river/src/output.zig
2020-03-22 22:42:55 +01:00

111 lines
4.5 KiB
Zig

const std = @import("std");
const c = @import("c.zig").c;
const Output = struct {
server: *Server,
wlr_output: *c.wlr_output,
frame: c.wl_listener,
};
fn output_frame(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
// This function is called every time an output is ready to display a frame,
// generally at the output's refresh rate (e.g. 60Hz).
var output = @fieldParentPtr(Output, "frame", listener);
var renderer = output.*.server.*.renderer;
var now: c.struct_timespec = undefined;
_ = c.clock_gettime(c.CLOCK_MONOTONIC, &now);
// wlr_output_attach_render makes the OpenGL context current.
if (!c.wlr_output_attach_render(output.*.wlr_output, null)) {
return;
}
// The "effective" resolution can change if you rotate your outputs.
var width: c_int = undefined;
var height: c_int = undefined;
c.wlr_output_effective_resolution(output.*.wlr_output, &width, &height);
// Begin the renderer (calls glViewport and some other GL sanity checks)
c.wlr_renderer_begin(renderer, width, height);
const color = [_]f32{ 0.3, 0.3, 0.3, 1.0 };
c.wlr_renderer_clear(renderer, &color);
// Each subsequent window we render is rendered on top of the last. Because
// our view list is ordered front-to-back, we iterate over it backwards.
for (output.*.server.views.span()) |*view| {
if (!view.*.mapped) {
// An unmapped view should not be rendered.
continue;
}
var rdata = RenderData{
.output = output.*.wlr_output,
.view = view,
.renderer = renderer,
.when = &now,
};
// This calls our render_surface function for each surface among the
// xdg_surface's toplevel and popups.
c.wlr_xdg_surface_for_each_surface(view.*.xdg_surface, render_surface, &rdata);
}
// Hardware cursors are rendered by the GPU on a separate plane, and can be
// moved around without re-rendering what's beneath them - which is more
// efficient. However, not all hardware supports hardware cursors. For this
// reason, wlroots provides a software fallback, which we ask it to render
// here. wlr_cursor handles configuring hardware vs software cursors for you,
// and this function is a no-op when hardware cursors are in use.
c.wlr_output_render_software_cursors(output.*.wlr_output, null);
// Conclude rendering and swap the buffers, showing the final frame
// on-screen.
c.wlr_renderer_end(renderer);
// TODO: handle failure
_ = c.wlr_output_commit(output.*.wlr_output);
}
fn server_new_output(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
var server = @fieldParentPtr(Server, "new_output", listener);
var wlr_output = @ptrCast(*c.wlr_output, @alignCast(@alignOf(*c.wlr_output), data));
// Some backends don't have modes. DRM+KMS does, and we need to set a mode
// before we can use the output. The mode is a tuple of (width, height,
// refresh rate), and each monitor supports only a specific set of modes. We
// just pick the monitor's preferred mode, a more sophisticated compositor
// would let the user configure it.
// if not empty
if (c.wl_list_empty(&wlr_output.*.modes) == 0) {
var mode = c.wlr_output_preferred_mode(wlr_output);
c.wlr_output_set_mode(wlr_output, mode);
c.wlr_output_enable(wlr_output, true);
if (!c.wlr_output_commit(wlr_output)) {
return;
}
}
// Allocates and configures our state for this output
server.*.outputs.append(Output{
.server = undefined,
.wlr_output = undefined,
.frame = undefined,
}) catch unreachable;
var output = &server.*.outputs.span()[server.*.outputs.span().len - 1];
output.*.wlr_output = wlr_output;
output.*.server = server;
// Sets up a listener for the frame notify event.
output.*.frame.notify = output_frame;
c.wl_signal_add(&wlr_output.*.events.frame, &output.*.frame);
// Adds this to the output layout. The add_auto function arranges outputs
// from left-to-right in the order they appear. A more sophisticated
// compositor would let the user configure the arrangement of outputs in the
// layout.
c.wlr_output_layout_add_auto(server.*.output_layout, wlr_output);
// Creating the global adds a wl_output global to the display, which Wayland
// clients can see to find out information about the output (such as
// DPI, scale factor, manufacturer, etc).
c.wlr_output_create_global(wlr_output);
}