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mod: default params
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@qiao
qiao committed Feb 16, 2012
1 parent 6da32ca commit 40f353e
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Showing 3 changed files with 49 additions and 36 deletions.
22 changes: 11 additions & 11 deletions demo/index.html
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Expand Up @@ -50,7 +50,7 @@ <h1 id="title">Fractal Terrain Generator</h1>
<input class="opt" id="opt-smoothness" type="text" name="smoothness" min="0.1" max="5" step="0.1" value="1.0"><br>

<label for="z-scale">Z-Scale:</label>
<input class="opt" id="opt-z" type="text" name="z-scale" min="0" max="400" step="20" value="200"><br>
<input class="opt" id="opt-z" type="text" name="z-scale" min="0" max="500" step="20" value="340"><br>

<a id="new" href="#">new</a>
</form>
Expand All @@ -61,17 +61,17 @@ <h1 id="title">Fractal Terrain Generator</h1>
<a href="https://github.com/qiao/fractal-terrain-generator"><img style="position: absolute; top: 0; right: 0; border: 0;" src="https://a248.e.akamai.net/assets.github.com/img/71eeaab9d563c2b3c590319b398dd35683265e85/687474703a2f2f73332e616d617a6f6e6177732e636f6d2f6769746875622f726962626f6e732f666f726b6d655f72696768745f677261795f3664366436642e706e67" alt="Fork me on GitHub"></img></a>
<script type="text/javascript" src="./main.js"></script>
<script type="text/javascript">
$(function() {
var _gaq = _gaq || [];
_gaq.push(['_setAccount', 'UA-21856083-3']);
_gaq.push(['_trackPageview']);
TerrainController.init();

(function() {
var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
})();
});
var _gaq = _gaq || [];
_gaq.push(['_setAccount', 'UA-21856083-3']);
_gaq.push(['_trackPageview']);

(function() {
var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
})();
</script>
</body>
</html>
2 changes: 0 additions & 2 deletions demo/main.js
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Expand Up @@ -378,5 +378,3 @@ var TerrainController = (function() {
return { init: init };

})();

TerrainController.init();
61 changes: 38 additions & 23 deletions lib/terrain.js
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Expand Up @@ -106,15 +106,17 @@
*/
function diamond(matrix, depth, smoothness) {

var matSize = matrix.length - 1;
var len = matrix.length;
var terrainSize = len - 1;
var numSegs = 1 << (depth - 1);
var span = matSize / numSegs;
var span = terrainSize / numSegs;
var half = span / 2;

// enumerate sub-squares
// for each sub-square, the height of the center is caculated
// by averaging the height of its four vertices plus a random offset.
for (var x = 0; x < matSize; x += span) {
for (var y = 0; y < matSize; y += span) {
for (var x = 0; x < terrainSize; x += span) {
for (var y = 0; y < terrainSize; y += span) {
// (x, y)
// \
// a---b---c
Expand All @@ -129,7 +131,7 @@
//
var va = [x, y];
var vc = [x + span, y];
var ve = [x + span / 2, y + span / 2];
var ve = [x + half, y + half];
var vg = [x, y + span];
var vi = [x + span, y + span];

Expand Down Expand Up @@ -159,13 +161,15 @@
*/
function square(matrix, depth, smoothness) {

var matSize = matrix.length - 1;
var len = matrix.length
var terrainSize = len - 1;
var numSegs = 1 << (depth - 1);
var span = matSize / numSegs;
var span = terrainSize / numSegs;
var half = span / 2;

// enumerate sub-dimaonds
for (var x = 0; x < matSize; x += span) {
for (var y = 0; y < matSize; y += span) {
for (var x = 0; x < terrainSize; x += span) {
for (var y = 0; y < terrainSize; y += span) {
// for each sub-square, the height of the center is caculated
// by averaging the height of its four vertices plus a random offset.
// for example,
Expand All @@ -190,19 +194,30 @@
// span
//
var va = [x, y];
var vb = [x + span / 2, y];
var vb = [x + half, y];
var vc = [x + span, y];
var vf = [x, y + span / 2];
var vg = [x + span / 2, y + span / 2];
var vh = [x + span, y + span / 2];
var vf = [x, y + half];
var vg = [x + half, y + half];
var vh = [x + span, y + half];
var vk = [x, y + span];
var vl = [x + span / 2, y + span];
var vl = [x + half, y + span];
var vm = [x + span, y + span];

// right of h
var vhr = [x + half * 3, y + half];
if (vhr[0] > terrainSize) vhr[0] = half;

var vhr = [(x + span / 2 * 3) % matrix.length, y + span / 2]; // right of h
var vfl = [(x - span / 2 + matrix.length) % matrix.length, y + span / 2]; // left of f
var vlu = [x + span / 2, (y + span / 2 * 3) % matrix.length]; // under l
var vba = [x + span / 2, (y - span / 2 + matrix.length) % matrix.length]; // above b
// left of f
var vfl = [x - half, y + half]
if (vfl[0] < 0) vfl[0] = terrainSize - half;

// under l
var vlu = [x + half, y + half * 3];
if (vlu[1] > terrainSize) vlu[1] = half;

// above b
var vba = [x + half, y - half]
if (vba[1] < 0) vba[1] = terrainSize - half;

squareHelper(matrix, depth, smoothness, va, vg, vk, vfl, vf);
squareHelper(matrix, depth, smoothness, va, vba, vc, vg, vb);
Expand All @@ -213,11 +228,11 @@

// set the elevations of the rightmost and bottom vertices to
// equal the leftmost and topmost ones'.
for (var y = 0; y < matSize; y += span) {
matrix[y][matSize] = matrix[y][0];
for (var y = 0; y < terrainSize; y += span) {
matrix[y][terrainSize] = matrix[y][0];
}
for (var x = 0; x < matSize; x += span) {
matrix[matSize][x] = matrix[0][x];
for (var x = 0; x < terrainSize; x += span) {
matrix[terrainSize][x] = matrix[0][x];
}
}

Expand All @@ -240,7 +255,7 @@
function getH(smoothness, depth) {
var sign = Math.random() > 0.5 ? 1 : -1;
var reduce = 1;
for (var i = 1; i < depth; ++i) {
for (var i = 0; i < depth; ++i) {
reduce *= Math.pow(2, -smoothness);
}
return sign * Math.random() * reduce;
Expand Down

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