diff --git a/src/tgp.c b/src/tgp.c deleted file mode 100644 --- a/src/tgp.c +++ /dev/null @@ -1,829 +0,0 @@ -/* $Id$ */ - -#include "stdafx.h" -#include -#include "openttd.h" -#include "clear_map.h" -#include "functions.h" -#include "map.h" -#include "table/strings.h" -#include "clear_map.h" -#include "tile.h" -#include "variables.h" -#include "void_map.h" -#include "tgp.h" -#include "console.h" -#include "genworld.h" - -/* - * OTTD Perlin Noise Landscape Generator, aka TerraGenesis Perlin - * - * Quickie guide to Perlin Noise - * Perlin noise is a predictable pseudo random number sequence. By generating - * it in 2 dimensions, it becomes a useful random map, that for a given seed - * and starting X & Y is entirely predictable. On the face of it, that may not - * be useful. However, it means that if you want to replay a map in a different - * terrain, or just vary the sea level, you just re-run the generator with the - * same seed. The seed is an int32, and is randomised on each run of New Game. - * The Scenario Generator does not randomise the value, so that you can - * experiment with one terrain until you are happy, or click "Random" for a new - * random seed. - * - * Perlin Noise is a series of "octaves" of random noise added together. By - * reducing the amplitude of the noise with each octave, the first octave of - * noise defines the main terrain sweep, the next the ripples on that, and the - * next the ripples on that. I use 6 octaves, with the amplitude controlled by - * a power ratio, usually known as a persistence or p value. This I vary by the - * smoothness selection, as can be seen in the table below. The closer to 1, - * the more of that octave is added. Each octave is however raised to the power - * of its position in the list, so the last entry in the "smooth" row, 0.35, is - * raised to the power of 6, so can only add 0.001838... of the amplitude to - * the running total. - * - * In other words; the first p value sets the general shape of the terrain, the - * second sets the major variations to that, ... until finally the smallest - * bumps are added. - * - * Usefully, this routine is totally scaleable; so when 32bpp comes along, the - * terrain can be as bumpy as you like! It is also infinitely expandable; a - * single random seed terrain continues in X & Y as far as you care to - * calculate. In theory, we could use just one seed value, but randomly select - * where in the Perlin XY space we use for the terrain. Personally I prefer - * using a simple (0, 0) to (X, Y), with a varying seed. - * - * - * Other things i have had to do: mountainous wasnt 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 - * uplift. - * - * 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. - * - * - * For a full discussion of Perlin Noise, please visit: - * http://freespace.virgin.net/hugo.elias/models/m_perlin.htm - * - * - * Evolution II - * - * The algorithm as described in the above link suggests to compute each tile height - * as composition of several noise waves. Some of them are computed directly by - * noise(x, y) function, some are calculated using linear approximation. Our - * first implementation of perlin_noise_2D() used 4 noise(x, y) calls plus - * 3 linear interpolations. It was called 6 times for each tile. This was a bit - * CPU expensive. - * - * 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. - * - * 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 - * 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 - * h01 = lerp(lerp(-3, 3, 1/4), lerp(3, -3, 1/4), 0/4) + lerp(lerp(-2, 2, 1/2), lerp( 2, -2, 1/2), 0/2) + 1 = lerp(-1.5, 1.5, 0/4) + lerp( 0, 0, 0/2) + 1 = -1.5 + 0 + 1 = -0.5 - * h02 = lerp(lerp(-3, 3, 2/4), lerp(3, -3, 2/4), 0/4) + lerp(lerp( 2, -2, 0/2), lerp(-2, 2, 0/2), 0/2) + -1 = lerp( 0, 0, 0/4) + lerp( 2, -2, 0/2) + -1 = 0 + 2 + -1 = 1.0 - * h03 = lerp(lerp(-3, 3, 3/4), lerp(3, -3, 3/4), 0/4) + lerp(lerp( 2, -2, 1/2), lerp(-2, 2, 1/2), 0/2) + 1 = lerp( 1.5, -1.5, 0/4) + lerp( 0, 0, 0/2) + 1 = 1.5 + 0 + 1 = 2.5 - * - * h10 = lerp(lerp(-3, 3, 0/4), lerp(3, -3, 0/4), 1/4) + lerp(lerp(-2, 2, 0/2), lerp( 2, -2, 0/2), 1/2) + 1 = lerp(-3.0, 3.0, 1/4) + lerp(-2, 2, 1/2) + 1 = -1.5 + 0 + 1 = -0.5 - * h11 = lerp(lerp(-3, 3, 1/4), lerp(3, -3, 1/4), 1/4) + lerp(lerp(-2, 2, 1/2), lerp( 2, -2, 1/2), 1/2) + -1 = lerp(-1.5, 1.5, 1/4) + lerp( 0, 0, 1/2) + -1 = -0.75 + 0 + -1 = -1.75 - * h12 = lerp(lerp(-3, 3, 2/4), lerp(3, -3, 2/4), 1/4) + lerp(lerp( 2, -2, 0/2), lerp(-2, 2, 0/2), 1/2) + 1 = lerp( 0, 0, 1/4) + lerp( 2, -2, 1/2) + 1 = 0 + 0 + 1 = 1.0 - * h13 = lerp(lerp(-3, 3, 3/4), lerp(3, -3, 3/4), 1/4) + lerp(lerp( 2, -2, 1/2), lerp(-2, 2, 1/2), 1/2) + -1 = lerp( 1.5, -1.5, 1/4) + lerp( 0, 0, 1/2) + -1 = 0.75 + 0 + -1 = -0.25 - * - * - * Optimization 1: - * - * 1) we need to allocate a bit more tiles: (size_x + 1) * (size_y + 1) = (5 * 5): - * - * 2) setup corner values using amplitude 3 - * { -3.0 X X X 3.0 } - * { X X X X X } - * { X X X X X } - * { X X X X X } - * { 3.0 X X X -3.0 } - * - * 3a) interpolate values in the middle - * { -3.0 X 0.0 X 3.0 } - * { X X X X X } - * { 0.0 X 0.0 X 0.0 } - * { X X X X X } - * { 3.0 X 0.0 X -3.0 } - * - * 3b) add patches with amplitude 2 to them - * { -5.0 X 2.0 X 1.0 } - * { X X X X X } - * { 2.0 X -2.0 X 2.0 } - * { X X X X X } - * { 1.0 X 2.0 X -5.0 } - * - * 4a) interpolate values in the middle - * { -5.0 -1.5 2.0 1.5 1.0 } - * { -1.5 -0.75 0.0 0.75 1.5 } - * { 2.0 0.0 -2.0 0.0 2.0 } - * { 1.5 0.75 0.0 -0.75 -1.5 } - * { 1.0 1.5 2.0 -1.5 -5.0 } - * - * 4b) add patches with amplitude 1 to them - * { -6.0 -0.5 1.0 2.5 0.0 } - * { -0.5 -1.75 1.0 -0.25 2.5 } - * { 1.0 1.0 -3.0 1.0 1.0 } - * { 2.5 -0.25 1.0 -1.75 -0.5 } - * { 0.0 2.5 1.0 -0.5 -6.0 } - * - * - * - * Optimization 2: - * - * As you can see above, each noise function was called just once. Therefore - * we don't need to use noise function that calculates the noise from x, y and - * some prime. The same quality result we can obtain using standard Random() - * function instead. - * - */ - -#ifndef M_PI_2 -#define M_PI_2 1.57079632679489661923 -#define M_PI 3.14159265358979323846 -#endif /* M_PI_2 */ - -/** Fixed point type for heights */ -typedef int16 height_t; -static const int height_decimal_bits = 4; -static const height_t _invalid_height = -32768; - -/** Fixed point array for amplitudes (and percent values) */ -typedef int amplitude_t; -static const int amplitude_decimal_bits = 10; - -/** Height map - allocated array of heights (MapSizeX() + 1) x (MapSizeY() + 1) */ -typedef struct HeightMap -{ - height_t *h; //! array of heights - uint dim_x; //! height map size_x MapSizeX() + 1 - uint total_size; //! height map total size - uint size_x; //! MapSizeX() - uint size_y; //! MapSizeY() -} HeightMap; - -/** Global height map instance */ -static HeightMap _height_map = {NULL, 0, 0, 0, 0}; - -/** Height map accessors */ -#define HeightMapXY(x, y) _height_map.h[(x) + (y) * _height_map.dim_x] - -/** Conversion: int to height_t */ -#define I2H(i) ((i) << height_decimal_bits) -/** Conversion: height_t to int */ -#define H2I(i) ((i) >> height_decimal_bits) - -/** Conversion: int to amplitude_t */ -#define I2A(i) ((i) << amplitude_decimal_bits) -/** Conversion: amplitude_t to int */ -#define A2I(i) ((i) >> amplitude_decimal_bits) - -/** Conversion: amplitude_t to height_t */ -#define A2H(a) ((height_decimal_bits < amplitude_decimal_bits) \ - ? ((a) >> (amplitude_decimal_bits - height_decimal_bits)) \ - : ((a) << (height_decimal_bits - amplitude_decimal_bits))) - -/** Walk through all items of _height_map.h */ -#define FOR_ALL_TILES_IN_HEIGHT(h) for (h = _height_map.h; h < &_height_map.h[_height_map.total_size]; h++) - -/** Noise amplitudes (multiplied by 1024) - * - indexed by "smoothness setting" and log2(frequency) */ -static const amplitude_t _amplitudes_by_smoothness_and_frequency[4][12] = { - // Very smooth - {1000, 350, 123, 43, 15, 1, 1, 0, 0, 0, 0, 0}, - // Smooth - {1000, 1000, 403, 200, 64, 8, 1, 0, 0, 0, 0, 0}, - // Rough - {1000, 1200, 800, 500, 200, 16, 4, 0, 0, 0, 0, 0}, - // Very Rough - {1500, 1000, 1200, 1000, 500, 32, 20, 0, 0, 0, 0, 0}, -}; - -/** Desired water percentage (100% == 1024) - indexed by _opt.diff.quantity_sea_lakes */ -static const amplitude_t _water_percent[4] = {20, 80, 250, 400}; - -/** Desired maximum height - indexed by _opt.diff.terrain_type */ -static const int8 _max_height[4] = { - 6, // Very flat - 9, // Flat - 12, // Hilly - 15 // Mountainous -}; - -/** Check if a X/Y set are within the map. */ -static inline bool IsValidXY(uint x, uint y) -{ - return ((int)x) >= 0 && x < _height_map.size_x && ((int)y) >= 0 && y < _height_map.size_y; -} - - -/** Allocate array of (MapSizeX()+1)*(MapSizeY()+1) heights and init the _height_map structure members */ -static inline bool AllocHeightMap(void) -{ - height_t *h; - - _height_map.size_x = MapSizeX(); - _height_map.size_y = MapSizeY(); - - /* Allocate memory block for height map row pointers */ - _height_map.total_size = (_height_map.size_x + 1) * (_height_map.size_y + 1); - _height_map.dim_x = _height_map.size_x + 1; - _height_map.h = calloc(_height_map.total_size, sizeof(*_height_map.h)); - if (_height_map.h == NULL) return false; - - /* Iterate through height map initialize values */ - FOR_ALL_TILES_IN_HEIGHT(h) *h = _invalid_height; - - return true; -} - -/** Free height map */ -static inline void FreeHeightMap(void) -{ - if (_height_map.h == NULL) return; - free(_height_map.h); - _height_map.h = NULL; -} - -/** RandomHeight() generator */ -static inline height_t RandomHeight(amplitude_t rMax) -{ - amplitude_t ra = (Random() << 16) | (Random() & 0x0000FFFF); - height_t rh; - /* Scale the amplitude for better resolution */ - rMax *= 16; - /* Spread height into range -rMax..+rMax */ - rh = A2H(ra % (2 * rMax + 1) - rMax); - return rh; -} - -/** One interpolation and noise round */ -static bool ApplyNoise(uint log_frequency, amplitude_t amplitude) -{ - uint size_min = min(_height_map.size_x, _height_map.size_y); - uint step = size_min >> log_frequency; - uint x, y; - - assert(_height_map.h != NULL); - - /* Are we finished? */ - if (step == 0) return false; - - if (log_frequency == 0) { - /* This is first round, we need to establish base heights with step = size_min */ - for (y = 0; y <= _height_map.size_y; y += step) { - for (x = 0; x <= _height_map.size_x; x += step) { - height_t height = (amplitude > 0) ? RandomHeight(amplitude) : 0; - HeightMapXY(x, y) = height; - } - } - return true; - } - - /* It is regular iteration round. - * Interpolate height values at odd x, even y tiles */ - for (y = 0; y <= _height_map.size_y; y += 2 * step) { - for (x = 0; x < _height_map.size_x; x += 2 * step) { - height_t h00 = HeightMapXY(x + 0 * step, y); - height_t h02 = HeightMapXY(x + 2 * step, y); - height_t h01 = (h00 + h02) / 2; - HeightMapXY(x + 1 * step, y) = h01; - } - } - - /* Interpolate height values at odd y tiles */ - for (y = 0; y < _height_map.size_y; y += 2 * step) { - for (x = 0; x <= _height_map.size_x; x += step) { - height_t h00 = HeightMapXY(x, y + 0 * step); - height_t h20 = HeightMapXY(x, y + 2 * step); - height_t h10 = (h00 + h20) / 2; - HeightMapXY(x, y + 1 * step) = h10; - } - } - - for (y = 0; y <= _height_map.size_y; y += step) { - for (x = 0; x <= _height_map.size_x; x += step) { - HeightMapXY(x, y) += RandomHeight(amplitude); - } - } - return (step > 1); -} - -/** Base Perlin noise generator - fills height map with raw Perlin noise */ -static void HeightMapGenerate(void) -{ - uint size_min = min(_height_map.size_x, _height_map.size_y); - uint iteration_round = 0; - amplitude_t amplitude; - bool continue_iteration; - uint log_size_min, log_frequency_min; - int log_frequency; - - /* Find first power of two that fits */ - for (log_size_min = 6; (1U << log_size_min) < size_min; log_size_min++) { } - log_frequency_min = log_size_min - 6; - - do { - log_frequency = iteration_round - log_frequency_min; - if (log_frequency >= 0) { - amplitude = _amplitudes_by_smoothness_and_frequency[_patches.tgen_smoothness][log_frequency]; - } else { - amplitude = 0; - } - continue_iteration = ApplyNoise(iteration_round, amplitude); - iteration_round++; - } while(continue_iteration); -} - -/** Returns min, max and average height from height map */ -static void HeightMapGetMinMaxAvg(height_t *min_ptr, height_t *max_ptr, height_t *avg_ptr) -{ - height_t h_min, h_max, h_avg, *h; - int64 h_accu = 0; - h_min = h_max = HeightMapXY(0, 0); - - /* Get h_min, h_max and accumulate heights into h_accu */ - FOR_ALL_TILES_IN_HEIGHT(h) { - if (*h < h_min) h_min = *h; - if (*h > h_max) h_max = *h; - h_accu += *h; - } - - /* Get average height */ - h_avg = (height_t)(h_accu / (_height_map.size_x * _height_map.size_y)); - - /* Return required results */ - if (min_ptr != NULL) *min_ptr = h_min; - if (max_ptr != NULL) *max_ptr = h_max; - if (avg_ptr != NULL) *avg_ptr = h_avg; -} - -/** Dill histogram and return pointer to its base point - to the count of zero heights */ -static int *HeightMapMakeHistogram(height_t h_min, height_t h_max, int *hist_buf) -{ - int *hist = hist_buf - h_min; - height_t *h; - - /* Fill histogram */ - FOR_ALL_TILES_IN_HEIGHT(h) { - assert(*h >= h_min); - assert(*h <= h_max); - hist[*h]++; - } - return hist; -} - -/** Applies sine wave redistribution onto height map */ -static void HeightMapSineTransform(height_t h_min, height_t h_max) -{ - height_t *h; - - FOR_ALL_TILES_IN_HEIGHT(h) { - double fheight; - - if (*h < h_min) continue; - - /* Transform height into 0..1 space */ - fheight = (double)(*h - h_min) / (double)(h_max - h_min); - /* Apply sine transform depending on landscape type */ - switch(_opt.landscape) { - case LT_CANDY: - case LT_NORMAL: - /* Move and scale 0..1 into -1..+1 */ - fheight = 2 * fheight - 1; - /* Sine transform */ - fheight = sin(fheight * M_PI_2); - /* Transform it back from -1..1 into 0..1 space */ - fheight = 0.5 * (fheight + 1); - break; - - case LT_HILLY: - { - /* Arctic terrain needs special height distribution. - * Redistribute heights to have more tiles at highest (75%..100%) range */ - double sine_upper_limit = 0.75; - double linear_compression = 2; - if (fheight >= sine_upper_limit) { - /* Over the limit we do linear compression up */ - fheight = 1.0 - (1.0 - fheight) / linear_compression; - } else { - double m = 1.0 - (1.0 - sine_upper_limit) / linear_compression; - /* Get 0..sine_upper_limit into -1..1 */ - fheight = 2.0 * fheight / sine_upper_limit - 1.0; - /* Sine wave transform */ - fheight = sin(fheight * M_PI_2); - /* Get -1..1 back to 0..(1 - (1 - sine_upper_limit) / linear_compression) == 0.0..m */ - fheight = 0.5 * (fheight + 1.0) * m; - } - } - break; - - case LT_DESERT: - { - /* Desert terrain needs special height distribution. - * Half of tiles should be at lowest (0..25%) heights */ - double sine_lower_limit = 0.5; - double linear_compression = 2; - if (fheight <= sine_lower_limit) { - /* Under the limit we do linear compression down */ - fheight = fheight / linear_compression; - } else { - double m = sine_lower_limit / linear_compression; - /* Get sine_lower_limit..1 into -1..1 */ - fheight = 2.0 * ((fheight - sine_lower_limit) / (1.0 - sine_lower_limit)) - 1.0; - /* Sine wave transform */ - fheight = sin(fheight * M_PI_2); - /* Get -1..1 back to (sine_lower_limit / linear_compression)..1.0 */ - fheight = 0.5 * ((1.0 - m) * fheight + (1.0 + m)); - } - } - break; - - default: - NOT_REACHED(); - break; - } - /* Transform it back into h_min..h_max space */ - *h = fheight * (h_max - h_min) + h_min; - if (*h < 0) *h = I2H(0); - if (*h >= h_max) *h = h_max - 1; - } -} - -/** Adjusts heights in height map to contain required amount of water tiles */ -static void HeightMapAdjustWaterLevel(amplitude_t water_percent, height_t h_max_new) -{ - height_t h_min, h_max, h_avg, h_water_level; - int water_tiles, desired_water_tiles; - height_t *h; - int *hist_buf, *hist; - - HeightMapGetMinMaxAvg(&h_min, &h_max, &h_avg); - - /* Allocate histogram buffer and clear its cells */ - hist_buf = calloc(h_max - h_min + 1, sizeof(*hist_buf)); - /* Fill histogram */ - hist = HeightMapMakeHistogram(h_min, h_max, hist_buf); - - /* How many water tiles do we want? */ - desired_water_tiles = (int)(((int64)water_percent) * (int64)(_height_map.size_x * _height_map.size_y)) >> amplitude_decimal_bits; - - /* Raise water_level and accumulate values from histogram until we reach required number of water tiles */ - for (h_water_level = h_min, water_tiles = 0; h_water_level < h_max; h_water_level++) { - water_tiles += hist[h_water_level]; - if (water_tiles >= desired_water_tiles) break; - } - - /* We now have the proper water level value. - * Transform the height map into new (normalized) height map: - * values from range: h_min..h_water_level will become negative so it will be clamped to 0 - * values from range: h_water_level..h_max are transformed into 0..h_max_new - * , where h_max_new is 4, 8, 12 or 16 depending on terrain type (very flat, flat, hilly, mountains) - */ - FOR_ALL_TILES_IN_HEIGHT(h) { - /* Transform height from range h_water_level..h_max into 0..h_max_new range */ - *h = (height_t)(((int)h_max_new) * (*h - h_water_level) / (h_max - h_water_level)) + I2H(1); - /* Make sure all values are in the proper range (0..h_max_new) */ - if (*h < 0) *h = I2H(0); - if (*h >= h_max_new) *h = h_max_new - 1; - } - - free(hist_buf); -} - -static double perlin_coast_noise_2D(const double x, const double y, const double p, const int prime); - -/** - * 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 - * 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 - * creates a very realistic coastline. Other times the variation is less, and - * the map-edge shows its cliff-like roots. - * - * This routine may be extended to randomly sculpt the height of the terrain - * near the edge. This will have the coast edge at low level (1-3), rising in - * smoothed steps inland to about 15 tiles in. This should make it look as - * though the map has been built for the map size, rather than a slice through - * a larger map. - * - * Please note that all the small numbers; 53, 101, 167, etc. are small primes - * to help give the perlin noise a bit more of a random feel. - */ -static void HeightMapCoastLines(void) -{ - int smallest_size = min(_patches.map_x, _patches.map_y); - const int margin = 4; - uint y, x; - uint max_x; - uint max_y; - - /* Lower to sea level */ - for (y = 0; y <= _height_map.size_y; y++) { - /* Top right */ - max_x = myabs((perlin_coast_noise_2D(_height_map.size_y - y, y, 0.9, 53) + 0.25) * 5 + (perlin_coast_noise_2D(y, y, 0.35, 179) + 1) * 12); - max_x = max((smallest_size * smallest_size / 16) + max_x, (smallest_size * smallest_size / 16) + margin - max_x); - if (smallest_size < 8 && max_x > 5) max_x /= 1.5; - for (x = 0; x < max_x; x++) { - HeightMapXY(x, y) = 0; - } - - /* Bottom left */ - max_x = myabs((perlin_coast_noise_2D(_height_map.size_y - y, y, 0.85, 101) + 0.3) * 6 + (perlin_coast_noise_2D(y, y, 0.45, 67) + 0.75) * 8); - max_x = max((smallest_size * smallest_size / 16) + max_x, (smallest_size * smallest_size / 16) + margin - max_x); - if (smallest_size < 8 && max_x > 5) max_x /= 1.5; - for (x = _height_map.size_x; x > (_height_map.size_x - 1 - max_x); x--) { - HeightMapXY(x, y) = 0; - } - } - - /* Lower to sea level */ - for (x = 0; x <= _height_map.size_x; x++) { - /* Top left */ - max_y = myabs((perlin_coast_noise_2D(x, _height_map.size_y / 2, 0.9, 167) + 0.4) * 5 + (perlin_coast_noise_2D(x, _height_map.size_y / 3, 0.4, 211) + 0.7) * 9); - max_y = max((smallest_size * smallest_size / 16) + max_y, (smallest_size * smallest_size / 16) + margin - max_y); - if (smallest_size < 8 && max_y > 5) max_y /= 1.5; - for (y = 0; y < max_y; y++) { - HeightMapXY(x, y) = 0; - } - - - /* Bottom right */ - max_y = myabs((perlin_coast_noise_2D(x, _height_map.size_y / 3, 0.85, 71) + 0.25) * 6 + (perlin_coast_noise_2D(x, _height_map.size_y / 3, 0.35, 193) + 0.75) * 12); - max_y = max((smallest_size * smallest_size / 16) + max_y, (smallest_size * smallest_size / 16) + margin - max_y); - if (smallest_size < 8 && max_y > 5) max_y /= 1.5; - for (y = _height_map.size_y; y > (_height_map.size_y - 1 - max_y); y--) { - HeightMapXY(x, y) = 0; - } - } -} - -/** Start at given point, move in given direction, find and Smooth coast in that direction */ -static void HeightMapSmoothCoastInDirection(int org_x, int org_y, int dir_x, int dir_y) -{ - const int max_coast_dist_from_edge = 35; - const int max_coast_Smooth_depth = 35; - - int x, y; - int ed; // coast distance from edge - int depth; - - height_t h_prev = 16; - height_t h; - - assert(IsValidXY(org_x, org_y)); - - /* Search for the coast (first non-water tile) */ - for (x = org_x, y = org_y, ed = 0; IsValidXY(x, y) && ed < max_coast_dist_from_edge; x += dir_x, y += dir_y, ed++) { - /* Coast found? */ - if (HeightMapXY(x, y) > 15) break; - - /* Coast found in the neighborhood? */ - if (IsValidXY(x + dir_y, y + dir_x) && HeightMapXY(x + dir_y, y + dir_x) > 0) break; - - /* Coast found in the neighborhood on the other side */ - if (IsValidXY(x - dir_y, y - dir_x) && HeightMapXY(x - dir_y, y - dir_x) > 0) break; - } - - /* Coast found or max_coast_dist_from_edge has been reached. - * Soften the coast slope */ - for (depth = 0; IsValidXY(x, y) && depth <= max_coast_Smooth_depth; depth++, x += dir_x, y += dir_y) { - h = HeightMapXY(x, y); - h = min(h, h_prev + (4 + depth)); // coast softening formula - HeightMapXY(x, y) = h; - h_prev = h; - } -} - -/** Smooth coasts by modulating height of tiles close to map edges with cosine of distance from edge */ -static void HeightMapSmoothCoasts(void) -{ - uint x, y; - /* First Smooth NW and SE coasts (y close to 0 and y close to size_y) */ - for (x = 0; x < _height_map.size_x; x++) { - HeightMapSmoothCoastInDirection(x, 0, 0, 1); - HeightMapSmoothCoastInDirection(x, _height_map.size_y - 1, 0, -1); - } - /* First Smooth NE and SW coasts (x close to 0 and x close to size_x) */ - for (y = 0; y < _height_map.size_y; y++) { - HeightMapSmoothCoastInDirection(0, y, 1, 0); - HeightMapSmoothCoastInDirection(_height_map.size_x - 1, y, -1, 0); - } -} - -/** - * This routine provides the essential cleanup necessary before OTTD can - * display the terrain. When generated, the terrain heights can jump more than - * one level between tiles. This routine smooths out those differences so that - * the most it can change is one level. When OTTD can support cliffs, this - * routine may not be necessary. - */ -static void HeightMapSmoothSlopes(height_t dh_max) -{ - int x, y; - for (y = 1; y <= (int)_height_map.size_y; y++) { - for (x = 1; x <= (int)_height_map.size_x; x++) { - height_t h_max = min(HeightMapXY(x - 1, y), HeightMapXY(x, y - 1)) + dh_max; - if (HeightMapXY(x, y) > h_max) HeightMapXY(x, y) = h_max; - } - } - for (y = _height_map.size_y - 1; y >= 0; y--) { - for (x = _height_map.size_x - 1; x >= 0; x--) { - height_t h_max = min(HeightMapXY(x + 1, y), HeightMapXY(x, y + 1)) + dh_max; - if (HeightMapXY(x, y) > h_max) HeightMapXY(x, y) = h_max; - } - } -} - -/** Height map terraform post processing: - * - water level adjusting - * - coast Smoothing - * - slope Smoothing - * - height histogram redistribution by sine wave transform */ -static void HeightMapNormalize(void) -{ - const amplitude_t water_percent = _water_percent[_opt.diff.quantity_sea_lakes]; - const height_t h_max_new = I2H(_max_height[_opt.diff.terrain_type]); - const height_t roughness = 7 + 3 * _patches.tgen_smoothness; - - HeightMapAdjustWaterLevel(water_percent, h_max_new); - - HeightMapCoastLines(); - HeightMapSmoothSlopes(roughness); - - HeightMapSmoothCoasts(); - HeightMapSmoothSlopes(roughness); - - HeightMapSineTransform(12, h_max_new); - HeightMapSmoothSlopes(16); -} - -static inline int perlin_landXY(uint x, uint y) -{ - return HeightMapXY(x, y); -} - - -/* The following decimals are the octave power modifiers for the Perlin noise */ -static const double _perlin_p_values[][7] = { // perlin frequency per power - { 0.35, 0.35, 0.35, 0.35, 0.35, 0.25, 0.539 }, // Very smooth - { 0.45, 0.55, 0.45, 0.45, 0.35, 0.25, 0.89 }, // Smooth - { 0.85, 0.80, 0.70, 0.45, 0.45, 0.35, 1.825 }, // Rough 1.825 - { 0.95, 0.85, 0.80, 0.55, 0.55, 0.45, 2.245 } // Very Rough 2.25 -}; - -/** - * The Perlin Noise calculation using large primes - * The initial number is adjusted by two values; the generation_seed, and the - * passed parameter; prime. - * prime is used to allow the perlin noise generator to create useful random - * numbers from slightly different series. - */ -static double int_noise(const long x, const long y, const int prime) -{ - long n = x + y * prime + _patches.generation_seed; - - n = (n << 13) ^ n; - - /* Pseudo-random number generator, using several large primes */ - return 1.0 - (double)((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff) / 1073741824.0; -} - - -/** - * Hj. Malthaner's routine included 2 different noise smoothing methods. - * We now use the "raw" int_noise one. - * However, it may be useful to move to the other routine in future. - * So it is included too. - */ -static double smoothed_noise(const int x, const int y, const int prime) -{ -#if 0 - /* A hilly world (four corner smooth) */ - const double sides = int_noise(x - 1, y) + int_noise(x + 1, y) + int_noise(x, y - 1) + int_noise(x, y + 1); - const double center = int_noise(x, y); - return (sides + sides + center * 4) / 8.0; -#endif - - /* This gives very hilly world */ - return int_noise(x, y, prime); -} - - -/** - * This routine determines the interpolated value between a and b - */ -static inline double linear_interpolate(const double a, const double b, const double x) -{ - return a + x * (b - a); -} - - -/** - * This routine returns the smoothed interpolated noise for an x and y, using - * the values from the surrounding positions. - */ -static double interpolated_noise(const double x, const double y, const int prime) -{ - const int integer_X = (int)x; - const int integer_Y = (int)y; - - const double fractional_X = x - (double)integer_X; - const double fractional_Y = y - (double)integer_Y; - - const double v1 = smoothed_noise(integer_X, integer_Y, prime); - const double v2 = smoothed_noise(integer_X + 1, integer_Y, prime); - const double v3 = smoothed_noise(integer_X, integer_Y + 1, prime); - const double v4 = smoothed_noise(integer_X + 1, integer_Y + 1, prime); - - const double i1 = linear_interpolate(v1, v2, fractional_X); - const double i2 = linear_interpolate(v3, v4, fractional_X); - - return linear_interpolate(i1, i2, fractional_Y); -} - - -/** - * This is a similar function to the main perlin noise calculation, but uses - * the value p passed as a parameter rather than selected from the predefined - * sequences. as you can guess by its title, i use this to create the indented - * coastline, which is just another perlin sequence. - */ -static double perlin_coast_noise_2D(const double x, const double y, const double p, const int prime) -{ - double total = 0.0; - int i; - - for (i = 0; i < 6; i++) { - const double frequency = (double)(1 << i); - const double amplitude = pow(p, (double)i); - - total += interpolated_noise((x * frequency) / 64.0, (y * frequency) / 64.0, prime) * amplitude; - } - - return total; -} - - -/** A small helper function */ -static void TgenSetTileHeight(TileIndex tile, int height) -{ - SetTileHeight(tile, height); - MakeClear(tile, CLEAR_GRASS, 3); -} - -/** - * The main new land generator using Perlin noise. Desert landscape is handled - * different to all others to give a desert valley between two high mountains. - * Clearly if a low height terrain (flat/very flat) is chosen, then the tropic - * areas wont be high enough, and there will be very little tropic on the map. - * Thus Tropic works best on Hilly or Mountainous. - */ -void GenerateTerrainPerlin(void) -{ - uint x, y; - - if (!AllocHeightMap()) return; - GenerateWorldSetAbortCallback(FreeHeightMap); - - HeightMapGenerate(); - - IncreaseGeneratingWorldProgress(GWP_LANDSCAPE); - - HeightMapNormalize(); - - IncreaseGeneratingWorldProgress(GWP_LANDSCAPE); - - /* Transfer height map into OTTD map */ - for (y = 2; y < _height_map.size_y - 2; y++) { - for (x = 2; x < _height_map.size_x - 2; x++) { - int height = H2I(HeightMapXY(x, y)); - if (height < 0) height = 0; - if (height > 15) height = 15; - TgenSetTileHeight(TileXY(x, y), height); - } - } - - IncreaseGeneratingWorldProgress(GWP_LANDSCAPE); - - /* Recreate void tiles at the border in case they have been affected by generation */ - for (y = 0; y < _height_map.size_y - 1; y++) MakeVoid(_height_map.size_x * y + _height_map.size_x - 1); - for (x = 0; x < _height_map.size_x; x++) MakeVoid(_height_map.size_x * y + x); - - FreeHeightMap(); - GenerateWorldSetAbortCallback(NULL); -}