OpenTTD Source  20241120-master-g6d3adc6169
gfx_layout.h
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1 /*
2  * This file is part of OpenTTD.
3  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
4  * OpenTTD 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.
5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
6  */
7 
10 #ifndef GFX_LAYOUT_H
11 #define GFX_LAYOUT_H
12 
13 #include "fontcache.h"
14 #include "gfx_func.h"
15 #include "core/math_func.hpp"
16 
17 #include <stack>
18 #include <string_view>
19 
24 struct FontState {
27 
28  std::stack<TextColour, std::vector<TextColour>> colour_stack;
29 
30  FontState() : fontsize(FS_END), cur_colour(TC_INVALID) {}
32 
37  inline void SetColour(TextColour c)
38  {
39  assert(((c & TC_COLOUR_MASK) >= TC_BLUE && (c & TC_COLOUR_MASK) <= TC_BLACK) || (c & TC_COLOUR_MASK) == TC_INVALID);
40  assert((c & (TC_COLOUR_MASK | TC_FLAGS_MASK)) == c);
41  if ((this->cur_colour & TC_FORCED) == 0) this->cur_colour = c;
42  }
43 
47  inline void PopColour()
48  {
49  if (colour_stack.empty()) return;
50  SetColour(colour_stack.top());
51  colour_stack.pop();
52  }
53 
57  inline void PushColour()
58  {
59  colour_stack.push(this->cur_colour);
60  }
61 
66  inline void SetFontSize(FontSize f)
67  {
68  this->fontsize = f;
69  }
70 };
71 
75 class Font {
76 public:
79 
81 };
82 
84 using FontMap = std::map<int, Font *>;
85 
90 public:
91  virtual ~ParagraphLayouter() = default;
92 
94  class Position {
95  public:
96  int16_t left;
97  int16_t right;
98  int16_t top;
99 
100  constexpr inline Position(int16_t left, int16_t right, int16_t top) : left(left), right(right), top(top) { }
101 
103  constexpr inline Position(const Point &pt) : left(pt.x), right(pt.x), top(pt.y) { }
104  };
105 
107  class VisualRun {
108  public:
109  virtual ~VisualRun() = default;
110  virtual const Font *GetFont() const = 0;
111  virtual int GetGlyphCount() const = 0;
112  virtual std::span<const GlyphID> GetGlyphs() const = 0;
113  virtual std::span<const Position> GetPositions() const = 0;
114  virtual int GetLeading() const = 0;
115  virtual std::span<const int> GetGlyphToCharMap() const = 0;
116  };
117 
119  class Line {
120  public:
121  virtual ~Line() = default;
122  virtual int GetLeading() const = 0;
123  virtual int GetWidth() const = 0;
124  virtual int CountRuns() const = 0;
125  virtual const VisualRun &GetVisualRun(int run) const = 0;
126  virtual int GetInternalCharLength(char32_t c) const = 0;
127  };
128 
129  virtual void Reflow() = 0;
130  virtual std::unique_ptr<const Line> NextLine(int max_width) = 0;
131 };
132 
138 class Layouter : public std::vector<std::unique_ptr<const ParagraphLayouter::Line>> {
139  std::string_view string;
140 
142  struct LineCacheKey {
144  std::string str;
145  };
146 
147  struct LineCacheQuery {
149  std::string_view str;
150  };
151 
154  using is_transparent = void;
155 
157  template<typename Key1, typename Key2>
158  bool operator()(const Key1 &lhs, const Key2 &rhs) const
159  {
160  if (lhs.state_before.fontsize != rhs.state_before.fontsize) return lhs.state_before.fontsize < rhs.state_before.fontsize;
161  if (lhs.state_before.cur_colour != rhs.state_before.cur_colour) return lhs.state_before.cur_colour < rhs.state_before.cur_colour;
162  if (lhs.state_before.colour_stack != rhs.state_before.colour_stack) return lhs.state_before.colour_stack < rhs.state_before.colour_stack;
163  return lhs.str < rhs.str;
164  }
165  };
166 public:
168  struct LineCacheItem {
169  /* Stuff that cannot be freed until the ParagraphLayout is freed */
170  void *buffer;
172 
175 
176  LineCacheItem() : buffer(nullptr), layout(nullptr) {}
177  ~LineCacheItem() { delete layout; free(buffer); }
178  };
179 private:
180  typedef std::map<LineCacheKey, LineCacheItem, LineCacheCompare> LineCache;
181  static LineCache *linecache;
182 
183  static LineCacheItem &GetCachedParagraphLayout(std::string_view str, const FontState &state);
184 
185  using FontColourMap = std::map<TextColour, std::unique_ptr<Font>>;
186  static FontColourMap fonts[FS_END];
187 public:
188  static Font *GetFont(FontSize size, TextColour colour);
189 
190  Layouter(std::string_view str, int maxw = INT32_MAX, FontSize fontsize = FS_NORMAL);
192  ParagraphLayouter::Position GetCharPosition(std::string_view::const_iterator ch) const;
193  ptrdiff_t GetCharAtPosition(int x, size_t line_index) const;
194 
195  static void Initialize();
196  static void ResetFontCache(FontSize size);
197  static void ResetLineCache();
198  static void ReduceLineCache();
199 };
200 
201 ParagraphLayouter::Position GetCharPosInString(std::string_view str, const char *ch, FontSize start_fontsize = FS_NORMAL);
202 ptrdiff_t GetCharAtPosition(std::string_view str, int x, FontSize start_fontsize = FS_NORMAL);
203 
204 #endif /* GFX_LAYOUT_H */
Font cache for basic fonts.
Definition: fontcache.h:21
Container with information about a font.
Definition: gfx_layout.h:75
Font(FontSize size, TextColour colour)
Construct a new font.
Definition: gfx_layout.cpp:48
FontCache * fc
The font we are using.
Definition: gfx_layout.h:77
TextColour colour
The colour this font has to be.
Definition: gfx_layout.h:78
The layouter performs all the layout work.
Definition: gfx_layout.h:138
static void Initialize()
Perform initialization of layout engine.
Definition: gfx_layout.cpp:342
static FontColourMap fonts[FS_END]
Cache of Font instances.
Definition: gfx_layout.h:186
Layouter(std::string_view str, int maxw=INT32_MAX, FontSize fontsize=FS_NORMAL)
Create a new layouter.
Definition: gfx_layout.cpp:130
ptrdiff_t GetCharAtPosition(int x, size_t line_index) const
Get the character that is at a pixel position in the first line of the layouted text.
Definition: gfx_layout.cpp:290
static void ResetFontCache(FontSize size)
Reset cached font information.
Definition: gfx_layout.cpp:353
ParagraphLayouter::Position GetCharPosition(std::string_view::const_iterator ch) const
Get the position of a character in the layout.
Definition: gfx_layout.cpp:228
static Font * GetFont(FontSize size, TextColour colour)
Get a static font instance.
Definition: gfx_layout.cpp:330
std::string_view string
Pointer to the original string.
Definition: gfx_layout.h:139
static void ResetLineCache()
Clear line cache.
Definition: gfx_layout.cpp:397
Dimension GetBounds()
Get the boundaries of this paragraph.
Definition: gfx_layout.cpp:199
static LineCacheItem & GetCachedParagraphLayout(std::string_view str, const FontState &state)
Get reference to cache item.
Definition: gfx_layout.cpp:375
static LineCache * linecache
Cache of ParagraphLayout lines.
Definition: gfx_layout.h:181
static void ReduceLineCache()
Reduce the size of linecache if necessary to prevent infinite growth.
Definition: gfx_layout.cpp:405
A single line worth of VisualRuns.
Definition: gfx_layout.h:119
Position of a glyph within a VisualRun.
Definition: gfx_layout.h:94
int16_t right
Right-most position of glyph.
Definition: gfx_layout.h:97
constexpr Position(const Point &pt)
Conversion from a single point to a Position.
Definition: gfx_layout.h:103
int16_t left
Left-most position of glyph.
Definition: gfx_layout.h:96
int16_t top
Top-most position of glyph.
Definition: gfx_layout.h:98
Visual run contains data about the bit of text with the same font.
Definition: gfx_layout.h:107
Interface to glue fallback and normal layouter into one.
Definition: gfx_layout.h:89
Functions to read fonts from files and cache them.
Functions related to the gfx engine.
ParagraphLayouter::Position GetCharPosInString(std::string_view str, const char *ch, FontSize start_fontsize=FS_NORMAL)
Get the leading corner of a character in a single-line string relative to the start of the string.
Definition: gfx_layout.cpp:421
ptrdiff_t GetCharAtPosition(std::string_view str, int x, FontSize start_fontsize=FS_NORMAL)
Get the character from a string that is drawn at a specific position.
Definition: gfx_layout.cpp:438
std::map< int, Font * > FontMap
Mapping from index to font.
Definition: gfx_layout.h:84
FontSize
Available font sizes.
Definition: gfx_type.h:208
@ FS_NORMAL
Index of the normal font in the font tables.
Definition: gfx_type.h:209
TextColour
Colour of the strings, see _string_colourmap in table/string_colours.h or docs/ottd-colourtext-palett...
Definition: gfx_type.h:260
@ TC_FORCED
Ignore colour changes from strings.
Definition: gfx_type.h:285
@ TC_FLAGS_MASK
Mask to test if TextColour (with flags) is within limits.
Definition: gfx_type.h:288
@ TC_COLOUR_MASK
Mask to test if TextColour (without flags) is within limits.
Definition: gfx_type.h:287
Integer math functions.
void free(const void *ptr)
Version of the standard free that accepts const pointers.
Definition: stdafx.h:334
Dimensions (a width and height) of a rectangle in 2D.
Text drawing parameters, which can change while drawing a line, but are kept between multiple parts o...
Definition: gfx_layout.h:24
void PushColour()
Push the current colour on to the stack.
Definition: gfx_layout.h:57
void SetColour(TextColour c)
Switch to new colour c.
Definition: gfx_layout.h:37
void PopColour()
Switch to and pop the last saved colour on the stack.
Definition: gfx_layout.h:47
void SetFontSize(FontSize f)
Switch to using a new font f.
Definition: gfx_layout.h:66
FontSize fontsize
Current font size.
Definition: gfx_layout.h:25
std::stack< TextColour, std::vector< TextColour > > colour_stack
Stack of colours to assist with colour switching.
Definition: gfx_layout.h:28
TextColour cur_colour
Current text colour.
Definition: gfx_layout.h:26
Comparator for std::map.
Definition: gfx_layout.h:153
bool operator()(const Key1 &lhs, const Key2 &rhs) const
Comparison operator for LineCacheKey and LineCacheQuery.
Definition: gfx_layout.h:158
void is_transparent
Enable map queries with various key types.
Definition: gfx_layout.h:154
Item in the linecache.
Definition: gfx_layout.h:168
ParagraphLayouter * layout
Layout of the line.
Definition: gfx_layout.h:174
FontMap runs
Accessed by our ParagraphLayout::nextLine.
Definition: gfx_layout.h:171
void * buffer
Accessed by our ParagraphLayout::nextLine.
Definition: gfx_layout.h:170
FontState state_after
Font state after the line.
Definition: gfx_layout.h:173
Key into the linecache.
Definition: gfx_layout.h:142
FontState state_before
Font state at the beginning of the line.
Definition: gfx_layout.h:143
std::string str
Source string of the line (including colour and font size codes).
Definition: gfx_layout.h:144
const FontState & state_before
Font state at the beginning of the line.
Definition: gfx_layout.h:148
std::string_view str
Source string of the line (including colour and font size codes).
Definition: gfx_layout.h:149
Coordinates of a point in 2D.