Game | Learn C Games Programming Blog

Category: Game

An example of a game idea

Posted on August 23, 2020August 17, 2020 by David

Sometimes I wake up in the middle of the night and my brain is bursting with ideas. I’ve just finished reading Shaman by Kim Stanley Robinson that’s set 30,000 years ago and came up with ideas for a tribes game very loosely based on that (Absolutely nothing to do with the plot of the book!) . I opened up my iPhone around 3:00 a.m. and these are the notes I wrote down in the Notes app.

I opened my email (Gmail) which picks up notes from my phone automatically, so I have the notes now here in my PC. They are as I wrote them so they are quite rough.

“Tribe game. All players start with a small village and 50 tribes people.
Can relocate, hunt, plant etc. Can raid other tribes. Can split tribes spread over land. Have children. Found religion. Use animals. New options as tribe progresses. Discover and trade gold, furs. Tribes can move to other places or settle and form villages.
Raids build up resentment between tribes. Enough resentment leads to war. But can reduce resentment by gifts of women, food, furs etc st festivals.
Can do crafts, paint, culture, spirituality, warfare, building. Each has 1-10 levels with names. Orders focus on an area.
Better food means stronger, smarter.
Periodic festivals. Tribes get together and share attributes.
Run for 1,000 years. 100 turns x 10 years. “

And that’s how they go into WikidPad. Then I start fleshing them out into a fuller multi-player game. Of course I come up with lots of ideas and few will make it into an actual game creation but its always a good idea to keep them. In the future it may yet become a game…

And how was the book? Very good.

Geomorphing for the masses

Posted on August 18, 2020August 11, 2020 by David

This is very clever. The website Davesmapper.com lets you create different type of geomorphic terrain maps, whether it be dungeons, city or village or even the interior of a spaceship. You get a choice of tile sets according to what type of terrain you’ve picked. If you are artistic, you can upload your own designs. This mixing and mashing of tile sets can lead to some very odd looking cities with each tile a different style!

The view options controls lets you change how many tiles wide and high your map is, but watch out, the tiles are quite big so go above say 16 x 16 and you start to generate maps that are too big to export. The village at the top of the post was 2100 x 2100 pixels when exported.

The terrain maps generated are very nice. If you think these look a bit rough, it’s probably my fault. To speed up this website all images are both shrunk to typically 350-450 pixels wide and compressed and some images are possibly not quite as nice looking as their uncompressed originals.

This city below shows you the type of thing with two greenish tiles and a bluish one. You can untick the tile sets that you don’t want.

Geomorphic means it’s made of tiles that are almost always square and they fit together so that doors or passageways always join up.

Back in my D & D (Dungeons and Dragons, not drunk and disorderly!) dungeon mastering days (about 1979) I use to have a set of physical geomorph tiles. They were great but sadly lost along with my D & D toolbox that had all my figures.

There are some computer games where you might use geomorphic graphics; perhaps a procedurally-generated dungeon crawler.

What is the best way to include text?

Posted on August 10, 2020August 3, 2020 by David

One of the games I’m working on needs to include a 1.9 MB text file (200,000 words). Now it’s not that big a deal but using 7zip I can compress it down to 400 KB and that’s 20% of the uncompressed size. So I’m thinking of including some C# code to decompress it.

But I did wonder if there was any kind of built in decompression, so you could add it to say Resources and have it decompressed automatically when read. I haven’t seen anything like that but it would be cool if if existed.

Ideas for multi-player games

Posted on August 7, 2020August 2, 2020 by David

Simple word game — Image by brainygames from Pixabay

One side-project I’m working on that uses the MonoGame library involves creating a bunch of simple multi-player games. I’ve started with that Poker game (Top Banana or Manana Banana as I’ve called it) and the next one will likely be a variation of the game Boggle but not called that and not based on a 4 x 4 grid as Boggle is. I’m not daft!

The danger with doing this and just copying existing commercial games is you might get sued or a nasty cease and desist letter/email come your way if you infringe someones copyright or (far far worse!) their trademark. If you have a bit of money, you might be able to license the game from the original designer/creator but that’s probably not at all cheap. Games like Fluxx, Acquire, Settlers of Catan and Ticket-to-Ride are favourites but not something I shall be doing until and unless I can afford to license them.

Some games like card games are in the public domain and I’ve no qualms about producing my own version. Scheduled in after It’s-Not-Boggle is one based on 3-card Brag which is very easy to play and quite fun. I’m also trying to come up with an idea based on word Searching or Sudoku but as those are primarily solo-play games and not quite so easy to do multi-player.

But I’m sure there are multi-player games, i.e. Texas Holdem Poker that are legal to create my own so if you know any I might do, add a comment!

Mobile game development progress

Posted on August 3, 2020July 29, 2020 by David

Development continues with the first game, which is a card game. I know the game as Top Banana, but I think that is the name of a commercial game, so for now the working title is Manana Banana. All it does currently is display the cards and backs as you can see. No photo this time, I learnt how to take snapshots on the phone (Hold down the power and Lower volume buttons at the same time) As it’s plugged in to my PC,. copying it across was not difficult.

This uses my virtual screen technology working on an 800 x 1400 virtual screen then scaling output onto the real screen which in this case on the Alps X27 Plus is 480 wide by 960 deep. As you can see I have a black rectangle at the top and the Android controls are visible at the bottom, neither of which I programmed for. I’ll get those fixed.

You play this game by clicking on the six top cards one-by-one and then tap the back of the card where you want to play that top card. So you end up with three poker hands. In this case I’d put the 7 and 9 on the top row for one pair, the two fives on the 2nd row also for a apir and the King and Jack for an Ace-high straight on the bottom row. The gap on the right will show the text of the hand so will say Pair, Pair and Ace Straight or something like that.

Next thing is making the cards clickable. That is the top six cards and the the three sets of two backs below. Once that’s done I’ll make that bit work then plug in the Jessie Chunn’s poker hand evaluation code to figure out what each hand of five cards is and more importantly give it a numeric score.

The gradient that covers the screen came from Unsplash.com.

Space Invaders done faithfully in C

Posted on July 30, 2020July 24, 2020 by David

I was around when space invaders came out in the late 70s and played it a bit, although I preferred Galaxian, Gorf, Defender and Battle Zone (3D Tanks on the moon- vector graphics).

This project (catchily named si78) though is a memory accurate re-implementation of the 1978 arcade game Space Invaders in C.

To build and run this (on a Linux box) you’ll need to download the invaders ROM which is available in one of the Mame sets. The game is written in the subset of C99 that is compatible with C++, and uses no compiler extensions apart from attribute packed.

Using Excel for level design

Posted on July 24, 2020July 25, 2020 by David

In the asteroids game and shortly in my MatchThree game, I’ll be creating a level data array of struct. This has a struct for each level containing a count of particular features for that level.

This is the struct and array for a level in asteroids.

struct level {
	int nums[4]; // how many of each size of asteroid
	int aliens; // how many aliens
	float factor; // from 1.0 to 1.5 - multiply asteroid speed by this
};

struct level levels[50];

This is the first 3 levels and level 50.

#include "levels.h"

struct level levels[50] = {
{ .factor = (float)1,.aliens = 1,.nums = { 0,0,3,3 } }, // Level 1
{ .factor = (float)1,.aliens = 0,.nums = { 0,1,3,3 } }, // Level 2
{ .factor = (float)1,.aliens = 0,.nums = { 0,1,3,3 } }, // Level 3
..
{ .factor = (float)1.5,.aliens = 3,.nums = { 4,4,5,5 } } // Level 50

I didn’t type any of this in. Instead, I created that spreadsheet above. It’s easy to work out difficulty levels in column H. The formula that calculates this is ins this on row 5. If you don’t know Excel, the $ in the factors means that as you copy this into successive row, it keeps the $ row value constant.

=(B5*B$4)+(C5*C$4)+(D5*D$4)+(E5*E$4)+(F5*F$4)+(G5*G$4)   - Row 5

=(B6*B$4)+(C6*C$4)+(D6*D$4)+(E6*E$4)+(F6*F$4)+(G6*G$4) - Row 6

So you can see its multiplying the values in rows 5 6 etc by the values in row 4. Having put that in place I could tinker with the values in rows 5,6 etc to make the difficulty level increase roughly at the same pace. The difficulty level for level 50 is 77.5.

This is what the Excel formula looks like to generate the C code, it’s in cell M5 in the spreadsheet and then copied and pasted down.

="{.factor =(float)"&G5&", .aliens="&F5&", .nums = {"&B5&","&C5&","&D5&","&E5&"}}, // Level "&A5

and this is what it looks like. C code that can be copied and pasted directly. It even includes the comment for the level number!

{.factor =(float)1, .aliens=0, .nums = {0,0,3,3}}, // Level 1

Creating a spreadsheet and C code from it this way saved a lot of typing but let me quantify the numerical difficulty which increases from 17.5 on level 1 to 77.5 on level 50. There’s no meaning to this value, it’s just a calculation.

A tictactoe (aka noughts and crosses) game in C

Posted on July 23, 2020July 16, 2020 by David

I was asked to write this a few month’s back and it took me 2 or 3 evenings. It’s 312 lines long in just one file. Hopefully there are enough sensible function and variable names to make sense of it.

It runs in a terminal. It was compiled with Visual Studio but should not need many changes to compile with gcc/clang. (I hope!).

I made extensive use of pointers. For instance this function uses pointers in a for-loop.

int InDanger(char piece, int * x, int * y) {

    for (*y = 0; *y < 3; (*y)++) {
        if (CountRows(piece, y,0)==2) return 1;
    }

    for (*x = 0; *x < 3; (*x)++) {
        if (CountCols(piece, x,0) == 2) return 2;
    }
    *x = 0;
    if (CountDiagonal(piece, x,0) == 2) return 3;
    *x = 2;
    if (CountDiagonal(piece, x,0) == 2) return 4;

    return 0; // no danger
}

I’ve added this to the GitHub C games repository and updated the C games source page.

Playing Solitaire in a terminal

Posted on July 21, 2020July 14, 2020 by David

I thought this looked quite neat so I’ve added it to the C Codes Link page. It’s a game of Solitair (the Klondike version) running in a terminal.

It’s quite a detailed explanation of how its been implemented and of course it’s all in C. If you know of any games written in C (and open source), please let me know and I’ll add them.

Deciding what level features to be used in the Match Three game

Posted on July 17, 2020July 13, 2020 by David

I’m at the point of deciding what features will be included in the game and then determining what % of features are used on each level. how to make the game harder etc. As with asteroids I’ll use Excel.

These are features to enhance the game and maybe increase difficulty.

Wanted animals. Most levels have a target of a number of pieces of one type. The level is completed when all of that piece have been removed. These ‘wanted’ animals are shown onscreen with a count of how many remain.
Locked pieces. On some levels, pieces are randomly locked. The lock is removed only when the piece is in a matched line or in the area affected (from bonus pieces). Locked pieces do not move even if there is a space beneath them. For really hard levels, two locks can be used on a piece. Each lock has to be removed.
Skulls. Some levels have a number of skull pieces to be removed. This can only be done by removing pieces below so the skull drops and eventually reaches the bottom row where it is automatically removed.
Timed levels. Some levels will have a count down timer; so many animal pieces have to be removed before the timer runs out.
Bonus Pieces. These appear when a 4-match, a 5-match or a 6-match occurs and show special pieces- a 4-piece, 5-piece etc. Two 4-pieces dragged together clear a 5 x5 area of all pieces (remove locks on locked pieces). Two 5-pieces dragged together wipe out all pieces in both the row and column. A 4 and a 5-piece together wipe out all animal pieces of the animal piece (picked randomly) next to the 5-piece. Two 6-pieces together wipe out all pieces on the board (locked pieces aren’t wiped, just unlocked). A 6-piece dragged on a 4-piece or 5-piece wipes out all pieces in 3 rows wide and 3 columns deeps.
Board Rotation. The board can be rotated clockwise or anti-clockwise. This allows spaces created under locked pieces to be possibly filled. It also helps get rid of skulls that are now on the bottom row. But some levels start with a number of board rotations. Once used up, the only way to earn them is to do something like drag two four-match pieces together.

So now I have to decide how these fit together on the different levels, what weighting each has and calculate a difficulty score that should increase as you progress through levels. Oh the joys of game design!