From 73f47423e7cec915a903fe8328aaa4120a184fb6 Mon Sep 17 00:00:00 2001
From: Brackyt <60280126+Brackyt@users.noreply.github.com>
Date: Sun, 25 Jan 2026 18:49:42 +0100
Subject: [PATCH] fix: rendering correctly + alpha channel

---
 lib/GfxRenderer/Bitmap.cpp      | 44 +++++++++++++++++++++++++++++----
 lib/GfxRenderer/GfxRenderer.cpp | 13 +++++++---
 2 files changed, 49 insertions(+), 8 deletions(-)

diff --git a/lib/GfxRenderer/Bitmap.cpp b/lib/GfxRenderer/Bitmap.cpp
index 603954d2..4f7173a2 100644
--- a/lib/GfxRenderer/Bitmap.cpp
+++ b/lib/GfxRenderer/Bitmap.cpp
@@ -155,6 +155,11 @@ BmpReaderError Bitmap::parseHeaders() {
   if (colorsUsed > 256u) return BmpReaderError::PaletteTooLarge;
   seekCur(4);
 
+  // Robustness Fix: Skip extended header bytes (V4/V5)
+  if (biSize > 40) {
+    seekCur(biSize - 40);
+  }
+
   if (width <= 0 || height <= 0) return BmpReaderError::BadDimensions;
 
   constexpr int MAX_IMAGE_WIDTH = 2048;
@@ -165,11 +170,33 @@ BmpReaderError Bitmap::parseHeaders() {
 
   rowBytes = (width * bpp + 31) / 32 * 4;
 
-  for (int i = 0; i < 256; i++) paletteLum[i] = static_cast<uint8_t>(i);
-  if (colorsUsed > 0) {
-    for (uint32_t i = 0; i < colorsUsed; i++) {
+  // Initialize safe default palette
+  if (bpp == 1) {
+    // For 1-bit, default to Black(0) and White(1)
+    paletteLum[0] = 0;
+    paletteLum[1] = 255;
+  } else if (bpp <= 8) {
+    int maxIdx = (1 << bpp) - 1;
+    for (int i = 0; i <= maxIdx; i++) {
+      paletteLum[i] = (i * 255) / maxIdx;
+    }
+  } else {
+    for (int i = 0; i < 256; i++) paletteLum[i] = static_cast<uint8_t>(i);
+  }
+
+  // If indexed color (<=8bpp), we MUST load the palette.
+  // The palette is located AFTER the DIB header.
+  if (bpp <= 8) {
+    // Explicit seek to palette start
+    if (!seekSet(14 + biSize)) return BmpReaderError::SeekStartFailed;
+
+    uint32_t colorsToRead = colorsUsed;
+    if (colorsToRead == 0) colorsToRead = 1 << bpp;
+    if (colorsToRead > 256) colorsToRead = 256;
+
+    for (uint32_t i = 0; i < colorsToRead; i++) {
       uint8_t rgb[4];
-      readBytes(rgb, 4);
+      if (readBytes(rgb, 4) != 4) break;
       paletteLum[i] = (77u * rgb[2] + 150u * rgb[1] + 29u * rgb[0]) >> 8;
     }
   }
@@ -224,7 +251,14 @@ BmpReaderError Bitmap::readNextRow(uint8_t* data, uint8_t* rowBuffer) const {
     case 32: {
       const uint8_t* p = rowBuffer;
       for (int x = 0; x < width; x++) {
-        uint8_t lum = (77u * p[2] + 150u * p[1] + 29u * p[0]) >> 8;
+        uint8_t lum;  // Declare lum here
+        // Handle Alpha channel (byte 3). If transparent (<128), treat as White.
+        // This fixes 32-bit icons appearing as black squares on white backgrounds.
+        if (p[3] < 128) {
+          lum = 255;
+        } else {
+          lum = (77u * p[2] + 150u * p[1] + 29u * p[0]) >> 8;
+        }
         packPixel(lum);
         p += 4;
       }
diff --git a/lib/GfxRenderer/GfxRenderer.cpp b/lib/GfxRenderer/GfxRenderer.cpp
index 7d62e33c..d6bcea78 100644
--- a/lib/GfxRenderer/GfxRenderer.cpp
+++ b/lib/GfxRenderer/GfxRenderer.cpp
@@ -584,7 +584,13 @@ void GfxRenderer::drawBitmap(const Bitmap &bitmap, const int x, const int y,
 
       const uint8_t val = outputRow[bmpX / 4] >> (6 - ((bmpX * 2) % 8)) & 0x3;
 
-      if (renderMode == BW && val < 3) {
+      // In BW mode:
+      // 0 = Black (< 45)
+      // 1 = Dark Gray (< 70)
+      // 2 = Light Gray (< 140)
+      // 3 = White
+      // Draw black for val < 2 (everything below 70), treating Light Gray as White.
+      if (renderMode == BW && val < 2) {
         drawPixel(screenX, screenY);
       } else if (renderMode == GRAYSCALE_MSB && (val == 1 || val == 2)) {
         drawPixel(screenX, screenY, false);
@@ -631,8 +637,9 @@ void GfxRenderer::draw2BitImage(const uint8_t data[], int x, int y, int w,
         // Extract 2-bit value (4 pixels per byte)
         const uint8_t val = (srcRow[col / 4] >> (6 - ((col % 4) * 2))) & 0x3;
 
-        // val < 3 means black pixel in 2-bit representation
-        if (val < 3) {
+        // val < 2 means black pixel in 2-bit representation (0=Black, 1=DarkGray)
+        // 2=LightGray, 3=White -> Treat as White
+        if (val < 2) {
           // In Portrait: physical Y = DISPLAY_HEIGHT - 1 - screenX
           const int physY = HalDisplay::DISPLAY_HEIGHT - 1 - screenX;
           const uint16_t byteIndex =