Crosspoint/lib/GfxRenderer/GfxRenderer.h

#pragma once

#include <EpdFontFamily.h>
#include <HalDisplay.h>

class FontCacheManager;
class SdCardFont;

#include <atomic>
#include <cstring>
#include <map>
#include <string>
#include <vector>

#include "Bitmap.h"

// Color representation: uint8_t mapped to 4x4 Bayer matrix dithering levels
// 0 = transparent, 1-16 = gray levels (white to black)
enum Color : uint8_t { Clear = 0x00, White = 0x01, LightGray = 0x05, DarkGray = 0x0A, Black = 0x10 };

class GfxRenderer {
 public:
  enum RenderMode { BW, GRAYSCALE_LSB, GRAYSCALE_MSB };

  // Logical screen orientation from the perspective of callers
  enum Orientation {
    Portrait,                  // 480x800 logical coordinates (current default)
    LandscapeClockwise,        // 800x480 logical coordinates, rotated 180° (swap top/bottom)
    PortraitInverted,          // 480x800 logical coordinates, inverted
    LandscapeCounterClockwise  // 800x480 logical coordinates, native panel orientation
  };

 private:
  static constexpr size_t BW_BUFFER_CHUNK_SIZE = 8000;  // 8KB chunks to allow for non-contiguous memory
  static constexpr unsigned int REFRESH_OVERRIDE_NONE = 0;

  HalDisplay& display;
  std::atomic<int> renderMode;
  std::atomic<int> orientation;
  std::atomic<bool> fadingFix;
  // Text darkness for 2-bit grayscale glyph rendering.
  std::atomic<uint8_t> textDarkness;
  //   0 = Normal     — true 4-level AA (raw=1 → light gray, raw=2 → dark gray)
  //   1 = Dark       — historical default; raw=2 collapses to black
  //   2 = Extra Dark — both AA shades go black in the grayscale plane
  //   3 = Maximum    — grayscale pass skipped entirely; only the hard BW
  //                    pass remains, so AA pixels render as solid black
  //                    with the FAST waveform (no gray-LUT softening)
  // Only affects AA pixels in GRAYSCALE_MSB / GRAYSCALE_LSB rendering of 2-bit fonts.
  // 1-bit fonts and the BW pass are unchanged. Default is 1 to preserve historical
  // rendering. See drawMaskFor2BitMode() in GfxRenderer.cpp for the per-level
  // pixel breakdown and a worked example glyph.
  uint8_t* frameBuffer = nullptr;
  uint16_t panelWidth = 0;       // set in begin()
  uint16_t panelHeight = 0;      // set in begin()
  uint16_t panelWidthBytes = 0;  // set in begin()
  uint32_t frameBufferSize = 0;  // set in begin()
  uint16_t bwSnapshotRowStart = 0;
  uint16_t bwSnapshotRowEnd = 0;
  size_t bwSnapshotSizeBytes = 0;
  size_t bwBufferChunkSize = BW_BUFFER_CHUNK_SIZE;
  std::vector<uint8_t*> bwBufferChunks;
  std::map<int, EpdFontFamily> fontMap;
  // Mutable because ensureSdCardFontReady() is const (called from layout code that
  // holds a const GfxRenderer&) but triggers SD card reads and heap allocation
  // inside the SdCardFont objects. Same pragmatic compromise as fontCacheManager_.
  mutable std::map<int, SdCardFont*> sdCardFonts_;

  // Mutable because drawText() is const but needs to delegate scan-mode
  // recording to the (non-const) FontCacheManager. Same pragmatic compromise
  // as before, concentrated in a single pointer instead of four fields.
  mutable FontCacheManager* fontCacheManager_ = nullptr;
  mutable std::atomic<unsigned int> refreshOverride = REFRESH_OVERRIDE_NONE;

  // Tiled grayscale strip target. When active, drawPixel(), clearScreen(),
  // fillPhysicalHSpanByte() and renderGlyphFast2Bit() write into a caller-owned
  // scratch holding one horizontal band of physical rows
  // [_stripY0, _stripY0 + _stripRows) (panelWidthBytes wide) instead of the
  // shared framebuffer; pixels outside the band are clipped. Lets grayscale
  // planes render band-by-band straight to the controller without destroying
  // the BW framebuffer (no storeBwBuffer). Mutable because the render path is
  // const. See beginStripTarget()/endStripTarget().
  mutable uint8_t* stripBuf_ = nullptr;
  mutable int stripY0_ = 0;
  mutable int stripRows_ = 0;
  mutable bool stripActive_ = false;

  void renderChar(const EpdFontFamily& fontFamily, uint32_t cp, int* x, int* y, bool pixelState,
                  EpdFontFamily::Style style) const;
  void freeBwBufferChunks();
  template <Color color>
  void drawPixelDither(int x, int y) const;
  template <Color color>
  void fillArc(int maxRadius, int cx, int cy, int xDir, int yDir) const;
  // Write a patterned horizontal span directly to the physical framebuffer using byte-level operations.
  // phyY: physical row; phyX_start/phyX_end: inclusive physical column range.
  // patternByte is repeated across the span; partial edge bytes are blended with existing content.
  // Bit layout: MSB-first (bit 7 = phyX=0); 0 bits = dark pixel, 1 bits = white pixel.
  void fillPhysicalHSpanByte(int phyY, int phyX_start, int phyX_end, uint8_t patternByte) const;
  // Write a solid horizontal span directly to the physical framebuffer using byte-level operations.
  // Thin wrapper around fillPhysicalHSpanByte: state=true → 0x00 (dark), false → 0xFF (white).
  void fillPhysicalHSpan(int phyY, int phyX_start, int phyX_end, bool state) const;

 public:
  explicit GfxRenderer(HalDisplay& halDisplay)
      : display(halDisplay),
        renderMode(static_cast<int>(BW)),
        orientation(static_cast<int>(Portrait)),
        fadingFix(false),
        textDarkness(1) {}
  ~GfxRenderer() { freeBwBufferChunks(); }

  static constexpr int VIEWABLE_MARGIN_TOP = 9;
  static constexpr int VIEWABLE_MARGIN_RIGHT = 3;
  static constexpr int VIEWABLE_MARGIN_BOTTOM = 3;
  static constexpr int VIEWABLE_MARGIN_LEFT = 3;

  // Setup
  void begin();  // must be called right after display.begin()
  void insertFont(int fontId, EpdFontFamily font);
  void removeFont(int fontId) { fontMap.erase(fontId); }
  void setFontCacheManager(FontCacheManager* m) { fontCacheManager_ = m; }
  FontCacheManager* getFontCacheManager() const { return fontCacheManager_; }
  const std::map<int, EpdFontFamily>& getFontMap() const { return fontMap; }
  void registerSdCardFont(int fontId, SdCardFont* font) { sdCardFonts_[fontId] = font; }
  void unregisterSdCardFont(int fontId) { sdCardFonts_.erase(fontId); }
  void clearSdCardFonts() { sdCardFonts_.clear(); }
  const std::map<int, SdCardFont*>& getSdCardFonts() const { return sdCardFonts_; }
  bool isSdCardFont(int fontId) const { return sdCardFonts_.count(fontId) > 0; }
  // Ensure SD card font glyph data is loaded for the given text. Called from layout code
  // (which holds a const GfxRenderer&) before measuring word widths. Safe to call on
  // non-SD fonts (no-op).
  void ensureSdCardFontReady(int fontId, const char* utf8Text) const;
  // Clear the cumulative SD card font metadata cache built up by repeated
  // ensureSdCardFontReady() calls. Call between sections to bound the cumulative
  // codepoint set growth across pagination. Safe to call when no SD font is active.
  void clearSdCardFontAccumulation() const;

  // Orientation control (affects logical width/height and coordinate transforms)
  void setOrientation(const Orientation o) { orientation.store(static_cast<int>(o), std::memory_order_relaxed); }
  Orientation getOrientation() const { return static_cast<Orientation>(orientation.load(std::memory_order_relaxed)); }

  // Fading fix control
  void setFadingFix(const bool enabled) { fadingFix.store(enabled, std::memory_order_relaxed); }

  // Screen ops
  int getScreenWidth() const;
  int getScreenHeight() const;
  void displayBuffer(HalDisplay::RefreshMode refreshMode = HalDisplay::FAST_REFRESH) const;
  void setNextDisplayRefreshMode(HalDisplay::RefreshMode refreshMode) const;
  // EXPERIMENTAL: Windowed update - display only a rectangular region
  // void displayWindow(int x, int y, int width, int height) const;
  void invertScreen() const;
  void clearScreen(uint8_t color = 0xFF) const;
  void getOrientedViewableTRBL(int* outTop, int* outRight, int* outBottom, int* outLeft) const;

  // Drawing
  void drawPixel(int x, int y, bool state = true) const;
  void drawLine(int x1, int y1, int x2, int y2, bool state = true) const;
  void drawLine(int x1, int y1, int x2, int y2, int lineWidth, bool state) const;
  void drawArc(int maxRadius, int cx, int cy, int xDir, int yDir, int lineWidth, bool state) const;
  void drawRect(int x, int y, int width, int height, bool state = true) const;
  void drawRect(int x, int y, int width, int height, int lineWidth, bool state) const;
  void drawRoundedRect(int x, int y, int width, int height, int lineWidth, int cornerRadius, bool state) const;
  void drawRoundedRect(int x, int y, int width, int height, int lineWidth, int cornerRadius, bool roundTopLeft,
                       bool roundTopRight, bool roundBottomLeft, bool roundBottomRight, bool state) const;
  void fillRect(int x, int y, int width, int height, bool state = true) const;
  void fillRectDither(int x, int y, int width, int height, Color color) const;
  void fillRoundedRect(int x, int y, int width, int height, int cornerRadius, Color color) const;
  void fillRoundedRect(int x, int y, int width, int height, int cornerRadius, bool roundTopLeft, bool roundTopRight,
                       bool roundBottomLeft, bool roundBottomRight, Color color) const;
  void drawImage(const uint8_t bitmap[], int x, int y, int width, int height) const;
  void drawIcon(const uint8_t bitmap[], int x, int y, int width, int height) const;
  void drawIconInverted(const uint8_t bitmap[], int x, int y, int width, int height) const;
  void drawBitmap(const Bitmap& bitmap, int x, int y, int maxWidth, int maxHeight, float cropX = 0,
                  float cropY = 0) const;
  void drawBitmap1Bit(const Bitmap& bitmap, int x, int y, int maxWidth, int maxHeight) const;
  void fillPolygon(const int* xPoints, const int* yPoints, int numPoints, bool state = true) const;

  // Text
  int getTextWidth(int fontId, const char* text, EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
  void drawCenteredText(int fontId, int y, const char* text, bool black = true,
                        EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
  void drawText(int fontId, int x, int y, const char* text, bool black = true,
                EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
  int getSpaceWidth(int fontId, EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
  /// Returns the total inter-word advance: fp4::toPixel(spaceAdvance + kern(leftCp,' ') + kern(' ',rightCp)).
  /// Using a single snap avoids the +/-1 px rounding error that arises when space advance and kern are
  /// snapped separately and then added as integers.
  int getSpaceAdvance(int fontId, uint32_t leftCp, uint32_t rightCp, EpdFontFamily::Style style) const;
  /// Returns the kerning adjustment between two adjacent codepoints.
  int getKerning(int fontId, uint32_t leftCp, uint32_t rightCp, EpdFontFamily::Style style) const;
  int getTextAdvanceX(int fontId, const char* text, EpdFontFamily::Style style) const;
  int getFontAscenderSize(int fontId) const;
  int getLineHeight(int fontId) const;
  std::string truncatedText(int fontId, const char* text, int maxWidth,
                            EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
  /// Word-wrap \p text into at most \p maxLines lines, each no wider than
  /// \p maxWidth pixels. Overflowing words and excess lines are UTF-8-safely
  /// truncated with an ellipsis (U+2026).
  std::vector<std::string> wrappedText(int fontId, const char* text, int maxWidth, int maxLines,
                                       EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;

  // Helper for drawing rotated text (90 degrees clockwise, for side buttons)
  void drawTextRotated90CW(int fontId, int x, int y, const char* text, bool black = true,
                           EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
  int getTextHeight(int fontId) const;

  // Grayscale functions
  void setRenderMode(const RenderMode mode) {
    this->renderMode.store(static_cast<int>(mode), std::memory_order_relaxed);
  }
  RenderMode getRenderMode() const { return static_cast<RenderMode>(renderMode.load(std::memory_order_relaxed)); }

  // Text darkness control:
  //   0 = Normal, 1 = Dark, 2 = Extra Dark, 3 = Maximum.
  // Only affects anti-aliased pixels in 2-bit (grayscale) glyph rendering;
  // 1-bit fonts and the BW pass are unchanged. See drawMaskFor2BitMode() in
  // GfxRenderer.cpp for the per-level pixel breakdown and a worked example.
  void setTextDarkness(const uint8_t d) { textDarkness.store(d, std::memory_order_relaxed); }
  uint8_t getTextDarkness() const { return static_cast<uint8_t>(textDarkness.load(std::memory_order_relaxed)); }
  void copyGrayscaleLsbBuffers() const;
  void copyGrayscaleMsbBuffers() const;
  void displayGrayBuffer() const;

  // Tiled grayscale (X4 + X3): stream one band of a plane straight to
  // controller RAM from `scratch` (panelWidthBytes * numRows, physical rows
  // [yStart, yStart+numRows)), bypassing the framebuffer.
  // supportsStripGrayscale() gates use.
  void writeGrayscalePlaneStrip(bool lsbPlane, const uint8_t* scratch, int yStart, int numRows) const;
  bool supportsStripGrayscale() const;

  // X3-only: trade AA visual fidelity for ~2.2 s faster page-flip wall clock.
  // No effect on X4 (its single grayscale LUT already runs at ~500 ms).
  void setFastGrayscaleLut(bool fast) const { display.setFastGrayscaleLut(fast); }
  bool getFastGrayscaleLut() const { return display.getFastGrayscaleLut(); }

  // Tiled grayscale strip target. While active, drawPixel(), clearScreen(),
  // fillPhysicalHSpanByte() and renderGlyphFast2Bit() operate on `scratch`
  // (panelWidthBytes * stripRows bytes, holding physical rows
  // [stripY0, stripY0 + stripRows)) instead of the framebuffer; pixels whose
  // physical row falls outside the band are clipped. The clip is applied after
  // the orientation rotate, so it is orientation-agnostic. Used to render
  // grayscale planes band-by-band without a full second buffer.
  void beginStripTarget(uint8_t* scratch, int stripY0, int stripRows) const;
  void endStripTarget() const;

  // Active pixel-write target for raw writers that bypass drawPixel for speed.
  // When a strip target is active these return the band scratch plus its
  // physical-row origin and extent; otherwise the full framebuffer ([0,
  // panelHeight)). Writers subtract the origin and clip to the extent, so they
  // honor tiled-grayscale banding without per-pixel method calls.
  uint8_t* getWriteTarget() const { return stripActive_ ? stripBuf_ : frameBuffer; }
  int getWriteOriginY() const { return stripActive_ ? stripY0_ : 0; }
  int getWriteRows() const { return stripActive_ ? stripRows_ : static_cast<int>(panelHeight); }
  bool isStripActive() const { return stripActive_; }

  // Band culling. Takes a glyph bounding box in logical screen coords and
  // returns false only when a strip is active AND the box's physical y-extent
  // lies entirely outside the active band, letting callers skip expensive
  // bitmap decode. Returns true when no strip is active.
  bool glyphIntersectsStrip(int x0, int y0, int x1, int y1) const;

  bool storeBwBuffer();                                         // Returns true if buffer was stored successfully
  bool storeBwBufferRect(int x, int y, int width, int height);  // Store only rows intersecting logical rect
  void restoreBwBuffer();                                       // Restore and free the stored buffer
  void cleanupGrayscaleWithFrameBuffer() const;

  // Font helpers
  const uint8_t* getGlyphBitmap(const EpdFontData* fontData, const EpdGlyph* glyph) const;

  // Low level functions
  uint8_t* getFrameBuffer() const;
  size_t getBufferSize() const;
  uint16_t getDisplayWidth() const { return panelWidth; }
  uint16_t getDisplayHeight() const { return panelHeight; }
  uint16_t getDisplayWidthBytes() const { return panelWidthBytes; }

  // Region cache helpers: operate on a logical (orientation-aware) rect and
  // copy only the framebuffer bytes it touches. Used by HomeActivity to snapshot
  // the cover tile (~16 KB) instead of the full 48 KB framebuffer.
  size_t getRegionByteSize(int logicalX, int logicalY, int logicalW, int logicalH) const;
  bool copyRegionToBuffer(int logicalX, int logicalY, int logicalW, int logicalH, uint8_t* buf, size_t bufSize) const;
  bool copyBufferToRegion(int logicalX, int logicalY, int logicalW, int logicalH, const uint8_t* buf,
                          size_t bufSize) const;
};