Description
Lab 10: Meme Generator
Overview
In this lab, students will use an external library to create a meme generator library and executable. The purposes of this assignment is to give students practice with setting up, importing, using, and writing libraries in C++.
SFML Setup
In this assignment, students will import and use SFML (Simple and Fast Multimedia Library). This section describes how to install SFML and integrate it into a project.
Installation
1. Download GCC 7.3.0 MinGW (SEH) – 64-bit; decompress into reasonable path (e.g., C:\Libraries).
2. Add path (e.g., C:\Libraries\SFML-2.5.1) as variable SFML_INSTALL to system variables.
3. Add binary path (e.g., C:\Libraries\SFML-2.5.1\bin) to PATH system variable.
Integration
Under the compiler settings, add the following lines to your CMakeLists.txt to integrate SFML into the project:
set(SFML_DIR “C:/Libraries/SFML-2.5.1/lib/cmake/SFML”) find_package(SFML 2.5 COMPONENTS graphics audio REQUIRED)
You can add the library to your memer library target by specifying link instructions:
add_library(memer memer.cpp) target_link_libraries(memer sfml-graphics sfml-audio)
Likewise, you can link your memer library to your memeify executable:
add_executable (memeify memeify.cpp) target_link_libraries(memeify memer sfml-graphics sfml-audio)
Use
To use SFML, you simply include the appropriate header in your code and use SFML constructs in your project:
#include <SFML/Graphics.hpp>
The Cave-Story.ttf open-source font file has also been provided for this project.
Classes
There are a few important classes that you will want to read about in the SFML documentation.
sf::Image
This object is an image in system memory (RAM), stored as a series of pixels.
sf::Texture
This object represents a read-only version of image data pre-formatted and stored in video memory (VRAM).
sf::Font
A font for use in SFML routines. Typically loaded from a file.
sf::String
The SFML native String format.
sf::Sprite
A drawable class; it references a section of a texture that is used for display / drawing.
sf::Text
A drawable text element; incorporates a Font and a String. Positioning can be set as needed.
sf::RenderTexture
A read-write texture; data is stored in video memory. This object can be drawn on.
Specification
In this assignment, students will generate two artifacts, a memer library and a memeify executable.
Library
The library will be named memer. It should incorporate the function below and include memer.h:
sf::Image generateMeme(sf::Image base, sf::String topText, sf::String bottomText = “”, int topX = -1, int topY = -1, int bottomX = -1, int bottomY = -1)
Takes in an base to be used as the base image. Returns a new sf::Image with topText drawn over it at location (topX, topY) in the provided font. If no coordinates are provided, topText should be centered horizontally and be 1/3 from the top of the image. If it is provided, bottomText is drawn at location (bottomX, bottomY). If provided, the tbottomText should be placed 1/3 from the bottom of the image.
In general, adding text to an image will consist of the following steps:
1. Converting the Image into a Texture
2. Wrapping the Texture in a Sprite
3. Drawing the Sprite on a fresh & empty RenderTexture
4. Loading a Font, and using it to construct a Text element
5. Drawing the Text on the RenderTexture
6. Extracting an Image from a Texture, derived from the RenderTexture.
NOTE: graphics are traditionally done differently in 2D and 3D, resulting in the Image from a Texture being upside down; make sure to flip it horizontally before returning it!
Executable
Executable should function with just file & top text: … but should also accept a partial / full complement:
finn@BMO:~$ ./memeify doge.jpg “Such memes”
finn@BMO:~$ ./memeify doge.jpg “Such memes”\ > “wow” 360 90 120 360
The executable should 1) display the image in a window until the window is closed, and 2) save the image with a new name based on the old one in the form of STEM-meme.EXT; e.g., if the original image was “doge.jpg”, the new image saved should be “doge-meme.jpg”.
Submissions
NOTE: Your output must match the example output *exactly*. If it does not, you will not receive full credit for your submission! (Note that matching sample output is necessary, but not sufficient, for full credit.)
Files: memeify.zip
Method: Submit on Canvas
Compressed Archive (memeify.zip)
We do not list required source files, only headers. You should include additional source or header files in addition to those listed – based on your design – but you must have the listed files at a minimum.
Your compressed file should have the following directory/file structure:
memeify.zip memeify (directory)
CMakeLists.txt memer.h
(Other sources / folders)
