Terminator — 11 of 33

Chapter 7 - The Planet's Surface

Table of Planetary Surface

To decide what number is the z-coordinate of (item - a thing):

let x be the x-coordinate of the item;

let y be the y-coordinate of the item;

if the x by the y is off the grid:

decide on 0;

otherwise:

if the item is a crater, now x is x + 1; [calculate the height of the east wall rather than the bowl]

choose row x graphed by y in the Table of Planetary Surface;

decide on the elevation entry.

To decide what number is the z-coordinate of (item - a crater): [for craters, we pick a graph point that's off by one so we get the height of the crater wall rather than the height of the crater center; when you have a crater overlapping with the side of a peak this will be off but I hope to get away with it]

if the x-coordinate of the item + 1 by the y-coordinate of the item is off the grid:

decide on 0;

otherwise:

choose row x-coordinate of item + 1 graphed by y-coordinate of item in the Table of Planetary Surface;

decide on the elevation entry.

A terrain feature is a kind of thing. A terrain feature is usually improper-named.

A crater is a kind of terrain feature.

A ridge is a kind of terrain feature. A ridge can be north-south or east-west.

A peak is a kind of terrain feature.

Texture is a kind of value. The textures are jagged, crumbling, flat-topped, rounded, and pointed. A texture can be used or unused. A texture is usually unused. [This helps us make sure we don't generate more than one of each feature with the same texture.]

A terrain feature has a texture. Before printing the name of a terrain feature: say "[texture of the item described] ".

The seen name of a terrain feature is usually "[item described]". [Because the seen name is usually set to the printed name, which won't capture the texture.]

The indefinite article of a terrain feature is usually "a".

There are four craters. There are five ridges. There are three peaks.

To say a seen name of (item - a thing):

say "[if item is improper-named][indefinite article of item] [end if][seen name of item]".

When play begins:

initialize the grid map.

To dump the planet map:

say fixed letter spacing;

repeat with inverse y running from 0 to grid size - 1:

if grid size - inverse y < 10, say " ";

say grid size - inverse y;

say " ";

repeat with x running from 1 to grid size:

choose row x graphed by (grid size - inverse y) in the Table of Planetary Surface;

unless there is a feature entry:

say ",";

otherwise:

if the feature entry is a crater, say "C";

if the feature entry is a ridge, say "R";

if the feature entry is a peak, say "P";

say line break;

repeat with inverse y running from 0 to grid size - 1:

if grid size - inverse y < 10, say " ";

say grid size - inverse y;

say " ";

repeat with x running from 1 to grid size:

choose row x graphed by (grid size - inverse y) in the Table of Planetary Surface;

if the elevation entry < 0:

say "x";

otherwise:

say the elevation entry;

say line break.

To initialize the grid map:

repeat with index running from 1 to (grid size * grid size):

choose row index in the Table of Planetary Surface;

now the x-coordinate entry is (index / grid size) + 1;

now the y-coordinate entry is the remainder after dividing index by grid size;

if the y-coordinate entry is 0: [change an entry like "2, 0" to "1, 18," if the grid size is 18]

now the y-coordinate entry is grid size;

now the x-coordinate entry is the x-coordinate entry minus 1;

now the elevation entry is 0.

To decide what number is (x - a number) graphed by (y - a number):

decide on ((x - 1) * grid size) + y. [This is going to get used in looking up rows in the Table of Planetary Surface.]

The texture to be used is a texture that varies.

To randomly place the terrain features:

now every texture is unused;

repeat with feature running through craters:

now the texture to be used is a random unused texture;

deploy feature;

now every texture is unused;

repeat with feature running through ridges:

now the texture to be used is a random unused texture;

deploy feature;

now every texture is unused;

repeat with feature running through peaks:

now the texture to be used is a random unused texture;

deploy feature.

To deploy (caldera - a crater):

let placing succeeded be a truth state;

repeat with placing attempt running from 1 to 10: [we try ten times and if we can't deploy it, we give up]

now placing succeeded is true; [until we run into a problem]

now x-coordinate of caldera is a random number between 2 and grid size - 1;

now y-coordinate of caldera is a random number between 2 and grid size - 1;

repeat with obstructor running through things in the Planet:

if the squared distance from obstructor to caldera is less than 15: [I think this should prevent things from getting placed a knight's move apart or closer]

now placing succeeded is false;

break; [no need to continue with obstructor running through everything else]

if placing succeeded is true: [it's placed; give it its properties and adjust the Table of Planetary Surface accordingly]

now the texture of the caldera is the texture to be used;

now the texture to be used is used;

now the caldera is in Planet;

let crater height be a random number between 1 and 3; [craters whose centers are higher than the surrounding surface are volcanic rather than meteoric, and you can't prove they aren't]

now the sight radius of caldera is the greater of crater height + 1 and 3; [since we actually measure from crater center, we add one to make it easier to see the crater wall]

repeat with x running from x-coordinate of caldera - 1 to x-coordinate of caldera + 1:

repeat with y running from y-coordinate of caldera - 1 to y-coordinate of caldera + 1: [this is going to create a square crater]

choose row x graphed by y in the Table of Planetary Surface;

now the elevation entry is crater height;

now the feature entry is caldera;

if x is the x-coordinate of caldera and y is the y-coordinate of caldera:

let depth be a random number between 1 and 2;

now the elevation entry is crater height minus depth;

break; [this breaks out of the placing attempt loop]

if placing succeeded is false: [we couldn't place it, so we reset its coordinates]

now x-coordinate of caldera is -99;

now y-coordinate of caldera is -99.

To deploy (spine - a ridge):

let placing succeeded be a truth state;

repeat with placing attempt running from 1 to 10: [we try ten times and if we can't deploy it, we give up]

now placing succeeded is true; [until we run into a problem]

now x-coordinate of spine is a random number between 2 and grid size - 1;

now y-coordinate of spine is a random number between 2 and grid size - 1;

repeat with obstructor running through things in the Planet:

if the squared distance from obstructor to spine is less than 13: [ridges can be a bit closer than craters]

now placing succeeded is false;

break; [no need to continue with obstructor running through everything else]

if placing succeeded is true: [it's placed; give it its properties and adjust the Table of Planetary Surface accordingly]

now the texture of the spine is the texture to be used;

now the texture to be used is used;

now the spine is in Planet;

let ridge height be a random number between 1 and 2;

now the sight radius of spine is 2;

if a random chance of 1 in 2 succeeds: [determines whether the ridge runs north-south or east-west]

now spine is east-west;

repeat with x running from x-coordinate of spine - 1 to x-coordinate of spine + 1:

choose row x graphed by y-coordinate of spine in the Table of Planetary Surface;

now the elevation entry is ridge height;

now the feature entry is spine;

otherwise:

now spine is north-south;

repeat with y running from y-coordinate of spine - 1 to y-coordinate of spine + 1:

choose row x-coordinate of spine graphed by y in the Table of Planetary Surface;

now the elevation entry is ridge height;

now the feature entry is spine;

break; [this breaks out of the placing attempt loop]

if placing succeeded is false: [we couldn't place it, so we reset its coordinates]

now x-coordinate of spine is -99;

now y-coordinate of spine is -99.

To deploy (mountain - a peak):

let placing succeeded be a truth state;

repeat with placing attempt running from 1 to 10: [we try ten times and if we can't deploy it, we give up]

now placing succeeded is true; [until we run into a problem]

now x-coordinate of mountain is a random number between 2 and grid size - 1;

now y-coordinate of mountain is a random number between 2 and grid size - 1;

repeat with obstructor running through things in the Planet:

if the squared distance from obstructor to mountain is less than 15: [I think this should prevent things from getting placed a knight's move apart or closer]

now placing succeeded is false;

break; [no need to continue with obstructor running through everything else]

if placing succeeded is true: [it's placed; give it its properties and adjust the Table of Planetary Surface accordingly]

now the texture of the mountain is the texture to be used;

now the texture to be used is used;

now the mountain is in Planet;

let mountain height be a random number between 2 and 4;

now the sight radius of mountain is mountain height;

repeat with x-increment running from 0 - mountain height to mountain height: [lower things gradually in a square from the peak]

repeat with y-increment running from 0 - mountain height to mountain height:

let new x be x-coordinate of mountain plus x-increment;

let new y be y-coordinate of mountain plus y-increment;

if new x by new y is on the grid: [peaks can go off the map so we sanity check]

choose row new x graphed by new y in the Table of Planetary Surface;

let z be mountain height minus (the greater of the integer absolute value of x-increment and the integer absolute value of y-increment);

increase the elevation entry by z;

if z >= mountain height - 1: [only the very top shows up as a peak on the feature map]

now the feature entry is the mountain;

break; [out of the placing attempt loop, since placing succeeded is true]

if placing succeeded is false: [we couldn't place it, so we reset its coordinates]

now x-coordinate of mountain is -99;

now y-coordinate of mountain is -99.