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Revision 353f7580

Added by Leszek Koltunski over 5 years ago

Make Distort truly 3D.

View differences:

src/main/res/raw/main_vertex_shader.glsl
59 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 60 
// We do that by first multiplying the above 'float d' with sign(denominator1*denominator2)^2.
61 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) !
62 64 
//////////////////////////////////////////////////////////////////////////////////////////////
63 
// return degree of the point as defined by the bitmap rectangle
65 
// return degree of the point as defined by the object cuboid (u_objD.x X u_objD.y X u_objD.z)
64 66 

  		




  65
  
  
    
float degree_bitmap(in vec3 S, in vec3 PS)


  		




  
  67
  
    
float degree_object(in vec3 S, in vec3 PS)


  		




  66
  68
  
    
  {


  		




  
  69
  
    
  vec3 ONE = vec3(1.0,1.0,1.0);


  		




  67
  70
  
    
  vec3 A = sign(PS)*u_objD + S;


  		




  68
  71
  
    

  		




  69
  
  
    
  vec3 signA = sign(A);                                    //


  		




  70
  
  
    
  vec3 signA_SQ = signA*signA;                             // div = PS/A if A!=0, 0 otherwise.


  		




  71
  
  
    
  vec3 div = signA_SQ*PS/(A-(vec3(1.0,1.0,1.0)-signA_SQ)); //


  		




  
  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)); //


  		




  72
  75
  
    

  		




  73
  
  
    
  return 1.0-max(div.x,div.y);


  		




  
  76
  
    
  float d1= div.x-div.y;


  		




  
  77
  
    
  float d2= div.y-div.z;


  		




  
  78
  
    
  float d3= div.x-div.z;


  		




  
  79
  
    

  		




  
  80
  
    
  if( d1*d2>0.0 ) return 1.0-div.y;          //


  		




  
  81
  
    
  if( d1*d3>0.0 ) return 1.0-div.z;          // return 1-middle(div.x,div.y,div.z)


  		




  
  82
  
    
  return 1.0-div.x;                          //


  		




  74
  83
  
    
  }


  		




  75
  84
  
    

  		




  76
  85
  
    
//////////////////////////////////////////////////////////////////////////////////////////////


  		




  77
  
  
    
// Return degree of the point as defined by the Region. Currently only supports circular regions.


  		




  
  86
  
    
// Return degree of the point as defined by the Region. Currently only supports spherical regions.


  		




  78
  87
  
    
//


  		




  79
  
  
    
// Let us first introduce some notation.


  		




  80
  88
  
    
// Let 'PS' be the vector from point P (the current vertex) to point S (the center of the effect).


  		




  81
  
  
    
// Let region.xy be the vector from point S to point O (the center point of the region circle)


  		




  82
  
  
    
// Let region.z be the radius of the region circle.


  		




  83
  
  
    
// (This all should work regardless if S is inside or outside of the circle).


  		




  
  89
  
    
// Let region.xyz be the vector from point S to point O (the center point of the region sphere)


  		




  
  90
  
    
// Let region.w be the radius of the region sphere.


  		




  
  91
  
    
// (This all should work regardless if S is inside or outside of the sphere).


  		




  84
  92
  
    
//


  		




  85
  
  
    
// Then, the degree of a point with respect to a given (circular!) Region is defined by:


  		




  
  93
  
    
// Then, the degree of a point with respect to a given (spherical!) Region is defined by:


  		




  86
  94
  
    
//


  		




  87
  
  
    
// If P is outside the circle, return 0.


  		




  88
  
  
    
// Otherwise, let X be the point where the halfline SP meets the region circle - then return |PX|/||SX|,


  		




  
  95
  
    
// If P is outside the sphere, return 0.


  		




  
  96
  
    
// Otherwise, let X be the point where the halfline SP meets the sphere - then return |PX|/||SX|,


  		




  89
  97
  
    
// aka the 'degree' of point P.


  		




  90
  98
  
    
//


  		




  91
  99
  
    
// We solve the triangle OPX.


  		




  ......




  117
  125
  
    
  }


  		




  118
  126
  
    

  		




  119
  127
  
    
//////////////////////////////////////////////////////////////////////////////////////////////


  		




  120
  
  
    
// return min(degree_bitmap,degree_region). Just like degree_region, currently only supports circles.


  		




  
  128
  
    
// return min(degree_object,degree_region). Just like degree_region, currently only supports spheres.


  		




  121
  129
  
    

  		




  122
  130
  
    
float degree(in vec4 region, in vec3 S, in vec3 PS)


  		




  123
  131
  
    
  {


  		




  ......




  130
  138
  
    
  vec3 signA = sign(A);


  		




  131
  139
  
    
  vec3 signA_SQ = signA*signA;


  		




  132
  140
  
    
  vec3 div = signA_SQ*PS/(A-(vec3(1.0,1.0,1.0)-signA_SQ));


  		




  133
  
  
    
  float E = 1.0-max(div.x,div.y);


  		




  
  141
  
    

  		




  
  142
  
    
  float d1= div.x-div.y;


  		




  
  143
  
    
  float d2= div.y-div.z;


  		




  
  144
  
    
  float d3= div.x-div.z;


  		




  
  145
  
    
  float E;


  		




  
  146
  
    

  		




  
  147
  
    
       if( d1*d2>0.0 ) E= 1.0-div.y;


  		




  
  148
  
    
  else if( d1*d3>0.0 ) E= 1.0-div.z;


  		




  
  149
  
    
  else                 E= 1.0-div.x;


  		




  134
  150
  
    

  		




  135
  151
  
    
  float ps_sq = dot(PS,PS);


  		




  136
  152
  
    
  float one_over_ps_sq = 1.0/(ps_sq-(sign(ps_sq)-1.0));  // return 1.0 if ps_sq = 0.0


  		












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