weston/libweston/color.c

/*
 * Copyright 2021 Collabora, Ltd.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial
 * portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "config.h"

#include <libweston/libweston.h>
#include <assert.h>

#include "color.h"
#include "libweston-internal.h"

/**
 * Increase reference count of the color transform object
 *
 * \param xform The color transform. NULL is accepted too.
 * \return xform.
 */
WL_EXPORT struct weston_color_transform *
weston_color_transform_ref(struct weston_color_transform *xform)
{
	/* NULL is a valid color transform: identity */
	if (!xform)
		return NULL;

	assert(xform->ref_count > 0);
	xform->ref_count++;
	return xform;
}

/**
 * Decrease and potentially destroy the color transform object
 *
 * \param xform The color transform. NULL is accepted too.
 */
WL_EXPORT void
weston_color_transform_unref(struct weston_color_transform *xform)
{
	if (!xform)
		return;

	assert(xform->ref_count > 0);
	if (--xform->ref_count > 0)
		return;

	wl_signal_emit(&xform->destroy_signal, xform);
	xform->cm->destroy_color_transform(xform);
}

/**
 * Initializes a newly allocated color transform object
 *
 * This is used only by color managers. They sub-class weston_color_transform.
 *
 * The reference count starts at 1.
 *
 * To destroy a weston_color_transform, use weston_color_transfor_unref().
 */
WL_EXPORT void
weston_color_transform_init(struct weston_color_transform *xform,
			    struct weston_color_manager *cm)
{
	xform->cm = cm;
	xform->ref_count = 1;
	wl_signal_init(&xform->destroy_signal);
}

/** Deep copy */
void
weston_surface_color_transform_copy(struct weston_surface_color_transform *dst,
				    const struct weston_surface_color_transform *src)
{
	*dst = *src;
	dst->transform = weston_color_transform_ref(src->transform);
}

/** Unref contents */
void
weston_surface_color_transform_fini(struct weston_surface_color_transform *surf_xform)
{
	weston_color_transform_unref(surf_xform->transform);
}

/**
 * Ensure that the surface's color transformation for the given output is
 * populated in the paint nodes for all the views.
 *
 * Creates the color transformation description if necessary by calling
 * into the color manager.
 *
 * \param pnode Paint node defining the surface and the output. All
 * paint nodes with the same surface and output will be ensured.
 */
void
weston_paint_node_ensure_color_transform(struct weston_paint_node *pnode)
{
	struct weston_surface *surface = pnode->surface;
	struct weston_output *output = pnode->output;
	struct weston_color_manager *cm = surface->compositor->color_manager;
	struct weston_surface_color_transform surf_xform = {};
	struct weston_paint_node *it;
	bool ok;

	/*
	 * Invariant: all paint nodes with the same surface+output have the
	 * same surf_xform state.
	 */
	if (pnode->surf_xform_valid)
		return;

	ok = cm->get_surface_color_transform(cm, surface, output, &surf_xform);

	wl_list_for_each(it, &surface->paint_node_list, surface_link) {
		if (it->output == output) {
			assert(it->surf_xform_valid == false);
			assert(it->surf_xform.transform == NULL);
			weston_surface_color_transform_copy(&it->surf_xform,
							    &surf_xform);
			it->surf_xform_valid = ok;
		}
	}

	weston_surface_color_transform_fini(&surf_xform);

	if (!ok) {
		if (surface->resource)
			wl_resource_post_no_memory(surface->resource);
		weston_log("Failed to create color transformation for a surface.\n");
	}
}