subtitlerenderer.h

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#pragma once
 
 
#include <promeki/config.h>
#if PROMEKI_ENABLE_PROAV
#include <promeki/color.h>
#include <promeki/enums_subtitle.h>
#include <promeki/error.h>
#if PROMEKI_ENABLE_FREETYPE
#include <promeki/fastfont.h>
#endif
#include <promeki/namespace.h>
#include <promeki/rect.h>
#include <promeki/string.h>
 
PROMEKI_NAMESPACE_BEGIN
 
class Subtitle;
class UncompressedVideoPayload;
 
class SubtitleRenderer {
        public:
                SubtitleRenderer();
                ~SubtitleRenderer();
 
                SubtitleRenderer(const SubtitleRenderer &) = delete;
                SubtitleRenderer &operator=(const SubtitleRenderer &) = delete;
 
                // ---- Configuration ------------------------------------------
 
                void setFontFilename(const String &val);
 
                void setFontSize(int val);
 
                void setDefaultForeground(const Color &c);
 
                void setDefaultBackground(const Color &c);
 
                void setDrawBackground(bool v);
 
                void setMargin(int v);
 
                void setAnchorOverride(const SubtitleAnchor &v);
 
                void setTopReserved(int lines);
 
                void setBottomReserved(int lines);
 
                // ---- Configuration accessors --------------------------------
 
                const String         &fontFilename() const { return _fontFilename; }
                int                   fontSize() const { return _fontSize; }
                const Color          &defaultForeground() const { return _defaultFg; }
                const Color          &defaultBackground() const { return _defaultBg; }
                bool                  drawBackground() const { return _drawBackground; }
                int                   margin() const { return _margin; }
                const SubtitleAnchor &anchorOverride() const { return _anchorOverride; }
                int                   topReserved() const { return _topReserved; }
                int                   bottomReserved() const { return _bottomReserved; }
 
                // ---- Rendering ----------------------------------------------
 
                Error render(const Subtitle &subtitle, UncompressedVideoPayload &target);
 
        private:
                struct StyledRun {
                                SubtitleSpan span;
                                int          width = 0; 
                };
 
                using StyledRunList = List<StyledRun>;
                using StyledLineList = List<StyledRunList>;
 
                SubtitleAnchor effectiveAnchor(const SubtitleAnchor &cueAnchor) const;
 
                void layoutSpans(const SubtitleSpan::List &spans, StyledLineList &lines);
 
                void computePosition(const SubtitleAnchor &anchor, const Rect2Di32 &bounds, int maxLineWidth,
                                     int totalHeight, int ascender, int &outX, int &outBaselineY) const;
 
#if PROMEKI_ENABLE_FREETYPE
                FastFont::DrawStyle styleFor(const SubtitleSpan &span) const;
#endif
 
                String         _fontFilename;
                int            _fontSize = 0; // 0 = auto.
                Color          _defaultFg = Color::White;
                Color          _defaultBg = Color::Black;
                bool           _drawBackground = true;
                int            _margin = 16;
                SubtitleAnchor _anchorOverride; // Default = honour cue's anchor.
                int            _topReserved = 0;
                int            _bottomReserved = 0;
 
                // Mutable state — updated from @ref render.  The glyph
                // renderer is only present when FreeType is compiled in;
                // without it @ref render returns @c Error::FontUnavailable.
#if PROMEKI_ENABLE_FREETYPE
                FastFont::UPtr _font;
#endif
                int            _effectiveFontSize = 0;
                bool           _fontDirty = true;
};
 
PROMEKI_NAMESPACE_END
 
#endif // PROMEKI_ENABLE_PROAV