File content as of revision 42:596c207519de:

#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);
        }
    }
}