src/script/common/c_content.cpp

/*
Minetest
Copyright (C) 2019 EvicenceBKidscode / Pierre-Yves Rollo <dev@pyrollo.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "IGUIEnvironment.h"
#include "IGUIElement.h"
#include "guiScrollBar.h"
#include "IGUIFont.h"
#include <vector>
#include <list>
#include <unordered_map>
using namespace irr::gui;
#include "client/fontengine.h"
#include <SColor.h>
#include "client/tile.h"
#include "IVideoDriver.h"
#include "client/client.h"
#include "client/renderingengine.h"
#include "hud.h"
#include "guiHyperText.h"
#include "util/string.h"

bool check_color(const std::string &str)
{
	irr::video::SColor color;
	return parseColorString(str, color, false);
}

bool check_integer(const std::string &str)
{
	if (str.empty())
		return false;

	char *endptr = nullptr;
	strtol(str.c_str(), &endptr, 10);

	return *endptr == '\0';
}

// -----------------------------------------------------------------------------
// ParsedText - A text parser

void ParsedText::Element::setStyle(StyleList &style)
{
	this->underline = is_yes(style["underline"]);

	video::SColor color;

	if (parseColorString(style["color"], color, false))
		this->color = color;
	if (parseColorString(style["hovercolor"], color, false))
		this->hovercolor = color;

	unsigned int font_size = std::atoi(style["fontsize"].c_str());
	FontMode font_mode = FM_Standard;
	if (style["fontstyle"] == "mono")
		font_mode = FM_Mono;

	FontSpec spec(font_size, font_mode,
		is_yes(style["bold"]), is_yes(style["italic"]));

	// TODO: find a way to check font validity
	// Build a new fontengine ?
	this->font = g_fontengine->getFont(spec);

	if (!this->font)
		printf("No font found ! Size=%d, mode=%d, bold=%s, italic=%s\n",
				font_size, font_mode, style["bold"].c_str(),
				style["italic"].c_str());
}

void ParsedText::Paragraph::setStyle(StyleList &style)
{
	if (style["halign"] == "center")
		this->halign = HALIGN_CENTER;
	else if (style["halign"] == "right")
		this->halign = HALIGN_RIGHT;
	else if (style["halign"] == "justify")
		this->halign = HALIGN_JUSTIFY;
	else
		this->halign = HALIGN_LEFT;
}

ParsedText::ParsedText(const wchar_t *text)
{
	// Default style
	m_root_tag.name = "root";
	m_root_tag.style["fontsize"] = "16";
	m_root_tag.style["fontstyle"] = "normal";
	m_root_tag.style["bold"] = "false";
	m_root_tag.style["italic"] = "false";
	m_root_tag.style["underline"] = "false";
	m_root_tag.style["halign"] = "left";
	m_root_tag.style["color"] = "#EEEEEE";
	m_root_tag.style["hovercolor"] = "#FF0000";

	m_active_tags.push_front(&m_root_tag);
	m_style = m_root_tag.style;

	// Default simple tags definitions
	StyleList style;

	style["color"] = "#0000FF";
	style["underline"] = "true";
	m_elementtags["action"] = style;
	style.clear();

	style["bold"] = "true";
	m_elementtags["b"] = style;
	style.clear();

	style["italic"] = "true";
	m_elementtags["i"] = style;
	style.clear();

	style["underline"] = "true";
	m_elementtags["u"] = style;
	style.clear();

	style["fontstyle"] = "mono";
	m_elementtags["mono"] = style;
	style.clear();

	style["fontsize"] = m_root_tag.style["fontsize"];
	m_elementtags["normal"] = style;
	style.clear();

	style["fontsize"] = "24";
	m_elementtags["big"] = style;
	style.clear();

	style["fontsize"] = "36";
	m_elementtags["bigger"] = style;
	style.clear();

	style["halign"] = "center";
	m_paragraphtags["center"] = style;
	style.clear();

	style["halign"] = "justify";
	m_paragraphtags["justify"] = style;
	style.clear();

	style["halign"] = "left";
	m_paragraphtags["left"] = style;
	style.clear();

	style["halign"] = "right";
	m_paragraphtags["right"] = style;
	style.clear();

	m_element = NULL;
	m_paragraph = NULL;
	m_end_paragraph_reason = ER_NONE;

	parse(text);
}

ParsedText::~ParsedText()
{
	for (auto &tag : m_not_root_tags)
		delete tag;
}

void ParsedText::parse(const wchar_t *text)
{
	wchar_t c;
	u32 cursor = 0;
	bool escape = false;

	while ((c = text[cursor]) != L'\0') {
		cursor++;

		if (c == L'\r') { // Mac or Windows breaks
			if (text[cursor] == L'\n')
				cursor++;
			// If text has begun, don't skip empty line
			if (m_paragraph) {
				endParagraph(ER_NEWLINE);
				enterElement(ELEMENT_SEPARATOR);
			}
			escape = false;
			continue;
		}

		if (c == L'\n') { // Unix breaks
			// If text has begun, don't skip empty line
			if (m_paragraph) {
				endParagraph(ER_NEWLINE);
				enterElement(ELEMENT_SEPARATOR);
			}
			escape = false;
			continue;
		}

		if (escape) {
			escape = false;
			pushChar(c);
			continue;
		}

		if (c == L'\\') {
			escape = true;
			continue;
		}

		// Tag check
		if (c == L'<') {
			u32 newcursor = parseTag(text, cursor);
			if (newcursor > 0) {
				cursor = newcursor;
				continue;
			}
		}

		// Default behavior
		pushChar(c);
	}

	endParagraph(ER_NONE);
}

void ParsedText::endElement()
{
	m_element = NULL;
}

void ParsedText::endParagraph(EndReason reason)
{
	if (!m_paragraph)
		return;

	EndReason previous = m_end_paragraph_reason;
	m_end_paragraph_reason = reason;
	if (m_empty_paragraph && (reason == ER_TAG ||
			(reason == ER_NEWLINE && previous == ER_TAG))) {
		// Ignore last empty paragraph
		m_paragraph = nullptr;
		m_paragraphs.pop_back();
		return;
	}
	endElement();
	m_paragraph = NULL;
}

void ParsedText::enterParagraph()
{
	if (!m_paragraph) {
		m_paragraphs.emplace_back();
		m_paragraph = &m_paragraphs.back();
		m_paragraph->setStyle(m_style);
		m_empty_paragraph = true;
	}
}

void ParsedText::enterElement(ElementType type)
{
	enterParagraph();

	if (!m_element || m_element->type != type) {
		m_paragraph->elements.emplace_back();
		m_element = &m_paragraph->elements.back();
		m_element->type = type;
		m_element->tags = m_active_tags;
		m_element->setStyle(m_style);
	}
}

void ParsedText::pushChar(wchar_t c)
{
	// New word if needed
	if (c == L' ' || c == L'\t') {
		if (!m_empty_paragraph)
			enterElement(ELEMENT_SEPARATOR);
		else
			return;
	} else {
		m_empty_paragraph = false;
		enterElement(ELEMENT_TEXT);
	}
	m_element->text += c;
}

ParsedText::Tag *ParsedText::newTag(const std::string &name, const AttrsList &attrs)
{
	endElement();
	Tag *newtag = new Tag();
	newtag->name = name;
	newtag->attrs = attrs;
	m_not_root_tags.push_back(newtag);
	return newtag;
}

ParsedText::Tag *ParsedText::openTag(const std::string &name, const AttrsList &attrs)
{
	Tag *newtag = newTag(name, attrs);
	m_active_tags.push_front(newtag);
	return newtag;
}

bool ParsedText::closeTag(const std::string &name)
{
	bool found = false;
	for (auto id = m_active_tags.begin(); id != m_active_tags.end(); ++id)
		if ((*id)->name == name) {
			m_active_tags.erase(id);
			found = true;
			break;
		}
	return found;
}

void ParsedText::parseGenericStyleAttr(
		const std::string &name, const std::string &value, StyleList &style)
{
	// Color styles
	if (name == "color" || name == "hovercolor") {
		if (check_color(value))
			style[name] = value;

		// Boolean styles
	} else if (name == "bold" || name == "italic" || name == "underline") {
		style[name] = is_yes(value);

	} else if (name == "size") {
		if (check_integer(value))
			style["fontsize"] = value;

	} else if (name == "font") {
		if (value == "mono" || value == "normal")
			style["fontstyle"] = value;
	}
}

void ParsedText::parseStyles(const AttrsList &attrs, StyleList &style)
{
	for (auto const &attr : attrs)
		parseGenericStyleAttr(attr.first, attr.second, style);
}

void ParsedText::globalTag(const AttrsList &attrs)
{
	for (const auto &attr : attrs) {
		// Only page level style
		if (attr.first == "margin") {
			if (check_integer(attr.second))
				margin = stoi(attr.second.c_str());

		} else if (attr.first == "valign") {
			if (attr.second == "top")
				valign = ParsedText::VALIGN_TOP;
			else if (attr.second == "bottom")
				valign = ParsedText::VALIGN_BOTTOM;
			else if (attr.second == "middle")
				valign = ParsedText::VALIGN_MIDDLE;
		} else if (attr.first == "background") {
			irr::video::SColor color;
			if (attr.second == "none") {
				background_type = BACKGROUND_NONE;
			} else if (parseColorString(attr.second, color, false)) {
				background_type = BACKGROUND_COLOR;
				background_color = color;
			}

			// Inheriting styles

		} else if (attr.first == "halign") {
			if (attr.second == "left" || attr.second == "center" ||
					attr.second == "right" ||
					attr.second == "justify")
				m_root_tag.style["halign"] = attr.second;

			// Generic default styles

		} else {
			parseGenericStyleAttr(attr.first, attr.second, m_root_tag.style);
		}
	}
}

u32 ParsedText::parseTag(const wchar_t *text, u32 cursor)
{
	// Tag name
	bool end = false;
	std::string name = "";
	wchar_t c = text[cursor];

	if (c == L'/') {
		end = true;
		c = text[++cursor];
		if (c == L'\0')
			return 0;
	}

	while (c != ' ' && c != '>') {
		name += c;
		c = text[++cursor];
		if (c == L'\0')
			return 0;
	}

	// Tag attributes
	AttrsList attrs;
	while (c != L'>') {
		std::string attr_name = "";
		core::stringw attr_val = L"";

		while (c == ' ') {
			c = text[++cursor];
			if (c == L'\0' || c == L'=')
				return 0;
		}

		while (c != L' ' && c != L'=') {
			attr_name += (char)c;
			c = text[++cursor];
			if (c == L'\0' || c == L'>')
				return 0;
		}

		while (c == L' ') {
			c = text[++cursor];
			if (c == L'\0' || c == L'>')
				return 0;
		}

		if (c != L'=')
			return 0;

		c = text[++cursor];

		if (c == L'\0')
			return 0;

		while (c != L'>' && c != L' ') {
			attr_val += c;
			c = text[++cursor];
			if (c == L'\0')
				return 0;
		}

		attrs[attr_name] = stringw_to_utf8(attr_val);
	}

	++cursor; // Last ">"

	// Tag specific processing
	StyleList style;

	if (name == "global") {
		if (end)
			return 0;
		globalTag(attrs);

	} else if (name == "style") {
		if (end) {
			closeTag(name);
		} else {
			parseStyles(attrs, style);
			openTag(name, attrs)->style = style;
		}
		endElement();
	} else if (name == "img" || name == "item") {
		if (end)
			return 0;

		// Name is a required attribute
		if (!attrs.count("name"))
			return 0;

		// Rotate attribute is only for <item>
		if (attrs.count("rotate") && name != "item")
			return 0;

		// Angle attribute is only for <item>
		if (attrs.count("angle") && name != "item")
			return 0;

		// Ok, element can be created
		newTag(name, attrs);

		if (name == "img")
			enterElement(ELEMENT_IMAGE);
		else
			enterElement(ELEMENT_ITEM);

		m_element->text = utf8_to_stringw(attrs["name"]);

		if (attrs.count("float")) {
			if (attrs["float"] == "left")
				m_element->floating = FLOAT_LEFT;
			if (attrs["float"] == "right")
				m_element->floating = FLOAT_RIGHT;
		}

		if (attrs.count("width")) {
			int width = stoi(attrs["width"]);
			if (width > 0)
				m_element->dim.Width = width;
		}

		if (attrs.count("height")) {
			int height = stoi(attrs["height"]);
			if (height > 0)
				m_element->dim.Height = height;
		}

		if (attrs.count("angle")) {
			std::string str = attrs["angle"];
			std::vector<std::string> parts = split(str, ',');
			if (parts.size() == 3) {
				m_element->angle = v3s16(
						rangelim(stoi(parts[0]), -180, 180),
						rangelim(stoi(parts[1]), -180, 180),
						rangelim(stoi(parts[2]), -180, 180));
				m_element->rotation = v3s16(0, 0, 0);
			}
		}

		if (attrs.count("rotate")) {
			if (attrs["rotate"] == "yes") {
				m_element->rotation = v3s16(0, 100, 0);
			} else {
				std::string str = attrs["rotate"];
				std::vector<std::string> parts = split(str, ',');
				if (parts.size() == 3) {
					m_element->rotation = v3s16 (
							rangelim(stoi(parts[0]), -1000, 1000),
							rangelim(stoi(parts[1]), -1000, 1000),
							rangelim(stoi(parts[2]), -1000, 1000));
				}
			}
		}

		endElement();

	} else if (name == "tag") {
		// Required attributes
		if (!attrs.count("name"))
			return 0;

		StyleList tagstyle;
		parseStyles(attrs, tagstyle);

		if (is_yes(attrs["paragraph"]))
			m_paragraphtags[attrs["name"]] = tagstyle;
		else
			m_elementtags[attrs["name"]] = tagstyle;

	} else if (name == "action") {
		if (end) {
			closeTag(name);
		} else {
			if (!attrs.count("name"))
				return 0;
			openTag(name, attrs)->style = m_elementtags["action"];
		}

	} else if (m_elementtags.count(name)) {
		if (end) {
			closeTag(name);
		} else {
			openTag(name, attrs)->style = m_elementtags[name];
		}
		endElement();

	} else if (m_paragraphtags.count(name)) {
		if (end) {
			closeTag(name);
		} else {
			openTag(name, attrs)->style = m_paragraphtags[name];
		}
		endParagraph(ER_TAG);

	} else
		return 0; // Unknown tag

	// Update styles accordingly
	m_style.clear();
	for (auto tag = m_active_tags.crbegin(); tag != m_active_tags.crend(); ++tag)
		for (const auto &prop : (*tag)->style)
			m_style[prop.first] = prop.second;

	return cursor;
}

// -----------------------------------------------------------------------------
// Text Drawer

TextDrawer::TextDrawer(const wchar_t *text, Client *client,
		gui::IGUIEnvironment *environment, ISimpleTextureSource *tsrc) :
		m_text(text),
		m_client(client), m_environment(environment)
{
	// Size all elements
	for (auto &p : m_text.m_paragraphs) {
		for (auto &e : p.elements) {
			switch (e.type) {
			case ParsedText::ELEMENT_SEPARATOR:
			case ParsedText::ELEMENT_TEXT:
				if (e.font) {
					e.dim.Width = e.font->getDimension(e.text.c_str()).Width;
					e.dim.Height = e.font->getDimension(L"Yy").Height;
#if USE_FREETYPE
					if (e.font->getType() == irr::gui::EGFT_CUSTOM) {
						e.baseline = e.dim.Height - 1 -
							((irr::gui::CGUITTFont *)e.font)->getAscender() / 64;
					}
#endif
				} else {
					e.dim = {0, 0};
				}
				break;

			case ParsedText::ELEMENT_IMAGE:
			case ParsedText::ELEMENT_ITEM:
				// Resize only non sized items
				if (e.dim.Height != 0 && e.dim.Width != 0)
					break;

				// Default image and item size
				core::dimension2d<u32> dim(80, 80);

				if (e.type == ParsedText::ELEMENT_IMAGE) {
					video::ITexture *texture =
						m_client->getTextureSource()->
							getTexture(stringw_to_utf8(e.text));
					if (texture)
						dim = texture->getOriginalSize();
				}

				if (e.dim.Height == 0)
					if (e.dim.Width == 0)
						e.dim = dim;
					else
						e.dim.Height = dim.Height * e.dim.Width /
								dim.Width;
				else
					e.dim.Width = dim.Width * e.dim.Height /
							dim.Height;
				break;
			}
		}
	}
}

// Get element at given coordinates. Coordinates are inner coordinates (starting
// at 0,0).
ParsedText::Element *TextDrawer::getElementAt(core::position2d<s32> pos)
{
	pos.Y -= m_voffset;
	for (auto &p : m_text.m_paragraphs) {
		for (auto &el : p.elements) {
			core::rect<s32> rect(el.pos, el.dim);
			if (rect.isPointInside(pos))
				return &el;
		}
	}
	return 0;
}

/*
   This function places all elements according to given width. Elements have
   been previously sized by constructor and will be later drawed by draw.
   It may be called each time width changes and resulting height can be
   retrieved using getHeight. See GUIHyperText constructor, it uses it once to
   test if text fits in window and eventually another time if width is reduced
   m_floating because of scrollbar added.
*/
void TextDrawer::place(const core::rect<s32> &dest_rect)
{
	m_floating.clear();
	s32 y = 0;
	s32 ymargin = m_text.margin;

	// Iterator used :
	// p - Current paragraph, walked only once
	// el - Current element, walked only once
	// e and f - local element and floating operators

	for (auto &p : m_text.m_paragraphs) {
		// Find and place floating stuff in paragraph
		for (auto e = p.elements.begin(); e != p.elements.end(); ++e) {
			if (e->floating != ParsedText::FLOAT_NONE) {
				if (y)
					e->pos.Y = y + std::max(ymargin, e->margin);
				else
					e->pos.Y = ymargin;

				if (e->floating == ParsedText::FLOAT_LEFT)
					e->pos.X = m_text.margin;
				if (e->floating == ParsedText::FLOAT_RIGHT)
					e->pos.X = dest_rect.getWidth() - e->dim.Width -
							m_text.margin;

				RectWithMargin floating;
				floating.rect = core::rect<s32>(e->pos, e->dim);
				floating.margin = e->margin;

				m_floating.push_back(floating);
			}
		}

		if (y)
			y = y + std::max(ymargin, p.margin);

		ymargin = p.margin;

		// Place non floating stuff
		std::vector<ParsedText::Element>::iterator el = p.elements.begin();

		while (el != p.elements.end()) {
			// Determine line width and y pos
			s32 left, right;
			s32 nexty = y;
			do {
				y = nexty;
				nexty = 0;

				// Inner left & right
				left = m_text.margin;
				right = dest_rect.getWidth() - m_text.margin;

				for (const auto &f : m_floating) {
					// Does floating rect intersect paragraph y line?
					if (f.rect.UpperLeftCorner.Y - f.margin <= y &&
							f.rect.LowerRightCorner.Y + f.margin >= y) {

						// Next Y to try if no room left
						if (!nexty || f.rect.LowerRightCorner.Y +
								std::max(f.margin, p.margin) < nexty) {
							nexty = f.rect.LowerRightCorner.Y +
									std::max(f.margin, p.margin) + 1;
						}

						if (f.rect.UpperLeftCorner.X - f.margin <= left &&
								f.rect.LowerRightCorner.X + f.margin < right) {
							// float on left
							if (f.rect.LowerRightCorner.X +
									std::max(f.margin, p.margin) > left) {
								left = f.rect.LowerRightCorner.X +
										std::max(f.margin, p.margin);
							}
						} else if (f.rect.LowerRightCorner.X + f.margin >= right &&
								f.rect.UpperLeftCorner.X - f.margin > left) {
							// float on right
							if (f.rect.UpperLeftCorner.X -
									std::max(f.margin, p.margin) < right)
								right = f.rect.UpperLeftCorner.X -
										std::max(f.margin, p.margin);

						} else if (f.rect.UpperLeftCorner.X - f.margin <= left &&
							 	f.rect.LowerRightCorner.X + f.margin >= right) {
							// float taking all space
							left = right;
						}
						else
						{ // float in the middle -- should not occure yet, see that later
						}
					}
				}
			} while (nexty && right <= left);

			u32 linewidth = right - left;
			float x = left;

			u32 charsheight = 0;
			u32 charswidth = 0;
			u32 wordcount = 0;

			// Skip begining of line separators but include them in height
			// computation.
			while (el != p.elements.end() &&
					el->type == ParsedText::ELEMENT_SEPARATOR) {
				if (el->floating == ParsedText::FLOAT_NONE) {
					el->drawwidth = 0;
					if (charsheight < el->dim.Height)
						charsheight = el->dim.Height;
				}
				el++;
			}

			std::vector<ParsedText::Element>::iterator linestart = el;
			std::vector<ParsedText::Element>::iterator lineend = p.elements.end();

			// First pass, find elements fitting into line
			// (or at least one element)
			while (el != p.elements.end() && (charswidth == 0 ||
					charswidth + el->dim.Width <= linewidth)) {
				if (el->floating == ParsedText::FLOAT_NONE) {
					if (el->type != ParsedText::ELEMENT_SEPARATOR) {
						lineend = el;
						wordcount++;
					}
					charswidth += el->dim.Width;
					if (charsheight < el->dim.Height)
						charsheight = el->dim.Height;
				}
				el++;
			}

			// Empty line, nothing to place only go down line height
			if (lineend == p.elements.end()) {
				y += charsheight;
				continue;
			}

			// Point to the first position outside line (may be end())
			lineend++;

			// Second pass, compute printable line width and adjustments
			charswidth = 0;
			s32 top = 0;
			s32 bottom = 0;
			for (auto e = linestart; e != lineend; ++e) {
				if (e->floating == ParsedText::FLOAT_NONE) {
					charswidth += e->dim.Width;
					if (top < (s32)e->dim.Height - e->baseline)
						top = e->dim.Height - e->baseline;
					if (bottom < e->baseline)
						bottom = e->baseline;
				}
			}

			float extraspace = 0.f;

			switch (p.halign) {
			case ParsedText::HALIGN_CENTER:
				x += (linewidth - charswidth) / 2.f;
				break;
			case ParsedText::HALIGN_JUSTIFY:
				if (wordcount > 1 && // Justification only if at least two words
					!(lineend == p.elements.end())) // Don't justify last line
					extraspace = ((float)(linewidth - charswidth)) / (wordcount - 1);
				break;
			case ParsedText::HALIGN_RIGHT:
				x += linewidth - charswidth;
				break;
			case ParsedText::HALIGN_LEFT:
				break;
			}

			// Third pass, actually place everything
			for (auto e = linestart; e != lineend; ++e) {
				if (e->floating != ParsedText::FLOAT_NONE)
					continue;

				e->pos.X = x;
				e->pos.Y = y;

				switch (e->type) {
				case ParsedText::ELEMENT_TEXT:
				case ParsedText::ELEMENT_SEPARATOR:
					e->pos.X = x;

					// Align char baselines
					e->pos.Y = y + top + e->baseline - e->dim.Height;

					x += e->dim.Width;
					if (e->type == ParsedText::ELEMENT_SEPARATOR)
						x += extraspace;
					break;

				case ParsedText::ELEMENT_IMAGE:
				case ParsedText::ELEMENT_ITEM:
					x += e->dim.Width;
					break;
				}

				// Draw width for separator can be different than element
				// width. This will be important for char effects like
				// underline.
				e->drawwidth = x - e->pos.X;
			}
			y += charsheight;
		} // Elements (actually lines)
	} // Paragraph

	// Check if float goes under paragraph
	for (const auto &f : m_floating) {
		if (f.rect.LowerRightCorner.Y >= y)
			y = f.rect.LowerRightCorner.Y;
	}

	m_height = y + m_text.margin;
	// Compute vertical offset according to vertical alignment
	if (m_height < dest_rect.getHeight())
		switch (m_text.valign) {
		case ParsedText::VALIGN_BOTTOM:
			m_voffset = dest_rect.getHeight() - m_height;
			break;
		case ParsedText::VALIGN_MIDDLE:
			m_voffset = (dest_rect.getHeight() - m_height) / 2;
			break;
		case ParsedText::VALIGN_TOP:
		default:
			m_voffset = 0;
		}
	else
		m_voffset = 0;
}

// Draw text in a rectangle with a given offset. Items are actually placed in
// relative (to upper left corner) coordinates.
void TextDrawer::draw(const core::rect<s32> &clip_rect,
		const core::position2d<s32> &dest_offset)
{
	irr::video::IVideoDriver *driver = m_environment->getVideoDriver();
	core::position2d<s32> offset = dest_offset;
	offset.Y += m_voffset;

	if (m_text.background_type == ParsedText::BACKGROUND_COLOR)
		driver->draw2DRectangle(m_text.background_color, clip_rect);

	for (auto &p : m_text.m_paragraphs) {
		for (auto &el : p.elements) {
			core::rect<s32> rect(el.pos + offset, el.dim);
			if (!rect.isRectCollided(clip_rect))
				continue;

			switch (el.type) {
			case ParsedText::ELEMENT_SEPARATOR:
			case ParsedText::ELEMENT_TEXT: {
				irr::video::SColor color = el.color;

				for (auto tag : el.tags)
					if (&(*tag) == m_hovertag)
						color = el.hovercolor;

				if (!el.font)
					break;

				if (el.type == ParsedText::ELEMENT_TEXT)
					el.font->draw(el.text, rect, color, false, true,
							&clip_rect);

				if (el.underline &&  el.drawwidth) {
					s32 linepos = el.pos.Y + offset.Y +
							el.dim.Height - (el.baseline >> 1);

					core::rect<s32> linerect(el.pos.X + offset.X,
							linepos - (el.baseline >> 3) - 1,
							el.pos.X + offset.X + el.drawwidth,
							linepos + (el.baseline >> 3));

					driver->draw2DRectangle(color, linerect, &clip_rect);
				}
			} break;

			case ParsedText::ELEMENT_IMAGE: {
				video::ITexture *texture =
						m_client->getTextureSource()->getTexture(
								stringw_to_utf8(el.text));
				if (texture != 0)
					m_environment->getVideoDriver()->draw2DImage(
							texture, rect,
							irr::core::rect<s32>(
									core::position2d<s32>(0, 0),
									texture->getOriginalSize()),
							&clip_rect, 0, true);
			} break;

			case ParsedText::ELEMENT_ITEM: {
				IItemDefManager *idef = m_client->idef();
				ItemStack item;
				item.deSerialize(stringw_to_utf8(el.text), idef);

				drawItemStack(
						m_environment->getVideoDriver(),
						g_fontengine->getFont(), item, rect, &clip_rect,
						m_client, IT_ROT_OTHER, el.angle, el.rotation
				);
			} break;
			}
		}
	}
}

// -----------------------------------------------------------------------------
// GUIHyperText - The formated text area formspec item

//! constructor
GUIHyperText::GUIHyperText(const wchar_t *text, IGUIEnvironment *environment,
		IGUIElement *parent, s32 id, const core::rect<s32> &rectangle,
		Client *client, ISimpleTextureSource *tsrc) :
		IGUIElement(EGUIET_ELEMENT, environment, parent, id, rectangle),
		m_client(client), m_vscrollbar(nullptr),
		m_drawer(text, client, environment, tsrc), m_text_scrollpos(0, 0)
{

#ifdef _DEBUG
	setDebugName("GUIHyperText");
#endif

	IGUISkin *skin = 0;
	if (Environment)
		skin = Environment->getSkin();

	m_scrollbar_width = skin ? skin->getSize(gui::EGDS_SCROLLBAR_SIZE) : 16;

	core::rect<s32> rect = irr::core::rect<s32>(
			RelativeRect.getWidth() - m_scrollbar_width, 0,
			RelativeRect.getWidth(), RelativeRect.getHeight());

	m_vscrollbar = new GUIScrollBar(Environment, this, -1, rect, false, true);
	m_vscrollbar->setVisible(false);
}

//! destructor
GUIHyperText::~GUIHyperText()
{
	m_vscrollbar->remove();
	m_vscrollbar->drop();
}

ParsedText::Element *GUIHyperText::getElementAt(s32 X, s32 Y)
{
	core::position2d<s32> pos{X, Y};
	pos -= m_display_text_rect.UpperLeftCorner;
	pos -= m_text_scrollpos;
	return m_drawer.getElementAt(pos);
}

void GUIHyperText::checkHover(s32 X, s32 Y)
{
	m_drawer.m_hovertag = nullptr;

	if (AbsoluteRect.isPointInside(core::position2d<s32>(X, Y))) {
		ParsedText::Element *element = getElementAt(X, Y);

		if (element) {
			for (auto &tag : element->tags) {
				if (tag->name == "action") {
					m_drawer.m_hovertag = tag;
					break;
				}
			}
		}
	}

#ifndef HAVE_TOUCHSCREENGUI
	if (m_drawer.m_hovertag)
		RenderingEngine::get_raw_device()->getCursorControl()->setActiveIcon(
				gui::ECI_HAND);
	else
		RenderingEngine::get_raw_device()->getCursorControl()->setActiveIcon(
				gui::ECI_NORMAL);
#endif
}

bool GUIHyperText::OnEvent(const SEvent &event)
{
	// Scroll bar
	if (event.EventType == EET_GUI_EVENT &&
			event.GUIEvent.EventType == EGET_SCROLL_BAR_CHANGED &&
			event.GUIEvent.Caller == m_vscrollbar) {
		m_text_scrollpos.Y = -m_vscrollbar->getPos();
	}

	// Reset hover if element left
	if (event.EventType == EET_GUI_EVENT &&
			event.GUIEvent.EventType == EGET_ELEMENT_LEFT) {
		m_drawer.m_hovertag = nullptr;
#ifndef HAVE_TOUCHSCREENGUI
		gui::ICursorControl *cursor_control =
				RenderingEngine::get_raw_device()->getCursorControl();
		if (cursor_control->isVisible())
			cursor_control->setActiveIcon(gui::ECI_NORMAL);
#endif
	}

	if (event.EventType == EET_MOUSE_INPUT_EVENT) {
		if (event.MouseInput.Event == EMIE_MOUSE_MOVED)
			checkHover(event.MouseInput.X, event.MouseInput.Y);

		if (event.MouseInput.Event == EMIE_MOUSE_WHEEL && m_vscrollbar->isVisible()) {
			m_vscrollbar->setPos(m_vscrollbar->getPos() -
					event.MouseInput.Wheel * m_vscrollbar->getSmallStep());
			m_text_scrollpos.Y = -m_vscrollbar->getPos();
			m_drawer.draw(m_display_text_rect, m_text_scrollpos);
			checkHover(event.MouseInput.X, event.MouseInput.Y);
			return true;

		} else if (event.MouseInput.Event == EMIE_LMOUSE_PRESSED_DOWN) {
			ParsedText::Element *element = getElementAt(
					event.MouseInput.X, event.MouseInput.Y);

			if (element) {
				for (auto &tag : element->tags) {
					if (tag->name == "action") {
						Text = core::stringw(L"action:") +
						       utf8_to_stringw(tag->attrs["name"]);
						if (Parent) {
							SEvent newEvent;
							newEvent.EventType = EET_GUI_EVENT;
							newEvent.GUIEvent.Caller = this;
							newEvent.GUIEvent.Element = 0;
							newEvent.GUIEvent.EventType = EGET_BUTTON_CLICKED;
							Parent->OnEvent(newEvent);
						}
						break;
					}
				}
			}
		}
	}

	return IGUIElement::OnEvent(event);
}

//! draws the element and its children
void GUIHyperText::draw()
{
	if (!IsVisible)
		return;

	// Text
	m_display_text_rect = AbsoluteRect;
	m_drawer.place(m_display_text_rect);

	// Show scrollbar if text overflow
	if (m_drawer.getHeight() > m_display_text_rect.getHeight()) {
		m_vscrollbar->setSmallStep(m_display_text_rect.getHeight() * 0.1f);
		m_vscrollbar->setLargeStep(m_display_text_rect.getHeight() * 0.5f);
		m_vscrollbar->setMax(m_drawer.getHeight() - m_display_text_rect.getHeight());

		m_vscrollbar->setVisible(true);

		m_vscrollbar->setPageSize(s32(m_drawer.getHeight()));

		core::rect<s32> smaller_rect = m_display_text_rect;

		smaller_rect.LowerRightCorner.X -= m_scrollbar_width;
		m_drawer.place(smaller_rect);
	} else {
		m_vscrollbar->setMax(0);
		m_vscrollbar->setPos(0);
		m_vscrollbar->setVisible(false);
	}
	m_drawer.draw(AbsoluteClippingRect,
			m_display_text_rect.UpperLeftCorner + m_text_scrollpos);

	// draw children
	IGUIElement::draw();
}
	Commit message (Collapse)	Author	Age
*	Allow nodes to specify which sides to connect to.	Auke Kok	2016-03-12
\| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \|	NDT_CONNECTED attempts to connect to any side of nodes that it can connect to, which is troublesome for FACEDIR type nodes that generally may only have one usable face, and can be rotated. We introduce a node parameter `connect_sides` that is valid for any node type. If specified, it lists faces of the node (in "top", "bottom", "front", "left", "back", "right", form, as array) that connecting nodeboxes can connect to. "front" corresponds to the south facing side of a node with facedir = 0. If the node is rotatable using simple FACEDIR, then the attached face is properly rotated before checking. This allows e.g. a chest to be attached to only from the rear side.
*	Nodebox: Allow nodeboxes to "connect"	Auke Kok	2016-03-12
\| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \|	We introduce a new nodebox type "connected", and allow these nodes to have optional nodeboxes that connect it to other connecting nodeboxes. This is all done at scenedraw time in the client. The client will inspect the surrounding nodes and if they are to be connected to, it will draw the appropriate connecting nodeboxes to make those connections. In the node_box definition, we have to specify separate nodeboxes for each valid connection. This allows us to make nodes that connect only horizontally (the common case) by providing optional nodeboxes for +x, -x, +z, -z directions. Or this allows us to make wires that can connect up and down, by providing nodeboxes that connect it up and down (+y, -y) as well. The optional nodeboxes can be arrays. They are named "connect_top, "connect_bottom", "connect_front", "connect_left", "connect_back" and "connect_right". Here, "front" means the south facing side of the node that has facedir = 0. Additionally, a "fixed" nodebox list present will always be drawn, so one can make a central post, for instance. This "fixed" nodebox can be omitted, or it can be an array of nodeboxes. Collision boxes are also updated in exactly the same fashion, which allows you to walk over the upper extremities of the individual node boxes, or stand really close to them. You can also walk up node noxes that are small in height, all as expected, and unlike the NDT_FENCELIKE nodes. I've posted a screenshot demonstrating the flexibility at http://i.imgur.com/zaJq8jo.png In the screenshot, all connecting nodes are of this new subtype. Transparent textures render incorrectly, Which I don't think is related to this text, as other nodeboxes also have issues with this. A protocol bump is performed in order to be able to send older clients a nodeblock that is usable for them. In order to avoid abuse of users we send older clients a "full-size" node, so that it's impossible for them to try and walk through a fence or wall that's created in this fashion. This was tested with a pre-bump client connected against a server running the new protocol. These nodes connect to other nodes, and you can select which ones those are by specifying node names (or group names) in the connects_to string array: connects_to = { "group:fence", "default:wood" } By default, nodes do not connect to anything, allowing you to create nodes that always have to be paired in order to connect. lua_api.txt is updated to reflect the extension to the node_box API. Example lua code needed to generate these nodes can be found here: https://gist.github.com/sofar/b381c8c192c8e53e6062
*	Allow per-tiles culling.	Auke Kok	2016-01-20
\| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \|	Backface culling is enabled by default for all tiles, as this is how the lua parser initializes each tiledef. We revert to always using the value from the tiledef since it is always read and serialized. Mods that wish to enable culling for e.g. mesh nodes, now can specify the following to enable backface culling: tiles = {{ name = "tex.png", backface_culling = true }}, Note the double '{' and use of 'name' key here! In the same fashion, backface_culling can be disabled for any node now. I've tested this against the new door models and this properly allows me to disable culling per node. I've also tested this against my crops mod which uses mesh nodes where culling needs to be disabled, and tested also with plantlike drawtype nodes where we want this to continue to be disabled. No default setting has changed. The defaults are just migrated from nodedef.cpp to c_content.cpp.
*	Show infotext with description for item entities	RealBadAngel	2016-01-18
\|
*	Liquids: Flow into and destroy 'floodable' nodes	paramat	2016-01-07
\| \| \| \| \|	Add new node property 'floodable', default false Define "air" as floodable = true in C++ and lua
*	Revert "Add support for using arbitrary meshes as items"	Sapier	2015-12-29
\| \| \| \| \| \|	This reverts commit 91bafceee6606fab79db1bde4cba01b84fed65c7. Reverted due to missinterpretation of agreement, obvious dislike and me not interested in doing fights for feature I don't actually need
*	Add support for using arbitrary meshes as items	Sapier	2015-12-29
\|
*	Fix lua object:get_properties() being broken	Sapier	2015-12-21
\|
*	Fix missing pop	est31	2015-12-20
\| \| \| \| \| \| \| \| \| \| \|	Previous commit 70ea5d552e283bd5bce3278cbf3819bd87ba2602 "Add support for limiting rotation of automatic face movement dir entitys" by sapier has broken minetest's feature to open worlds. This was due to a missing stack pop operation. Thanks to @oleastre for reporting this bug and suggesting the fix.
*	Add support for limiting rotation of automatic face movement dir entitys	Sapier	2015-12-19
\|
*	Add option to give every object a nametag	BlockMen	2015-12-15
\| \| \| \|	or change the nametag text of players
*	Add support for audio feedback if placing node failed	BlockMen	2015-11-07
\|
*	Add option to disable backface culling for models	BlockMen	2015-10-25
\| \| \| \| \|	- Disabled by default (except players) - Fixes #2984
*	Use warningstream for deprecated field messages and refactor log_deprecated	ShadowNinja	2015-10-15
\|
*	Fix tiling issues for PLANTLIKE and FIRELIKE with FSAA	RealBadAngel	2015-08-05
\|
*	Fix relief mapping issues	RealBadAngel	2015-07-16
\|
*	Fix code style from recent commits and add misc. optimizations	kwolekr	2015-07-02
\|
*	Add some missing getter functions to the lua API	TeTpaAka	2015-05-28
\| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \|	ObjectRef: get_properties get_armor_groups get_animation get_attach get_bone_position Players: get_physics_override hud_get_hotbar_itemcount hud_get_hotbar_image hud_get_hotbar_selected_image get_sky get_day_night_ratio get_local_animation get_eye_offset Global: minetest.get_gen_notify minetest.get_noiseparams
*	SAPI: Accept either ARGB8 table or ColorString to specify colors	kwolekr	2015-05-16
\|
*	Add 'persistence' alias for Lua noiseparams and validate more vector parameters	kwolekr	2015-04-19
\|
*	Don't use luaL_checkstring to read node names, it's only for arguments	ShadowNinja	2015-03-07
\| \| \| \|	This caused confusing error messages like "argument #4 to set_node is not a string."
*	Remove freezemelt (the remainder of proller nonsense)	kwolekr	2015-01-04
\|
*	Move get_schematic and read_schematic to l_mapgen.cpp	kwolekr	2014-12-10
\|
*	Remove get_noiseparams function. read_noiseparams should be used from now on	kwolekr	2014-12-10
\|
*	Add flags and lacunarity as new noise parameters	kwolekr	2014-12-07
\| \| \| \| \| \| \|	Add 'absolute value' option to noise map functions Extend persistence modulation to 3D noise Extend 'eased' option to noise2d_perlin* functions Some noise.cpp formatting fixups
*	Schematics: Fix minetest.place_schematic() when defined by a Lua table	kwolekr	2014-12-06
\|
*	Don't corrupt stepheight when setting other properties	Ciaran Gultnieks	2014-11-26
\|
*	Add option 'eased' to NoiseParams	SmallJoker	2014-11-13
\| \| \| \|	Signed-off-by: Craig Robbins <kde.psych@gmail.com>
*	Add Generator Element Management framework	kwolekr	2014-11-12
\| \| \| \|	Add BiomeManager, OreManager, DecorationManager, and SchematicManager
*	Split up mapgen.cpp	kwolekr	2014-11-01
\|
*	Custom collision boxes node property.	RealBadAngel	2014-10-19
\|
*	Add meshnode drawtype.	RealBadAngel	2014-10-18
\|
*	Use "core" namespace internally	ShadowNinja	2014-05-08
\|
*	Remove lua_State parameter from LuaError::LuaError	ShadowNinja	2014-03-15
\|
*	Revert "Make sure we get a stacktrace for as many lua errors as possible"	ShadowNinja	2014-03-15
\| \| \| \| \| \| \| \|	This reverts commit 362ef5f6ced862daa4733034810d0b07e2ad5d89. Stack tracebacks couldn't be generated in LuaError::LuaError anyway and this caused a second, empty traceback in most cases. In cases where there wasn't annother traceback the stack had already unwound and the traceback was empty.
*	Make sure we get a stacktrace for as many lua errors as possible	Sfan5	2014-03-15
\|
*	Update set_mapgen_params and set_gen_notify Lua API to use new flag format	kwolekr	2014-03-08
\|
*	Add minetest.set_noiseparam_defaults() Lua API	kwolekr	2014-02-15
\|
*	Define strlcpy on platforms that do not have it	kwolekr	2014-02-09
\|
*	Add capability to read table flag fields from Lua API	kwolekr	2014-02-09
\|
*	Make flag strings clear specified flag with 'no' prefix	kwolekr	2014-02-08
\| \| \| \| \|	Remove flagmask field from set_mapgen_params table Add small bits of needed documentation
*	Schematic: Read slice probability table from schematic descriptors	kwolekr	2014-01-19
\|
*	Add maximum recursion depth to read_json_value	ShadowNinja	2014-01-11
\|
*	Rename get_json_value to read_json_value	ShadowNinja	2014-01-11
\|
*	Fix InventoryList reading order	ShadowNinja	2013-12-30
\| \| \| \|	Lua does not guarantee that the indexes of a table will be in numerical order.
*	Don't throw a error when writing JSON fails	ShadowNinja	2013-12-18
\|
*	Add 'minetest.write_json'	ShadowNinja	2013-12-18
\|
*	Handle LuaErrors in Lua -> C++ calls on LuaJIT	ShadowNinja	2013-12-18
\|
*	Shaders rework.	RealBadAngel	2013-12-03
\|
*	Optimize table creation	ShadowNinja	2013-11-30
\|