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/**
* Copyright (c) Vispy Development Team
* Distributed under the (new) BSD License. See LICENSE.txt for more info.
*
* This file contains the fragment shader template for arrow heads.
*
* Variables
* ---------
*
* $arrow_type
* The type of arrow head. Examples incude: curved, stealth, triangle_30
* and more.
* $fill_type
* How to fill the arrow head. Possible values: "filled", "outline" or
* "stroke".
*
* Varyings
* --------
* v_size
* The arrow head size in pixels
* v_point_size
* The actual size of the point used for drawing. This is larger than the
* given arrow head size to make sure rotating goes well, and allows some
* space for anti-aliasing.
* v_color
* The color for the arrow head
* v_orientation
* A direction vector for the orientation of the arrow head
* v_antialias
* Anti-alias width
* v_linewidth
* Width for the stroke or outline of the shape.
*/
#version 120
#include "math/constants.glsl"
#include "arrowheads/arrowheads.glsl"
#include "antialias/antialias.glsl"
// Varyings
// ------------------------------------
varying float v_size;
varying float v_point_size;
varying vec4 v_color;
varying vec3 v_orientation;
varying float v_antialias;
varying float v_linewidth;
void main()
{
// 1. Move the origin to the center of the point
// 2. Rotate the canvas for drawing the arrow
// 3. Scale the coordinates with v_point_size
vec2 P = gl_PointCoord.xy - vec2(0.5, 0.5);
P = vec2(v_orientation.x*P.x - v_orientation.y*P.y,
v_orientation.y*P.x + v_orientation.x*P.y) * v_point_size;
float distance = arrow_$arrow_type(P, v_size, v_linewidth, v_antialias);
gl_FragColor = $fill_type(distance, v_linewidth, v_antialias, v_color,
v_color);
}
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