file-online-preview/server/libreoffice/program/opengl/lineVertexShader.glsl

38 lines
1.3 KiB
Java

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
attribute vec2 position;
attribute vec4 extrusion_vectors;
varying float fade_factor; // fade factor for anti-aliasing
uniform float line_width;
uniform float feather; // width where we fade the line
uniform mat4 mvp;
void main()
{
vec2 extrusion_vector = extrusion_vectors.xy;
// miter factor to additionally lengthen the distance of vertex (needed for miter)
// if 1.0 - miter_factor has no effect
float miter_factor = 1.0f / abs(extrusion_vectors.z);
// fade factor is always -1.0 or 1.0 -> we transport that info together with length
fade_factor = sign(extrusion_vectors.z);
float rendered_thickness = (line_width + feather * 2.0) * miter_factor;
// lengthen the vertex in direction of the extrusion vector by line width.
vec4 position = vec4(position + (extrusion_vector * (rendered_thickness / 2.0) ), 0.0, 1.0);
gl_Position = mvp * position;
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */