl_scale_to_logical(w->content.height, scale);
+    int gx = yasl_private_scale_to_logical(w->content.x, scale);
+    int gy = yasl_private_scale_to_logical(w->content.y, scale);
+    int gw = yasl_private_scale_to_logical(w->content.width, scale);
+    int gh = yasl_private_scale_to_logical(w->content.height, scale);
     if (gw < 1) gw = 1;
     if (gh < 1) gh = 1;
     if (gx + gw > w->logical_width)
@@ -91,41 +101,45 @@ static void popup_set_geometry(struct wayland_surface *w)
 }
 
 static struct xdg_positioner *popup_positioner(struct wayland_surface *w,
-        const struct yasl_popup_spec *spec)
+        const struct yasl_private_popup_spec *spec)
 {
     struct wayland_surface *parent = w->parent;
     struct xdg_positioner *pos = xdg_wm_base_create_positioner(w->conn->wm_base);
     if (!pos)
         return NULL;
     uint32_t scale = parent->scale_120;
-    int gw = yasl_scale_to_logical(w->content.width, scale);
-    int gh = yasl_scale_to_logical(w->content.height, scale);
+    int gw = yasl_private_scale_to_logical(w->content.width, scale);
+    int gh = yasl_private_scale_to_logical(w->content.height, scale);
     xdg_positioner_set_size(pos, gw > 0 ? gw : 1, gh > 0 ? gh : 1);
-    struct yasl_vector2i at = {
+    struct yasl_private_vector2i at = {
         .x = spec->anchor.x - parent->content.x,
         .y = spec->anchor.y - parent->content.y,
     };
-    int aw = yasl_scale_to_logical(spec->anchor.width, scale);
-    int ah = yasl_scale_to_logical(spec->anchor.height, scale);
+    int aw = yasl_private_scale_to_logical(spec->anchor.width, scale);
+    int ah = yasl_private_scale_to_logical(spec->anchor.height, scale);
     xdg_positioner_set_anchor_rect(pos,
-        yasl_scale_to_logical(at.x, scale),
-        yasl_scale_to_logical(at.y, scale),
+        yasl_private_scale_to_logical(at.x, scale),
+        yasl_private_scale_to_logical(at.y, scale),
         aw > 0 ? aw : 1, ah > 0 ? ah : 1);
-    xdg_positioner_set_anchor(pos, spec->beside ? XDG_POSITIONER_ANCHOR_TOP_RIGHT
-                                                : XDG_POSITIONER_ANCHOR_TOP_LEFT);
-    xdg_positioner_set_gravity(pos, XDG_POSITIONER_GRAVITY_BOTTOM_RIGHT);
-    xdg_positioner_set_constraint_adjustment(pos,
+    uint32_t anchor = spec->positioner_explicit ? spec->anchor_edges :
+        (spec->beside ? XDG_POSITIONER_ANCHOR_TOP_RIGHT : XDG_POSITIONER_ANCHOR_TOP_LEFT);
+    uint32_t gravity = spec->positioner_explicit ? spec->gravity :
+        XDG_POSITIONER_GRAVITY_BOTTOM_RIGHT;
+    uint32_t constraints = spec->positioner_explicit ? spec->constraints :
         XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_FLIP_X |
         XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_FLIP_Y |
         XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_SLIDE_X |
-        XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_SLIDE_Y);
+        XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_SLIDE_Y;
+    xdg_positioner_set_anchor(pos, anchor);
+    xdg_positioner_set_gravity(pos, gravity);
+    xdg_positioner_set_constraint_adjustment(pos, constraints);
     if (xdg_positioner_get_version(pos) >= XDG_POSITIONER_SET_REACTIVE_SINCE_VERSION)
         xdg_positioner_set_reactive(pos);
     return pos;
 }
 
 struct wayland_surface *wayland_surface_create_popup(struct wayland_surface *parent,
-        const struct yasl_popup_spec *spec)
+        const struct yasl_private_popup_spec *spec)
 {
     struct wayland_display *c = parent ? parent->conn : NULL;
     struct seat *seat = c ? (c->active_seat ? c->active_seat : c->seats) : NULL;
@@ -137,7 +151,8 @@ struct wayland_surface *wayland_surface_create_popup(struct wayland_surface *par
     if (!w)
         return NULL;
     w->base.display = &c->base;
-    w->base.state = YASL_STATE_CSD;
+    w->base.state = YASL_PRIVATE_STATE_CSD;
+    w->base.presenter = YASL_PRIVATE_PRESENTER_CPU;
     w->input.leave_ends_press = true;
     w->conn = c;
     w->conn_next = c->surfaces;
@@ -150,7 +165,7 @@ struct wayland_surface *wayland_surface_create_popup(struct wayland_surface *par
     if (!w->surface)
         goto err;
     w->base.native_handle = w->surface;
-    w->base.size = (struct yasl_vector2i){spec->size.x, spec->size.y};
+    w->base.size = (struct yasl_private_vector2i){spec->size.x, spec->size.y};
     w->base.scale_120 = parent->scale_120;
     wl_surface_set_user_data(w->surface, w);
     if (surface_init_scaling(w) < 0)
@@ -180,13 +195,13 @@ err:
     return NULL;
 }
 
-bool wayland_surface_popup_reposition(struct wayland_surface *w, const struct yasl_popup_spec *spec)
+bool wayland_surface_popup_reposition(struct wayland_surface *w, const struct yasl_private_popup_spec *spec)
 {
     if (!w || !w->popup || w->closed || !w->conn || w->conn->lost ||
         !popup_spec_valid(w->parent, spec) ||
         xdg_popup_get_version(w->popup) < XDG_POPUP_REPOSITION_SINCE_VERSION)
         return false;
-    struct yasl_popup_spec old = {
+    struct yasl_private_popup_spec old = {
         .size = { .x = w->width, .y = w->height },
         .content_offset = { .x = w->content.x, .y = w->content.y },
         .content_size = { .x = w->content.width, .y = w->content.height },