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OpenRCT2/src/openrct2/world/mapgen.c

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#pragma region Copyright (c) 2014-2017 OpenRCT2 Developers
/*****************************************************************************
* OpenRCT2, an open source clone of Roller Coaster Tycoon 2.
*
* OpenRCT2 is the work of many authors, a full list can be found in contributors.md
* For more information, visit https://github.com/OpenRCT2/OpenRCT2
*
* OpenRCT2 is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* A full copy of the GNU General Public License can be found in licence.txt
*****************************************************************************/
#pragma endregion
#include "../common.h"
#include <math.h>
#include "../Context.h"
#include "../Imaging.h"
#include "../core/Guard.hpp"
#include "../game.h"
#include "../localisation/string_ids.h"
#include "../object.h"
#include "../platform/platform.h"
#include "../util/util.h"
#include "map.h"
#include "map_helpers.h"
#include "mapgen.h"
#include "scenery.h"
#pragma region Height map struct
static struct {
uint32 width, height;
uint8 *mono_bitmap;
} _heightMapData = {
.width = 0,
.height = 0,
.mono_bitmap = NULL
};
#pragma endregion Height map struct
#pragma region Random objects
static const char *GrassTrees[] = {
// Dark
"TCF ", // Caucasian Fir Tree
"TRF ", // Red Fir Tree
"TRF2 ", // Red Fir Tree
"TSP ", // Scots Pine Tree
"TMZP ", // Montezuma Pine Tree
"TAP ", // Aleppo Pine Tree
"TCRP ", // Corsican Pine Tree
"TBP ", // Black Poplar Tree
// Light
"TCL ", // Cedar of Lebanon Tree
"TEL ", // European Larch Tree
};
static const char *DesertTrees[] = {
"TMP ", // Monkey-Puzzle Tree
"THL ", // Honey Locust Tree
"TH1 ", // Canary Palm Tree
"TH2 ", // Palm Tree
"TPM ", // Palm Tree
"TROPT1 ", // Tree
"TBC ", // Cactus
"TSC ", // Cactus
};
static const char *SnowTrees[] = {
"TCFS ", // Snow-covered Caucasian Fir Tree
"TNSS ", // Snow-covered Norway Spruce Tree
"TRF3 ", // Snow-covered Red Fir Tree
"TRFS ", // Snow-covered Red Fir Tree
};
#pragma endregion
// Randomly chosen base terrains. We rarely want a whole map made out of chequerboard or rock.
static const uint8 BaseTerrain[] = { TERRAIN_GRASS, TERRAIN_SAND, TERRAIN_SAND_LIGHT, TERRAIN_DIRT, TERRAIN_ICE };
#define BLOB_HEIGHT 255
static void mapgen_place_trees();
static void mapgen_set_water_level(sint32 waterLevel);
static void mapgen_blobs(sint32 count, sint32 lowSize, sint32 highSize, sint32 lowHeight, sint32 highHeight);
static void mapgen_blob(sint32 cx, sint32 cy, sint32 size, sint32 height);
static void mapgen_smooth_height(sint32 iterations);
static void mapgen_set_height();
static void mapgen_simplex(mapgen_settings *settings);
static sint32 _heightSize;
static uint8 *_height;
static sint32 get_height(sint32 x, sint32 y)
{
if (x >= 0 && y >= 0 && x < _heightSize && y < _heightSize)
return _height[x + y * _heightSize];
else
return 0;
}
static void set_height(sint32 x, sint32 y, sint32 height)
{
if (x >= 0 && y >= 0 && x < _heightSize && y < _heightSize)
_height[x + y * _heightSize] = height;
}
void mapgen_generate_blank(mapgen_settings *settings)
{
sint32 x, y;
rct_tile_element *tileElement;
map_clear_all_elements();
map_init(settings->mapSize);
for (y = 1; y < settings->mapSize - 1; y++) {
for (x = 1; x < settings->mapSize - 1; x++) {
tileElement = map_get_surface_element_at(x, y);
tile_element_set_terrain(tileElement, settings->floor);
tile_element_set_terrain_edge(tileElement, settings->wall);
tileElement->base_height = settings->height;
tileElement->clearance_height = settings->height;
}
}
mapgen_set_water_level(settings->water_level);
}
void mapgen_generate(mapgen_settings *settings)
{
sint32 x, y, mapSize, floorTexture, wallTexture, waterLevel;
rct_tile_element *tileElement;
util_srand((sint32)platform_get_ticks());
mapSize = settings->mapSize;
floorTexture = settings->floor;
wallTexture = settings->wall;
waterLevel = settings->water_level;
if (floorTexture == -1)
floorTexture = BaseTerrain[util_rand() % countof(BaseTerrain)];
if (wallTexture == -1) {
// Base edge type on surface type
switch (floorTexture) {
case TERRAIN_DIRT:
wallTexture = TERRAIN_EDGE_WOOD_RED;
break;
case TERRAIN_ICE:
wallTexture = TERRAIN_EDGE_ICE;
break;
default:
wallTexture = TERRAIN_EDGE_ROCK;
break;
}
}
map_clear_all_elements();
// Initialise the base map
map_init(mapSize);
for (y = 1; y < mapSize - 1; y++) {
for (x = 1; x < mapSize - 1; x++) {
tileElement = map_get_surface_element_at(x, y);
tile_element_set_terrain(tileElement, floorTexture);
tile_element_set_terrain_edge(tileElement, wallTexture);
tileElement->base_height = settings->height;
tileElement->clearance_height = settings->height;
}
}
// Create the temporary height map and initialise
_heightSize = mapSize * 2;
_height = (uint8*)malloc(_heightSize * _heightSize * sizeof(uint8));
memset(_height, 0, _heightSize * _heightSize * sizeof(uint8));
if (1) {
mapgen_simplex(settings);
mapgen_smooth_height(2 + (util_rand() % 6));
} else {
// Keep overwriting the map with rough circular blobs of different sizes and heights.
// This procedural method can produce intersecting contour like land and lakes.
// Large blobs, general shape of map
mapgen_blobs(6, _heightSize / 2, _heightSize * 4, 4, 16);
// Medium blobs
mapgen_blobs(12, _heightSize / 16, _heightSize / 8, 4, 18);
// Small blobs, small hills and lakes
mapgen_blobs(32, _heightSize / 32, _heightSize / 16, 4, 18);
// Smooth the land so that there aren't cliffs round every blob.
mapgen_smooth_height(2);
}
// Set the game map to the height map
mapgen_set_height();
free(_height);
// Set the tile slopes so that there are no cliffs
while (map_smooth(1, 1, mapSize - 1, mapSize - 1)) { }
// Add the water
mapgen_set_water_level(waterLevel);
// Add sandy beaches
sint32 beachTexture = floorTexture;
if (settings->floor == -1 && floorTexture == TERRAIN_GRASS) {
switch (util_rand() % 4) {
case 0:
beachTexture = TERRAIN_SAND;
break;
case 1:
beachTexture = TERRAIN_SAND_LIGHT;
break;
}
}
for (y = 1; y < mapSize - 1; y++) {
for (x = 1; x < mapSize - 1; x++) {
tileElement = map_get_surface_element_at(x, y);
if (tileElement->base_height < waterLevel + 6)
tile_element_set_terrain(tileElement, beachTexture);
}
}
// Place the trees
if (settings->trees != 0)
mapgen_place_trees();
map_reorganise_elements();
}
static void mapgen_place_tree(sint32 type, sint32 x, sint32 y)
{
sint32 surfaceZ;
rct_tile_element *tileElement;
rct_scenery_entry *sceneryEntry = get_small_scenery_entry(type);
surfaceZ = tile_element_height(x * 32 + 16, y * 32 + 16) / 8;
tileElement = tile_element_insert(x, y, surfaceZ, (1 | 2 | 4 | 8));
assert(tileElement != NULL);
tileElement->clearance_height = surfaceZ + (sceneryEntry->small_scenery.height >> 3);
tileElement->type = TILE_ELEMENT_TYPE_SCENERY | (util_rand() & 3);
tileElement->properties.scenery.type = type;
tileElement->properties.scenery.age = 0;
scenery_small_set_primary_colour(tileElement, COLOUR_YELLOW);
}
/**
* Randomly places a selection of preset trees on the map. Picks the right tree for the terrain it is placing it on.
*/
static void mapgen_place_trees()
{
sint32 numGrassTreeIds = 0, numDesertTreeIds = 0, numSnowTreeIds = 0;
sint32 *grassTreeIds = (sint32*)malloc(countof(GrassTrees) * sizeof(sint32));
sint32 *desertTreeIds = (sint32*)malloc(countof(DesertTrees) * sizeof(sint32));
sint32 *snowTreeIds = (sint32*)malloc(countof(SnowTrees) * sizeof(sint32));
for (sint32 i = 0; i < object_entry_group_counts[OBJECT_TYPE_SMALL_SCENERY]; i++) {
rct_scenery_entry *sceneryEntry = get_small_scenery_entry(i);
rct_object_entry_extended *entry = &object_entry_groups[OBJECT_TYPE_SMALL_SCENERY].entries[i];
if (sceneryEntry == NULL)
continue;
sint32 j;
for (j = 0; j < countof(GrassTrees); j++)
if (strncmp(GrassTrees[j], entry->name, 8) == 0)
break;
if (j != countof(GrassTrees)) {
grassTreeIds[numGrassTreeIds++] = i;
continue;
}
for (j = 0; j < countof(DesertTrees); j++)
if (strncmp(DesertTrees[j], entry->name, 8) == 0)
break;
if (j != countof(DesertTrees)) {
desertTreeIds[numDesertTreeIds++] = i;
continue;
}
for (j = 0; j < countof(SnowTrees); j++)
if (strncmp(SnowTrees[j], entry->name, 8) == 0)
break;
if (j != countof(SnowTrees)) {
snowTreeIds[numSnowTreeIds++] = i;
continue;
}
}
sint32 availablePositionsCount = 0;
struct { sint32 x; sint32 y; } tmp, *pos, *availablePositions;
availablePositions = malloc(MAXIMUM_MAP_SIZE_TECHNICAL * MAXIMUM_MAP_SIZE_TECHNICAL * sizeof(tmp));
// Create list of available tiles
for (sint32 y = 1; y < gMapSize - 1; y++) {
for (sint32 x = 1; x < gMapSize - 1; x++) {
rct_tile_element *tileElement = map_get_surface_element_at(x, y);
// Exclude water tiles
if (map_get_water_height(tileElement) > 0)
continue;
pos = &availablePositions[availablePositionsCount++];
pos->x = x;
pos->y = y;
}
}
// Shuffle list
for (sint32 i = 0; i < availablePositionsCount; i++) {
sint32 rindex = util_rand() % availablePositionsCount;
if (rindex == i)
continue;
tmp = availablePositions[i];
availablePositions[i] = availablePositions[rindex];
availablePositions[rindex] = tmp;
}
// Place trees
float treeToLandRatio = (10 + (util_rand() % 30)) / 100.0f;
sint32 numTrees = max(4, (sint32)(availablePositionsCount * treeToLandRatio));
for (sint32 i = 0; i < numTrees; i++) {
pos = &availablePositions[i];
sint32 type = -1;
rct_tile_element *tileElement = map_get_surface_element_at(pos->x, pos->y);
switch (tile_element_get_terrain(tileElement)) {
case TERRAIN_GRASS:
case TERRAIN_DIRT:
case TERRAIN_GRASS_CLUMPS:
if (numGrassTreeIds == 0)
break;
type = grassTreeIds[util_rand() % numGrassTreeIds];
break;
case TERRAIN_SAND:
case TERRAIN_SAND_DARK:
case TERRAIN_SAND_LIGHT:
if (numDesertTreeIds == 0)
break;
if (util_rand() % 4 == 0)
type = desertTreeIds[util_rand() % numDesertTreeIds];
break;
case TERRAIN_ICE:
if (numSnowTreeIds == 0)
break;
type = snowTreeIds[util_rand() % numSnowTreeIds];
break;
}
if (type != -1)
mapgen_place_tree(type, pos->x, pos->y);
}
free(availablePositions);
free(grassTreeIds);
free(desertTreeIds);
free(snowTreeIds);
}
/**
* Sets each tile's water level to the specified water level if underneath that water level.
*/
static void mapgen_set_water_level(sint32 waterLevel)
{
sint32 x, y, mapSize;
rct_tile_element *tileElement;
mapSize = gMapSize;
for (y = 1; y < mapSize - 1; y++) {
for (x = 1; x < mapSize - 1; x++) {
tileElement = map_get_surface_element_at(x, y);
if (tileElement->base_height < waterLevel)
tileElement->properties.surface.terrain |= (waterLevel / 2);
}
}
}
static void mapgen_blobs(sint32 count, sint32 lowSize, sint32 highSize, sint32 lowHeight, sint32 highHeight)
{
sint32 i;
sint32 sizeRange = highSize - lowSize;
sint32 heightRange = highHeight - lowHeight;
sint32 border = 2 + (util_rand() % 24);
sint32 borderRange = _heightSize - (border * 2);
for (i = 0; i < count; i++) {
sint32 radius = lowSize + (util_rand() % sizeRange);
mapgen_blob(
border + (util_rand() % borderRange),
border + (util_rand() % borderRange),
(sint32)(M_PI * radius * radius),
lowHeight + (util_rand() % heightRange)
);
}
}
/**
* Sets any holes within a new created blob to the specified height.
*/
static void mapgen_blob_fill(sint32 height)
{
// For each square find out whether it is landlocked by BLOB_HEIGHT and then fill it if it is
sint32 left = 0,
top = 0,
right = _heightSize - 1,
bottom = _heightSize - 1;
uint8 *landX = (uint8*)malloc(_heightSize * _heightSize * sizeof(uint8));
sint32 firstLand, lastLand;
// Check each row and see if each tile is between first land x and last land x
for (sint32 y = top; y <= bottom; y++) {
// Calculate first land
firstLand = -1;
for (sint32 xx = left; xx <= right; xx++) {
if (get_height(xx, y) == BLOB_HEIGHT) {
firstLand = xx;
break;
}
}
lastLand = -1;
if (firstLand >= 0) {
// Calculate last land
for (sint32 xx = right; xx >= left; xx--) {
if (get_height(xx, y) == BLOB_HEIGHT) {
lastLand = xx;
break;
}
}
} else {
// No land on this row
continue;
}
for (sint32 x = left; x <= right; x++)
if (x >= firstLand && x <= lastLand)
landX[x * _heightSize + y] = 1;
}
// Do the same for Y
for (sint32 x = left; x <= right; x++) {
// Calculate first land
firstLand = -1;
for (sint32 yy = top; yy <= bottom; yy++) {
if (get_height(x, yy) == BLOB_HEIGHT) {
firstLand = yy;
break;
}
}
lastLand = -1;
if (firstLand >= 0) {
// Calculate last land
for (sint32 yy = bottom; yy >= top; yy--) {
if (get_height(x, yy) == BLOB_HEIGHT) {
lastLand = yy;
break;
}
}
} else {
// No land on this row
continue;
}
for (sint32 y = top; y <= bottom; y++) {
if (y >= firstLand && y <= lastLand && landX[x * _heightSize + y]) {
// Not only do we know it's landlocked to both x and y
// we can change the land too
set_height(x, y, BLOB_HEIGHT);
}
}
}
// Replace all the BLOB_HEIGHT with the actual land height
for (sint32 x = left; x <= right; x++)
for (sint32 y = top; y <= bottom; y++)
if (get_height(x, y) == BLOB_HEIGHT)
set_height(x, y, height);
free(landX);
}
/**
* Sets a rough circular blob of tiles of the specified size to the specified height.
*/
static void mapgen_blob(sint32 cx, sint32 cy, sint32 size, sint32 height)
{
sint32 x, y, currentSize, direction;
x = cx;
y = cy;
currentSize = 1;
direction = 0;
set_height(x, y, BLOB_HEIGHT);
while (currentSize < size) {
if (util_rand() % 2 == 0) {
set_height(x, y, BLOB_HEIGHT);
currentSize++;
}
switch (direction) {
case 0:
if (y == 0) {
currentSize = size;
break;
}
y--;
if (get_height(x + 1, y) != BLOB_HEIGHT)
direction = 1;
else if (get_height(x, y - 1) != BLOB_HEIGHT)
direction = 0;
else if (get_height(x - 1, y) != BLOB_HEIGHT)
direction = 3;
break;
case 1:
if (x == _heightSize - 1) {
currentSize = size;
break;
}
x++;
if (get_height(x, y + 1) != BLOB_HEIGHT)
direction = 2;
else if (get_height(x + 1, y) != BLOB_HEIGHT)
direction = 1;
else if (get_height(x, y - 1) != BLOB_HEIGHT)
direction = 0;
break;
case 2:
if (y == _heightSize - 1) {
currentSize = size;
break;
}
y++;
if (get_height(x - 1, y) != BLOB_HEIGHT)
direction = 3;
else if (get_height(x, y + 1) != BLOB_HEIGHT)
direction = 2;
else if (get_height(x + 1, y) != BLOB_HEIGHT)
direction = 1;
break;
case 3:
if (x == 0) {
currentSize = size;
break;
}
x--;
if (get_height(x, y - 1) != BLOB_HEIGHT)
direction = 0;
else if (get_height(x - 1, y) != BLOB_HEIGHT)
direction = 3;
else if (get_height(x, y + 1) != BLOB_HEIGHT)
direction = 2;
break;
}
}
mapgen_blob_fill(height);
}
/**
* Smooths the height map.
*/
static void mapgen_smooth_height(sint32 iterations)
{
sint32 i, x, y, xx, yy, avg;
sint32 arraySize = _heightSize * _heightSize * sizeof(uint8);
uint8 *copyHeight = malloc(arraySize);
for (i = 0; i < iterations; i++) {
memcpy(copyHeight, _height, arraySize);
for (y = 1; y < _heightSize - 1; y++) {
for (x = 1; x < _heightSize - 1; x++) {
avg = 0;
for (yy = -1; yy <= 1; yy++)
for (xx = -1; xx <= 1; xx++)
avg += copyHeight[(y + yy) * _heightSize + (x + xx)];
avg /= 9;
set_height(x, y, avg);
}
}
}
free(copyHeight);
}
/**
* Sets the height of the actual game map tiles to the height map.
*/
static void mapgen_set_height()
{
sint32 x, y, heightX, heightY, mapSize;
rct_tile_element *tileElement;
mapSize = _heightSize / 2;
for (y = 1; y < mapSize - 1; y++) {
for (x = 1; x < mapSize - 1; x++) {
heightX = x * 2;
heightY = y * 2;
uint8 q00 = get_height(heightX + 0, heightY + 0);
uint8 q01 = get_height(heightX + 0, heightY + 1);
uint8 q10 = get_height(heightX + 1, heightY + 0);
uint8 q11 = get_height(heightX + 1, heightY + 1);
uint8 baseHeight = (q00 + q01 + q10 + q11) / 4;
tileElement = map_get_surface_element_at(x, y);
tileElement->base_height = max(2, baseHeight * 2);
tileElement->clearance_height = tileElement->base_height;
if (q00 > baseHeight)
tileElement->properties.surface.slope |= 4;
if (q01 > baseHeight)
tileElement->properties.surface.slope |= 8;
if (q10 > baseHeight)
tileElement->properties.surface.slope |= 2;
if (q11 > baseHeight)
tileElement->properties.surface.slope |= 1;
}
}
}
#pragma region Noise
/**
* Simplex Noise Algorithm with Fractional Brownian Motion
* Based on:
* - https://code.google.com/p/simplexnoise/
* - https://code.google.com/p/fractalterraingeneration/wiki/Fractional_Brownian_Motion
*/
static float generate(float x, float y);
static sint32 fast_floor(float x);
static float grad(sint32 hash, float x, float y);
static uint8 perm[512];
static void noise_rand()
{
for (sint32 i = 0; i < countof(perm); i++)
perm[i] = util_rand() & 0xFF;
}
static float fractal_noise(sint32 x, sint32 y, float frequency, sint32 octaves, float lacunarity, float persistence)
{
float total = 0.0f;
float amplitude = persistence;
for (sint32 i = 0; i < octaves; i++) {
total += generate(x * frequency, y * frequency) * amplitude;
frequency *= lacunarity;
amplitude *= persistence;
}
return total;
}
static float generate(float x, float y)
{
const float F2 = 0.366025403f; // F2 = 0.5*(sqrt(3.0)-1.0)
const float G2 = 0.211324865f; // G2 = (3.0-Math.sqrt(3.0))/6.0
float n0, n1, n2; // Noise contributions from the three corners
// Skew the input space to determine which simplex cell we're in
float s = (x + y) * F2; // Hairy factor for 2D
float xs = x + s;
float ys = y + s;
sint32 i = fast_floor(xs);
sint32 j = fast_floor(ys);
float t = (float)(i + j) * G2;
float X0 = i - t; // Unskew the cell origin back to (x,y) space
float Y0 = j - t;
float x0 = x - X0; // The x,y distances from the cell origin
float y0 = y - Y0;
// For the 2D case, the simplex shape is an equilateral triangle.
// Determine which simplex we are in.
sint32 i1, j1; // Offsets for second (middle) corner of simplex in (i,j) coords
if (x0 > y0) { i1 = 1; j1 = 0; } // lower triangle, XY order: (0,0)->(1,0)->(1,1)
else { i1 = 0; j1 = 1; } // upper triangle, YX order: (0,0)->(0,1)->(1,1)
// A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and
// a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where
// c = (3-sqrt(3))/6
float x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords
float y1 = y0 - j1 + G2;
float x2 = x0 - 1.0f + 2.0f * G2; // Offsets for last corner in (x,y) unskewed coords
float y2 = y0 - 1.0f + 2.0f * G2;
// Wrap the integer indices at 256, to avoid indexing perm[] out of bounds
sint32 ii = i % 256;
sint32 jj = j % 256;
// Calculate the contribution from the three corners
float t0 = 0.5f - x0 * x0 - y0 * y0;
if (t0 < 0.0f) n0 = 0.0f;
else {
t0 *= t0;
n0 = t0 * t0 * grad(perm[ii + perm[jj]], x0, y0);
}
float t1 = 0.5f - x1 * x1 - y1 * y1;
if (t1 < 0.0f) n1 = 0.0f;
else {
t1 *= t1;
n1 = t1 * t1 * grad(perm[ii + i1 + perm[jj + j1]], x1, y1);
}
float t2 = 0.5f - x2 * x2 - y2 * y2;
if (t2 < 0.0f) n2 = 0.0f;
else {
t2 *= t2;
n2 = t2 * t2 * grad(perm[ii + 1 + perm[jj + 1]], x2, y2);
}
// Add contributions from each corner to get the final noise value.
// The result is scaled to return values in the interval [-1,1].
return 40.0f * (n0 + n1 + n2); // TODO: The scale factor is preliminary!
}
static sint32 fast_floor(float x)
{
return (x > 0) ? ((sint32)x) : (((sint32)x) - 1);
}
static float grad(sint32 hash, float x, float y)
{
sint32 h = hash & 7; // Convert low 3 bits of hash code
float u = h < 4 ? x : y; // into 8 simple gradient directions,
float v = h < 4 ? y : x; // and compute the dot product with (x,y).
return ((h & 1) != 0 ? -u : u) + ((h & 2) != 0 ? -2.0f * v : 2.0f * v);
}
static void mapgen_simplex(mapgen_settings *settings)
{
sint32 x, y;
float freq = settings->simplex_base_freq * (1.0f / _heightSize);
sint32 octaves = settings->simplex_octaves;
sint32 low = settings->simplex_low;
sint32 high = settings->simplex_high;
noise_rand();
for (y = 0; y < _heightSize; y++) {
for (x = 0; x < _heightSize; x++) {
float noiseValue = clamp(-1.0f, fractal_noise(x, y, freq, octaves, 2.0f, 0.65f), 1.0f);
float normalisedNoiseValue = (noiseValue + 1.0f) / 2.0f;
set_height(x, y, low + (sint32)(normalisedNoiseValue * high));
}
}
}
#pragma endregion
#pragma region Heightmap
bool mapgen_load_heightmap(const utf8 *path)
{
const char* extension = path_get_extension(path);
uint8 *pixels;
size_t pitch;
uint32 numChannels;
uint32 width, height;
if (strcicmp(extension, ".png") == 0) {
if (!image_io_png_read(&pixels, &width, &height, path)) {
log_warning("Error reading PNG");
context_show_error(STR_HEIGHT_MAP_ERROR, STR_ERROR_READING_PNG);
return false;
}
numChannels = 4;
pitch = width * numChannels;
}
else if (strcicmp(extension, ".bmp") == 0) {
if (!context_read_bmp((void *)&pixels, &width, &height, path)) {
// ReadBMP contains context_show_error calls
return false;
}
numChannels = 4;
pitch = width * numChannels;
}
else
{
openrct2_assert(false, "A file with an invalid file extension was selected.");
return false;
}
if (width != height) {
context_show_error(STR_HEIGHT_MAP_ERROR, STR_ERROR_WIDTH_AND_HEIGHT_DO_NOT_MATCH);
free(pixels);
return false;
}
if (width > MAXIMUM_MAP_SIZE_PRACTICAL) {
context_show_error(STR_HEIGHT_MAP_ERROR, STR_ERROR_HEIHGT_MAP_TOO_BIG);
width = height = min(height, MAXIMUM_MAP_SIZE_PRACTICAL);
}
// Allocate memory for the height map values, one byte pixel
free(_heightMapData.mono_bitmap);
_heightMapData.mono_bitmap = (uint8*)malloc(width * height);
_heightMapData.width = width;
_heightMapData.height = height;
// Copy average RGB value to mono bitmap
for (uint32 x = 0; x < _heightMapData.width; x++)
{
for (uint32 y = 0; y < _heightMapData.height; y++)
{
const uint8 red = pixels[x * numChannels + y * pitch];
const uint8 green = pixels[x * numChannels + y * pitch + 1];
const uint8 blue = pixels[x * numChannels + y * pitch + 2];
_heightMapData.mono_bitmap[x + y * _heightMapData.width] = (red + green + blue) / 3;
}
}
free(pixels);
return true;
}
/**
* Frees the memory used to store the selected height map
*/
void mapgen_unload_heightmap()
{
free(_heightMapData.mono_bitmap);
_heightMapData.mono_bitmap = NULL;
_heightMapData.width = 0;
_heightMapData.height = 0;
}
/**
* Applies box blur to the surface N times
*/
static void mapgen_smooth_heightmap(uint8 *src, sint32 strength)
{
// Create buffer to store one channel
uint8 *dest = (uint8*)malloc(_heightMapData.width * _heightMapData.height);
for (sint32 i = 0; i < strength; i++)
{
// Calculate box blur value to all pixels of the surface
for (uint32 y = 0; y < _heightMapData.height; y++)
{
for (uint32 x = 0; x < _heightMapData.width; x++)
{
uint32 heightSum = 0;
// Loop over neighbour pixels, all of them have the same weight
for (sint8 offsetX = -1; offsetX <= 1; offsetX++)
{
for (sint8 offsetY = -1; offsetY <= 1; offsetY++)
{
// Clamp x and y so they stay within the image
// This assumes the height map is not tiled, and increases the weight of the edges
const sint32 readX = clamp((sint32)x + offsetX, 0, (sint32)_heightMapData.width - 1);
const sint32 readY = clamp((sint32)y + offsetY, 0, (sint32)_heightMapData.height - 1);
heightSum += src[readX + readY * _heightMapData.width];
}
}
// Take average
dest[x + y * _heightMapData.width] = heightSum / 9;
}
}
// Now apply the blur to the source pixels
for (uint32 y = 0; y < _heightMapData.height; y++)
{
for (uint32 x = 0; x < _heightMapData.width; x++)
{
src[x + y * _heightMapData.width] = dest[x + y * _heightMapData.width];
}
}
}
free(dest);
}
void mapgen_generate_from_heightmap(mapgen_settings *settings)
{
openrct2_assert(_heightMapData.width == _heightMapData.height, "Invalid height map size");
openrct2_assert(_heightMapData.mono_bitmap != NULL, "No height map loaded");
openrct2_assert(settings->simplex_high != settings->simplex_low, "Low and high setting cannot be the same");
// Make a copy of the original height map that we can edit
uint8 *dest = (uint8*)malloc(_heightMapData.width * _heightMapData.height);
memcpy(dest, _heightMapData.mono_bitmap, _heightMapData.width * _heightMapData.width);
map_init(_heightMapData.width + 2); // + 2 for the black tiles around the map
if (settings->smooth_height_map)
{
mapgen_smooth_heightmap(dest, settings->smooth_strength);
}
uint8 maxValue = 255;
uint8 minValue = 0;
if (settings->normalize_height)
{
// Get highest and lowest pixel value
maxValue = 0;
minValue = 0xff;
for (uint32 y = 0; y < _heightMapData.height; y++)
{
for (uint32 x = 0; x < _heightMapData.width; x++)
{
uint8 value = dest[x + y * _heightMapData.width];
maxValue = max(maxValue, value);
minValue = min(minValue, value);
}
}
if (minValue == maxValue)
{
context_show_error(STR_HEIGHT_MAP_ERROR, STR_ERROR_CANNOT_NORMALIZE);
free(dest);
return;
}
}
openrct2_assert(maxValue > minValue, "Input range is invalid");
openrct2_assert(settings->simplex_high > settings->simplex_low, "Output range is invalid");
const uint8 rangeIn = maxValue - minValue;
const uint8 rangeOut = settings->simplex_high - settings->simplex_low;
for (uint32 y = 0; y < _heightMapData.height; y++)
{
for (uint32 x = 0; x < _heightMapData.width; x++)
{
// The x and y axis are flipped in the world, so this uses y for x and x for y.
rct_tile_element *const surfaceElement = map_get_surface_element_at(y + 1, x + 1);
// Read value from bitmap, and convert its range
uint8 value = dest[x + y * _heightMapData.width];
value = (uint8)((float)(value - minValue) / rangeIn * rangeOut) + settings->simplex_low;
surfaceElement->base_height = value;
// Floor to even number
surfaceElement->base_height /= 2;
surfaceElement->base_height *= 2;
surfaceElement->clearance_height = surfaceElement->base_height;
// Set water level
if (surfaceElement->base_height < settings->water_level)
{
surfaceElement->properties.surface.terrain |= settings->water_level / 2;
}
}
}
// Smooth map
if (settings->smooth)
{
// Keep smoothing the entire map until no tiles are changed anymore
while (true)
{
uint32 numTilesChanged = 0;
for (uint32 y = 1; y <= _heightMapData.height; y++)
{
for (uint32 x = 1; x <= _heightMapData.width; x++)
{
numTilesChanged += tile_smooth(x, y);
}
}
if (numTilesChanged == 0)
break;
}
}
// Clean up
free(dest);
}
#pragma endregion
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