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source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/SkyPreetham.cpp @ 3193

Revision 3193, 11.4 KB checked in by mattausch, 16 years ago (diff)
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1	#include "SkyPreetham.h"
2	#include "common.h"
3	#include "Vector3.h"
4	#include "SceneEntity.h"
5	#include "Transform3.h"
6	#include "Camera.h"
7	#include "RenderState.h"
8	#include "ShaderProgram.h"
9	#include "Shape.h"
10	#include "Material.h"
11	#include "ShaderManager.h"
12
13
14
15	#ifdef _CRT_SET
16	#define _CRTDBG_MAP_ALLOC
17	#include <stdlib.h>
18	#include <crtdbg.h>
19
20	// redefine new operator
21	#define DEBUG_NEW new(_NORMAL_BLOCK, __FILE__, __LINE__)
22	#define new DEBUG_NEW
23	#endif
24
25
26
27
28	using namespace CHCDemoEngine;
29	using namespace std;
30
31
32
33	inline float CBQ(float x)
34	{
35	return x * x * x;
36	}
37
38
39	inline float SQR(float x)
40	{
41	return x * x ;
42	}
43
44
45	void SkyPreetham::InitCG()
46	{
47	mSkyVtxProgram =
48	ShaderManager::GetSingleton()->CreateVertexProgram("sky_preetham", "default_vs", "skyVtx");
49
50	if (mSkyVtxProgram->IsValid())
51	{
52	mSkyVtxProgram->AddParameter("lightDir", 0);
53	mSkyVtxProgram->AddParameter("thetaSun", 1);
54	mSkyVtxProgram->AddParameter("zenithColor", 2);
55	mSkyVtxProgram->AddParameter("aColor", 3);
56	mSkyVtxProgram->AddParameter("bColor", 4);
57	mSkyVtxProgram->AddParameter("cColor", 5);
58	mSkyVtxProgram->AddParameter("dColor", 6);
59	mSkyVtxProgram->AddParameter("eColor", 7);
60	mSkyVtxProgram->AddParameter("multiplier", 8);
61	}
62	else
63	cerr << "sky program failed to load" << endl;
64
65	mSkyFragProgram =
66	ShaderManager::GetSingleton()->CreateFragmentProgram("sky_preetham", "frag_skydome", "skyFragMrt");
67	}
68
69
70	SkyPreetham::SkyPreetham(float turbitity, SceneEntity *skyDome):
71	mSkyDome(skyDome),
72	mTurbidity(turbitity)
73	//, mSunQuad(NULL)
74	{
75	CreateSunQuad();
76	Shape *shape = mSkyDome->GetShape(0);
77
78	InitCG();
79
80	Material *mat = shape->GetMaterial();
81
82	mat->GetTechnique(0)->SetFragmentProgram(mSkyFragProgram);
83	mat->GetTechnique(0)->SetVertexProgram(mSkyVtxProgram);
84
85	mat->GetTechnique(1)->SetFragmentProgram(mSkyFragProgram);
86	mat->GetTechnique(1)->SetVertexProgram(mSkyVtxProgram);
87	}
88
89
90	SkyPreetham::~SkyPreetham()
91	{
92	//DEL_PTR(mSunQuad);
93	}
94
95
96	void SkyPreetham::RenderSkyDome(const Vector3 &sunDir,
97	Camera *camera,
98	RenderState *state,
99	bool scaleToRange)
100	{
101	pair<float, float> sun_theta;
102	Vector3 zenithColor;
103	vector<Vector3> ABCDE;
104
105	ComputeFactors(sunDir, zenithColor, ABCDE, sun_theta);
106
107	// Move skybox with camera.
108	Vector3 position = camera->GetPosition();
109
110	const float scaleFactor = 80.0f;
111	//const float scaleFactor = 5.0f;
112
113	position.z -= 3.0f * scaleFactor;
114	Matrix4x4 m = TranslationMatrix(position);
115
116	Matrix4x4 s = ScaleMatrix(scaleFactor, scaleFactor, scaleFactor);
117	mSkyDome->GetTransform()->SetMatrix(s * m);
118
119	Material *mat = mSkyDome->GetShape(0)->GetMaterial();
120
121	Technique *tech;
122
123	tech = mat->GetTechnique(state->GetRenderTechnique());
124
125	GPUProgramParameters *vtxParams = tech->GetVertexProgramParameters();
126
127	vtxParams->SetValue3f(0, sunDir.x, sunDir.y, sunDir.z);
128	vtxParams->SetValue2f(1, sun_theta.first, sun_theta.second);
129	vtxParams->SetValue3f(2, zenithColor.x, zenithColor.y, zenithColor.z);
130
131	vtxParams->SetValue3f(3, ABCDE[0].x, ABCDE[0].y, ABCDE[0].z);
132	vtxParams->SetValue3f(4, ABCDE[1].x, ABCDE[1].y, ABCDE[1].z);
133	vtxParams->SetValue3f(5, ABCDE[2].x, ABCDE[2].y, ABCDE[2].z);
134	vtxParams->SetValue3f(6, ABCDE[3].x, ABCDE[3].y, ABCDE[3].z);
135	vtxParams->SetValue3f(7, ABCDE[4].x, ABCDE[4].y, ABCDE[4].z);
136
137
138	if (!scaleToRange)
139	{
140	// use tone mapping
141	vtxParams->SetValue1f(8, 1.0f);
142	}
143	else
144	{
145	// no tone mapping => linearily scale to displayable dynamic range
146	vtxParams->SetValue1f(8, 8e-5f);
147	}
148
149	// render sky dome
150	mSkyDome->Render(state);
151
152	// render additively blended sun disc.
153	//RenderSunDisk(sunDir, camera);
154	}
155
156
157	void SkyPreetham::RenderSunDisk(const Vector3 &sunDir, Camera *camera)
158	{
159	#if TODO
160	// Move skybox with camera.
161	Vector3 position = camera->GetPosition();
162
163	const float scaleFactor = 100.0f;
164	position.z -= 10 * scaleFactor;
165
166	// Set world matrix to sun disc position.
167	Matrix4x4 sunPos = TranslationMatrix(position);
168
169	Vector3 ndir = -Normalize(sunDir);
170
171	const float pitch = -atan2(ndir.x, ndir.y);
172	const float yaw = atan2(ndir.z, sqrt((ndir.x * ndir.x) + (ndir.y * ndir.y)));
173
174	Matrix4x4 roty = RotationYMatrix(pitch);
175	Matrix4x4 rotx = RotationXMatrix(yaw);
176
177	sunPos *= roty;
178	sunPos *= rotx;;
179
180	sunposition.rotateAroundY(-D().getScene().getLight().getHorizontalOrientation() + 90.0f);
181	sunposition.rotateAroundX(-D().getScene().getLight().getVerticalOrientation());
182
183	glMatrixMode(GL_MODELVIEW);
184	glMultMatrixf((float *)sunPos.x);
185
186	float ambient[] = {1.0f, 1.0f, 1.0f, 1.0f};
187
188	glMaterialfv(GL_FRONT, GL_AMBIENT, ambient);
189
190	Float size = 0.5f + (1.0f - lightdirection.y) * 0.5f;
191
192	mSunEffect->setVariableVector3("LightDiffuseColor", D().getScene().getLight().getDiffuseColor());
193	mSunEffect->setVariableFloat("SunSize", size);
194	mSunEffect->setVariableTexture2D("SunTexture", mSunTexture);
195
196	mSunEffect->activate();
197
198	mSunQuad->render();
199
200	mSunEffect->deactivate();
201	F().getRenderDevice().setDefaultBlendingMode(FRenderDevice::BLENDING_NONE);
202
203	glPopMatrix();
204	#endif
205	}
206
207
208	void SkyPreetham::CreateSunQuad()
209	{
210	#if TODO
211	mSunQuad = new FVertexBuffer();
212	mSunQuad->setupPrimitiveType(FVertexBuffer::PRIMITIVES_TRIANGLES);
213	mSunQuad->setupVertexFormat(3, 0, 0, true);
214	mSunQuad->setupTexCoordSet(0, 2);
215	mSunQuad->setVertexBufferSize(4, 6);
216
217	mSunQuad->setVertexPosition(0, FVector3(-0.1f, 0.1f, 1.0f));
218	mSunQuad->setVertexPosition(1, FVector3( 0.1f, 0.1f, 1.0f));
219	mSunQuad->setVertexPosition(2, FVector3(-0.1f, -0.1f, 1.0f));
220	mSunQuad->setVertexPosition(3, FVector3( 0.1f, -0.1f, 1.0f));
221	mSunQuad->setVertexTexCoord(0, 0, FVector2(0.0f, 0.0f));
222	mSunQuad->setVertexTexCoord(1, 0, FVector2(1.0f, 0.0f));
223	mSunQuad->setVertexTexCoord(2, 0, FVector2(0.0f, 1.0f));
224	mSunQuad->setVertexTexCoord(3, 0, FVector2(1.0f, 1.0f));
225
226	mSunQuad->setIndex(0, 0);
227	mSunQuad->setIndex(1, 1);
228	mSunQuad->setIndex(2, 2);
229	mSunQuad->setIndex(3, 2);
230	mSunQuad->setIndex(4, 1);
231	mSunQuad->setIndex(5, 3);
232	#endif
233	}
234
235
236	void SkyPreetham::ComputeFactors(const Vector3 &sunDir,
237	Vector3 &zenithColor,
238	vector<Vector3> &ABCDE,
239	std::pair<float, float> &sunThetha) const
240	{
241	sunThetha.first = acos(sunDir.z);
242
243	const float cos_theta = cos(sunThetha.first);
244	sunThetha.second = cos_theta * cos_theta;
245
246	zenithColor.x = ( 0.00165f * CBQ(sunThetha.first) - 0.00374f * SQR(sunThetha.first) + 0.00208f * sunThetha.first + 0.0f) * SQR(mTurbidity) +
247	(-0.02902f * CBQ(sunThetha.first) + 0.06377f * SQR(sunThetha.first) - 0.03202f * sunThetha.first + 0.00394f) * mTurbidity +
248	( 0.11693f * CBQ(sunThetha.first) - 0.21196f * SQR(sunThetha.first) + 0.06052f * sunThetha.first + 0.25885f);
249
250	zenithColor.y = ( 0.00275f * CBQ(sunThetha.first) - 0.00610f * SQR(sunThetha.first) + 0.00316f * sunThetha.first + 0.0f) * SQR(mTurbidity) +
251	(-0.04214f * CBQ(sunThetha.first) + 0.08970f * SQR(sunThetha.first) - 0.04153f * sunThetha.first + 0.00515f) * mTurbidity +
252	( 0.15346f * CBQ(sunThetha.first) - 0.26756f * SQR(sunThetha.first) + 0.06669f * sunThetha.first + 0.26688f);
253
254	zenithColor.z = (float)((4.0453f * mTurbidity - 4.9710f) * tan((4.0f / 9.0f - mTurbidity / 120.0f) *
255	(M_PI - 2.0f * sunThetha.first)) - 0.2155f * mTurbidity + 2.4192f);
256
257	// convert kcd/m² to cd/m²
258	zenithColor.z *= 1000.0f;
259
260	ABCDE.push_back(Vector3(-0.01925 * mTurbidity - 0.25922, -0.01669 * mTurbidity - 0.26078, 0.17872 * mTurbidity - 1.46303));
261	ABCDE.push_back(Vector3(-0.06651 * mTurbidity + 0.00081, -0.09495 * mTurbidity + 0.00921, -0.35540 * mTurbidity + 0.42749));
262	ABCDE.push_back(Vector3(-0.00041 * mTurbidity + 0.21247, -0.00792 * mTurbidity + 0.21023, -0.02266 * mTurbidity + 5.32505));
263	ABCDE.push_back(Vector3(-0.06409 * mTurbidity - 0.89887, -0.04405 * mTurbidity - 1.65369, 0.12064 * mTurbidity - 2.57705));
264	ABCDE.push_back(Vector3(-0.00325 * mTurbidity + 0.04517, -0.01092 * mTurbidity + 0.05291, -0.06696 * mTurbidity + 0.37027));
265	}
266
267
268	void SkyPreetham::ComputeSunColor(const Vector3 &sunDir,
269	Vector3 &ambient,
270	Vector3 &diffuse,
271	bool scaleToRange) const
272	{
273	// sunDir is sun direction
274	// ambient color: shadow color
275	// diffuse color: sun color
276	pair<float, float> sun_theta;
277
278	Vector3 zenithColor;
279	vector<Vector3> ABCDE;
280
281	ComputeFactors(sunDir, zenithColor, ABCDE, sun_theta);
282
283	Vector3 zenith_XYZ;
284
285	zenith_XYZ.x = (zenithColor.x / zenithColor.y) * zenithColor.z;
286	zenith_XYZ.y = zenithColor.z;
287	zenith_XYZ.z = ((1.0f - zenithColor.x - zenithColor.y) / zenithColor.y) * zenithColor.z;
288
289	ambient.x = 3.240479f * zenith_XYZ.x - 1.537150f * zenith_XYZ.y - 0.498535f * zenith_XYZ.z;
290	ambient.y = -0.969256f * zenith_XYZ.x + 1.875992f * zenith_XYZ.y + 0.041556f * zenith_XYZ.z;
291	ambient.z = 0.055648f * zenith_XYZ.x - 0.204043f * zenith_XYZ.y + 1.057311f * zenith_XYZ.z;
292
293	// downscale ambient color
294	if (scaleToRange)
295	ambient *= 8e-6f;
296	else
297	ambient *= 1e-1f;
298
299	// simulate the sun intensity by modulating the ambient term.
300	ambient = (10.0f - 9.0f DotProd(sunDir, Vector3::UNIT_Z()));
301
302
303	Vector3 num;
304
305	num.x = (1.0f + ABCDE[0].x * exp(ABCDE[1].x / sunDir.z)) * (1.0f + ABCDE[2].x)+ ABCDE[4].x;
306	num.y = (1.0f + ABCDE[0].y * exp(ABCDE[1].y / sunDir.z)) * (1.0f + ABCDE[2].y)+ ABCDE[4].y;
307	num.z = (1.0f + ABCDE[0].z * exp(ABCDE[1].z / sunDir.z)) * (1.0f + ABCDE[2].z)+ ABCDE[4].z;
308
309	Vector3 den;
310
311	den.x = (1.0f + ABCDE[0].x * exp(ABCDE[1].x)) * (1.0f + ABCDE[2].x * exp(ABCDE[3].x * sun_theta.first) + ABCDE[4].x * sun_theta.second);
312	den.y = (1.0f + ABCDE[0].y * exp(ABCDE[1].y)) * (1.0f + ABCDE[2].y * exp(ABCDE[3].y * sun_theta.first) + ABCDE[4].y * sun_theta.second);
313	den.z = (1.0f + ABCDE[0].z * exp(ABCDE[1].z)) * (1.0f + ABCDE[2].z * exp(ABCDE[3].z * sun_theta.first) + ABCDE[4].z * sun_theta.second);
314
315
316	Vector3 xyY = zenithColor * num / den;
317
318	Vector3 XYZ;
319
320	XYZ.x = (xyY.x / xyY.y) * xyY.z;
321	XYZ.y = xyY.z;
322	XYZ.z = ((1.0f - xyY.x - xyY.y) / xyY.y) * xyY.z;
323
324
325	/////////////
326	//-- transform to rgb
327
328	Vector3 color;
329	color.x = 3.240479f * XYZ.x - 1.537150f * XYZ.y - 0.498535f * XYZ.z;
330	color.y = -0.969256f * XYZ.x + 1.875992f * XYZ.y + 0.041556f *XYZ.z;
331	color.z = 0.055648f * XYZ.x - 0.204043f * XYZ.y + 1.057311f * XYZ.z;
332
333	// calculate final sun diffuse color.
334	if (scaleToRange)
335	diffuse = color * 3e-5f;
336	else
337	diffuse = color * 3e-1f;
338
339	// diffuse component should be more saturated (and less blueish) for high sun positions
340	diffuse.x *= 1.3f;
341	diffuse.z *= 0.7f;
342
343	// scale diffuse component in order to make sky look less bright in relation to
344	// the geometry in the evening
345	diffuse = (2.0f - 1.0f DotProd(sunDir, Vector3::UNIT_Z()));
346
347	//cout << "diffuse: " << Magnitude(diffuse) << " ambient: " << Magnitude(ambient) << endl;
348	}

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