C++ Bitmap Image Reader Writer Library http://partow.net/programming/…

…bitmap/index.html

.travis.yml

@@ -2,7 +2,7 @@ language: cpp
 
 sudo: required
 
-dist: trusty
+dist: xenial
 
 compiler:
   - gcc

bitmap_image.hpp

@@ -49,6 +49,13 @@ class bitmap_image
                        red_plane   = 2
                     };
 
+   struct rgb_t
+   {
+      unsigned char   red;
+      unsigned char green;
+      unsigned char  blue;
+   };
+
    bitmap_image()
    : file_name_(""),
      width_          (0),
@@ -164,10 +171,11 @@ class bitmap_image
    {
       const unsigned int y_offset = y * row_increment_;
       const unsigned int x_offset = x * bytes_per_pixel_;
+      const unsigned int offset   = y_offset + x_offset;
 
-      blue  = data_[y_offset + x_offset + 0];
-      green = data_[y_offset + x_offset + 1];
-      red   = data_[y_offset + x_offset + 2];
+      blue  = data_[offset + 0];
+      green = data_[offset + 1];
+      red   = data_[offset + 2];
    }
 
    template <typename RGB>
@@ -176,17 +184,25 @@ class bitmap_image
       get_pixel(x, y, colour.red, colour.green, colour.blue);
    }
 
+   inline rgb_t get_pixel(const unsigned int x, const unsigned int y) const
+   {
+      rgb_t colour;
+      get_pixel(x, y, colour.red, colour.green, colour.blue);
+      return colour;
+   }
+
    inline void set_pixel(const unsigned int x, const unsigned int y,
                          const unsigned char red,
                          const unsigned char green,
                          const unsigned char blue)
    {
       const unsigned int y_offset = y * row_increment_;
       const unsigned int x_offset = x * bytes_per_pixel_;
+      const unsigned int offset   = y_offset + x_offset;
 
-      data_[y_offset + x_offset + 0] = blue;
-      data_[y_offset + x_offset + 1] = green;
-      data_[y_offset + x_offset + 2] = red;
+      data_[offset + 0] = blue;
+      data_[offset + 1] = green;
+      data_[offset + 2] = red;
    }
 
    template <typename RGB>
@@ -418,7 +434,8 @@ class bitmap_image
 
       if (!stream)
       {
-         std::cerr << "bitmap_image::save_image(): Error - Could not open file "  << file_name << " for writing!" << std::endl;
+         std::cerr << "bitmap_image::save_image(): Error - Could not open file "
+                   << file_name << " for writing!" << std::endl;
          return;
       }
 
@@ -1495,7 +1512,8 @@ class bitmap_image
 
       if (!stream)
       {
-         std::cerr << "bitmap_image::load_bitmap() ERROR: bitmap_image - file " << file_name_ << " not found!" << std::endl;
+         std::cerr << "bitmap_image::load_bitmap() ERROR: bitmap_image - "
+                   << "file " << file_name_ << " not found!" << std::endl;
          return;
       }
 
@@ -1513,36 +1531,41 @@ class bitmap_image
 
       if (bfh.type != 19778)
       {
+         std::cerr << "bitmap_image::load_bitmap() ERROR: bitmap_image - "
+                   << "Invalid type value " << bfh.type << " expected 19778." << std::endl;
+
          bfh.clear();
          bih.clear();
 
          stream.close();
 
-         std::cerr << "bitmap_image::load_bitmap() ERROR: bitmap_image - Invalid type value " << bfh.type << " expected 19778." << std::endl;
          return;
       }
 
       if (bih.bit_count != 24)
       {
+         std::cerr << "bitmap_image::load_bitmap() ERROR: bitmap_image - "
+                   << "Invalid bit depth " << bih.bit_count << " expected 24." << std::endl;
+
          bfh.clear();
          bih.clear();
 
          stream.close();
 
-         std::cerr << "bitmap_image::load_bitmap() ERROR: bitmap_image - Invalid bit depth " << bih.bit_count << " expected 24." << std::endl;
-
          return;
       }
 
       if (bih.size != bih.struct_size())
       {
+         std::cerr << "bitmap_image::load_bitmap() ERROR: bitmap_image - "
+                   << "Invalid BIH size " << bih.size
+                   << " expected " << bih.struct_size() << std::endl;
+
          bfh.clear();
          bih.clear();
 
          stream.close();
 
-         std::cerr << "bitmap_image::load_bitmap() ERROR: bitmap_image - Invalid BIH size " << bih.size << " expected " << bih.struct_size() << std::endl;
-
          return;
       }
 
@@ -1552,7 +1575,7 @@ class bitmap_image
       bytes_per_pixel_ = bih.bit_count >> 3;
 
       unsigned int padding = (4 - ((3 * width_) % 4)) % 4;
-      char padding_data[4] = {0,0,0,0};
+      char padding_data[4] = { 0x00, 0x00, 0x00, 0x00 };
 
       std::size_t bitmap_file_size = file_size(file_name_);
 
@@ -1563,15 +1586,16 @@ class bitmap_image
 
       if (bitmap_file_size != bitmap_logical_size)
       {
+         std::cerr << "bitmap_image::load_bitmap() ERROR: bitmap_image - "
+                   << "Mismatch between logical and physical sizes of bitmap. "
+                   << "Logical: "  << bitmap_logical_size << " "
+                   << "Physical: " << bitmap_file_size    << std::endl;
+
          bfh.clear();
          bih.clear();
 
          stream.close();
 
-         std::cerr << "bitmap_image::load_bitmap() ERROR: bitmap_image - Mismatch between logical and physical sizes of bitmap. " <<
-                      "Logical: "  << bitmap_logical_size << " " <<
-                      "Physical: " << bitmap_file_size    << std::endl;
-
          return;
       }
 
@@ -1606,12 +1630,7 @@ class bitmap_image
    std::vector<unsigned char> data_;
 };
 
-struct rgb_t
-{
-   unsigned char   red;
-   unsigned char green;
-   unsigned char  blue;
-};
+typedef bitmap_image::rgb_t rgb_t;
 
 inline bool operator==(const rgb_t& c0, const rgb_t& c1)
 {