Files
crosspoint-reader-mod/lib/GfxRenderer/GfxRenderer.h
Adrian Wilkins-Caruana c1d1e98909 perf: Reduce overall flash usage by 30.7% by compressing built-in fonts (#831)
**What is the goal of this PR?**

Compress reader font bitmaps to reduce flash usage by 30.7%.

**What changes are included?**

- New `EpdFontGroup` struct and extended `EpdFontData` with
`groups`/`groupCount` fields
- `--compress` flag in `fontconvert.py`: groups glyphs (ASCII base group
+ groups of 8) and compresses each with raw DEFLATE
- `FontDecompressor` class with 4-slot LRU cache for on-demand
decompression during rendering
- `GfxRenderer` transparently routes bitmap access through
`getGlyphBitmap()` (compressed or direct flash)
- Uses `uzlib` for decompression with minimal heap overhead.
- 48 reader fonts (Bookerly, NotoSans 12-18pt, OpenDyslexic) regenerated
with compression; 5 UI fonts unchanged
- Round-trip verification script (`verify_compression.py`) runs as part
of font generation

| | baseline | font-compression | Difference |
|--|--------|-----------------|------------|
| Flash (ELF) | 6,302,476 B (96.2%) | 4,365,022 B (66.6%) | -1,937,454 B
(-30.7%) |
| firmware.bin | 6,468,192 B | 4,531,008 B | -1,937,184 B (-29.9%) |
| RAM | 101,700 B (31.0%) | 103,076 B (31.5%) | +1,376 B (+0.5%) |

Comparison of uncompressed baseline vs script-based group compression
(4-slot LRU cache, cleared each page). Glyphs are grouped by Unicode
block (ASCII, Latin-1, Latin Extended-A, Combining Marks, Cyrillic,
General Punctuation, etc.) instead of sequential groups of 8.

| | Baseline | Compressed (cold cache) | Difference |
|---|---|---|---|
| **Median** | 414.9 ms | 431.6 ms | +16.7 ms (+4.0%) |
| **Pages** | 37 | 37 | |

| | Baseline | Compressed (cold cache) | Difference |
|---|---|---|---|
| **Heap free (median)** | 187.0 KB | 176.3 KB | -10.7 KB |
| **Heap free (min)** | 186.0 KB | 166.5 KB | -19.5 KB |
| **Largest block (median)** | 148.0 KB | 128.0 KB | -20.0 KB |
| **Largest block (min)** | 148.0 KB | 120.0 KB | -28.0 KB |

| | Misses/page | Hit rate |
|---|---|---|
| **Compressed (cold cache)** | 2.1 | 99.85% |

------

While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.

  Did you use AI tools to help write this code? _**YES**_
Implementation was done by Claude Code (Opus 4.6) based on a plan
developed collaboratively. All generated font headers were verified with
an automated round-trip decompression test. The firmware was compiled
successfully but has not yet been tested on-device.

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-02-19 10:39:11 -05:00

143 lines
7.1 KiB
C++

#pragma once
#include <EpdFontFamily.h>
#include <FontDecompressor.h>
#include <HalDisplay.h>
#include <map>
#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 size_t BW_BUFFER_NUM_CHUNKS = HalDisplay::BUFFER_SIZE / BW_BUFFER_CHUNK_SIZE;
static_assert(BW_BUFFER_CHUNK_SIZE * BW_BUFFER_NUM_CHUNKS == HalDisplay::BUFFER_SIZE,
"BW buffer chunking does not line up with display buffer size");
HalDisplay& display;
RenderMode renderMode;
Orientation orientation;
bool fadingFix;
uint8_t* frameBuffer = nullptr;
uint8_t* bwBufferChunks[BW_BUFFER_NUM_CHUNKS] = {nullptr};
std::map<int, EpdFontFamily> fontMap;
FontDecompressor* fontDecompressor = nullptr;
void renderChar(const EpdFontFamily& fontFamily, uint32_t cp, int* x, const int* y, bool pixelState,
EpdFontFamily::Style style) const;
void freeBwBufferChunks();
const uint8_t* getGlyphBitmap(const EpdFontData* fontData, const EpdGlyph* glyph) const;
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;
public:
explicit GfxRenderer(HalDisplay& halDisplay)
: display(halDisplay), renderMode(BW), orientation(Portrait), fadingFix(false) {}
~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 setFontDecompressor(FontDecompressor* d) { fontDecompressor = d; }
void clearFontCache() {
if (fontDecompressor) fontDecompressor->clearCache();
}
// Orientation control (affects logical width/height and coordinate transforms)
void setOrientation(const Orientation o) { orientation = o; }
Orientation getOrientation() const { return orientation; }
// Fading fix control
void setFadingFix(const bool enabled) { fadingFix = enabled; }
// Screen ops
int getScreenWidth() const;
int getScreenHeight() const;
void displayBuffer(HalDisplay::RefreshMode refreshMode = HalDisplay::FAST_REFRESH) const;
// EXPERIMENTAL: Windowed update - display only a rectangular region
void displayWindow(int x, int y, int width, int height,
HalDisplay::RefreshMode mode = HalDisplay::FAST_REFRESH) 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 drawPixelGray(int x, int y, uint8_t val2bit) 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 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;
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;
// Helpers for drawing rotated text (for side buttons)
void drawTextRotated90CW(int fontId, int x, int y, const char* text, bool black = true,
EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
void drawTextRotated90CCW(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 = mode; }
RenderMode getRenderMode() const { return renderMode; }
void copyGrayscaleLsbBuffers() const;
void copyGrayscaleMsbBuffers() const;
void displayGrayBuffer() const;
bool storeBwBuffer(); // Returns true if buffer was stored successfully
void restoreBwBuffer(); // Restore and free the stored buffer
void cleanupGrayscaleWithFrameBuffer() const;
// Low level functions
uint8_t* getFrameBuffer() const;
static size_t getBufferSize();
};