summaryrefslogtreecommitdiff
path: root/servers/rendering/renderer_scene_occlusion_cull.h
blob: 565b39309483bba8b0e11e46574e361194b23d95 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
/**************************************************************************/
/*  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;

	public:
		bool is_empty() const;
		virtual void clear();
		virtual void resize(const Size2i &p_size);

		void update_mips();

		_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 = Vector3(CLAMP(p_cam_position.x, p_bounds[0], p_bounds[3]), CLAMP(p_cam_position.y, p_bounds[1], p_bounds[4]), CLAMP(p_cam_position.z, p_bounds[2], 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.min(Vector2(1, 1));
			rect_min = rect_min.max(Vector2(0, 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;
		}

		RID get_debug_texture();

		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