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generator: optimize leaves generation routine with LUT

pull/6/head
EmaMaker 2023-07-28 16:25:57 +02:00
parent 381cd698c7
commit baa8d14bb3
1 changed files with 73 additions and 53 deletions
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126
src/chunkgenerator.cpp
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@ -38,8 +38,25 @@ OpenSimplexNoise::Noise noiseGen1(mt());
OpenSimplexNoise::Noise noiseGen2(mt());
OpenSimplexNoise::Noise noiseGenWood(mt());
// cover CHUNK_SIZE with WOOD_CELLS + 2 cells before and after the chunk
constexpr int TREE_LUT_SIZE = std::ceil(static_cast<float>(CHUNK_SIZE)/static_cast<float>(WOOD_CELL_SIZE)) + 2;
// Info on the tree cell to generate
struct TreeCellInfo{
// Cell coordinates (in "tree cell space")
int wcx, wcz;
// trunk offset from 0,0 in the cell
int wcx_offset, wcz_offset;
// Global x,z position of the trunk
int wx, wz;
// Y of the center of the leaves sphere
int leaves_y_pos;
};
// Lookup tables for generation
std::array<int, CHUNK_SIZE * CHUNK_SIZE> grassNoiseLUT;
std::array<int, CHUNK_SIZE * CHUNK_SIZE> dirtNoiseLUT;
std::array<TreeCellInfo, TREE_LUT_SIZE*TREE_LUT_SIZE> treeLUT;
void generateChunk(Chunk::Chunk *chunk)
{
@ -61,12 +78,7 @@ double evaluateNoise(OpenSimplexNoise::Noise noiseGen, double x, double y, doubl
const int TREE_MASTER_SEED_X = mt();
const int TREE_MASTER_SEED_Z = mt();
void evaluateTreeCell(int cx, int cz, int wcx, int wcz, int* wcx_offset, int*
wcz_offset, int* wx, int* wz, int* bwx, int* bwz, int* leaves_noise){
static int old_cx = -1, old_cz = -1, old_leaves_noise = -1;
struct TreeCellInfo evaluateTreeCell(int wcx, int wcz){
int anglex = TREE_MASTER_SEED_X*wcx+TREE_MASTER_SEED_Z*wcz;
int anglez = TREE_MASTER_SEED_Z*wcz+TREE_MASTER_SEED_X*wcx;
@ -74,37 +86,32 @@ void evaluateTreeCell(int cx, int cz, int wcx, int wcz, int* wcx_offset, int*
int wcx_off = WOOD_CELL_CENTER + WOOD_MAX_OFFSET * sines[anglex % 360];
int wcz_off = WOOD_CELL_CENTER + WOOD_MAX_OFFSET * cosines[anglez % 360];
//std::cout << "cell: (" << wcx << "," << wcz << "): offset: (" << (int)wcx_off << "," << (int)wcz_off << ")\n";
struct TreeCellInfo result{};
// Cell to world coordinates
*wx = wcx * WOOD_CELL_SIZE + wcx_off;
*wz = wcz * WOOD_CELL_SIZE + wcz_off;
result.wx = wcx * WOOD_CELL_SIZE + wcx_off;
result.wz = wcz * WOOD_CELL_SIZE + wcz_off;
*wcx_offset = wcx_off;
*wcz_offset = wcz_off;
result.wcx_offset = wcx_off;
result.wcz_offset = wcz_off;
*bwx = *wx - cx;
*bwz = *wz - cz;
result.leaves_y_pos = 1 + TREE_STANDARD_HEIGHT + GRASS_OFFSET + evaluateNoise(noiseGen1,
result.wx, result.wz, NOISE_GRASS_MULT, 0.01, 0.35, 2.1, 5);
if(old_leaves_noise == -1 || old_cx != cx || old_cz != cx || *bwx < 0 || *bwz < 0 || *bwx >= CHUNK_SIZE || *bwz >= CHUNK_SIZE)
*leaves_noise = TREE_STANDARD_HEIGHT + GRASS_OFFSET + evaluateNoise(noiseGen1, *wx, *wz, NOISE_GRASS_MULT, 0.01, 0.35, 2.1, 5);
else *leaves_noise = TREE_STANDARD_HEIGHT + grassNoiseLUT[*bwx * CHUNK_SIZE + *bwz];
old_leaves_noise = *leaves_noise;
old_cx = cx;
old_cz = cz;
return result;
}
Block block;
void generateNoise(Chunk::Chunk *chunk)
{
Block block;
int cx = chunk->getPosition().x * CHUNK_SIZE;
int cy = chunk->getPosition().y * CHUNK_SIZE;
int cz = chunk->getPosition().z * CHUNK_SIZE;
// Precalculate LUTs
// Terrain LUTs
for (int i = 0; i < grassNoiseLUT.size(); i++)
{
int bx = i / CHUNK_SIZE;
@ -115,13 +122,25 @@ void generateNoise(Chunk::Chunk *chunk)
cz+bz * NOISE_DIRT_Z_MULT)) * NOISE_DIRT_MULT);
}
// Tree LUT
int tree_lut_x_offset = cx / WOOD_CELL_SIZE - 1;
int tree_lut_z_offset = cz / WOOD_CELL_SIZE - 1;
for(int i = 0; i < TREE_LUT_SIZE; i++)
for(int k = 0; k < TREE_LUT_SIZE; k++){
int wcx = (tree_lut_x_offset + i);
int wcz = (tree_lut_z_offset + k);
treeLUT[i * TREE_LUT_SIZE + k] = evaluateTreeCell(wcx, wcz);
}
// Generation of terrain
Block block_prev{Block::AIR};
int block_prev_start{0};
// A space filling curve is continuous, so there is no particular order
for (int s = 0; s < CHUNK_VOLUME; s++)
{
int bx = HILBERT_XYZ_DECODE[s][0];
int by = HILBERT_XYZ_DECODE[s][1];
int bz = HILBERT_XYZ_DECODE[s][2];
@ -144,43 +163,44 @@ void generateNoise(Chunk::Chunk *chunk)
block = Block::AIR;
// Divide the world into cells, so that no two trees will be adjacent of each other
int wcx = x / WOOD_CELL_SIZE, wcz = z / WOOD_CELL_SIZE;
int wcx_offset, wcz_offset, wx, wz, bwx, bwz, leavesNoise;
// Divide the world into cells, each with exactly one tree, so that no two trees will be adjacent of each other
struct TreeCellInfo info;
int wcx = (int)(x / WOOD_CELL_SIZE) - tree_lut_x_offset;
int wcz = (int)(z / WOOD_CELL_SIZE) - tree_lut_z_offset;
evaluateTreeCell(cx, cz, wcx, wcz, &wcx_offset, &wcz_offset, &wx, &wz, &bwx, &bwz,
&leavesNoise);
// Retrieve info on the cell from LUT
info = treeLUT[wcx * TREE_LUT_SIZE + wcz];
// A tree is to be places if the coordinates are those of the tree of the current cell
int wood_height = TREE_STANDARD_HEIGHT;// + noiseGenWood.eval(wcx * NOISE_TREE_X_MULT, wcz * NOISE_TREE_Z_MULT) * TREE_HEIGHT_VARIATION;
bool wood = x == wx && z == wz && y > grassNoiseLUT[d2] && y <= leavesNoise;
bool leaf = false;
// A tree is to be placed in this position if the coordinates are those of the tree of the current cell
int wood_height = TREE_STANDARD_HEIGHT;
bool wood = x == info.wx && z == info.wz && y > grassNoiseLUT[d2] && y <= info.leaves_y_pos;
bool leaf{false};
leaf = wood && y > leavesNoise && y < leavesNoise+LEAVES_RADIUS;
if(!leaf) leaf = utils::withinDistance(x,y,z, wx, leavesNoise, wz, LEAVES_RADIUS);
// Check placing of leaves
if(wood) leaf = y > info.leaves_y_pos && y < info.leaves_y_pos+LEAVES_RADIUS;
else{
if(!leaf) leaf = utils::withinDistance(x,y,z, info.wx, info.leaves_y_pos, info.wz, LEAVES_RADIUS);
if(!leaf){
evaluateTreeCell(cx, cz, wcx+1, wcz, &wcx_offset, &wcz_offset, &wx, &wz, &bwx, &bwz,
&leavesNoise);
leaf = utils::withinDistance(x,y,z, wx, leavesNoise, wz, LEAVES_RADIUS);
}
// Eventually search neighboring cells
if(!leaf && wcx+1 < TREE_LUT_SIZE){
info = treeLUT[(wcx+1) * TREE_LUT_SIZE + wcz];
leaf = utils::withinDistance(x,y,z, info.wx, info.leaves_y_pos, info.wz, LEAVES_RADIUS);
}
if(!leaf){
evaluateTreeCell(cx, cz, wcx, wcz+1, &wcx_offset, &wcz_offset, &wx, &wz, &bwx, &bwz,
&leavesNoise);
leaf = utils::withinDistance(x,y,z, wx, leavesNoise, wz, LEAVES_RADIUS);
}
if(!leaf && wcx-1 >= 0){
info = treeLUT[(wcx-1) * TREE_LUT_SIZE + wcz];
leaf = utils::withinDistance(x,y,z, info.wx, info.leaves_y_pos, info.wz, LEAVES_RADIUS);
}
if(!leaf){
evaluateTreeCell(cx, cz, wcx-1, wcz, &wcx_offset, &wcz_offset, &wx, &wz, &bwx, &bwz,
&leavesNoise);
leaf = utils::withinDistance(x,y,z, wx, leavesNoise, wz, LEAVES_RADIUS);
}
if(!leaf && wcz-1 >= 0){
info = treeLUT[wcx * TREE_LUT_SIZE + (wcz-1)];
leaf = utils::withinDistance(x,y,z, info.wx, info.leaves_y_pos, info.wz, LEAVES_RADIUS);
}
if(!leaf){
evaluateTreeCell(cx, cz, wcx, wcz-1, &wcx_offset, &wcz_offset, &wx, &wz, &bwx, &bwz,
&leavesNoise);
leaf = utils::withinDistance(x,y,z, wx, leavesNoise, wz, LEAVES_RADIUS);
if(!leaf && wcz+1 < TREE_LUT_SIZE){
info = treeLUT[wcx * TREE_LUT_SIZE + (wcz+1)];
leaf = utils::withinDistance(x,y,z, info.wx, info.leaves_y_pos, info.wz, LEAVES_RADIUS);
}
}
if(wood) block = Block::WOOD;