Opening Title Fire'nIce Team Member: Zhang Yujie

Wang Huan Xiao Fei Cheng Peng

Tutor: Alexandre Devert

SSE USTC

Team Leader: Wei Qiang

Content

Object

Tools and means

Design

Tasks

Object

In our project, we clone an action-puzzle game named 'Fire And Ice' which was first released in 1992.

At last, we will try to make the final code high-efficiency in memory and CPU time.

Leading role：Dana

Tools and Means

Language: C++ Function Library: SDL(Simple DirectMedia Layer) SDM: Agile Development Development Tool: visual studio 2010 Gimp

Design

The project uses agile development methods. In our weekly work, we complete a certain task and realize the gradual optimization of the code.

So,our initial design for this project is not so perfect.It is just for an easy beginning.Look the picture in the next page:

Design

Task1:

Play the game to the end ,make a printscreen

for each level.So we have more than 100 maps that printed from the game.Using the maps we make an HTML as a guide:

Task2

Task: Showing a picture in the window and move it

with key pressing.

Task2

To Show: Using the function “SDL_BlitSurface”, “put” a

png to the screen. Record the offset of the png: (x, y)

Task2

To Move: Two new parameters: (xVel, yVel) xVel: speed of the motion on horizontal←→ yVel: speed of the motion on vertical ↑↓

Get events from the keyboard: Case: UP: yVel -= some value Case: DOWN: yVel +=some value Case: ….

Task2

Then, change the offset(x, y) according to the speed on vertical and horizontal.following the formula ：

x += xVel; y += yVel; Put the image on the new position according to the

new offset(x, y). But, before put a new image on the screen we

should always flush the screen ,otherwise we will see a lot of shadows like this:

Task2

Task3 Part1

Task: Make the mario move, using an image sheet.

How to get a small clip of the sheet? We need three parameters: offset, height and

width. Like this:

Task3 Part1

Task3 Part1

The animation needs a sequence of small clips of the Mario.

We use an array to store the sequence of the clips.

Task3 Part1

We make a new parameter: status. If the keyboard state is UP: Set status = UP, then put the “up clips”

sequence to the screen according to the position we get from the (x, y).

Task3 Part1

Transparency

The result will be

Task3 Part2

Read a text file which looks like that################ ## ### D## ## ###############

Where '#' is a wall, 'D' is a little guy. The program load a picture containing pictures for the little guys and the walls.After this task we can load pictures and show them.

Task3 Part2

We built a new class named Tile, including its position, width, height.

Then we built a new array named tiles. Read the map, case ‘#’, new a Tile, calculate

its position, then put it in the tiles array.

Task3 Part2

Put the tile pictures according to the positions of the tiles.

Task3 Part2

But now, the tiles are only images, Mario can walk across them.

How to solve this problem? We built a function: Collision Detection.

First, we add a property in both Mario and Tiles: SDL_Rect. It’s like a box or a “shell”, like this:

Task3 Part2

When the two boxes get close to each other, one can not cross another’s boundary.

Then ， Apply the collision detection function to every tile.

Task4

In task3, there are only one kind of tile: block, and the block has only one status. But in the game, there are many kinds of things: blocks, fire, ice, jar, pipe…as:

Task4

The blocks and the ices also have 4 kinds of status:

none-joined: left-joined: right-joined: Both-joined:

Task4

Because in the map file, every block is the same:

We need to judge every block and ice what kind of status they are.

Task4

Before, we read the map file, store every character into an array like this:

Eg: file: ’####’; in the array: ‘####’ But, in this task, we judge and change the

type of every tile, like this: File:’####’; in the array they are turned into:

‘[##]’

Task4

Case ‘[’: put a onto the map; Case ‘]’: put a onto the map; Case ‘#’:put a onto the map; Case ‘^’: put a onto the map. So, in the map, file ‘####’ will be showed like

this: Not like this:

Task5

Change one most important algorithm in our project:

Collision Detection is replaced by Position Detection!

Reason:Collision detection can not get Dana's next action after the 'collision';But position detection can do different actions after the collision,such as dropping,climing,stopping or dying.

Task5

With position detection, when Dana come to some place, we can know what’s around it. It makes many problems easy to solve.

Such as:

Task5

In this situation, there is a block in front of Dana, and we can know from position that there is no block in the left-up position, or up position. According to the rules, after pressing “left” key, Dana will climb to the top of the block.

Task6

Each of us draw 10 maps for this project.

Like:

Task……

Now we begin to making music and sound effect,but have not finished…

Next term ， We will try to make the code more efficient ,reducing the amount of ‘if…else…’ that we use, optimizing the algorithm in detection, in level selecting, etc.

The End

Thanks for Alexandre Devert very much! AND

Merry Christmas! Happy New Year!