summaryrefslogtreecommitdiff
path: root/gfx/gl/shadowMapper.cpp
blob: 177bd2298ffec885ef91baed3858bd8aafab6638 (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
#include "shadowMapper.h"
#include "camera.h"
#include "collections.h"
#include "game/gamestate.h"
#include "gfx/gl/shaders/fs-shadowDynamicPointInstWithTextures.h"
#include "gfx/gl/shaders/gs-commonShadowPoint.h"
#include "gfx/gl/shaders/gs-shadowDynamicPointInstWithTextures.h"
#include "gfx/gl/shaders/vs-shadowDynamicPoint.h"
#include "gfx/gl/shaders/vs-shadowDynamicPointInst.h"
#include "gfx/gl/shaders/vs-shadowDynamicPointInstWithTextures.h"
#include "gfx/gl/shaders/vs-shadowLandmass.h"
#include "gfx/gl/shadowStenciller.h"
#include "gfx/renderable.h"
#include "gl_traits.h"
#include "location.h"
#include "maths.h"
#include "sceneProvider.h"
#include "sceneShader.h"
#include "sorting.h"
#include <glm/gtc/type_ptr.hpp>
#include <glm/gtx/transform.hpp>
#include <glm/matrix.hpp>
#include <vector>

ShadowMapper::ShadowMapper(const TextureAbsCoord & s) :
	landmess {shadowLandmass_vs}, dynamicPointInst {shadowDynamicPointInst_vs},
	dynamicPointInstWithTextures {shadowDynamicPointInstWithTextures_vs, shadowDynamicPointInstWithTextures_gs,
			shadowDynamicPointInstWithTextures_fs},
	size {s}
{
	glBindTexture(GL_TEXTURE_2D_ARRAY, depthMap);
	glTexImage3D(
			GL_TEXTURE_2D_ARRAY, 0, GL_DEPTH_COMPONENT, size.x, size.y, 4, 0, GL_DEPTH_COMPONENT, GL_FLOAT, nullptr);
	glTexParameter(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameter(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameter(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
	glTexParameter(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
	static constexpr RGBA border {std::numeric_limits<RGBA::value_type>::infinity()};
	glTexParameter(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_BORDER_COLOR, border);

	glBindFramebuffer(GL_FRAMEBUFFER, depthMapFBO);
	glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, depthMap, 0);
	glDrawBuffer(GL_NONE);
	glReadBuffer(GL_NONE);
	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
		throw std::runtime_error("Framebuffer not complete!");
	}
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

constexpr std::array<GlobalDistance, ShadowMapper::SHADOW_BANDS + 1> shadowBands {
		1000,
		250000,
		750000,
		2500000,
		10000000,
};

std::vector<std::array<RelativePosition3D, 4>>
ShadowMapper::getBandViewExtents(const Camera & camera, const glm::mat4 & lightViewDir)
{
	std::vector<std::array<RelativePosition3D, 4>> bandViewExtents;
	for (const auto dist : shadowBands) {
		const auto extents = camera.extentsAtDist(dist);
		bandViewExtents.emplace_back(extents * [&lightViewDir, cameraPos = camera.getPosition()](const auto & e) {
			return glm::mat3(lightViewDir) * (e.xyz() - cameraPos);
		});
		if (std::none_of(extents.begin(), extents.end(), [targetDist = dist - 1](const auto & e) {
				return e.w > targetDist;
			})) {
			break;
		}
	}
	return bandViewExtents;
}

ShadowMapper::Definitions
ShadowMapper::update(const SceneProvider & scene, const Direction3D & dir, const Camera & camera) const
{
	glCullFace(GL_FRONT);
	glEnable(GL_DEPTH_TEST);

	shadowStenciller.setLightDirection(dir, up);
	for (const auto & [id, asset] : gameState->assets) {
		if (const auto r = std::dynamic_pointer_cast<const Renderable>(asset)) {
			r->updateStencil(shadowStenciller);
		}
	}

	glBindFramebuffer(GL_FRAMEBUFFER, depthMapFBO);
	glClear(GL_DEPTH_BUFFER_BIT);
	glViewport(0, 0, size.x, size.y);

	const auto lightViewDir = glm::lookAt({}, dir, up);
	const auto lightViewPoint = camera.getPosition();
	const auto bandViewExtents = getBandViewExtents(camera, lightViewDir);
	Definitions out;
	Sizes sizes;
	std::transform(bandViewExtents.begin(), std::prev(bandViewExtents.end()), std::next(bandViewExtents.begin()),
			std::back_inserter(out),
			[bands = bandViewExtents.size() - 2, &lightViewDir, &sizes](const auto & near, const auto & far) mutable {
				const auto extents_minmax = [extents = std::span {near.begin(), far.end()}](auto && comp) {
					const auto mm = std::minmax_element(extents.begin(), extents.end(), comp);
					return std::make_pair(comp.get(*mm.first), comp.get(*mm.second));
				};
				const std::array extents
						= {extents_minmax(CompareBy {0}), extents_minmax(CompareBy {1}), extents_minmax(CompareBy {2})};

				const auto lightProjection = [](const auto & x, const auto & y, const auto & z) {
					return glm::ortho(x.first, x.second, y.first, y.second, -z.second, -z.first);
				}(extents[0], extents[1], extents[2]);

				sizes.emplace_back(extents[0].second - extents[0].first, extents[1].second - extents[1].first,
						extents[2].second - extents[2].first);
				return lightProjection * lightViewDir;
			});
	for (const auto p : std::initializer_list<const ShadowProgram *> {
				 &landmess, &dynamicPoint, &dynamicPointInst, &dynamicPointInstWithTextures}) {
		p->setView(out, sizes, lightViewPoint);
	}
	scene.shadows(*this);

	glCullFace(GL_BACK);

	return out;
}

ShadowMapper::ShadowProgram::ShadowProgram(const Shader & vs) : Program {vs, commonShadowPoint_gs} { }

ShadowMapper::ShadowProgram::ShadowProgram(const Shader & vs, const Shader & gs, const Shader & fs) :
	Program {vs, gs, fs}
{
}

void
ShadowMapper::ShadowProgram::setView(const std::span<const glm::mat4x4> viewProjection,
		const std::span<const RelativePosition3D> sizes, const GlobalPosition3D viewPoint) const
{
	use();
	glUniform(viewPointLoc, viewPoint);
	glUniform(viewProjectionLoc, viewProjection);
	if (sizesLoc) {
		glUniform(sizesLoc, sizes);
	}
	glUniform(viewProjectionsLoc, static_cast<GLint>(viewProjection.size()));
}

void
ShadowMapper::ShadowProgram::use() const
{
	glUseProgram(*this);
}

ShadowMapper::DynamicPoint::DynamicPoint() : ShadowProgram {shadowDynamicPoint_vs} { }

void
ShadowMapper::DynamicPoint::use(const Location & location) const
{
	glUseProgram(*this);
	setModel(location);
}

void
ShadowMapper::DynamicPoint::setModel(const Location & location) const
{
	glUniform(modelLoc, location.getRotationTransform());
	glUniform(modelPosLoc, location.pos);
}