prosperon/source/shaders/gridfrag.glsl

29 lines
487 B
GLSL

#version 330
out vec4 frag_color;
in vec2 apos; /* Drawing coordinates of the grid */
uniform float thickness; /* thickness in pixels */
uniform float span;
uniform vec4 color;
void main(void)
{
float t = thickness / span;
t /= 2.0;
vec2 bpos;
bpos.x = mod(apos.x, span) / span;
bpos.y = mod(apos.y, span) / span;
bpos.x -= t;
bpos.y -= t;
float comp = min(bpos.x, bpos.y);
if (comp > t)
discard;
comp += t;
frag_color = color;
}