summaryrefslogtreecommitdiff
path: root/indra/newview/app_settings/shaders/class2/deferred/sunLightSSAOF.glsl
blob: 01e34ed792547cc994992145db801e27abf3db2a (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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
/** 
 * @file sunLightSSAOF.glsl
 * $LicenseInfo:firstyear=2007&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2007, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */
 
#extension GL_ARB_texture_rectangle : enable

#ifdef DEFINE_GL_FRAGCOLOR
out vec4 frag_color;
#else
#define frag_color gl_FragColor
#endif

//class 2 -- shadows and SSAO

uniform sampler2DRect depthMap;
uniform sampler2DRect normalMap;
uniform sampler2DShadow shadowMap0;
uniform sampler2DShadow shadowMap1;
uniform sampler2DShadow shadowMap2;
uniform sampler2DShadow shadowMap3;
uniform sampler2DShadow shadowMap4;
uniform sampler2DShadow shadowMap5;
uniform sampler2D noiseMap;


// Inputs
uniform mat4 shadow_matrix[6];
uniform vec4 shadow_clip;
uniform float ssao_radius;
uniform float ssao_max_radius;
uniform float ssao_factor;
uniform float ssao_factor_inv;

VARYING vec2 vary_fragcoord;

uniform mat4 inv_proj;
uniform vec2 screen_res;
uniform vec2 proj_shadow_res;
uniform vec3 sun_dir;

uniform vec2 shadow_res;

uniform float shadow_bias;
uniform float shadow_offset;

uniform float spot_shadow_bias;
uniform float spot_shadow_offset;

#ifdef SINGLE_FP_ONLY
vec2 encode_normal(vec3 n)
{
	vec2 sn;
	sn.xy = (n.xy * vec2(0.5f,0.5f)) + vec2(0.5f,0.5f);
	return sn;
}

vec3 decode_normal (vec2 enc)
{
	vec3 n;
	n.xy = (enc.xy * vec2(2.0f,2.0f)) - vec2(1.0f,1.0f);
	n.z = sqrt(1.0f - dot(n.xy,n.xy));
	return n;
}
#else
vec2 encode_normal(vec3 n)
{
	float f = sqrt(8 * n.z + 8);
	return n.xy / f + 0.5;
}

vec3 decode_normal (vec2 enc)
{
    vec2 fenc = enc*4-2;
    float f = dot(fenc,fenc);
    float g = sqrt(1-f/4);
    vec3 n;
    n.xy = fenc*g;
    n.z = 1-f/2;
    return n;
}
#endif

vec4 getPosition(vec2 pos_screen)
{
	float depth = texture2DRect(depthMap, pos_screen.xy).r;
	vec2 sc = pos_screen.xy*2.0;
	sc /= screen_res;
	sc -= vec2(1.0,1.0);
	vec4 ndc = vec4(sc.x, sc.y, 2.0*depth-1.0, 1.0);
	vec4 pos = inv_proj * ndc;
	pos /= pos.w;
	pos.w = 1.0;
	return pos;
}

vec2 getKern(int i)
{
	vec2 kern[8];
	// exponentially (^2) distant occlusion samples spread around origin
	kern[0] = vec2(-1.0, 0.0) * 0.125*0.125;
	kern[1] = vec2(1.0, 0.0) * 0.250*0.250;
	kern[2] = vec2(0.0, 1.0) * 0.375*0.375;
	kern[3] = vec2(0.0, -1.0) * 0.500*0.500;
	kern[4] = vec2(0.7071, 0.7071) * 0.625*0.625;
	kern[5] = vec2(-0.7071, -0.7071) * 0.750*0.750;
	kern[6] = vec2(-0.7071, 0.7071) * 0.875*0.875;
	kern[7] = vec2(0.7071, -0.7071) * 1.000*1.000;
       
	return kern[i];
}

//calculate decreases in ambient lighting when crowded out (SSAO)
float calcAmbientOcclusion(vec4 pos, vec3 norm)
{
	float ret = 1.0;

	vec2 pos_screen = vary_fragcoord.xy;
	vec3 pos_world = pos.xyz;
	vec2 noise_reflect = texture2D(noiseMap, vary_fragcoord.xy/128.0).xy;
		
	float angle_hidden = 0.0;
	float points = 0;
		
	float scale = min(ssao_radius / -pos_world.z, ssao_max_radius);
	
	// it was found that keeping # of samples a constant was the fastest, probably due to compiler optimizations (unrolling?)
	for (int i = 0; i < 8; i++)
	{
		vec2 samppos_screen = pos_screen + scale * reflect(getKern(i), noise_reflect);
		vec3 samppos_world = getPosition(samppos_screen).xyz; 
		
		vec3 diff = pos_world - samppos_world;
		float dist2 = dot(diff, diff);
			
		// assume each sample corresponds to an occluding sphere with constant radius, constant x-sectional area
		// --> solid angle shrinking by the square of distance
		//radius is somewhat arbitrary, can approx with just some constant k * 1 / dist^2
		//(k should vary inversely with # of samples, but this is taken care of later)
		
		float funky_val = (dot((samppos_world - 0.05*norm - pos_world), norm) > 0.0) ? 1.0 : 0.0;
		angle_hidden = angle_hidden + funky_val * min(1.0/dist2, ssao_factor_inv);
			
		// 'blocked' samples (significantly closer to camera relative to pos_world) are "no data", not "no occlusion" 
		float diffz_val = (diff.z > -1.0) ? 1.0 : 0.0;
		points = points + diffz_val;
	}
		
	angle_hidden = min(ssao_factor*angle_hidden/points, 1.0);
	
	float points_val = (points > 0.0) ? 1.0 : 0.0;
	ret = (1.0 - (points_val * angle_hidden));

	ret = max(ret, 0.0);
	return min(ret, 1.0);
}

float pcfShadow(sampler2DShadow shadowMap, vec4 stc, float scl, vec2 pos_screen)
{
	stc.xyz /= stc.w;
	stc.z += shadow_bias;

	stc.x = floor(stc.x*shadow_res.x + fract(pos_screen.y*0.666666666))/shadow_res.x;
	float cs = shadow2D(shadowMap, stc.xyz).x;
	
	float shadow = cs;
	
	shadow += shadow2D(shadowMap, stc.xyz+vec3(2.0/shadow_res.x, 1.5/shadow_res.y, 0.0)).x;
    shadow += shadow2D(shadowMap, stc.xyz+vec3(1.0/shadow_res.x, -1.5/shadow_res.y, 0.0)).x;
    shadow += shadow2D(shadowMap, stc.xyz+vec3(-1.0/shadow_res.x, 1.5/shadow_res.y, 0.0)).x;
    shadow += shadow2D(shadowMap, stc.xyz+vec3(-2.0/shadow_res.x, -1.5/shadow_res.y, 0.0)).x;
	         
        return shadow*0.2;
}

float pcfSpotShadow(sampler2DShadow shadowMap, vec4 stc, float scl, vec2 pos_screen)
{
	stc.xyz /= stc.w;
	stc.z += spot_shadow_bias*scl;
	stc.x = floor(proj_shadow_res.x * stc.x + fract(pos_screen.y*0.666666666)) / proj_shadow_res.x; // snap
		
	float cs = shadow2D(shadowMap, stc.xyz).x;
	float shadow = cs;

	vec2 off = 1.0/proj_shadow_res;
	off.y *= 1.5;
	
	shadow += shadow2D(shadowMap, stc.xyz+vec3(off.x*2.0, off.y, 0.0)).x;
	shadow += shadow2D(shadowMap, stc.xyz+vec3(off.x, -off.y, 0.0)).x;
	shadow += shadow2D(shadowMap, stc.xyz+vec3(-off.x, off.y, 0.0)).x;
	shadow += shadow2D(shadowMap, stc.xyz+vec3(-off.x*2.0, -off.y, 0.0)).x;

        return shadow*0.2;
}

void main() 
{
	vec2 pos_screen = vary_fragcoord.xy;
	
	//try doing an unproject here
	
	vec4 pos = getPosition(pos_screen);
	
	vec3 norm = texture2DRect(normalMap, pos_screen).xyz;
	norm = decode_normal(norm.xy); // unpack norm
		
	/*if (pos.z == 0.0) // do nothing for sky *FIX: REMOVE THIS IF/WHEN THE POSITION MAP IS BEING USED AS A STENCIL
	{
		frag_color = vec4(0.0); // doesn't matter
		return;
	}*/
	
	float shadow = 0.0;
	float dp_directional_light = max(0.0, dot(norm, sun_dir.xyz));
	
	vec3 shadow_pos = pos.xyz;
	vec3 offset = sun_dir.xyz * (1.0-dp_directional_light);
	
	vec4 spos = vec4(shadow_pos+offset*shadow_offset, 1.0);
	
	if (spos.z > -shadow_clip.w)
	{	
		if (dp_directional_light == 0.0)
		{
			// if we know this point is facing away from the sun then we know it's in shadow without having to do a squirrelly shadow-map lookup
			shadow = 0.0;
		}
		else
		{
			vec4 lpos;

			vec4 near_split = shadow_clip*-0.75;
			vec4 far_split = shadow_clip*-1.25;
			vec4 transition_domain = near_split-far_split;
			float weight = 0.0;

			if (spos.z < near_split.z)
			{
				lpos = shadow_matrix[3]*spos;
				
				float w = 1.0;
				w -= max(spos.z-far_split.z, 0.0)/transition_domain.z;
				shadow += pcfShadow(shadowMap3, lpos, 0.25, pos_screen)*w;
				weight += w;
				shadow += max((pos.z+shadow_clip.z)/(shadow_clip.z-shadow_clip.w)*2.0-1.0, 0.0);
			}

			if (spos.z < near_split.y && spos.z > far_split.z)
			{
				lpos = shadow_matrix[2]*spos;
				
				float w = 1.0;
				w -= max(spos.z-far_split.y, 0.0)/transition_domain.y;
				w -= max(near_split.z-spos.z, 0.0)/transition_domain.z;
				shadow += pcfShadow(shadowMap2, lpos, 0.5, pos_screen)*w;
				weight += w;
			}

			if (spos.z < near_split.x && spos.z > far_split.y)
			{
				lpos = shadow_matrix[1]*spos;
				
				float w = 1.0;
				w -= max(spos.z-far_split.x, 0.0)/transition_domain.x;
				w -= max(near_split.y-spos.z, 0.0)/transition_domain.y;
				shadow += pcfShadow(shadowMap1, lpos, 0.75, pos_screen)*w;
				weight += w;
			}

			if (spos.z > far_split.x)
			{
				lpos = shadow_matrix[0]*spos;
								
				float w = 1.0;
				w -= max(near_split.x-spos.z, 0.0)/transition_domain.x;
				
				shadow += pcfShadow(shadowMap0, lpos, 1.0, pos_screen)*w;
				weight += w;
			}
		

			shadow /= weight;

			// take the most-shadowed value out of these two:
			//  * the blurred sun shadow in the light (shadow) map
			//  * an unblurred dot product between the sun and this norm
			// the goal is to err on the side of most-shadow to fill-in shadow holes and reduce artifacting
			shadow = min(shadow, dp_directional_light);
			
			//lpos.xy /= lpos.w*32.0;
			//if (fract(lpos.x) < 0.1 || fract(lpos.y) < 0.1)
			//{
			//	shadow = 0.0;
			//}
			
		}
	}
	else
	{
		// more distant than the shadow map covers
		shadow = 1.0;
	}
	
	frag_color[0] = shadow;
	frag_color[1] = calcAmbientOcclusion(pos, norm);
	
	spos = vec4(shadow_pos+norm*spot_shadow_offset, 1.0);
	
	//spotlight shadow 1
	vec4 lpos = shadow_matrix[4]*spos;
	frag_color[2] = pcfSpotShadow(shadowMap4, lpos, 0.8, pos_screen);
	
	//spotlight shadow 2
	lpos = shadow_matrix[5]*spos;
	frag_color[3] = pcfSpotShadow(shadowMap5, lpos, 0.8, pos_screen);

	//frag_color.rgb = pos.xyz;
	//frag_color.b = shadow;
}