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Revision 5b1c0f47

Added by Leszek Koltunski over 7 years ago

Switch off the pre-compulting of sin and cos in CPU as it turns out that those two are single-instruction functions on any modern GPU ( http://www.gamedev.net/topic/322422-number-of-gpu-cycles-for-cos-and-sin-functions/ - link form 2005 ! )

View differences:

src/main/res/raw/main_vertex_shader.glsl
336 336 
  vec4 SO = vUniforms[effect+2];
337 337 
  float d1_circle = degree_region(SO,PS);
338 338 
  float d1_bitmap = degree_bitmap(center,PS);
339 
  float sinA = vUniforms[effect  ].x;                          // sin(A) precomputed in EffectListVertex.postprocess
340 
  float cosA = vUniforms[effect+1].x;                          // cos(A) precomputed in EffectListVertex.postprocess
339 

  		




  
  340
  
    
  float alpha = vUniforms[effect].x;


  		




  
  341
  
    
  float sinA = sin(alpha);


  		




  
  342
  
    
  float cosA = cos(alpha);


  		




  
  343
  
    

  		




  341
  344
  
    
  vec2 PS2 = vec2( PS.x*cosA+PS.y*sinA,-PS.x*sinA+PS.y*cosA ); // vector PS rotated by A radians clockwise around center.


  		




  342
  345
  
    
  vec4 SG = (1.0-d1_circle)*SO;                                // coordinates of the dilated circle P is going to get rotated around


  		




  343
  346
  
    
  float d2 = max(0.0,degree(SG,center,PS2));                   // make it a max(0,deg) because otherwise when center=left edge of the


  		




  ......




  401
  404
  
    
// d) compute the above and see that this is equal precisely to SX from (**).


  		




  402
  405
  
    
// e) repeat points b,c,d in direction Y and come up with (***).


  		




  403
  406
  
    
//


  		




  
  407
  
    
//////////////////////////////////////////////////////////////////////////////////////////////


  		




  404
  408
  
    
// Note: we should avoid passing certain combinations of parameters to this function. One such known


  		




  405
  409
  
    
// combination is ( A: small but positive, B: any, amplitude >= length ).


  		




  406
  410
  
    
// In this case, certain 'unlucky' points have their normals almost horizontal (they got moved by (almost!)


  		




  ......




  421
  425
  
    

  		




  422
  426
  
    
  if( deg != 0.0 && length != 0.0 )


  		




  423
  427
  
    
    {


  		




  424
  
  
    
    float sinA = vUniforms[effect  ].y;


  		




  425
  
  
    
    float cosA = vUniforms[effect+1].x;


  		




  426
  
  
    
    float sinB = vUniforms[effect  ].w;


  		




  427
  
  
    
    float cosB = vUniforms[effect+1].y;


  		




  
  428
  
    
    float alpha = vUniforms[effect].y;


  		




  
  429
  
    
    float beta  = vUniforms[effect].w;


  		




  
  430
  
    

  		




  
  431
  
    
    float sinA = sin(alpha);


  		




  
  432
  
    
    float cosA = cos(alpha);


  		




  
  433
  
    
    float sinB = sin(beta);


  		




  
  434
  
    
    float cosB = cos(beta);


  		




  428
  435
  
    

  		




  429
  436
  
    
    float angle= 1.578*(ps.x*cosB-ps.y*sinB) / length;


  		




  430
  437
  
    

  		












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