include/block.hpp

@@ -6,7 +6,9 @@ enum class Block{
     AIR,
     STONE,
     DIRT,
-    GRASS
+    GRASS,
+    WOOD,
+    LEAVES
 };
 
-#endif
+#endif

include/globals.hpp

@@ -16,6 +16,9 @@ extr Camera theCamera;
 constexpr int chunks_volume = static_cast<int>(1.333333333333*M_PI*(RENDER_DISTANCE*RENDER_DISTANCE*RENDER_DISTANCE));
 extr bool wireframe;
 
+extr float sines[360];
+extr float cosines[360];
+
 extr uint32_t MORTON_XYZ_ENCODE[CHUNK_SIZE][CHUNK_SIZE][CHUNK_SIZE];
 extr uint32_t MORTON_XYZ_DECODE[CHUNK_VOLUME][3];
 extr uint32_t HILBERT_XYZ_ENCODE[CHUNK_SIZE][CHUNK_SIZE][CHUNK_SIZE];

shaders/shader-texture.fs

@@ -23,6 +23,7 @@ void main(){
     // Load the texture
     // anti-gamma-correction of the texture. Without this it would be gamma corrected twice!
     vec3 vColor = pow(texture(textureArray, TexCoord).rgb, vec3(gamma));
+    if(TexCoord.z == 4) vColor = vColor * normalize(vec3(10, 250, 10));
     
     vec3 normal = normalize(Normal);
 

src/chunkgenerator.cpp

@@ -9,62 +9,111 @@
 #include "utils.hpp"
 
 #define GRASS_OFFSET 40
-#define NOISE_GRASS_MULT 20
+#define NOISE_GRASS_MULT 30
 #define NOISE_DIRT_MULT 3
-#define NOISE_DIRT_MIN 2
+#define NOISE_DIRT_MIN 3
 #define NOISE_DIRT_X_MULT 0.001f
 #define NOISE_DIRT_Z_MULT 0.001f
 #define NOISE_GRASS_X_MULT 0.018f
 #define NOISE_GRASS_Z_MULT 0.018f
+#define NOISE_TREE_X_MULT 0.01f
+#define NOISE_TREE_Z_MULT 0.01f
+
+#define LEAVES_RADIUS 3
+#define WOOD_CELL_SIZE 13
+#define WOOD_CELL_CENTER 7
+#define TREE_STANDARD_HEIGHT 7
+#define TREE_HEIGHT_VARIATION 2
+#define WOOD_CELL_BORDER (LEAVES_RADIUS-1)
+#define WOOD_MAX_OFFSET (WOOD_CELL_SIZE-WOOD_CELL_CENTER-WOOD_CELL_BORDER)
 
-void generatePyramid(Chunk::Chunk *chunk);
 void generateNoise(Chunk::Chunk *chunk);
 void generateNoise3D(Chunk::Chunk *chunk);
-
-void generateChunk(Chunk::Chunk *chunk)
-{
-    generateNoise(chunk);
-}
-
-Block block;
+double evaluateNoise(OpenSimplexNoise::Noise noiseGen, double x, double y, double amplitude, double
+	frequency, double persistence, double lacunarity, int octaves);
+struct TreeCellInfo evaluateTreeCell(int wcx, int wcz);
 
 std::random_device dev;
 std::mt19937 mt(dev());
 OpenSimplexNoise::Noise noiseGen1(mt());
 OpenSimplexNoise::Noise noiseGen2(mt());
+OpenSimplexNoise::Noise noiseGenWood(mt());
 
+// Trees are generated by virtually dividing the world into cells. Each cell can contain exactly one
+// tree, with some offset in the position. Having a border in the cell ensures that no trees are generated in
+// adjacent blocks
+// 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 trunk_x_offset, trunk_z_offset;
+    // Global x,z position of the trunk
+    int trunk_x, trunk_z;
+    // 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 generateNoise(Chunk::Chunk *chunk)
 {
+    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
+    // Noise value at a given (x,z), position represents:
+    // Grass Noise LUT: Height of the terrain: when the grass is placed and the player will stand
+    // Dirt Noise LUT: How many blocks of dirt to place before there is stone
+    // Anything below (grass-level - dirt_height) will be stone
     for (int i = 0; i < grassNoiseLUT.size(); i++)
     {
-        grassNoiseLUT[i] = -1;
-        dirtNoiseLUT[i] = -1;
+	int bx = i / CHUNK_SIZE;
+	int bz = i % CHUNK_SIZE;
+
+	grassNoiseLUT[i] = GRASS_OFFSET + evaluateNoise(noiseGen1, cx+bx, cz+bz, NOISE_GRASS_MULT, 0.01, 0.35, 2.1, 5);
+	dirtNoiseLUT[i] = NOISE_DIRT_MIN + (int)((1 + noiseGen2.eval(cx+bx * NOISE_DIRT_X_MULT,
+			cz+bz * NOISE_DIRT_Z_MULT)) * NOISE_DIRT_MULT);
     }
 
-    Block block_prev{Block::AIR};
-    int block_prev_start{0};
+    // Tree LUT
+    int tree_lut_x_offset = cx / WOOD_CELL_SIZE - 1;
+    int tree_lut_z_offset = cz / WOOD_CELL_SIZE - 1;
 
-    // A space filling curve is continuous, so there is no particular order
+    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
+    // March along the space-filling curve, calculate information about the block at every position
+    // A space-filling curve is continuous, so there is no particular order
+    // Take advantage of the interval-map structure by only inserting contigous runs of blocks
+    Block block_prev{Block::AIR}, block;
+    int block_prev_start{0};
     for (int s = 0; s < CHUNK_VOLUME; s++)
     {
-
-        int x = HILBERT_XYZ_DECODE[s][0] + CHUNK_SIZE * chunk->getPosition().x;
-        int y = HILBERT_XYZ_DECODE[s][1] + CHUNK_SIZE * chunk->getPosition().y;
-        int z = HILBERT_XYZ_DECODE[s][2] + CHUNK_SIZE * chunk->getPosition().z;
-        int d2 = HILBERT_XYZ_DECODE[s][0] * CHUNK_SIZE + HILBERT_XYZ_DECODE[s][2];
-
-        if (grassNoiseLUT[d2] == -1){
-            grassNoiseLUT[d2] = GRASS_OFFSET + (int)((0.5 + noiseGen1.eval(x * NOISE_GRASS_X_MULT, z * NOISE_GRASS_Z_MULT) * NOISE_GRASS_MULT));
-	}
-        if (dirtNoiseLUT[d2] == -1){
-            dirtNoiseLUT[d2] = NOISE_DIRT_MIN + (int)((0.5 + noiseGen2.eval(x * NOISE_DIRT_X_MULT, z * NOISE_DIRT_Z_MULT) * NOISE_DIRT_MULT));
-	}
-
-        int grassNoise = grassNoiseLUT[d2];
-        int dirtNoise = dirtNoiseLUT[d2];
+	int bx = HILBERT_XYZ_DECODE[s][0];
+	int by = HILBERT_XYZ_DECODE[s][1];
+	int bz = HILBERT_XYZ_DECODE[s][2];
+        int x = bx + cx;
+        int y = by + cy;
+        int z = bz + cz;
+        int lut_index = bx * CHUNK_SIZE + bz;
+	
+        int grassNoise = grassNoiseLUT[lut_index];
+        int dirtNoise = dirtNoiseLUT[lut_index];
         int stoneLevel = grassNoise - dirtNoise;
 
         if (y < stoneLevel)
@@ -73,24 +122,116 @@ void generateNoise(Chunk::Chunk *chunk)
             block = Block::DIRT;
         else if (y == grassNoise)
             block = Block::GRASS;
-        else
+	    else
             block = Block::AIR;
 
+
+	// 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; // wood cell x
+	int wcz = (int)(z / WOOD_CELL_SIZE) - tree_lut_z_offset; // wood cell z
+
+	// Retrieve info on the cell from LUT
+	info = treeLUT[wcx * TREE_LUT_SIZE + wcz];
+
+	// 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.trunk_x && z == info.trunk_z && y > grassNoiseLUT[lut_index] && y <= info.leaves_y_pos;
+	bool leaf{false};
+
+	// 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.trunk_x, info.leaves_y_pos, info.trunk_z, 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.trunk_x, info.leaves_y_pos, info.trunk_z, LEAVES_RADIUS);
+	    }
+
+	    if(!leaf && wcx-1 >= 0){
+		info = treeLUT[(wcx-1) * TREE_LUT_SIZE + wcz];
+		leaf = utils::withinDistance(x,y,z, info.trunk_x, info.leaves_y_pos, info.trunk_z, LEAVES_RADIUS);
+	    }
+
+	    if(!leaf && wcz-1 >= 0){
+		info = treeLUT[wcx * TREE_LUT_SIZE + (wcz-1)];
+		leaf = utils::withinDistance(x,y,z, info.trunk_x, info.leaves_y_pos, info.trunk_z, LEAVES_RADIUS);
+	    }
+
+	    if(!leaf && wcz+1 < TREE_LUT_SIZE){
+		info = treeLUT[wcx * TREE_LUT_SIZE + (wcz+1)];
+		leaf = utils::withinDistance(x,y,z, info.trunk_x, info.leaves_y_pos, info.trunk_z, LEAVES_RADIUS);
+	    }
+	}
+
+	if(wood) block = Block::WOOD;
+	if(leaf) block = Block::LEAVES;
+
+	// Use the interval-map structure of the chunk to compress the world: insert "runs" of
+	// equal blocks using indices in the hilbert curve
         if (block != block_prev)
         {
             chunk->setBlocks(block_prev_start, s, block_prev);
             block_prev_start = s;
         }
-
         block_prev = block;
     }
-
+    // Insert the last run of blocks
     chunk->setBlocks(block_prev_start, CHUNK_VOLUME, block_prev);
+    // Mark the chunk as generated, is needed to trigger the next steps
     chunk->setState(Chunk::CHUNK_STATE_GENERATED, true);
 }
 
+// Noise evaluation with Fractal Brownian Motion
+double evaluateNoise(OpenSimplexNoise::Noise noiseGen, double x, double y, double amplitude, double
+	frequency, double persistence, double lacunarity, int octaves){
+    double sum = 0;
+
+    for(int i = 0; i < octaves; i++){
+	sum += amplitude * noiseGen.eval(x*frequency, y*frequency);
+	amplitude *= persistence;
+	frequency *= lacunarity;
+    }
+
+    return sum;
+}
+
+// Tree cell Info
+const int TREE_MASTER_SEED_X = mt();
+const int TREE_MASTER_SEED_Z = mt();
+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;
+
+	// Start at the center of the cell, with a bit of random offset
+	int wcx_off = WOOD_CELL_CENTER + WOOD_MAX_OFFSET * sines[anglex % 360];
+	int wcz_off = WOOD_CELL_CENTER + WOOD_MAX_OFFSET * cosines[anglez % 360];
+
+	struct TreeCellInfo result{};
+
+	// Cell to world coordinates
+	result.trunk_x = wcx * WOOD_CELL_SIZE + wcx_off;
+	result.trunk_z = wcz * WOOD_CELL_SIZE + wcz_off;
+
+	result.trunk_x_offset = wcx_off;
+	result.trunk_z_offset = wcz_off;
+
+	result.leaves_y_pos = 1 + TREE_STANDARD_HEIGHT + GRASS_OFFSET + evaluateNoise(noiseGen1,
+		result.trunk_x, result.trunk_z, NOISE_GRASS_MULT, 0.01, 0.35, 2.1, 5);
+
+	return result;
+}
+
+void generateChunk(Chunk::Chunk *chunk)
+{
+    generateNoise(chunk);
+}
+
+/* EXPERIMENTAL STUFF */
 void generateNoise3D(Chunk::Chunk *chunk) {
-    Block block_prev{Block::AIR};
+    Block block_prev{Block::AIR}, block;
     int block_prev_start{0};
 
     // A space filling curve is continuous, so there is no particular order
@@ -124,11 +265,3 @@ void generateNoise3D(Chunk::Chunk *chunk) {
 
     chunk->setBlocks(block_prev_start, CHUNK_VOLUME, block_prev);
 }
-
-void generatePyramid(Chunk::Chunk *chunk)
-{
-    for (int i = 0; i < CHUNK_SIZE; i++)
-        for (int j = 0; j < CHUNK_SIZE; j++)
-            for (int k = 0; k < CHUNK_SIZE; k++)
-                chunk->setBlock(i >= j && i < CHUNK_SIZE - j && k >= j && k < CHUNK_SIZE - j ? (j & 1) == 0 ? Block::GRASS : Block::STONE : Block::AIR, i, j, k);
-}

src/main.cpp

@@ -63,8 +63,12 @@ int main()
 
     std::cout << "Using GPU: " << glGetString(GL_VENDOR) << " " << glGetString(GL_RENDERER) << "\n";
 
-    SpaceFilling::initLUT();
     wireframe = false;
+    for(int i = 0; i < 360; i++){
+	sines[i] = sin(3.14 / 180 * i);
+	cosines[i] = cos(3.14 / 180 * i);
+    }
+    SpaceFilling::initLUT();
     renderer::init();
     std::thread chunkmanager_thread = chunkmanager::init();
 

src/renderer.cpp

@@ -26,7 +26,7 @@ namespace renderer{
 	theShader = new Shader{"shaders/shader-texture.gs", "shaders/shader-texture.vs", "shaders/shader-texture.fs"};
 
 	// Create 3d array texture
-	constexpr int layerCount = 3;
+	constexpr int layerCount = 5;
 	glGenTextures(1, &chunkTexture);
 	glBindTexture(GL_TEXTURE_2D_ARRAY, chunkTexture);
 	
@@ -38,6 +38,10 @@ namespace renderer{
 	glTexSubImage3D(GL_TEXTURE_2D_ARRAY, 0, 0, 0, 1, width, height, 1, GL_RGBA, GL_UNSIGNED_BYTE, texels1);
 	unsigned char *texels2 = stbi_load("textures/grass_top.png", &width, &height, &nrChannels, 0);
 	glTexSubImage3D(GL_TEXTURE_2D_ARRAY, 0, 0, 0, 2, width, height, 1, GL_RGB, GL_UNSIGNED_BYTE, texels2);
+	unsigned char *texels3 = stbi_load("textures/wood.png", &width, &height, &nrChannels, 0);
+	glTexSubImage3D(GL_TEXTURE_2D_ARRAY, 0, 0, 0, 3, width, height, 1, GL_RGBA, GL_UNSIGNED_BYTE, texels3);
+	unsigned char *texels4 = stbi_load("textures/leaves.png", &width, &height, &nrChannels, 0);
+	glTexSubImage3D(GL_TEXTURE_2D_ARRAY, 0, 0, 0, 4, width, height, 1, GL_RGBA, GL_UNSIGNED_BYTE, texels4);
 
 	glTexParameteri(GL_TEXTURE_2D_ARRAY,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
 	glTexParameteri(GL_TEXTURE_2D_ARRAY,GL_TEXTURE_MAG_FILTER,GL_NEAREST);