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source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/SkyPreetham.cpp @ 2983

Revision 2983, 11.7 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
9	using namespace CHCDemoEngine;
10	using namespace std;
11
12
13
14	static CGprogram sCgSkyProgram = NULL;
15	static CGprogram sCgMrtFragmentSkyDomeProgram = NULL;
16
17
18	static CGparameter sLightDirParam;
19	static CGparameter sThetaSunParam;
20	static CGparameter sZenithColorParam;
21	static CGparameter sAColorParam;
22	static CGparameter sBColorParam;
23	static CGparameter sCColorParam;
24	static CGparameter sDColorParam;
25	static CGparameter sEColorParam;
26	static CGparameter sMultiplierParam;
27
28
29
30	inline float CBQ(float x)
31	{
32	return x * x * x;
33	}
34
35
36	inline float SQR(float x)
37	{
38	return x * x ;
39	}
40
41
42	void SkyPreetham::Init(CGcontext context)
43	{
44	sCgSkyProgram =
45	cgCreateProgramFromFile(context,
46	CG_SOURCE,
47	"src/shaders/sky_preetham.cg",
48	RenderState::sCgVertexProfile,
49	"default_vs",
50	NULL);
51
52	if (sCgSkyProgram != NULL)
53	{
54	cgGLLoadProgram(sCgSkyProgram);
55
56	sLightDirParam = cgGetNamedParameter(sCgSkyProgram, "lightDir");
57	sThetaSunParam = cgGetNamedParameter(sCgSkyProgram, "thetaSun");
58	sZenithColorParam = cgGetNamedParameter(sCgSkyProgram, "zenithColor");
59	sAColorParam = cgGetNamedParameter(sCgSkyProgram, "aColor");
60	sBColorParam = cgGetNamedParameter(sCgSkyProgram, "bColor");
61	sCColorParam = cgGetNamedParameter(sCgSkyProgram, "cColor");
62	sDColorParam = cgGetNamedParameter(sCgSkyProgram, "dColor");
63	sEColorParam = cgGetNamedParameter(sCgSkyProgram, "eColor");
64
65	sMultiplierParam = cgGetNamedParameter(sCgSkyProgram, "multiplier");
66	}
67	else
68	cerr << "sky program failed to load" << endl;
69
70	sCgMrtFragmentSkyDomeProgram =
71	cgCreateProgramFromFile(context,
72	CG_SOURCE,
73	"src/shaders/sky_preetham.cg",
74	RenderState::sCgFragmentProfile,
75	"frag_skydome",
76	NULL);
77
78	if (sCgMrtFragmentSkyDomeProgram != NULL)
79	{
80	cgGLLoadProgram(sCgMrtFragmentSkyDomeProgram);
81	//cgGLSetParameter1f(sMaxDepthParam, MAX_DEPTH_CONST / farDist);
82	}
83	else
84	cerr << "fragment skyprogram failed to load" << endl;
85	}
86
87
88	SkyPreetham::SkyPreetham(float turbitity, SceneEntity *skyDome):
89	mSkyDome(skyDome),
90	mTurbidity(turbitity)
91	//, mSunQuad(NULL)
92	{
93	CreateSunQuad();
94	}
95
96
97	SkyPreetham::~SkyPreetham()
98	{
99	//DEL_PTR(mSunQuad);
100	}
101
102
103	void SkyPreetham::RenderSkyDome(const Vector3 &sunDir,
104	Camera *camera,
105	RenderState *state,
106	bool scaleToRange)
107	{
108	pair<float, float> sun_theta;
109	Vector3 zenithColor;
110	vector<Vector3> ABCDE;
111	ComputeFactors(sunDir, zenithColor, ABCDE, sun_theta);
112
113	// Move skybox with camera.
114	Vector3 position = camera->GetPosition();
115
116	const float scaleFactor = 80.0f;
117	//const float scaleFactor = 5.0f;
118
119	position.z -= 3 * scaleFactor;
120	Matrix4x4 m = TranslationMatrix(position);
121
122	Matrix4x4 s = ScaleMatrix(scaleFactor, scaleFactor, scaleFactor);
123	mSkyDome->GetTransform()->SetMatrix(s * m);
124
125	cgGLSetParameter3f(sLightDirParam, sunDir.x, sunDir.y, sunDir.z);
126	cgGLSetParameter2f(sThetaSunParam, sun_theta.first, sun_theta.second);
127	cgGLSetParameter3f(sZenithColorParam, zenithColor.x, zenithColor.y, zenithColor.z);
128
129	cgGLSetParameter3f(sAColorParam, ABCDE[0].x, ABCDE[0].y, ABCDE[0].z);
130	cgGLSetParameter3f(sBColorParam, ABCDE[1].x, ABCDE[1].y, ABCDE[1].z);
131	cgGLSetParameter3f(sCColorParam, ABCDE[2].x, ABCDE[2].y, ABCDE[2].z);
132	cgGLSetParameter3f(sDColorParam, ABCDE[3].x, ABCDE[3].y, ABCDE[3].z);
133	cgGLSetParameter3f(sEColorParam, ABCDE[4].x, ABCDE[4].y, ABCDE[4].z);
134
135	if (state->GetRenderPassType() == RenderState::DEFERRED)
136	{
137	cgGLEnableProfile(RenderState::sCgFragmentProfile);
138	cgGLBindProgram(sCgMrtFragmentSkyDomeProgram);
139
140	}
141
142	if (!scaleToRange)
143	{
144	// use tone mapping
145	cgGLSetParameter1f(sMultiplierParam, 1.0f);
146	}
147	else
148	{
149	// no tone mapping => scale
150	cgGLSetParameter1f(sMultiplierParam, 8e-5f);
151	}
152
153	cgGLEnableProfile(RenderState::sCgVertexProfile);
154	cgGLBindProgram(sCgSkyProgram);
155
156	// Render sky dome.
157	mSkyDome->Render(state);
158
159	// Render additively blended sun disc.
160	//RenderSunDisk(sunDir, camera);
161
162	cgGLDisableProfile(RenderState::sCgFragmentProfile);
163	}
164
165
166	void SkyPreetham::RenderSunDisk(const Vector3 &sunDir, Camera *camera)
167	{
168	// Move skybox with camera.
169	Vector3 position = camera->GetPosition();
170
171	const float scaleFactor = 100.0f;
172	position.z -= 10 * scaleFactor;
173
174	// Set world matrix to sun disc position.
175	Matrix4x4 sunPos = TranslationMatrix(position);
176
177	Vector3 ndir = -Normalize(sunDir);
178
179	const float pitch = -atan2(ndir.x, ndir.y);
180	const float yaw = atan2(ndir.z, sqrt((ndir.x * ndir.x) + (ndir.y * ndir.y)));
181
182	Matrix4x4 roty = RotationYMatrix(pitch);
183	Matrix4x4 rotx = RotationXMatrix(yaw);
184
185	sunPos *= roty;
186	sunPos *= rotx;;
187
188	//sunposition.rotateAroundY(-D().getScene().getLight().getHorizontalOrientation() + 90.0f);
189	//sunposition.rotateAroundX(-D().getScene().getLight().getVerticalOrientation());
190
191	glMatrixMode(GL_MODELVIEW);
192	glMultMatrixf((float *)sunPos.x);
193
194	float ambient[] = {1.0f, 1.0f, 1.0f, 1.0f};
195
196	glMaterialfv(GL_FRONT, GL_AMBIENT, ambient);
197
198	//Float size = 0.5f + (1.0f - lightdirection.y) * 0.5f;
199
200	//mSunEffect->setVariableVector3("LightDiffuseColor", D().getScene().getLight().getDiffuseColor());
201	//mSunEffect->setVariableFloat("SunSize", size);
202	//mSunEffect->setVariableTexture2D("SunTexture", mSunTexture);
203
204	/*mSunEffect->activate();
205
206	mSunQuad->render();
207
208	mSunEffect->deactivate();
209	F().getRenderDevice().setDefaultBlendingMode(FRenderDevice::BLENDING_NONE);*/
210
211	glPopMatrix();
212	}
213
214
215	void SkyPreetham::CreateSunQuad()
216	{
217	/*
218	mSunQuad = new FVertexBuffer();
219	mSunQuad->setupPrimitiveType(FVertexBuffer::PRIMITIVES_TRIANGLES);
220	mSunQuad->setupVertexFormat(3, 0, 0, true);
221	mSunQuad->setupTexCoordSet(0, 2);
222	mSunQuad->setVertexBufferSize(4, 6);
223
224	mSunQuad->setVertexPosition(0, FVector3(-0.1f, 0.1f, 1.0f));
225	mSunQuad->setVertexPosition(1, FVector3( 0.1f, 0.1f, 1.0f));
226	mSunQuad->setVertexPosition(2, FVector3(-0.1f, -0.1f, 1.0f));
227	mSunQuad->setVertexPosition(3, FVector3( 0.1f, -0.1f, 1.0f));
228	mSunQuad->setVertexTexCoord(0, 0, FVector2(0.0f, 0.0f));
229	mSunQuad->setVertexTexCoord(1, 0, FVector2(1.0f, 0.0f));
230	mSunQuad->setVertexTexCoord(2, 0, FVector2(0.0f, 1.0f));
231	mSunQuad->setVertexTexCoord(3, 0, FVector2(1.0f, 1.0f));
232
233	mSunQuad->setIndex(0, 0);
234	mSunQuad->setIndex(1, 1);
235	mSunQuad->setIndex(2, 2);
236	mSunQuad->setIndex(3, 2);
237	mSunQuad->setIndex(4, 1);
238	mSunQuad->setIndex(5, 3);
239	*/
240	}
241
242
243	void SkyPreetham::ComputeFactors(const Vector3 &sunDir,
244	Vector3 &zenithColor,
245	vector<Vector3> &ABCDE,
246	std::pair<float, float> &sunThetha) const
247	{
248	sunThetha.first = acos(sunDir.z);
249
250	const float cos_theta = cos(sunThetha.first);
251	sunThetha.second = cos_theta * cos_theta;
252
253	zenithColor.x = ( 0.00165f * CBQ(sunThetha.first) - 0.00374f * SQR(sunThetha.first) + 0.00208f * sunThetha.first + 0.0f) * SQR(mTurbidity) +
254	(-0.02902f * CBQ(sunThetha.first) + 0.06377f * SQR(sunThetha.first) - 0.03202f * sunThetha.first + 0.00394f) * mTurbidity +
255	( 0.11693f * CBQ(sunThetha.first) - 0.21196f * SQR(sunThetha.first) + 0.06052f * sunThetha.first + 0.25885f);
256
257	zenithColor.y = ( 0.00275f * CBQ(sunThetha.first) - 0.00610f * SQR(sunThetha.first) + 0.00316f * sunThetha.first + 0.0f) * SQR(mTurbidity) +
258	(-0.04214f * CBQ(sunThetha.first) + 0.08970f * SQR(sunThetha.first) - 0.04153f * sunThetha.first + 0.00515f) * mTurbidity +
259	( 0.15346f * CBQ(sunThetha.first) - 0.26756f * SQR(sunThetha.first) + 0.06669f * sunThetha.first + 0.26688f);
260
261	zenithColor.z = (float)((4.0453f * mTurbidity - 4.9710f) * tan((4.0f / 9.0f - mTurbidity / 120.0f) *
262	(M_PI - 2.0f * sunThetha.first)) - 0.2155f * mTurbidity + 2.4192f);
263
264	// convert kcd/m² to cd/m²
265	zenithColor.z *= 1000.0f;
266
267	ABCDE.push_back(Vector3(-0.01925 * mTurbidity - 0.25922, -0.01669 * mTurbidity - 0.26078, 0.17872 * mTurbidity - 1.46303));
268	ABCDE.push_back(Vector3(-0.06651 * mTurbidity + 0.00081, -0.09495 * mTurbidity + 0.00921, -0.35540 * mTurbidity + 0.42749));
269	ABCDE.push_back(Vector3(-0.00041 * mTurbidity + 0.21247, -0.00792 * mTurbidity + 0.21023, -0.02266 * mTurbidity + 5.32505));
270	ABCDE.push_back(Vector3(-0.06409 * mTurbidity - 0.89887, -0.04405 * mTurbidity - 1.65369, 0.12064 * mTurbidity - 2.57705));
271	ABCDE.push_back(Vector3(-0.00325 * mTurbidity + 0.04517, -0.01092 * mTurbidity + 0.05291, -0.06696 * mTurbidity + 0.37027));
272	}
273
274
275	void SkyPreetham::ComputeSunColor(const Vector3 &sunDir,
276	Vector3 &ambient,
277	Vector3 &diffuse,
278	bool scaleToRange) const
279	{
280	// sunDir is sun direction
281	// ambient color: shadow color
282	// diffuse color: sun color
283	pair<float, float> sun_theta;
284	Vector3 zenithColor;
285	vector<Vector3> ABCDE;
286
287	ComputeFactors(sunDir, zenithColor, ABCDE, sun_theta);
288
289	Vector3 zenith_XYZ;
290
291	zenith_XYZ.x = (zenithColor.x / zenithColor.y) * zenithColor.z;
292	zenith_XYZ.y = zenithColor.z;
293	zenith_XYZ.z = ((1.0f - zenithColor.x - zenithColor.y) / zenithColor.y) * zenithColor.z;
294
295	ambient.x = 3.240479f * zenith_XYZ.x - 1.537150f * zenith_XYZ.y - 0.498535f * zenith_XYZ.z;
296	ambient.y = -0.969256f * zenith_XYZ.x + 1.875992f * zenith_XYZ.y + 0.041556f * zenith_XYZ.z;
297	ambient.z = 0.055648f * zenith_XYZ.x - 0.204043f * zenith_XYZ.y + 1.057311f * zenith_XYZ.z;
298
299	// downscale ambient color
300	if (scaleToRange)
301	ambient *= 2e-5f;
302	else
303	ambient *= 1e-1f;
304
305	// simulate the sun intensity by modulating the ambient term.
306	ambient = (10.0f - 9.0f DotProd(sunDir, Vector3::UNIT_Z()));
307	//ambient += Vector3(0.2f);
308
309	Vector3 num;
310
311	num.x = (1.0f + ABCDE[0].x * exp(ABCDE[1].x / sunDir.z)) * (1.0f + ABCDE[2].x)+ ABCDE[4].x;
312	num.y = (1.0f + ABCDE[0].y * exp(ABCDE[1].y / sunDir.z)) * (1.0f + ABCDE[2].y)+ ABCDE[4].y;
313	num.z = (1.0f + ABCDE[0].z * exp(ABCDE[1].z / sunDir.z)) * (1.0f + ABCDE[2].z)+ ABCDE[4].z;
314
315	Vector3 den;
316
317	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);
318	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);
319	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);
320
321
322	Vector3 xyY = zenithColor * num / den;
323
324	Vector3 XYZ;
325
326	XYZ.x = (xyY.x / xyY.y) * xyY.z;
327	XYZ.y = xyY.z;
328	XYZ.z = ((1.0f - xyY.x - xyY.y) / xyY.y) * xyY.z;
329
330
331	/////////////
332	//-- transform to rgb
333
334	Vector3 color;
335	color.x = 3.240479f * XYZ.x - 1.537150f * XYZ.y - 0.498535f * XYZ.z;
336	color.y = -0.969256f * XYZ.x + 1.875992f * XYZ.y + 0.041556f *XYZ.z;
337	color.z = 0.055648f * XYZ.x - 0.204043f * XYZ.y + 1.057311f * XYZ.z;
338
339	// Calculate final sun diffuse color.
340	if (scaleToRange)
341	diffuse = color * 5e-2f;
342	else
343	diffuse = color * 3e-1f;
344
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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