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low-hanging performance tweak, cache shapes for entries with identica…
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…l geometry
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@crocdialer
crocdialer committed Nov 25, 2024
1 parent 5112c6f commit 0fb4705
Showing 1 changed file with 62 additions and 40 deletions.
102 changes: 62 additions & 40 deletions src/physics_context.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -672,42 +672,53 @@ CollisionShapeId PhysicsContext::create_collision_shape(const mesh_buffer_bundle
{
JPH::StaticCompoundShapeSettings compound_shape_settings;

// avoid duplicates
std::map<std::tuple<uint32_t, uint32_t>, JPH::Ref<JPH::Shape>> shape_map;

for(const auto &entry: mesh_bundle.entries)
{
assert(!entry.lods.empty());
if(entry.lods.empty()) { continue; }
const auto &lod = entry.lods[std::min<uint32_t>(lod_bias, entry.lods.size() - 1)];

JPH::VertexList points(entry.num_vertices);
uint32_t num_triangles = lod.num_indices / 3;
JPH::IndexedTriangleList triangles(num_triangles);

auto data = mesh_bundle.vertex_buffer.data() + entry.vertex_offset * mesh_bundle.vertex_stride;
for(uint32_t i = 0; i < entry.num_vertices; ++i, data += mesh_bundle.vertex_stride)
auto shape_it = shape_map.find({entry.vertex_offset, lod.base_index});
if(shape_it == shape_map.end())
{
auto p = *reinterpret_cast<const glm::vec3 *>(data) * scale;
points[i] = {p.x, p.y, p.z};
}
for(uint32_t i = 0; i < num_triangles; i++)
{
uint32_t base_index = lod.base_index + 3 * i;
triangles[i] =
JPH::IndexedTriangle(mesh_bundle.index_buffer[base_index], mesh_bundle.index_buffer[base_index + 1],
mesh_bundle.index_buffer[base_index + 2], 0);
}
JPH::MeshShapeSettings mesh_shape_settings(points, triangles);
JPH::Shape::ShapeResult shape_result = mesh_shape_settings.Create();
JPH::VertexList points(entry.num_vertices);
uint32_t num_triangles = lod.num_indices / 3;
JPH::IndexedTriangleList triangles(num_triangles);

if(shape_result.IsValid())
{
auto scale_result = shape_result.Get()->ScaleShape(type_cast(entry.transform.scale));
auto data = mesh_bundle.vertex_buffer.data() + entry.vertex_offset * mesh_bundle.vertex_stride;
for(uint32_t i = 0; i < entry.num_vertices; ++i, data += mesh_bundle.vertex_stride)
{
auto p = *reinterpret_cast<const glm::vec3 *>(data) * scale;
points[i] = {p.x, p.y, p.z};
}
for(uint32_t i = 0; i < num_triangles; i++)
{
uint32_t base_index = lod.base_index + 3 * i;
triangles[i] = JPH::IndexedTriangle(mesh_bundle.index_buffer[base_index],
mesh_bundle.index_buffer[base_index + 1],
mesh_bundle.index_buffer[base_index + 2], 0);
}
JPH::MeshShapeSettings mesh_shape_settings(points, triangles);
JPH::Shape::ShapeResult shape_result = mesh_shape_settings.Create();

if(scale_result.IsValid())
if(shape_result.IsValid())
{
compound_shape_settings.AddShape(type_cast(entry.transform.translation),
type_cast(entry.transform.rotation), scale_result.Get());
auto [new_it, success] = shape_map.insert({{entry.vertex_offset, lod.base_index}, shape_result.Get()});
assert(success);
shape_it = new_it;
}
}

auto scale_result = shape_it->second->ScaleShape(type_cast(entry.transform.scale));

if(scale_result.IsValid())
{
compound_shape_settings.AddShape(type_cast(entry.transform.translation),
type_cast(entry.transform.rotation), scale_result.Get());
}
}

JPH::Shape::ShapeResult shape_result = compound_shape_settings.Create();
Expand All @@ -725,34 +736,45 @@ CollisionShapeId PhysicsContext::create_convex_collision_shape(const mesh_buffer
{
JPH::StaticCompoundShapeSettings compound_shape_settings;

// avoid duplicates
std::map<std::tuple<uint32_t, uint32_t>, JPH::Ref<JPH::Shape>> shape_map;

for(const auto &entry: mesh_bundle.entries)
{
assert(!entry.lods.empty());
if(entry.lods.empty()) { continue; }
const auto &lod = entry.lods[std::min<uint32_t>(lod_bias, entry.lods.size() - 1)];

JPH::Array<JPH::Vec3> points(lod.num_indices);

auto data = mesh_bundle.vertex_buffer.data() + entry.vertex_offset * mesh_bundle.vertex_stride;
auto indices = mesh_bundle.index_buffer.data() + lod.base_index;
for(uint32_t i = 0; i < lod.num_indices; ++i)
auto shape_it = shape_map.find({entry.vertex_offset, lod.base_index});
if(shape_it == shape_map.end())
{
auto v = *reinterpret_cast<const glm::vec3 *>(data + indices[i] * mesh_bundle.vertex_stride) * scale;
points[i] = {v.x, v.y, v.z};
}
JPH::Array<JPH::Vec3> points(lod.num_indices);

auto data = mesh_bundle.vertex_buffer.data() + entry.vertex_offset * mesh_bundle.vertex_stride;
auto indices = mesh_bundle.index_buffer.data() + lod.base_index;
for(uint32_t i = 0; i < lod.num_indices; ++i)
{
auto v = *reinterpret_cast<const glm::vec3 *>(data + indices[i] * mesh_bundle.vertex_stride) * scale;
points[i] = {v.x, v.y, v.z};
}

JPH::ConvexHullShapeSettings hull_shape_settings(points);
JPH::Shape::ShapeResult shape_result = hull_shape_settings.Create();
JPH::ConvexHullShapeSettings hull_shape_settings(points);
JPH::Shape::ShapeResult shape_result = hull_shape_settings.Create();

if(shape_result.IsValid())
{
auto scale_result = shape_result.Get()->ScaleShape(type_cast(entry.transform.scale));
if(scale_result.IsValid())
if(shape_result.IsValid())
{
compound_shape_settings.AddShape(type_cast(entry.transform.translation),
type_cast(entry.transform.rotation), scale_result.Get());
auto [new_it, success] = shape_map.insert({{entry.vertex_offset, lod.base_index}, shape_result.Get()});
assert(success);
shape_it = new_it;
}
}

auto scale_result = shape_it->second->ScaleShape(type_cast(entry.transform.scale));
if(scale_result.IsValid())
{
compound_shape_settings.AddShape(type_cast(entry.transform.translation),
type_cast(entry.transform.rotation), scale_result.Get());
}
}
JPH::Shape::ShapeResult shape_result = compound_shape_settings.Create();
if(shape_result.IsValid())
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