rootston: split rendering code into render.c

1 files changed, 324 insertions, 0 deletions

diff --git a/rootston/render.c b/rootston/render.c
new file mode 100644
index 00000000..988f8de0
--- /dev/null
+++ b/rootston/render.c
@@ -0,0 +1,324 @@
+#define _POSIX_C_SOURCE 200809L
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <time.h>
+#include <wlr/config.h>
+#include <wlr/types/wlr_compositor.h>
+#include <wlr/types/wlr_matrix.h>
+#include <wlr/util/log.h>
+#include <wlr/util/region.h>
+#include "rootston/layers.h"
+#include "rootston/output.h"
+#include "rootston/server.h"
+
+struct render_data {
+	pixman_region32_t *damage;
+	float alpha;
+};
+
+static void scissor_output(struct wlr_output *wlr_output,
+		pixman_box32_t *rect) {
+	struct wlr_renderer *renderer =
+		wlr_backend_get_renderer(wlr_output->backend);
+	assert(renderer);
+
+	struct wlr_box box = {
+		.x = rect->x1,
+		.y = rect->y1,
+		.width = rect->x2 - rect->x1,
+		.height = rect->y2 - rect->y1,
+	};
+
+	int ow, oh;
+	wlr_output_transformed_resolution(wlr_output, &ow, &oh);
+
+	enum wl_output_transform transform =
+		wlr_output_transform_invert(wlr_output->transform);
+	wlr_box_transform(&box, &box, transform, ow, oh);
+
+	wlr_renderer_scissor(renderer, &box);
+}
+
+static void render_texture(struct wlr_output *wlr_output,
+		pixman_region32_t *output_damage, struct wlr_texture *texture,
+		const struct wlr_box *box, const float matrix[static 9],
+		float rotation, float alpha) {
+	struct wlr_renderer *renderer =
+		wlr_backend_get_renderer(wlr_output->backend);
+	assert(renderer);
+
+	struct wlr_box rotated;
+	wlr_box_rotated_bounds(&rotated, box, rotation);
+
+	pixman_region32_t damage;
+	pixman_region32_init(&damage);
+	pixman_region32_union_rect(&damage, &damage, rotated.x, rotated.y,
+		rotated.width, rotated.height);
+	pixman_region32_intersect(&damage, &damage, output_damage);
+	bool damaged = pixman_region32_not_empty(&damage);
+	if (!damaged) {
+		goto damage_finish;
+	}
+
+	int nrects;
+	pixman_box32_t *rects = pixman_region32_rectangles(&damage, &nrects);
+	for (int i = 0; i < nrects; ++i) {
+		scissor_output(wlr_output, &rects[i]);
+		wlr_render_texture_with_matrix(renderer, texture, matrix, alpha);
+	}
+
+damage_finish:
+	pixman_region32_fini(&damage);
+}
+
+static void render_surface_iterator(struct roots_output *output,
+		struct wlr_surface *surface, struct wlr_box *_box, float rotation,
+		void *_data) {
+	struct render_data *data = _data;
+	struct wlr_output *wlr_output = output->wlr_output;
+	pixman_region32_t *output_damage = data->damage;
+	float alpha = data->alpha;
+
+	struct wlr_texture *texture = wlr_surface_get_texture(surface);
+	if (!texture) {
+		return;
+	}
+
+	struct wlr_box box = *_box;
+	scale_box(&box, wlr_output->scale);
+
+	float matrix[9];
+	enum wl_output_transform transform =
+		wlr_output_transform_invert(surface->current.transform);
+	wlr_matrix_project_box(matrix, &box, transform, rotation,
+		wlr_output->transform_matrix);
+
+	render_texture(wlr_output, output_damage,
+		texture, &box, matrix, rotation, alpha);
+}
+
+static void render_decorations(struct roots_output *output,
+		struct roots_view *view, struct render_data *data) {
+	if (!view->decorated || view->wlr_surface == NULL) {
+		return;
+	}
+
+	struct wlr_renderer *renderer =
+		wlr_backend_get_renderer(output->wlr_output->backend);
+	assert(renderer);
+
+	struct wlr_box box;
+	get_decoration_box(view, output, &box);
+
+	struct wlr_box rotated;
+	wlr_box_rotated_bounds(&rotated, &box, view->rotation);
+
+	pixman_region32_t damage;
+	pixman_region32_init(&damage);
+	pixman_region32_union_rect(&damage, &damage, rotated.x, rotated.y,
+		rotated.width, rotated.height);
+	pixman_region32_intersect(&damage, &damage, data->damage);
+	bool damaged = pixman_region32_not_empty(&damage);
+	if (!damaged) {
+		goto damage_finish;
+	}
+
+	float matrix[9];
+	wlr_matrix_project_box(matrix, &box, WL_OUTPUT_TRANSFORM_NORMAL,
+		view->rotation, output->wlr_output->transform_matrix);
+	float color[] = { 0.2, 0.2, 0.2, view->alpha };
+
+	int nrects;
+	pixman_box32_t *rects =
+		pixman_region32_rectangles(&damage, &nrects);
+	for (int i = 0; i < nrects; ++i) {
+		scissor_output(output->wlr_output, &rects[i]);
+		wlr_render_quad_with_matrix(renderer, color, matrix);
+	}
+
+damage_finish:
+	pixman_region32_fini(&damage);
+}
+
+static void render_view(struct roots_output *output, struct roots_view *view,
+		struct render_data *data) {
+	// Do not render views fullscreened on other outputs
+	if (view->fullscreen_output != NULL && view->fullscreen_output != output) {
+		return;
+	}
+
+	data->alpha = view->alpha;
+	if (view->fullscreen_output == NULL) {
+		render_decorations(output, view, data);
+	}
+	output_view_for_each_surface(output, view, render_surface_iterator, data);
+}
+
+static void render_layer(struct roots_output *output,
+		pixman_region32_t *damage, struct wl_list *layer_surfaces) {
+	struct render_data data = {
+		.damage = damage,
+		.alpha = 1.0f,
+	};
+	output_layer_for_each_surface(output, layer_surfaces,
+		render_surface_iterator, &data);
+}
+
+static void render_drag_icons(struct roots_output *output,
+		pixman_region32_t *damage, struct roots_input *input) {
+	struct render_data data = {
+		.damage = damage,
+		.alpha = 1.0f,
+	};
+	output_drag_icons_for_each_surface(output, input,
+		render_surface_iterator, &data);
+}
+
+static void surface_send_frame_done_iterator(struct roots_output *output,
+		struct wlr_surface *surface, struct wlr_box *box, float rotation,
+		void *data) {
+	struct timespec *when = data;
+	wlr_surface_send_frame_done(surface, when);
+}
+
+void output_render(struct roots_output *output) {
+	struct wlr_output *wlr_output = output->wlr_output;
+	struct roots_desktop *desktop = output->desktop;
+	struct roots_server *server = desktop->server;
+	struct wlr_renderer *renderer =
+		wlr_backend_get_renderer(wlr_output->backend);
+	assert(renderer);
+
+	if (!wlr_output->enabled) {
+		return;
+	}
+
+	struct timespec now;
+	clock_gettime(CLOCK_MONOTONIC, &now);
+
+	float clear_color[] = {0.25f, 0.25f, 0.25f, 1.0f};
+
+	const struct wlr_box *output_box =
+		wlr_output_layout_get_box(desktop->layout, wlr_output);
+
+	// Check if we can delegate the fullscreen surface to the output
+	if (output->fullscreen_view != NULL &&
+			output->fullscreen_view->wlr_surface != NULL) {
+		struct roots_view *view = output->fullscreen_view;
+
+		// Make sure the view is centered on screen
+		struct wlr_box view_box;
+		view_get_box(view, &view_box);
+		double view_x = (double)(output_box->width - view_box.width) / 2 +
+			output_box->x;
+		double view_y = (double)(output_box->height - view_box.height) / 2 +
+			output_box->y;
+		view_move(view, view_x, view_y);
+
+		// Fullscreen views are rendered on a black background
+		clear_color[0] = clear_color[1] = clear_color[2] = 0;
+	}
+
+	bool needs_swap;
+	pixman_region32_t damage;
+	pixman_region32_init(&damage);
+	if (!wlr_output_damage_make_current(output->damage, &needs_swap, &damage)) {
+		return;
+	}
+
+	struct render_data data = {
+		.damage = &damage,
+		.alpha = 1.0,
+	};
+
+	if (!needs_swap) {
+		// Output doesn't need swap and isn't damaged, skip rendering completely
+		goto damage_finish;
+	}
+
+	wlr_renderer_begin(renderer, wlr_output->width, wlr_output->height);
+
+	if (!pixman_region32_not_empty(&damage)) {
+		// Output isn't damaged but needs buffer swap
+		goto renderer_end;
+	}
+
+	if (server->config->debug_damage_tracking) {
+		wlr_renderer_clear(renderer, (float[]){1, 1, 0, 1});
+	}
+
+	int nrects;
+	pixman_box32_t *rects = pixman_region32_rectangles(&damage, &nrects);
+	for (int i = 0; i < nrects; ++i) {
+		scissor_output(output->wlr_output, &rects[i]);
+		wlr_renderer_clear(renderer, clear_color);
+	}
+
+	render_layer(output, &damage,
+		&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND]);
+	render_layer(output, &damage,
+		&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM]);
+
+	// If a view is fullscreen on this output, render it
+	if (output->fullscreen_view != NULL) {
+		struct roots_view *view = output->fullscreen_view;
+
+		render_view(output, view, &data);
+
+		// During normal rendering the xwayland window tree isn't traversed
+		// because all windows are rendered. Here we only want to render
+		// the fullscreen window's children so we have to traverse the tree.
+#if WLR_HAS_XWAYLAND
+		if (view->type == ROOTS_XWAYLAND_VIEW) {
+			struct roots_xwayland_surface *xwayland_surface =
+				roots_xwayland_surface_from_view(view);
+			output_xwayland_children_for_each_surface(output,
+				xwayland_surface->xwayland_surface,
+				render_surface_iterator, &data);
+		}
+#endif
+	} else {
+		// Render all views
+		struct roots_view *view;
+		wl_list_for_each_reverse(view, &desktop->views, link) {
+			render_view(output, view, &data);
+		}
+		// Render top layer above shell views
+		render_layer(output, &damage,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP]);
+	}
+
+	render_drag_icons(output, &damage, server->input);
+
+	render_layer(output, &damage,
+		&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY]);
+
+renderer_end:
+	wlr_output_render_software_cursors(wlr_output, &damage);
+	wlr_renderer_scissor(renderer, NULL);
+	wlr_renderer_end(renderer);
+
+	int width, height;
+	wlr_output_transformed_resolution(wlr_output, &width, &height);
+
+	if (server->config->debug_damage_tracking) {
+		pixman_region32_union_rect(&damage, &damage, 0, 0, width, height);
+	}
+
+	enum wl_output_transform transform =
+		wlr_output_transform_invert(wlr_output->transform);
+	wlr_region_transform(&damage, &damage, transform, width, height);
+
+	if (!wlr_output_damage_swap_buffers(output->damage, &now, &damage)) {
+		goto damage_finish;
+	}
+	output->last_frame = desktop->last_frame = now;
+
+damage_finish:
+	pixman_region32_fini(&damage);
+
+	// Send frame done events to all surfaces
+	output_for_each_surface(output, surface_send_frame_done_iterator,
+		&now);
+}