add bitmap drawing

low_level_render.cpp

@@ -419,6 +419,24 @@ void LowLevelRenderer::draw_arc(int center_x, int center_y, int radius, int star
     }
 }
 
+void LowLevelRenderer::draw_bitmap(const unsigned char* bitmap, int x, int y, int width, int height, bool invert)
+{
+    for (int py = 0; py < height; ++py) {
+        for (int px = 0; px < width; ++px) {
+            int bit_index = py * width + px;
+            int byte_index = bit_index / 8;
+            int bit_offset = 7 - (bit_index % 8);  // MSB first
+            bool pixel_on = (bitmap[byte_index] & (1 << bit_offset)) != 0;
+            if (invert) {
+                pixel_on = !pixel_on;
+            }
+            if (pixel_on) {
+                set_pixel(x + px, y + py, true);
+            }
+        }
+    }
+}
+
 void LowLevelRenderer::draw_circle(int x, int y, int radius, bool on)
 {
     int x_pos = radius;