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, 26 insertions, 4 deletions

diff --git a/meson.build b/meson.build
index 9a59016..4d7d7ce 100644
--- a/meson.build
+++ b/meson.build
@@ -21,6 +21,8 @@ sources = []
 has_wayland = false
 has_x11 = false
 has_dbus = false
+has_egl = false
+has_vulkan = false
 has_cocoa = system == 'darwin'
 
 if system == 'linux'
@@ -46,6 +48,17 @@ if system == 'linux'
     if has_dbus
         deps += [dbus]
     endif
+    egl_dep = dependency('egl', required: false)
+    wayland_egl_dep = dependency('wayland-egl', required: false)
+    has_egl = egl_dep.found() and (not has_wayland or wayland_egl_dep.found())
+    if has_egl
+        deps += egl_dep
+        if has_wayland
+            deps += wayland_egl_dep
+        endif
+    endif
+    vulkan_dep = dependency('vulkan', required: false)
+    has_vulkan = vulkan_dep.found()
     m_dep = cc.find_library('m', required: false)
     rt_dep = cc.find_library('rt', required: false)
     deps += [m_dep, rt_dep]
@@ -63,17 +76,24 @@ elif system == 'darwin'
         error('Cocoa requires macOS 14 or newer. Set MACOSX_DEPLOYMENT_TARGET=14.0 or a newer target before configuring.')
     endif
     deps += [
-        dependency('appleframeworks', modules: ['AppKit', 'Metal', 'QuartzCore', 'UserNotifications']),
+        dependency('appleframeworks', modules: ['AppKit', 'Metal', 'QuartzCore', 'UserNotifications', 'OpenGL']),
     ]
 else
     error('YASL supports Linux and macOS.')
 endif
 
+if has_cocoa
+    vulkan_dep = dependency('vulkan', required: false)
+    has_vulkan = vulkan_dep.found()
+endif
+
 if not has_wayland and not has_x11 and not has_cocoa
     error('Enable at least one window backend.')
 endif
 
 add_project_arguments(
+    '-DYASL_HAS_EGL=' + (has_egl ? '1' : '0'),
+    '-DYASL_HAS_VULKAN=' + (has_vulkan ? '1' : '0'),
     '-DYASL_HAS_WAYLAND=' + (has_wayland ? '1' : '0'),
     '-DYASL_HAS_X11=' + (has_x11 ? '1' : '0'),
     '-DYASL_HAS_COCOA=' + (has_cocoa ? '1' : '0'),
@@ -103,10 +123,12 @@ yasl_dep = declare_dependency(
 meson.override_dependency('yasl', yasl_dep)
 
 install_headers(
-    'include/yasl/yasl.h', 'include/yasl/app.h', 'include/yasl/loop.h',
-    'include/yasl/timing.h', 'include/yasl/keycodes.h', 'include/yasl/native.h',
-    'include/yasl/desktop.h', subdir: 'yasl',
+    'include/yasl/yasl.h', 'include/yasl/keycodes.h', 'include/yasl/cpu.h',
+    'include/yasl/gl.h', 'include/yasl/metal.h', 'include/yasl/desktop.h', subdir: 'yasl',
 )
+if has_vulkan
+    install_headers('include/yasl/vulkan.h', subdir: 'yasl')
+endif
 if has_wayland
     install_headers('include/yasl/native/wayland.h', subdir: 'yasl/native')
 endif