Learn OPENGL by making a Project - Painting App using C++

Explore the OpenGL coordinate system and the NDC, including origin placement and axis ranges, and learn the conversion formula to map OpenGL coordinates to NDC.

Create a pencil tool in OpenGL by handling mouse input with glut callbacks, converting coordinates to ndc, and storing points in a vector of pairs while drawing.

Master vector of pairs in C++ by learning dynamic arrays, pushing back make pair entries, and accessing the first element of pairs.

Implement a real-time pencil tool in OpenGL by drawing a line strip from a vector of points, updating the display after each input.

Store drawing steps as a vector of functions, copy points and colors into temporary buffers, push them into the function vector, and render by calling each function for real-time drawing.

Implement a tool switch using a switch statement and boolean flags in an OpenGL painting app; bind keys for pencil, eraser, line, fill, and rectangle tools.

Build a real-time eraser in an OpenGL painting app by switching tools with the keyboard, recording eraser curves, and enabling undo via lambda-stored actions.

learns to implement an eraser tool by storing eraser points in a memory buffer, using a vector of functions, and enabling real-time erase with undo via push and pop operations.

Change the pencil color with keyboard shortcuts by updating the current color array to RGB values (green, red, blue, white, black, yellow) and verify by painting with the pencil.

Implement the undo feature by popping the last action from a vector and triggering a redisplay with glut post redisplay, then test with pencil drawing and erase using z.

Learn to implement the line tool by placing two points in a fixed vector, with the first at the click and second at cursor, joined by gl line strip.

Implement a real-time line tool by capturing the initial click as the first point and updating the second point during drag, drawing a two-point line and supporting color changes.

Explore the flood fill algorithm, a stack-based iterative approach filling connected pixels until a boundary color. Use a 2D visited array to color neighboring pixels with the chosen color.

Implement a stack-based flood fill tool in C++ that fills arbitrary shapes from a mouse click, using a target color and a visited 2D array to guide processing.

Learn to implement a flood fill tool in OpenGL using a stack-based flood fill algorithm, boundary checks, color arrays, and pixel reading with glReadPixels to fill connected areas.

Learn the rectangle tool theory by defining four points from the initial click to current cursor, keeping the second point’s x fixed and its y aligned with the initial point.

Implement the rectangle tool by adapting the line tool, pushing four corner points, and updating them in real time as you drag to build the paint app rectangle.