labwc/src/common/graphic-helpers.c

// SPDX-License-Identifier: GPL-2.0-only

#include <assert.h>
#include <cairo.h>
#include <stdlib.h>
#include <wlr/types/wlr_scene.h>
#include "common/graphic-helpers.h"
#include "common/mem.h"

static void
multi_rect_destroy_notify(struct wl_listener *listener, void *data)
{
	struct multi_rect *rect = wl_container_of(listener, rect, destroy);
	free(rect);
}

struct multi_rect *
multi_rect_create(struct wlr_scene_tree *parent, float *colors[3], int line_width)
{
	struct multi_rect *rect = xzalloc(sizeof(*rect));
	rect->line_width = line_width;
	rect->tree = wlr_scene_tree_create(parent);
	rect->destroy.notify = multi_rect_destroy_notify;
	wl_signal_add(&rect->tree->node.events.destroy, &rect->destroy);
	for (size_t i = 0; i < 3; i++) {
		rect->top[i] = wlr_scene_rect_create(rect->tree, 0, 0, colors[i]);
		rect->right[i] = wlr_scene_rect_create(rect->tree, 0, 0, colors[i]);
		rect->bottom[i] = wlr_scene_rect_create(rect->tree, 0, 0, colors[i]);
		rect->left[i] = wlr_scene_rect_create(rect->tree, 0, 0, colors[i]);
		wlr_scene_node_set_position(&rect->top[i]->node,
			i * line_width, i * line_width);
		wlr_scene_node_set_position(&rect->left[i]->node,
			i * line_width, i * line_width);
	}
	return rect;
}

void
multi_rect_set_size(struct multi_rect *rect, int width, int height)
{
	assert(rect);
	int line_width = rect->line_width;

	for (size_t i = 0; i < 3; i++) {

		/* Reposition, top and left don't ever change */
		wlr_scene_node_set_position(&rect->right[i]->node,
			width - (i + 1) * line_width, i * line_width);
		wlr_scene_node_set_position(&rect->bottom[i]->node,
			i * line_width, height - (i + 1) * line_width);

		/* Update sizes */
		wlr_scene_rect_set_size(rect->top[i],
			width - i * line_width * 2, line_width);
		wlr_scene_rect_set_size(rect->bottom[i],
			width - i * line_width * 2, line_width);
		wlr_scene_rect_set_size(rect->left[i],
			line_width, height - i * line_width * 2);
		wlr_scene_rect_set_size(rect->right[i],
			line_width, height - i * line_width * 2);
	}
}

/* Draws a border with a specified line width */
void
draw_cairo_border(cairo_t *cairo, double width, double height, double line_width)
{
	cairo_save(cairo);

	double x, y, w, h;
	/* The anchor point of a line is in the center */
	x = y = line_width / 2;
	w = width - line_width;
	h = height - line_width;
	cairo_set_line_width(cairo, line_width);
	cairo_rectangle(cairo, x, y, w, h);
	cairo_stroke(cairo);

	cairo_restore(cairo);
}

/* Sets the cairo color. Splits the single color channels */
void
set_cairo_color(cairo_t *cairo, float *c)
{
	cairo_set_source_rgba(cairo, c[0], c[1], c[2], c[3]);
}