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/* <copyright>
This file contains proprietary software owned by Motorola Mobility, Inc.<br/>
No rights, expressed or implied, whatsoever to this software are provided by Motorola Mobility, Inc. hereunder.<br/>
(c) Copyright 2011 Motorola Mobility, Inc. All Rights Reserved.
</copyright> */
#ifdef GL_ES
precision highp float;
#endif
// attributes
attribute vec3 vert;
attribute vec3 normal;
attribute vec2 texcoord;
// scalar uniforms
uniform float u_limit1;
uniform float u_limit2;
uniform float u_limit3;
uniform float u_taperAmount;
uniform float u_minVal;
uniform float u_maxVal;
uniform float u_center;
// matrix uniforms
uniform mat4 u_mvMatrix;
uniform mat4 u_projMatrix;
uniform mat4 u_worldMatrix;
varying vec4 v_color;
float TaperAmount( float param )
{
// Bezier coordinates of the X coordinate.
// Adjust these to get tighter or looser
float tightness = 0.8;
float x0, y0, x1, y1, x2, y2;
float t;
if (param < 0.5)
{
t = 2.0*param;
x0 = 0.0; y0 = 0.0;
x1 = tightness; y1 = 0.0;
x2 = 1.0; y2 = 0.5;
}
else
{
t = (param - 0.5)*2.0;
x0 = 0.0; y0 = 0.5;
x1 = 1.0 - tightness; y1 = 1.0;
x2 = 1.0; y2 = 1.0;
}
float a = x0 - 2.0*x1 + x2;
float b = 2.0*(x1 - x0);
float c = x0 - t;
float descr = sqrt( b*b - 4.0*a*c );
float denom = 2.0*a;
float n1 = (-b + descr)/denom;
float n2 = (-b - descr)/denom;
if ((n1 >= 0.0) || (n1 <= 1.0)) t = n1;
else if ((n2 >= 0.0) || (n2 <= 1.0)) t = n2;
else
t = 0.0;
float ya = y0 + t*(y1 - y0);
float yb = y1 + t*(y2 - y1);
float yc = ya + t*(yb - ya);
return yc;
}
void main(void)
{
vec3 pos = vert;
vec2 uv = texcoord;
float limit1 = u_limit1,
limit2 = u_limit2,
limit3 = u_limit2;
v_color = vec4(texcoord.x, texcoord.y, 0, 1);
if ((uv.x > u_limit1) && (uv.x < u_limit3))
{
float t;
if (uv.x < u_limit2)
{
t = (uv.x - u_limit1)/(u_limit2 - u_limit1);
}
else
{
t = 1.0 - (uv.x - u_limit2)/(u_limit3 - u_limit2);
}
t = TaperAmount( t );
float maxVal;
if (pos.y > u_center)
{
maxVal = u_maxVal;
}
else
{
maxVal = u_minVal;
}
float yFrac = (pos.y - u_center)/(maxVal-u_center);
pos.y = pos.y - yFrac * (maxVal - u_center)*t*u_taperAmount;
}
gl_Position = u_projMatrix * u_mvMatrix * vec4(pos,1.0) ;
}
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