godot/servers/rendering/renderer_scene_occlusion_cull.h
2024-09-20 08:09:48 -05:00

241 lines
8.5 KiB
C++

/**************************************************************************/
/* renderer_scene_occlusion_cull.h */
/**************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/**************************************************************************/
#ifndef RENDERER_SCENE_OCCLUSION_CULL_H
#define RENDERER_SCENE_OCCLUSION_CULL_H
#include "core/math/projection.h"
#include "core/templates/local_vector.h"
#include "servers/rendering_server.h"
class RendererSceneOcclusionCull {
protected:
static RendererSceneOcclusionCull *singleton;
public:
class HZBuffer {
protected:
static const Vector3 corners[8];
LocalVector<float> data;
LocalVector<Size2i> sizes;
LocalVector<float *> mips;
RID debug_texture;
Ref<Image> debug_image;
PackedByteArray debug_data;
float debug_tex_range = 0.0f;
uint64_t occlusion_frame = 0;
Size2i occlusion_buffer_size;
_FORCE_INLINE_ bool _is_occluded(const real_t p_bounds[6], const Vector3 &p_cam_position, const Transform3D &p_cam_inv_transform, const Projection &p_cam_projection, real_t p_near) const {
if (is_empty()) {
return false;
}
Vector3 closest_point = p_cam_position.clamp(Vector3(p_bounds[0], p_bounds[1], p_bounds[2]), Vector3(p_bounds[3], p_bounds[4], p_bounds[5]));
if (closest_point == p_cam_position) {
return false;
}
Vector3 closest_point_view = p_cam_inv_transform.xform(closest_point);
if (closest_point_view.z > -p_near) {
return false;
}
float min_depth = -closest_point_view.z * 0.95f;
Vector2 rect_min = Vector2(FLT_MAX, FLT_MAX);
Vector2 rect_max = Vector2(FLT_MIN, FLT_MIN);
for (int j = 0; j < 8; j++) {
const Vector3 &c = RendererSceneOcclusionCull::HZBuffer::corners[j];
Vector3 nc = Vector3(1, 1, 1) - c;
Vector3 corner = Vector3(p_bounds[0] * c.x + p_bounds[3] * nc.x, p_bounds[1] * c.y + p_bounds[4] * nc.y, p_bounds[2] * c.z + p_bounds[5] * nc.z);
Vector3 view = p_cam_inv_transform.xform(corner);
Plane vp = Plane(view, 1.0);
Plane projected = p_cam_projection.xform4(vp);
float w = projected.d;
if (w < 1.0) {
rect_min = Vector2(0.0f, 0.0f);
rect_max = Vector2(1.0f, 1.0f);
break;
}
Vector2 normalized = Vector2(projected.normal.x / w * 0.5f + 0.5f, projected.normal.y / w * 0.5f + 0.5f);
rect_min = rect_min.min(normalized);
rect_max = rect_max.max(normalized);
}
rect_max = rect_max.minf(1);
rect_min = rect_min.maxf(0);
int mip_count = mips.size();
Vector2 screen_diagonal = (rect_max - rect_min) * sizes[0];
float size = MAX(screen_diagonal.x, screen_diagonal.y);
float l = Math::ceil(Math::log2(size));
int lod = CLAMP(l, 0, mip_count - 1);
const int max_samples = 512;
int sample_count = 0;
bool visible = true;
for (; lod >= 0; lod--) {
int w = sizes[lod].x;
int h = sizes[lod].y;
int minx = CLAMP(rect_min.x * w - 1, 0, w - 1);
int maxx = CLAMP(rect_max.x * w + 1, 0, w - 1);
int miny = CLAMP(rect_min.y * h - 1, 0, h - 1);
int maxy = CLAMP(rect_max.y * h + 1, 0, h - 1);
sample_count += (maxx - minx + 1) * (maxy - miny + 1);
if (sample_count > max_samples) {
return false;
}
visible = false;
for (int y = miny; y <= maxy; y++) {
for (int x = minx; x <= maxx; x++) {
float depth = mips[lod][y * w + x];
if (depth > min_depth) {
visible = true;
break;
}
}
if (visible) {
break;
}
}
if (!visible) {
return true;
}
}
return !visible;
}
public:
static bool occlusion_jitter_enabled;
bool is_empty() const;
virtual void clear();
virtual void resize(const Size2i &p_size);
void update_mips();
// Thin wrapper around _is_occluded(),
// allowing occlusion timers to delay the disappearance
// of objects to prevent flickering when using jittering.
_FORCE_INLINE_ bool is_occluded(const real_t p_bounds[6], const Vector3 &p_cam_position, const Transform3D &p_cam_inv_transform, const Projection &p_cam_projection, real_t p_near, uint64_t &r_occlusion_timeout) const {
bool occluded = _is_occluded(p_bounds, p_cam_position, p_cam_inv_transform, p_cam_projection, p_near);
// Special case, temporal jitter disabled,
// so we don't use occlusion timers.
if (!occlusion_jitter_enabled) {
return occluded;
}
if (!occluded) {
//#define DEBUG_RASTER_OCCLUSION_JITTER
#ifdef DEBUG_RASTER_OCCLUSION_JITTER
r_occlusion_timeout = occlusion_frame + 1;
#else
r_occlusion_timeout = occlusion_frame + 9;
#endif
} else if (r_occlusion_timeout) {
// Regular timeout, allow occlusion culling
// to proceed as normal after the delay.
if (occlusion_frame >= r_occlusion_timeout) {
r_occlusion_timeout = 0;
}
}
return occluded && !r_occlusion_timeout;
}
RID get_debug_texture();
const Size2i &get_occlusion_buffer_size() const { return occlusion_buffer_size; }
virtual ~HZBuffer() {}
};
static RendererSceneOcclusionCull *get_singleton() { return singleton; }
void _print_warning() {
WARN_PRINT_ONCE("Occlusion culling is disabled at build-time.");
}
virtual bool is_occluder(RID p_rid) { return false; }
virtual RID occluder_allocate() { return RID(); }
virtual void occluder_initialize(RID p_occluder) {}
virtual void free_occluder(RID p_occluder) { _print_warning(); }
virtual void occluder_set_mesh(RID p_occluder, const PackedVector3Array &p_vertices, const PackedInt32Array &p_indices) { _print_warning(); }
virtual void add_scenario(RID p_scenario) {}
virtual void remove_scenario(RID p_scenario) {}
virtual void scenario_set_instance(RID p_scenario, RID p_instance, RID p_occluder, const Transform3D &p_xform, bool p_enabled) { _print_warning(); }
virtual void scenario_remove_instance(RID p_scenario, RID p_instance) { _print_warning(); }
virtual void add_buffer(RID p_buffer) { _print_warning(); }
virtual void remove_buffer(RID p_buffer) { _print_warning(); }
virtual HZBuffer *buffer_get_ptr(RID p_buffer) {
return nullptr;
}
virtual void buffer_set_scenario(RID p_buffer, RID p_scenario) { _print_warning(); }
virtual void buffer_set_size(RID p_buffer, const Vector2i &p_size) { _print_warning(); }
virtual void buffer_update(RID p_buffer, const Transform3D &p_cam_transform, const Projection &p_cam_projection, bool p_cam_orthogonal) {}
virtual RID buffer_get_debug_texture(RID p_buffer) {
_print_warning();
return RID();
}
virtual void set_build_quality(RS::ViewportOcclusionCullingBuildQuality p_quality) {}
RendererSceneOcclusionCull() {
singleton = this;
};
virtual ~RendererSceneOcclusionCull() {
singleton = nullptr;
};
};
#endif // RENDERER_SCENE_OCCLUSION_CULL_H