The immediate display of the screen sometimes miss the update from the CPU side memory. No obvious synchronization mechanism is available. In order to make sure the screen updates properly, we set needsDisplay again after 16ms delay to ensure a second screen update.

This supports non-live window resize.

* devdraw: cocoa metal screen uses a dirty hack to make everything smooth * devdraw: cocoa metal screen uses a layer to make fullscreen applications behave * devdraw: macOS cocoa metal fix resizeimg without img * devdraw: macOS cocoa metal uses blit instead of render We directly use the blit command encoder to copy texture to the framebuffer. We no longer need to compile the metal shader every time the application starts just for rendering a flat 2D surface. * travis: add osx images covering 10.13 and 10.14

It is possible to receive multiple screen resize events, and resizeimg would be called for different sizes, before _flushmemscreen actually gets called with rectangle sizes different from the most recent resizeimg call. The size mismatch would trigger illegal memory access inside _flushmemscreen. This commit protects _flushmemscreen by returning early if the requested rectangle is outside of the current texture rectangle.

Fixes bug where devdraw does not "notice" mouse position after task switch. Fixes https://github.com/9fans/plan9port/issues/232.

This replaces the pixel-art scaling algorithm used for upscaling before. The results were not crisp enough to serve as everyday cursors.

Add a new macOS cocoa screen, cocoa-screen-metal.m. Rewrite the macOS cocoa drawing code to use the builtin runloop, and use Metal to push pixels with CAMetalLayer. Remove all of the deprecated code, and simplify some of the logic. Modify mkwsysrules.sh such that the new code is used only when the system version is equal or higher than 10.14. Allow touch events to simulate mouse clicks: three finger tap for the middle mouse button; four finger tap for the 2-1 chord. Support Tresize. Scale 16x16 Cursor up to 32x32 with an EPX algorithm. Support macOS input sources including the basic dead keys and the advanced CJK input methods. Increase the communication buffers in cocoa-srv.c to allow more input, especially for long sentences prepared by the macOS input souces.