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/**
* Copyright (c) Vispy Development Team
* Distributed under the (new) BSD License. See LICENSE.txt for more info.
*
* This file contains code for filling a shape with anti-alias.
*/
/**
* Compute antialiased fragment color for a filled shape.
*
* Parameters:
* -----------
*
* distance
* Signed distance to border (in pixels)
* linewidth
* Stroke line width (in pixels)
* antialias
* Stroke antialiased area (in pixels)
* bg_color
* Fill color
*
* Return:
* -------
* Fragment color (vec4)
*/
vec4 filled(float distance, float linewidth, float antialias, vec4 bg_color)
{
vec4 frag_color;
float t = linewidth/2.0 - antialias;
float signed_distance = distance;
float border_distance = abs(signed_distance) - t;
float alpha = border_distance/antialias;
alpha = exp(-alpha*alpha);
if( border_distance < 0.0 ) {
frag_color = bg_color;
} else if( signed_distance < 0.0 ) {
frag_color = bg_color;
} else {
frag_color = vec4(bg_color.rgb, alpha * bg_color.a);
}
return frag_color;
}
vec4 filled(float distance, float linewidth, float antialias, vec4 fg_color, vec4 bg_color)
{
return filled(distance, linewidth, antialias, fg_color);
}
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