1
|
//////////////////////////////////////////////////////////////////////////////////////////////
|
2
|
// Copyright 2016 Leszek Koltunski //
|
3
|
// //
|
4
|
// This file is part of DistortedLibrary. //
|
5
|
// //
|
6
|
// DistortedLibrary is free software: you can redistribute it and/or modify //
|
7
|
// it under the terms of the GNU General Public License as published by //
|
8
|
// the Free Software Foundation, either version 2 of the License, or //
|
9
|
// (at your option) any later version. //
|
10
|
// //
|
11
|
// DistortedLibrary is distributed in the hope that it will be useful, //
|
12
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of //
|
13
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
|
14
|
// GNU General Public License for more details. //
|
15
|
// //
|
16
|
// You should have received a copy of the GNU General Public License //
|
17
|
// along with DistortedLibrary. If not, see <http://www.gnu.org/licenses/>. //
|
18
|
//////////////////////////////////////////////////////////////////////////////////////////////
|
19
|
|
20
|
precision highp float;
|
21
|
precision highp int;
|
22
|
|
23
|
in vec3 a_Position; // Per-vertex position.
|
24
|
in vec3 a_Normal; // Per-vertex normal vector.
|
25
|
in vec3 a_Inflate; // This vector describes the direction this vertex needs to go when we 'inflate' the whole mesh.
|
26
|
// If the mesh is locally smooth, this is equal to the normal vector. Otherwise (on sharp edges) - no.
|
27
|
in vec2 a_TexCoordinate; // Per-vertex texture coordinate.
|
28
|
|
29
|
out vec3 v_Position; //
|
30
|
out vec3 v_endPosition; // for Transform Feedback only
|
31
|
out vec3 v_Normal; //
|
32
|
out vec2 v_TexCoordinate; //
|
33
|
|
34
|
uniform vec3 u_objD; // half of object width x half of object height X half the depth;
|
35
|
// point (0,0,0) is the center of the object
|
36
|
|
37
|
uniform mat4 u_MVPMatrix; // the combined model/view/projection matrix.
|
38
|
uniform mat4 u_MVMatrix; // the combined model/view matrix.
|
39
|
uniform float u_Inflate; // how much should we inflate (>0.0) or deflate (<0.0) the mesh.
|
40
|
|
41
|
#if NUM_VERTEX>0
|
42
|
uniform int vNumEffects; // total number of vertex effects
|
43
|
uniform int vName[NUM_VERTEX]; // their names.
|
44
|
uniform vec4 vUniforms[3*NUM_VERTEX];// i-th effect is 3 consecutive vec4's: [3*i], [3*i+1], [3*i+2].
|
45
|
// The first vec4 is the Interpolated values,
|
46
|
// second vec4: first float - cache, next 3: Center, the third - the Region.
|
47
|
|
48
|
//////////////////////////////////////////////////////////////////////////////////////////////
|
49
|
// HELPER FUNCTIONS
|
50
|
//////////////////////////////////////////////////////////////////////////////////////////////
|
51
|
// The trick below is the if-less version of the
|
52
|
//
|
53
|
// t = dx<0.0 ? (u_objD.x-v.x) / (u_objD.x-ux) : (u_objD.x+v.x) / (u_objD.x+ux);
|
54
|
// h = dy<0.0 ? (u_objD.y-v.y) / (u_objD.y-uy) : (u_objD.y+v.y) / (u_objD.y+uy);
|
55
|
// d = min(t,h);
|
56
|
//
|
57
|
// float d = min(-ps.x/(sign(ps.x)*u_objD.x+p.x),-ps.y/(sign(ps.y)*u_objD.y+p.y))+1.0;
|
58
|
//
|
59
|
// We still have to avoid division by 0 when p.x = +- u_objD.x or p.y = +- u_objD.y (i.e on the edge of the Object)
|
60
|
// We do that by first multiplying the above 'float d' with sign(denominator1*denominator2)^2.
|
61
|
//
|
62
|
// 2019-01-09: make this 3D. The trick: we want only the EDGES of the cuboid to stay constant.
|
63
|
// the interiors of the Faces move! Thus, we want the MIDDLE of the PS/(sign(PS)*u_objD+S) !
|
64
|
//////////////////////////////////////////////////////////////////////////////////////////////
|
65
|
// return degree of the point as defined by the object cuboid (u_objD.x X u_objD.y X u_objD.z)
|
66
|
|
67
|
float degree_object(in vec3 S, in vec3 PS)
|
68
|
{
|
69
|
vec3 ONE = vec3(1.0,1.0,1.0);
|
70
|
vec3 A = sign(PS)*u_objD + S;
|
71
|
|
72
|
vec3 signA = sign(A); //
|
73
|
vec3 signA_SQ = signA*signA; // div = PS/A if A!=0, 0 otherwise.
|
74
|
vec3 div = signA_SQ*PS/(A-(ONE-signA_SQ)); //
|
75
|
vec3 ret = sign(u_objD)-div;
|
76
|
|
77
|
float d1= ret.x-ret.y;
|
78
|
float d2= ret.y-ret.z;
|
79
|
float d3= ret.x-ret.z;
|
80
|
|
81
|
if( d1*d2>0.0 ) return ret.y; //
|
82
|
if( d1*d3>0.0 ) return ret.z; // return 1-middle(div.x,div.y,div.z)
|
83
|
return ret.x; // (unless size of object is 0 then 0-middle)
|
84
|
}
|
85
|
|
86
|
//////////////////////////////////////////////////////////////////////////////////////////////
|
87
|
// Return degree of the point as defined by the Region. Currently only supports spherical regions.
|
88
|
//
|
89
|
// Let 'PS' be the vector from point P (the current vertex) to point S (the center of the effect).
|
90
|
// Let region.xyz be the vector from point S to point O (the center point of the region sphere)
|
91
|
// Let region.w be the radius of the region sphere.
|
92
|
// (This all should work regardless if S is inside or outside of the sphere).
|
93
|
//
|
94
|
// Then, the degree of a point with respect to a given (spherical!) Region is defined by:
|
95
|
//
|
96
|
// If P is outside the sphere, return 0.
|
97
|
// Otherwise, let X be the point where the halfline SP meets the sphere - then return |PX|/|SX|,
|
98
|
// aka the 'degree' of point P.
|
99
|
//
|
100
|
// We solve the triangle OPX.
|
101
|
// We know the lengths |PO|, |OX| and the angle OPX, because cos(OPX) = cos(180-OPS) = -cos(OPS) = -PS*PO/(|PS|*|PO|)
|
102
|
// then from the law of cosines PX^2 + PO^2 - 2*PX*PO*cos(OPX) = OX^2 so PX = -a + sqrt(a^2 + OX^2 - PO^2)
|
103
|
// where a = PS*PO/|PS| but we are really looking for d = |PX|/(|PX|+|PS|) = 1/(1+ (|PS|/|PX|) ) and
|
104
|
// |PX|/|PS| = -b + sqrt(b^2 + (OX^2-PO^2)/PS^2) where b=PS*PO/|PS|^2 which can be computed with only one sqrt.
|
105
|
|
106
|
float degree_region(in vec4 region, in vec3 PS)
|
107
|
{
|
108
|
vec3 PO = PS + region.xyz;
|
109
|
float D = region.w*region.w-dot(PO,PO); // D = |OX|^2 - |PO|^2
|
110
|
|
111
|
if( D<=0.0 ) return 0.0;
|
112
|
|
113
|
float ps_sq = dot(PS,PS);
|
114
|
float one_over_ps_sq = 1.0/(ps_sq-(sign(ps_sq)-1.0)); // return 1.0 if ps_sq = 0.0
|
115
|
// Important: if we want to write
|
116
|
// b = 1/a if a!=0, b=1 otherwise
|
117
|
// we need to write that as
|
118
|
// b = 1 / ( a-(sign(a)-1) )
|
119
|
// [ and NOT 1 / ( a + 1 - sign(a) ) ]
|
120
|
// because the latter, if 0<a<2^-24,
|
121
|
// will suffer from round-off error and in this case
|
122
|
// a + 1.0 = 1.0 !! so 1 / (a+1-sign(a)) = 1/0 !
|
123
|
float DOT = dot(PS,PO)*one_over_ps_sq;
|
124
|
|
125
|
return 1.0 / (1.0 + 1.0/(sqrt(DOT*DOT+D*one_over_ps_sq)-DOT));
|
126
|
}
|
127
|
|
128
|
//////////////////////////////////////////////////////////////////////////////////////////////
|
129
|
// return min(degree_object,degree_region). Just like degree_region, currently only supports spheres.
|
130
|
|
131
|
float degree(in vec4 region, in vec3 S, in vec3 PS)
|
132
|
{
|
133
|
vec3 PO = PS + region.xyz;
|
134
|
float D = region.w*region.w-dot(PO,PO); // D = |OX|^2 - |PO|^2
|
135
|
|
136
|
if( D<=0.0 ) return 0.0;
|
137
|
|
138
|
vec3 A = sign(PS)*u_objD + S;
|
139
|
vec3 signA = sign(A);
|
140
|
vec3 signA_SQ = signA*signA;
|
141
|
vec3 div = signA_SQ*PS/(A-(vec3(1.0,1.0,1.0)-signA_SQ));
|
142
|
vec3 ret = sign(u_objD)-div; // if object is flat, make ret.z 0
|
143
|
|
144
|
float d1= ret.x-ret.y;
|
145
|
float d2= ret.y-ret.z;
|
146
|
float d3= ret.x-ret.z;
|
147
|
float degree_object;
|
148
|
|
149
|
if( d1*d2>0.0 ) degree_object= ret.y; //
|
150
|
else if( d1*d3>0.0 ) degree_object= ret.z; // middle of the ret.{x,y,z} triple
|
151
|
else degree_object= ret.x; //
|
152
|
|
153
|
float ps_sq = dot(PS,PS);
|
154
|
float one_over_ps_sq = 1.0/(ps_sq-(sign(ps_sq)-1.0)); // return 1.0 if ps_sq = 0.0
|
155
|
float DOT = dot(PS,PO)*one_over_ps_sq;
|
156
|
float degree_region = 1.0/(1.0 + 1.0/(sqrt(DOT*DOT+D*one_over_ps_sq)-DOT));
|
157
|
|
158
|
return min(degree_region,degree_object);
|
159
|
}
|
160
|
|
161
|
#endif // NUM_VERTEX>0
|
162
|
|
163
|
//////////////////////////////////////////////////////////////////////////////////////////////
|
164
|
|
165
|
void main()
|
166
|
{
|
167
|
vec3 v = 2.0*u_objD*a_Position;
|
168
|
vec3 n = a_Normal;
|
169
|
|
170
|
v += (u_objD.x+u_objD.y)*u_Inflate*a_Inflate;
|
171
|
|
172
|
#if NUM_VERTEX>0
|
173
|
int effect=0;
|
174
|
|
175
|
for(int i=0; i<vNumEffects; i++)
|
176
|
{
|
177
|
// ENABLED EFFECTS WILL BE INSERTED HERE
|
178
|
|
179
|
effect+=3;
|
180
|
}
|
181
|
#endif
|
182
|
|
183
|
v_Position = v;
|
184
|
v_endPosition = v + (0.3*u_objD.x)*n;
|
185
|
v_TexCoordinate = a_TexCoordinate;
|
186
|
v_Normal = normalize(vec3(u_MVMatrix*vec4(n,0.0)));
|
187
|
gl_Position = u_MVPMatrix*vec4(v,1.0);
|
188
|
}
|