RmlUi/Source/Core/ElementBackgroundBorder.cpp

/*
 * This source file is part of RmlUi, the HTML/CSS Interface Middleware
 *
 * For the latest information, see http://github.com/mikke89/RmlUi
 *
 * Copyright (c) 2008-2010 CodePoint Ltd, Shift Technology Ltd
 * Copyright (c) 2019-2023 The RmlUi Team, and contributors
 *
 * 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 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 "ElementBackgroundBorder.h"
#include "../../Include/RmlUi/Core/Box.h"
#include "../../Include/RmlUi/Core/ComputedValues.h"
#include "../../Include/RmlUi/Core/Context.h"
#include "../../Include/RmlUi/Core/DecorationTypes.h"
#include "../../Include/RmlUi/Core/Element.h"
#include "../../Include/RmlUi/Core/MeshUtilities.h"
#include "../../Include/RmlUi/Core/Profiling.h"
#include "../../Include/RmlUi/Core/RenderManager.h"
#include "BoxShadowCache.h"
#include "GeometryBoxShadow.h"

namespace Rml {

ElementBackgroundBorder::ElementBackgroundBorder() {}

void ElementBackgroundBorder::Render(Element* element)
{
	if (background_dirty || border_dirty)
	{
		for (auto& background : backgrounds)
		{
			if (background.first != BackgroundType::BackgroundBorder)
				background.second.geometry.Release();
		}

		GenerateGeometry(element);

		background_dirty = false;
		border_dirty = false;
	}

	if (Background* shadow = GetBackground(BackgroundType::BoxShadowAndBackgroundBorder))
	{
		const Vector2f offset = element->GetAbsoluteOffset(BoxArea::Border);
		shadow->box_shadow_and_background_border->geometry.Render(offset, shadow->box_shadow_and_background_border->texture);
	}
	else if (Background* background = GetBackground(BackgroundType::BackgroundBorder))
	{
		const Vector2f offset = element->GetAbsoluteOffset(BoxArea::Border);
		background->geometry.Render(offset);
	}
}

void ElementBackgroundBorder::DirtyBackground()
{
	background_dirty = true;
}

void ElementBackgroundBorder::DirtyBorder()
{
	border_dirty = true;
}

Geometry* ElementBackgroundBorder::GetClipGeometry(Element* element, BoxArea clip_area)
{
	BackgroundType type = {};
	switch (clip_area)
	{
	case Rml::BoxArea::Border: type = BackgroundType::ClipBorder; break;
	case Rml::BoxArea::Padding: type = BackgroundType::ClipPadding; break;
	case Rml::BoxArea::Content: type = BackgroundType::ClipContent; break;
	default: RMLUI_ERROR; return nullptr;
	}

	RenderManager* render_manager = element->GetRenderManager();
	Geometry& geometry = GetOrCreateBackground(type).geometry;
	if (render_manager && !geometry)
	{
		Mesh mesh = geometry.Release(Geometry::ReleaseMode::ClearMesh);
		MeshUtilities::GenerateBackground(mesh, element->GetRenderBox(clip_area), ColourbPremultiplied(255));
		geometry = render_manager->MakeGeometry(std::move(mesh));
	}

	return &geometry;
}

ElementBackgroundBorder::Background* ElementBackgroundBorder::GetBackground(BackgroundType type)
{
	auto it = backgrounds.find(type);
	if (it != backgrounds.end())
		return &it->second;
	return nullptr;
}

ElementBackgroundBorder::Background& ElementBackgroundBorder::GetOrCreateBackground(BackgroundType type)
{
	auto it = backgrounds.find(type);
	if (it != backgrounds.end())
		return it->second;

	Background& background = backgrounds[type];
	return background;
}

void ElementBackgroundBorder::EraseBackground(BackgroundType type)
{
	backgrounds.erase(type);
}

void ElementBackgroundBorder::GenerateGeometry(Element* element)
{
	RMLUI_ZoneScoped;
	RenderManager* render_manager = element->GetRenderManager();
	if (!render_manager)
		return;

	const ComputedValues& computed = element->GetComputedValues();
	const bool has_box_shadow = computed.has_box_shadow();

	if (has_box_shadow)
	{
		// The box shadow geometry also includes the element's background and border, thus we can skip the normal background generation.
		EraseBackground(BackgroundType::BackgroundBorder);
		Background& shadow_background = GetOrCreateBackground(BackgroundType::BoxShadowAndBackgroundBorder);
		shadow_background.box_shadow_and_background_border = BoxShadowCache::GetHandle(element, computed);
		return;
	}

	EraseBackground(BackgroundType::BoxShadowAndBackgroundBorder);

	const float opacity = computed.opacity();
	ColourbPremultiplied background_color = computed.background_color().ToPremultiplied(opacity);
	Array<ColourbPremultiplied, 4> border_colors = {
		computed.border_top_color().ToPremultiplied(opacity),
		computed.border_right_color().ToPremultiplied(opacity),
		computed.border_bottom_color().ToPremultiplied(opacity),
		computed.border_left_color().ToPremultiplied(opacity),
	};

	Geometry& geometry = GetOrCreateBackground(BackgroundType::BackgroundBorder).geometry;
	Mesh mesh = geometry.Release(Geometry::ReleaseMode::ClearMesh);

	for (int i = 0; i < element->GetNumBoxes(); i++)
		MeshUtilities::GenerateBackgroundBorder(mesh, element->GetRenderBox(BoxArea::Padding, i), background_color, border_colors.data());

	geometry = render_manager->MakeGeometry(std::move(mesh));
}

} // namespace Rml