Bresenham line drawing opengl cpp

Here is an explanation of each step involved in the Bresenham line drawing algorithm in C++ using OpenGL:

1. Import necessary libraries: Include the OpenGL and GLUT libraries to access the required functions for graphics rendering.

2. Initialize the OpenGL environment: Set up the display mode, window size, and window title using the appropriate OpenGL functions.

3. Define the line endpoints: Specify the coordinates of the starting point (x0, y0) and the ending point (x1, y1) of the line.

4. Calculate the differences: Calculate the differences between the x and y coordinates of the two endpoints: dx = x1 - x0 and dy = y1 - y0.

5. Determine the increments: Determine the increments for each coordinate: incrementX = 1 for dx > 0, -1 for dx < 0, and 0 for dx = 0. Similarly, incrementY = 1 for dy > 0, -1 for dy < 0, and 0 for dy = 0.

6. Determine the absolute differences: Calculate the absolute values of dx and dy: absDx = abs(dx) and absDy = abs(dy).

7. Determine the steps: Determine the number of steps required to draw the line by taking the maximum value between absDx and absDy: steps = max(absDx, absDy).

8. Calculate the increments for the error: Calculate the increments for the error term along the x and y axes: incrementXError = absDy 2 and incrementYError = absDx 2.

9. Initialize the error term: Set the initial error term to 0.

10. Draw the line: Use a loop to draw the line by incrementing the x coordinate by incrementX and the y coordinate by incrementY in each iteration. Update the error term by adding the incrementXError or incrementYError depending on the error term's value. If the error term exceeds or equals the steps, decrement the y coordinate by incrementY and update the error term accordingly.

11. End the OpenGL environment: Use the appropriate OpenGL functions to end the rendering process.

That's it! This algorithm allows you to draw a line using the Bresenham line drawing technique in C++ with OpenGL.