Diff: lib/Bitmap.cpp

Revision:

0:be41a15e7a86

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/Bitmap.cpp	Fri Dec 11 12:25:25 2020 +0000
@@ -0,0 +1,96 @@
+#include "Bitmap.h"
+
+#include <iostream>
+
+#include "N5110.h"
+
+Bitmap::Bitmap(int const               *contents,
+               unsigned int const       height,
+               unsigned int const       width)
+    :
+    _contents(std::vector<int>(height*width)),
+    _height(height),
+    _width(width)
+{
+    // Perform a quick sanity check of the dimensions
+    if (_contents.size() != height * width) {
+        std::cerr << "Contents of bitmap has size " << _contents.size()
+                  << " pixels, but its dimensions were specified as "
+                  << width << " * " << height << " = " << width * height << std::endl;
+    }
+
+    for(unsigned int i = 0; i < height*width; ++i) _contents[i] = contents[i];
+}
+
+/**
+ * @returns the value of the pixel at the given position
+ */
+int Bitmap::get_pixel(unsigned int const row,
+                      unsigned int const column) const
+{
+    // First check that row and column indices are within bounds
+    if(column >= _width || row >= _height)
+    {
+        std::cerr << "The requested pixel with index " << row << "," << column
+                  << "is outside the bitmap dimensions: " << _width << ","
+                  << _height << std::endl;
+    }
+
+    // Now return the pixel value, using row-major indexing
+    return _contents[row * _width + column];
+}
+
+/**
+ * @brief Prints the contents of the bitmap to the terminal
+ */
+void Bitmap::print() const
+{
+    for (unsigned int row = 0; row < _height; ++row)
+    {
+        // Print each element of the row
+        for (unsigned int column = 0; column < _width; ++column)
+        {
+            int pixel = get_pixel(row, column);
+            std::cout << pixel;
+        }
+
+        // And then terminate with a new-line character
+        std::cout << std::endl;
+    }
+}
+
+/**
+ * @brief Renders the contents of the bitmap onto an N5110 screen
+ *
+ * @param[in] lcd The screen to use for rendering
+ * @param[in] x0  The horizontal position in pixels at which to render the bitmap
+ * @param[in] y0  The vertical position in pixels at which to render the bitmap
+ *
+ * @details Note that x0, y0 gives the location of the top-left of the bitmap on
+ *          the screen.
+ *          This function only updates the buffer on the screen.  You still need
+ *          to refresh the screen in order to actually see the bitmap.
+ */
+void Bitmap::render(N5110 &lcd,
+                    unsigned int const x0,
+                    unsigned int const y0) const
+{
+    // Loop through each row of the bitmap image
+    for (unsigned int bitmap_row = 0; bitmap_row < _height; ++bitmap_row)
+    {
+        // Row index on the screen for rendering the row of pixels
+        unsigned int screen_row = y0 + bitmap_row;
+                
+        // Render each pixel in the row
+        for (unsigned int bitmap_col = 0; bitmap_col < _width; ++bitmap_col)
+        {
+            // Column index on the screen for rendering this pixel
+            int screen_col = x0 + bitmap_col;
+
+            // Find the required value of the pixel at the given location within
+            // the bitmap data and then write it to the LCD screen
+            int pixel = get_pixel(bitmap_row, bitmap_col);
+            lcd.setPixel(screen_col, screen_row, pixel);
+        }
+    }
+}
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