Terrain4J_Experimental_branch/resources/EngineResources/VoxelComputeShaders/meshGenerationShared.glsl

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7 KiB
GLSL

#version 460
layout(local_size_x = 4, local_size_y = 4, local_size_z = 4) in;
const int CHUNK_SIZE = 16;
const int CHUNK_AREA = CHUNK_SIZE * CHUNK_SIZE;
const int VOXEL_COUNT = CHUNK_SIZE * CHUNK_SIZE * CHUNK_SIZE;
const uint VERTICES_PER_FACE = 6u;
const uint MAX_VISIBLE_FACES_PER_CHUNK = uint(CHUNK_SIZE * CHUNK_SIZE * CHUNK_SIZE * 6);
layout(std430, binding = 0) readonly buffer VoxelData {
uint voxels[];
};
layout(std430, binding = 1) buffer FaceBuffer {
uint faces[];
};
struct DrawCommand {
uint vertexCount;
uint instanceCount;
uint firstVertex;
uint firstInstance;
};
layout(std430, binding = 2) buffer DrawCommands {
DrawCommand drawCmds[];
};
layout(std430, binding = 3) buffer Counters {
uint faceCount;
} counters;
struct Voxel {
uint MaterialIndex;
uint BlockType;
uvec2[2] UpIndex;
uvec2[2] DownIndex;
uvec2[2] NorthIndex;
uvec2[2] SouthIndex;
uvec2[2] EastIndex;
uvec2[2] WestIndex;
};
layout(std430, set = 1, binding = 0) readonly buffer VoxelUniform {
Voxel materials[];
} voxelReg;
layout(push_constant) uniform ChunkInfo {
ivec3 chunkPos;
int slot;
uint faceOffset;
uint voxelTypeCount;
uint indirectCommandIndex;
uint biomeCount;
uint structureCount;
uint worldSeed;
};
uint flatten(ivec3 pos) {
return uint((pos.x * CHUNK_AREA) + (pos.y * CHUNK_SIZE) + pos.z);
}
bool isSeeThrough(Voxel voxel, uint type) {
if (type == 0u || voxel.BlockType == 3u || type > voxelTypeCount) return true;
return voxelReg.materials[type - 1u].BlockType >= 1u;
}
uint getVoxel(ivec3 pos) {
if (pos.x < 0 || pos.x >= CHUNK_SIZE) return 0u;
if (pos.y < 0 || pos.y >= CHUNK_SIZE) return 0u;
if (pos.z < 0 || pos.z >= CHUNK_SIZE) return 0u;
return voxels[flatten(pos)];
}
uint hash21(uvec2 p) {
p = p * 1664525u + 1013904223u;
p.x += p.y * 1664525u;
p.y += p.x * 1664525u;
return p.x ^ (p.x >> 16);
}
uint pcg_hash(uint seed) {
uint state = seed * 747796405u + 289133645u;
uint word = ((state >> ((state >> 28u) + 4u)) ^ state) * 277803737u;
return (word >> 22u) ^ word;
}
uint randomRangeUint(uint seed, uint minVal, uint maxVal) {
uint range = maxVal - minVal + 1u;
return minVal + (pcg_hash(seed) % range);
}
uint random_1_to_3(vec2 uv, uint customSeed) {
uvec2 p = uvec2(floatBitsToUint(uv.x), floatBitsToUint(uv.y));
p.x ^= customSeed;
uint randInt = hash21(p);
return (randInt % 3u) + 1u;
}
uint packFace(uvec3 voxelPos, uint faceIndex, Voxel voxel) {
uint randomSeed = uint(voxelPos.x) * 73856093u ^ uint(voxelPos.z) * 19349663u;
uvec2 UpIndex = uvec2(randomRangeUint(randomSeed,voxel.UpIndex[0].x,voxel.UpIndex[1].x),randomRangeUint(randomSeed,voxel.UpIndex[0].y,voxel.UpIndex[1].y));
uvec2 DownIndex = uvec2(randomRangeUint(randomSeed,voxel.DownIndex[0].x,voxel.DownIndex[1].x),randomRangeUint(randomSeed,voxel.DownIndex[0].y,voxel.DownIndex[1].y));
uvec2 NorthIndex = uvec2(randomRangeUint(randomSeed,voxel.NorthIndex[0].x,voxel.NorthIndex[1].x),randomRangeUint(randomSeed,voxel.NorthIndex[0].y,voxel.NorthIndex[1].y));
uvec2 SouthIndex = uvec2(randomRangeUint(randomSeed,voxel.SouthIndex[0].x,voxel.SouthIndex[1].x),randomRangeUint(randomSeed,voxel.SouthIndex[0].y,voxel.SouthIndex[1].y));
uvec2 EastIndex = uvec2(randomRangeUint(randomSeed,voxel.EastIndex[0].x,voxel.EastIndex[1].x),randomRangeUint(randomSeed,voxel.EastIndex[0].y,voxel.EastIndex[1].y));
uvec2 WestIndex = uvec2(randomRangeUint(randomSeed,voxel.WestIndex[0].x,voxel.WestIndex[1].x),randomRangeUint(randomSeed,voxel.WestIndex[0].y,voxel.WestIndex[1].y));
uvec2 textureIndices[8] = uvec2[8](UpIndex, DownIndex, NorthIndex,
SouthIndex, EastIndex, WestIndex, NorthIndex,SouthIndex);
uvec2 tex = textureIndices[faceIndex];
uint textureIndexX = tex.x;
uint textureIndexY = tex.y;
uint materialId = voxel.MaterialIndex;
return (voxelPos.x & 0xFu) |
((voxelPos.y & 0xFu) << 4u) |
((voxelPos.z & 0xFu) << 8u) |
((faceIndex & 0x7u) << 12u) |
((materialId & 0x7FFu) << 15u) |
((textureIndexX & 0x7u) << 26u) |
((textureIndexY & 0x7u) << 29u);
}
uint packFace(uvec3 voxelPos, uint faceIndex, uint materialId) {
uint randomFaceValue = random_1_to_3(vec2(voxelPos.x, voxelPos.z),faceOffset);
uint textureIndexX = 0u;
uint textureIndexY = 0u;
if(materialId == 1u){
if(faceIndex == 0u){
textureIndexX = 0u;
textureIndexY = randomFaceValue;
} else if(faceIndex == 1u){
textureIndexX = 1u;
textureIndexY = 0u;
}
else{
textureIndexX = 0u;
textureIndexY = 0u;
}
} else if(materialId == 2u){
textureIndexX = 1u;
textureIndexY = 0u;
}else if(materialId == 3u){
textureIndexX = 1u;
textureIndexY = 0u;
}else if(materialId == 4u){
textureIndexX = 1u;
textureIndexY = randomFaceValue;
}else if(materialId == 5u){
textureIndexX = 2u;
textureIndexY = 3u;
}else if(materialId == 5u){
if (faceIndex == 0u || faceIndex == 1u){
textureIndexX = 2u;
textureIndexY = 1u;
} else{
textureIndexX = 2u;
textureIndexY = 2u;
}
}else if(materialId == 6u){
textureIndexX = 2u;
textureIndexY = 0u;
}
return (voxelPos.x & 0xFu) |
((voxelPos.y & 0xFu) << 4u) |
((voxelPos.z & 0xFu) << 8u) |
((faceIndex & 0x7u) << 12u) |
((materialId & 0x7FFu) << 15u) |
((textureIndexX & 0x7u) << 26u) |
((textureIndexY & 0x7u) << 29u);
}
void emitFace(ivec3 voxelPos, uint faceIndex, uint voxelType) {
if (voxelType == 0u || voxelType > voxelTypeCount) {
return;
}
uint localFace = atomicAdd(counters.faceCount, 1u);
if (localFace >= MAX_VISIBLE_FACES_PER_CHUNK) {
return;
}
Voxel voxel = voxelReg.materials[voxelType - 1u];
faces[faceOffset + localFace] = packFace(uvec3(voxelPos), faceIndex, voxel);
atomicAdd(drawCmds[indirectCommandIndex].vertexCount, VERTICES_PER_FACE);
}
void main() {
ivec3 pos = ivec3(gl_GlobalInvocationID.xyz);
if (pos.x >= CHUNK_SIZE || pos.y >= CHUNK_SIZE || pos.z >= CHUNK_SIZE) {
return;
}
uint current = getVoxel(pos);
if (current == 0u || current > voxelTypeCount) {
return;
}
Voxel voxel = voxelReg.materials[current - 1u];
if (voxel.BlockType == 1u) {
emitFace(pos, 6u, current);
emitFace(pos, 7u, current);
return;
}
if (isSeeThrough(voxel,getVoxel(pos + ivec3( 0, 1, 0)))) emitFace(pos, 0u, current);
if (isSeeThrough(voxel,getVoxel(pos + ivec3( 0, -1, 0)))) emitFace(pos, 1u, current);
if (isSeeThrough(voxel,getVoxel(pos + ivec3( 1, 0, 0)))) emitFace(pos, 2u, current);
if (isSeeThrough(voxel,getVoxel(pos + ivec3(-1, 0, 0)))) emitFace(pos, 3u, current);
if (isSeeThrough(voxel,getVoxel(pos + ivec3( 0, 0, 1)))) emitFace(pos, 4u, current);
if (isSeeThrough(voxel,getVoxel(pos + ivec3( 0, 0, -1)))) emitFace(pos, 5u, current);
}