mirror of https://github.com/mosra/magnum.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
68 lines
2.1 KiB
68 lines
2.1 KiB
/* |
|
This file is part of Magnum. |
|
|
|
Copyright © 2010, 2011, 2012, 2013, 2014 |
|
Vladimír Vondruš <mosra@centrum.cz> |
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a |
|
copy of this software and associated documentation files (the "Software"), |
|
to deal in the Software without restriction, including without limitation |
|
the rights to use, copy, modify, merge, publish, distribute, sublicense, |
|
and/or sell copies of the Software, and to permit persons to whom the |
|
Software is furnished to do so, subject to the following conditions: |
|
|
|
The above copyright notice and this permission notice shall be included |
|
in all copies or substantial portions of the Software. |
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
|
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
|
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
|
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
|
DEALINGS IN THE SOFTWARE. |
|
*/ |
|
|
|
#ifndef RUNTIME_CONST |
|
#define const |
|
#endif |
|
|
|
#ifdef EXPLICIT_UNIFORM_LOCATION |
|
layout(location = 1) uniform vec2 viewportSize; |
|
#else |
|
uniform vec2 viewportSize; |
|
#endif |
|
|
|
layout(triangles) in; |
|
|
|
layout(triangle_strip, max_vertices = 3) out; |
|
|
|
/* Interpolate in screen space */ |
|
noperspective out vec3 dist; |
|
|
|
void main() { |
|
/* Screen position of each vertex */ |
|
vec2 p[3]; |
|
for(int i = 0; i != 3; ++i) |
|
p[i] = viewportSize*gl_in[i].gl_Position.xy/gl_in[i].gl_Position.w; |
|
|
|
/* Vector of each triangle side */ |
|
const vec2 v[3] = { |
|
p[2]-p[1], |
|
p[2]-p[0], |
|
p[1]-p[0] |
|
}; |
|
|
|
/* Compute area using perp-dot product */ |
|
const float area = abs(dot(vec2(-v[1].y, v[1].x), v[2])); |
|
|
|
/* Add distance to opposite side to each vertex */ |
|
for(int i = 0; i != 3; ++i) { |
|
dist = vec3(0.0, 0.0, 0.0); |
|
dist[i] = area/length(v[i]); |
|
gl_Position = gl_in[i].gl_Position; |
|
EmitVertex(); |
|
} |
|
|
|
EndPrimitive(); |
|
}
|
|
|