- gpu_select takes Vulkan for a window on Windows; gvk_init asks for VK_KHR_surface,
VK_KHR_win32_surface and VK_KHR_swapchain when the renderer will present. A window elsewhere
stays on OpenGL with the reason.
- gvk_open opens the window without a GL context and makes the screen images at its client area;
gvk_swap_make builds the swapchain on the Win32 surface (FIFO with vsync, mailbox or immediate
without) and rebuilds it when it is out of date, suboptimal or the window changes size.
- gvk_present blits the screen image into the acquired swapchain image, flipped (the screen keeps
OpenGL's bottom-up rows), and presents it.
- Samplers pointed at a texture unit with u_i and then fed by binding units - the actors do this -
read that unit's texture; on Vulkan they drew with the white stand-in (the tent, the log, the
chair, the workbench).
- gl.ll carries a weak win_gl_drawable for headless macOS builds.
On the RTX 3070 Ti the windowed build runs the valley through Vulkan at 3840x2160 with the HUD and
the frame-rate readout (16 fps: every upload still waits on the frame, and buffers are
host-visible). The headless Vulkan frame is unchanged; OpenGL frames byte-identical at the five
viewpoints with 59 self-tests passing. The actor fix is compiled and OpenGL-verified, not yet
seen on the PC; blades at the grass's middle distance still draw black on Vulkan.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>