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(svn r24535) -Doc: Two additions, lots of small spelling fixes, and some Doxygen improvements.

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alberth
2012-09-21 09:47:21 +00:00
parent 89988c6163
commit 0849fb8d36
8 changed files with 33 additions and 27 deletions
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18
src/tgp.cpp
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@@ -53,7 +53,7 @@
* using a simple (0, 0) to (X, Y), with a varying seed.
*
*
* Other things i have had to do: mountainous wasnt mountainous enough, and
* Other things i have had to do: mountainous wasn't mountainous enough, and
* since we only have 0..15 heights available, I add a second generated map
* (with a modified seed), onto the original. This generally raises the
* terrain, which then needs scaling back down. Overall effect is a general
@@ -62,8 +62,8 @@
* However, the values on the top of mountains are then almost guaranteed to go
* too high, so large flat plateaus appeared at height 15. To counter this, I
* scale all heights above 12 to proportion up to 15. It still makes the
* mountains have flatish tops, rather than craggy peaks, but at least they
* arent smooth as glass.
* mountains have flattish tops, rather than craggy peaks, but at least they
* aren't smooth as glass.
*
*
* For a full discussion of Perlin Noise, please visit:
@@ -81,12 +81,12 @@
*
* The following implementation uses optimized algorithm that should produce
* the same quality result with much less computations, but more memory accesses.
* The overal speedup should be 300% to 800% depending on CPU and memory speed.
* The overall speedup should be 300% to 800% depending on CPU and memory speed.
*
* I will try to explain it on the example below:
*
* Have a map of 4 x 4 tiles, our simplifiead noise generator produces only two
* values -1 and +1, use 3 octaves with wave lenght 1, 2 and 4, with amplitudes
* Have a map of 4 x 4 tiles, our simplified noise generator produces only two
* values -1 and +1, use 3 octaves with wave length 1, 2 and 4, with amplitudes
* 3, 2, 1. Original algorithm produces:
*
* h00 = lerp(lerp(-3, 3, 0/4), lerp(3, -3, 0/4), 0/4) + lerp(lerp(-2, 2, 0/2), lerp( 2, -2, 0/2), 0/2) + -1 = lerp(-3.0, 3.0, 0/4) + lerp(-2, 2, 0/2) + -1 = -3.0 + -2 + -1 = -6.0
@@ -290,7 +290,7 @@ static inline height_t RandomHeight(amplitude_t rMax)
* One interpolation and noise round
*
* The heights on the map are generated in an iterative process.
* We start off with a frequency of 1 (log_frequency == 0), and generate heights only for corners on the most coarsly mesh
* We start off with a frequency of 1 (log_frequency == 0), and generate heights only for corners on the most coarsely mesh
* (i.e. only for x/y coordinates which are multiples of the minimum edge length).
*
* After this initial step the frequency is doubled (log_frequency incremented) each iteration to generate corners on the next finer mesh.
@@ -688,8 +688,8 @@ static double perlin_coast_noise_2D(const double x, const double y, const double
/**
* This routine sculpts in from the edge a random amount, again a Perlin
* sequence, to avoid the rigid flat-edge slopes that were present before. The
* Perlin noise map doesnt know where we are going to slice across, and so we
* often cut straight through high terrain. the smoothing routine makes it
* Perlin noise map doesn't know where we are going to slice across, and so we
* often cut straight through high terrain. The smoothing routine makes it
* legal, gradually increasing up from the edge to the original terrain height.
* By cutting parts of this away, it gives a far more irregular edge to the
* map-edge. Sometimes it works beautifully with the existing sea & lakes, and