godot/modules/jolt_physics/shapes/jolt_custom_ray_shape.cpp
Mikael Hermansson d470c2ac6a Add Jolt Physics as an alternative 3D physics engine
Co-authored-by: Jorrit Rouwe <jrouwe@gmail.com>
2024-12-11 13:57:25 +01:00

233 lines
11 KiB
C++

/**************************************************************************/
/* jolt_custom_ray_shape.cpp */
/**************************************************************************/
/* This file is part of: */
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
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#include "jolt_custom_ray_shape.h"
#include "../spaces/jolt_query_collectors.h"
#include "Jolt/Physics/Collision/CastResult.h"
#include "Jolt/Physics/Collision/RayCast.h"
#include "Jolt/Physics/Collision/TransformedShape.h"
#ifdef JPH_DEBUG_RENDERER
#include "Jolt/Renderer/DebugRenderer.h"
#endif
namespace {
class JoltCustomRayShapeSupport final : public JPH::ConvexShape::Support {
public:
explicit JoltCustomRayShapeSupport(float p_length) :
length(p_length) {}
virtual JPH::Vec3 GetSupport(JPH::Vec3Arg p_direction) const override {
if (p_direction.GetZ() > 0.0f) {
return JPH::Vec3(0.0f, 0.0f, length);
} else {
return JPH::Vec3::sZero();
}
}
virtual float GetConvexRadius() const override { return 0.0f; }
private:
float length = 0.0f;
};
static_assert(sizeof(JoltCustomRayShapeSupport) <= sizeof(JPH::ConvexShape::SupportBuffer), "Size of SeparationRayShape3D support is larger than size of support buffer.");
JPH::Shape *construct_ray() {
return new JoltCustomRayShape();
}
void collide_ray_vs_shape(const JPH::Shape *p_shape1, const JPH::Shape *p_shape2, JPH::Vec3Arg p_scale1, JPH::Vec3Arg p_scale2, JPH::Mat44Arg p_center_of_mass_transform1, JPH::Mat44Arg p_center_of_mass_transform2, const JPH::SubShapeIDCreator &p_sub_shape_id_creator1, const JPH::SubShapeIDCreator &p_sub_shape_id_creator2, const JPH::CollideShapeSettings &p_collide_shape_settings, JPH::CollideShapeCollector &p_collector, const JPH::ShapeFilter &p_shape_filter) {
ERR_FAIL_COND(p_shape1->GetSubType() != JoltCustomShapeSubType::RAY);
const JoltCustomRayShape *shape1 = static_cast<const JoltCustomRayShape *>(p_shape1);
const float margin = p_collide_shape_settings.mMaxSeparationDistance;
const float ray_length = shape1->length;
const float ray_length_padded = ray_length + margin;
const JPH::Mat44 transform1 = p_center_of_mass_transform1 * JPH::Mat44::sScale(p_scale1);
const JPH::Mat44 transform2 = p_center_of_mass_transform2 * JPH::Mat44::sScale(p_scale2);
const JPH::Mat44 transform_inv2 = transform2.Inversed();
const JPH::Vec3 ray_start = transform1.GetTranslation();
const JPH::Vec3 ray_direction = transform1.GetAxisZ();
const JPH::Vec3 ray_vector = ray_direction * ray_length;
const JPH::Vec3 ray_vector_padded = ray_direction * ray_length_padded;
const JPH::Vec3 ray_start2 = transform_inv2 * ray_start;
const JPH::Vec3 ray_direction2 = transform_inv2.Multiply3x3(ray_direction);
const JPH::Vec3 ray_vector_padded2 = transform_inv2.Multiply3x3(ray_vector_padded);
const JPH::RayCast ray_cast(ray_start2, ray_vector_padded2);
JPH::RayCastSettings ray_cast_settings;
ray_cast_settings.mTreatConvexAsSolid = false;
ray_cast_settings.mBackFaceModeTriangles = p_collide_shape_settings.mBackFaceMode;
JoltQueryCollectorClosest<JPH::CastRayCollector> ray_collector;
p_shape2->CastRay(ray_cast, ray_cast_settings, p_sub_shape_id_creator2, ray_collector);
if (!ray_collector.had_hit()) {
return;
}
const JPH::RayCastResult &hit = ray_collector.get_hit();
const float hit_distance = ray_length_padded * hit.mFraction;
const float hit_depth = ray_length - hit_distance;
if (-hit_depth >= p_collector.GetEarlyOutFraction()) {
return;
}
// Since `hit.mSubShapeID2` could represent a path not only from `p_shape2` but also any
// compound shape that it's contained within, we need to split this path into something that
// `p_shape2` can actually understand.
JPH::SubShapeID local_sub_shape_id2;
hit.mSubShapeID2.PopID(p_sub_shape_id_creator2.GetNumBitsWritten(), local_sub_shape_id2);
const JPH::Vec3 hit_point2 = ray_cast.GetPointOnRay(hit.mFraction);
const JPH::Vec3 hit_point_on_1 = ray_start + ray_vector;
const JPH::Vec3 hit_point_on_2 = transform2 * hit_point2;
JPH::Vec3 hit_normal2 = JPH::Vec3::sZero();
if (shape1->slide_on_slope) {
hit_normal2 = p_shape2->GetSurfaceNormal(local_sub_shape_id2, hit_point2);
// If we got a back-face normal we need to flip it.
if (hit_normal2.Dot(ray_direction2) > 0) {
hit_normal2 = -hit_normal2;
}
} else {
hit_normal2 = -ray_direction2;
}
const JPH::Vec3 hit_normal = transform2.Multiply3x3(hit_normal2);
JPH::CollideShapeResult result(hit_point_on_1, hit_point_on_2, -hit_normal, hit_depth, p_sub_shape_id_creator1.GetID(), hit.mSubShapeID2, JPH::TransformedShape::sGetBodyID(p_collector.GetContext()));
if (p_collide_shape_settings.mCollectFacesMode == JPH::ECollectFacesMode::CollectFaces) {
p_shape2->GetSupportingFace(local_sub_shape_id2, ray_direction2, p_scale2, p_center_of_mass_transform2, result.mShape2Face);
}
p_collector.AddHit(result);
}
void collide_noop(const JPH::Shape *p_shape1, const JPH::Shape *p_shape2, JPH::Vec3Arg p_scale1, JPH::Vec3Arg p_scale2, JPH::Mat44Arg p_center_of_mass_transform1, JPH::Mat44Arg p_center_of_mass_transform2, const JPH::SubShapeIDCreator &p_sub_shape_id_creator1, const JPH::SubShapeIDCreator &p_sub_shape_id_creator2, const JPH::CollideShapeSettings &p_collide_shape_settings, JPH::CollideShapeCollector &p_collector, const JPH::ShapeFilter &p_shape_filter) {
}
void cast_noop(const JPH::ShapeCast &p_shape_cast, const JPH::ShapeCastSettings &p_shape_cast_settings, const JPH::Shape *p_shape, JPH::Vec3Arg p_scale, const JPH::ShapeFilter &p_shape_filter, JPH::Mat44Arg p_center_of_mass_transform2, const JPH::SubShapeIDCreator &p_sub_shape_id_creator1, const JPH::SubShapeIDCreator &p_sub_shape_id_creator2, JPH::CastShapeCollector &p_collector) {
}
} // namespace
JPH::ShapeSettings::ShapeResult JoltCustomRayShapeSettings::Create() const {
if (mCachedResult.IsEmpty()) {
new JoltCustomRayShape(*this, mCachedResult);
}
return mCachedResult;
}
void JoltCustomRayShape::register_type() {
JPH::ShapeFunctions &shape_functions = JPH::ShapeFunctions::sGet(JoltCustomShapeSubType::RAY);
shape_functions.mConstruct = construct_ray;
shape_functions.mColor = JPH::Color::sDarkRed;
static constexpr JPH::EShapeSubType concrete_sub_types[] = {
JPH::EShapeSubType::Sphere,
JPH::EShapeSubType::Box,
JPH::EShapeSubType::Triangle,
JPH::EShapeSubType::Capsule,
JPH::EShapeSubType::TaperedCapsule,
JPH::EShapeSubType::Cylinder,
JPH::EShapeSubType::ConvexHull,
JPH::EShapeSubType::Mesh,
JPH::EShapeSubType::HeightField,
JPH::EShapeSubType::Plane,
JPH::EShapeSubType::TaperedCylinder
};
for (const JPH::EShapeSubType concrete_sub_type : concrete_sub_types) {
JPH::CollisionDispatch::sRegisterCollideShape(JoltCustomShapeSubType::RAY, concrete_sub_type, collide_ray_vs_shape);
JPH::CollisionDispatch::sRegisterCollideShape(concrete_sub_type, JoltCustomShapeSubType::RAY, JPH::CollisionDispatch::sReversedCollideShape);
}
JPH::CollisionDispatch::sRegisterCollideShape(JoltCustomShapeSubType::RAY, JoltCustomShapeSubType::RAY, collide_noop);
for (const JPH::EShapeSubType sub_type : JPH::sAllSubShapeTypes) {
JPH::CollisionDispatch::sRegisterCastShape(JoltCustomShapeSubType::RAY, sub_type, cast_noop);
JPH::CollisionDispatch::sRegisterCastShape(sub_type, JoltCustomShapeSubType::RAY, cast_noop);
}
}
JPH::AABox JoltCustomRayShape::GetLocalBounds() const {
const float radius = GetInnerRadius();
return JPH::AABox(JPH::Vec3(-radius, -radius, 0.0f), JPH::Vec3(radius, radius, length));
}
float JoltCustomRayShape::GetInnerRadius() const {
// There is no sensible value here, since this shape is infinitely thin, so we pick something
// that's hopefully small enough to effectively be zero, but big enough to not cause any
// numerical issues.
return 0.0001f;
}
JPH::MassProperties JoltCustomRayShape::GetMassProperties() const {
JPH::MassProperties mass_properties;
// Since this shape has no volume we can't really give it a correct set of mass properties, so
// instead we just give it some arbitrary ones.
mass_properties.mMass = 1.0f;
mass_properties.mInertia = JPH::Mat44::sIdentity();
return mass_properties;
}
#ifdef JPH_DEBUG_RENDERER
void JoltCustomRayShape::Draw(JPH::DebugRenderer *p_renderer, JPH::RMat44Arg p_center_of_mass_transform, JPH::Vec3Arg p_scale, JPH::ColorArg p_color, bool p_use_material_colors, bool p_draw_wireframe) const {
p_renderer->DrawArrow(p_center_of_mass_transform.GetTranslation(), p_center_of_mass_transform * JPH::Vec3(0, 0, length * p_scale.GetZ()), p_use_material_colors ? GetMaterial()->GetDebugColor() : p_color, 0.1f);
}
#endif
const JPH::ConvexShape::Support *JoltCustomRayShape::GetSupportFunction(JPH::ConvexShape::ESupportMode p_mode, JPH::ConvexShape::SupportBuffer &p_buffer, JPH::Vec3Arg p_scale) const {
return new (&p_buffer) JoltCustomRayShapeSupport(p_scale.GetZ() * length);
}