task01

Task01: Rasterization of lines and polygons

Deadline: April 18st (Thu) at 15:00pm

This is the blurred preview of the expected result:

When you execute the program, it will output an PNG image file (output.png) replacing the image below. Try making the image below and the image above look similar after doing the assignment.

Problem1: Build and Execute the Program

Follow the instruction below to build and execute the attached code main.ccp.

Set Up Programming Environment

You need to have git, cmake, and C++ compiler in your computer to complete this assignment. Read the following document to install these.

How to Set Up C++ Programming Environment

Go to Local Repository

if you don't have the local repository (repository on your computer), clone it from the remote repository (repository on the GitHub).

$ git clone https://github.com/ACG-2024S/acg-<username>.git

Go to the top of the local repository

$ cd acg-<username>     # go to the local repository

Update Local Repository

Please updat the local repository on your computer

$ git checkout main   # set main branch as the current branch
$ git fetch origin main    # download the main branch from remote repository
$ git reset --hard origin/main  # reset the local main branch same as remote repository

Create a Branch

To do this assignement, you need to be in the branch task01. You can always check your the current branch by

$ git branch -a   # list all branches, showing the current branch 

You are probably in the main branch. Let's create the task01 branch and set it as the current branch.

$ git branch task01   # create task0 branch
$ git checkout task01  # switch into the task01 branch
$ git branch -a   # make sure you are in the task01 branch

Compile the Code

After the environment is ready, let's build and compile the code. We do out-of-source build by making a new directory for build task01/build and compile inside that directory

$ cd task01
$ mkdir build
$ cd build
$ cmake .. 
$ cmake --build .

Now you will see the output.png is updated. The output.png will show a gray triangle around top-left corner. Now let's write a program to make more complicated images.

Problem2: Draw a Polygon

Edit the main.ccp around line #67 to implement the inside/outside test for a convex polygon using the winding number.

Problem3: Draw Lines

Edit main.ccp around line # 93 to implement line rasterization using DDA (digital differential analyzer).

Submit

Finally, you submit the document by pushing to the task01 branch of the remote repository.

cd acg-<username>    # go to the top of the repository
git status  # check the changes (this will hilight main.cpp and output.png)
git add .   # stage the changes
git status  # check the staged changes
git commit -m "task01 finished"   # the comment can be anything
git push --set-upstream origin task01  # up date the task01 branch of the remote repository

got to the GitHub webpage https://github.com/ACG-2024S/acg-<username> . If everything looks good on this page, make a pull request.

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Trouble Shooting

• I mistakenly submit the assignement in the main branch
  • Make a branch task01 and submit again
• When I type git status, it shows many files.
  • Do not commit intermediate files. Make sure you are correctly doing the "out-of-source build" If necessary edit the .gitignore file to remove the intermediate files.
• When something does wrong, consider doing from scratch (start from git clone).