diff --git a/lib/GfxRenderer/Bitmap.cpp b/lib/GfxRenderer/Bitmap.cpp index 8cc8a5f3..8878a145 100644 --- a/lib/GfxRenderer/Bitmap.cpp +++ b/lib/GfxRenderer/Bitmap.cpp @@ -8,12 +8,9 @@ // ============================================================================ // Note: For cover images, dithering is done in JpegToBmpConverter.cpp // This file handles BMP reading - use simple quantization to avoid double-dithering -constexpr bool USE_FLOYD_STEINBERG = false; // Disabled - dithering done at JPEG conversion +// constexpr bool USE_FLOYD_STEINBERG = true; // Disabled - dithering done at JPEG conversion constexpr bool USE_NOISE_DITHERING = false; // Hash-based noise dithering -// Brightness adjustments: -constexpr bool USE_BRIGHTNESS = false; // true: apply brightness/gamma adjustments -constexpr int BRIGHTNESS_BOOST = 20; // Brightness offset (0-50), only if USE_BRIGHTNESS=true -constexpr bool GAMMA_CORRECTION = false; // Gamma curve, only if USE_BRIGHTNESS=true +constexpr bool GAMMA_CORRECTION = true; // Gamma curve, only if USE_BRIGHTNESS=true // ============================================================================ // Integer approximation of gamma correction (brightens midtones) @@ -28,24 +25,19 @@ static inline int applyGamma(int gray) { return x > 255 ? 255 : x; } -// Simple quantization without dithering - just divide into 4 levels -static inline uint8_t quantizeSimple(int gray) { - if (USE_BRIGHTNESS) { - gray += BRIGHTNESS_BOOST; +static inline uint8_t boostBrightness(int gray, uint8_t boost) { + if (boost > 0) { + gray += boost; if (gray > 255) gray = 255; gray = applyGamma(gray); } - return static_cast(gray >> 6); + return gray; } +// Simple quantization without dithering - just divide into 4 levels +static inline uint8_t quantizeSimple(int gray) { return static_cast(gray >> 6); } // Hash-based noise dithering - survives downsampling without moiré artifacts static inline uint8_t quantizeNoise(int gray, int x, int y) { - if (USE_BRIGHTNESS) { - gray += BRIGHTNESS_BOOST; - if (gray > 255) gray = 255; - gray = applyGamma(gray); - } - uint32_t hash = static_cast(x) * 374761393u + static_cast(y) * 668265263u; hash = (hash ^ (hash >> 13)) * 1274126177u; const int threshold = static_cast(hash >> 24); @@ -75,7 +67,6 @@ static inline uint8_t quantizeFloydSteinberg(int gray, int x, int width, int16_t bool reverseDir) { // Add accumulated error to this pixel int adjusted = gray + errorCurRow[x + 1]; - // Clamp to valid range if (adjusted < 0) adjusted = 0; if (adjusted > 255) adjusted = 255; @@ -245,7 +236,7 @@ BmpReaderError Bitmap::parseHeaders() { } // Allocate Floyd-Steinberg error buffers if enabled - if (USE_FLOYD_STEINBERG) { + if (useFloydSteinberg) { delete[] errorCurRow; delete[] errorNextRow; errorCurRow = new int16_t[width + 2](); // +2 for boundary handling @@ -262,7 +253,7 @@ BmpReaderError Bitmap::readNextRow(uint8_t* data, uint8_t* rowBuffer) const { if (file.read(rowBuffer, rowBytes) != rowBytes) return BmpReaderError::ShortReadRow; // Handle Floyd-Steinberg error buffer progression - const bool useFS = USE_FLOYD_STEINBERG && errorCurRow && errorNextRow; + const bool useFS = useFloydSteinberg && errorCurRow && errorNextRow; if (useFS) { if (prevRowY != -1) { // Sequential access - swap buffers @@ -284,10 +275,12 @@ BmpReaderError Bitmap::readNextRow(uint8_t* data, uint8_t* rowBuffer) const { uint8_t color; if (useFS) { // Floyd-Steinberg error diffusion - color = quantizeFloydSteinberg(lum, currentX, width, errorCurRow, errorNextRow, false); + color = quantizeFloydSteinberg(boostBrightness(lum, brightnessBoost), currentX, width, errorCurRow, errorNextRow, + false); } else { // Simple quantization or noise dithering - color = quantize(lum, currentX, prevRowY); + + color = quantize(boostBrightness(lum, brightnessBoost), currentX, prevRowY); } currentOutByte |= (color << bitShift); if (bitShift == 0) { @@ -357,7 +350,7 @@ BmpReaderError Bitmap::rewindToData() const { } // Reset Floyd-Steinberg error buffers when rewinding - if (USE_FLOYD_STEINBERG && errorCurRow && errorNextRow) { + if (useFloydSteinberg && errorCurRow && errorNextRow) { memset(errorCurRow, 0, (width + 2) * sizeof(int16_t)); memset(errorNextRow, 0, (width + 2) * sizeof(int16_t)); prevRowY = -1; diff --git a/lib/GfxRenderer/Bitmap.h b/lib/GfxRenderer/Bitmap.h index a3f2e00c..80f6083e 100644 --- a/lib/GfxRenderer/Bitmap.h +++ b/lib/GfxRenderer/Bitmap.h @@ -2,6 +2,8 @@ #include +#include + enum class BmpReaderError : uint8_t { Ok = 0, FileInvalid, @@ -28,7 +30,8 @@ class Bitmap { public: static const char* errorToString(BmpReaderError err); - explicit Bitmap(FsFile& file) : file(file) {} + explicit Bitmap(FsFile& file, bool useFloydSteinberg = false, uint8_t brightnessBoost = 0) + : file(file), useFloydSteinberg(useFloydSteinberg), brightnessBoost(brightnessBoost) {} ~Bitmap(); BmpReaderError parseHeaders(); BmpReaderError readNextRow(uint8_t* data, uint8_t* rowBuffer) const; @@ -44,6 +47,8 @@ class Bitmap { static uint32_t readLE32(FsFile& f); FsFile& file; + bool useFloydSteinberg = false; + uint8_t brightnessBoost = 0; int width = 0; int height = 0; bool topDown = false; diff --git a/src/activities/boot_sleep/SleepActivity.cpp b/src/activities/boot_sleep/SleepActivity.cpp index 43e8e60b..b420cc0c 100644 --- a/src/activities/boot_sleep/SleepActivity.cpp +++ b/src/activities/boot_sleep/SleepActivity.cpp @@ -86,7 +86,7 @@ void SleepActivity::renderCustomSleepScreen() const { if (SdMan.openFileForRead("SLP", filename, file)) { Serial.printf("[%lu] [SLP] Randomly loading: /sleep/%s\n", millis(), files[randomFileIndex].c_str()); delay(100); - Bitmap bitmap(file); + Bitmap bitmap(file, true, 50); if (bitmap.parseHeaders() == BmpReaderError::Ok) { renderBitmapSleepScreen(bitmap); dir.close(); @@ -101,7 +101,7 @@ void SleepActivity::renderCustomSleepScreen() const { // render a custom sleep screen instead of the default. FsFile file; if (SdMan.openFileForRead("SLP", "/sleep.bmp", file)) { - Bitmap bitmap(file); + Bitmap bitmap(file, true, 50); if (bitmap.parseHeaders() == BmpReaderError::Ok) { Serial.printf("[%lu] [SLP] Loading: /sleep.bmp\n", millis()); renderBitmapSleepScreen(bitmap);