bgfx/tools/texturev/fs_texture_sdf.sc
2017-07-09 11:47:13 -07:00

29 lines
717 B
Python

$input v_texcoord0, v_color0
/*
* Copyright 2011-2017 Branimir Karadzic. All rights reserved.
* License: https://github.com/bkaradzic/bgfx#license-bsd-2-clause
*/
#include <bgfx_shader.sh>
SAMPLER2D(s_texColor, 0);
uniform vec4 u_params;
#define u_textureLod u_params.x
float median(float r, float g, float b)
{
return max(min(r, g), min(max(r, g), b) );
}
void main() {
vec4 bgColor = vec4(1.0, 1.0, 1.0, 1.0);
vec4 fgColor = vec4(0.0, 0.0, 0.0, 1.0);
vec3 sample = texture2DLod(s_texColor, v_texcoord0.xy, u_textureLod).rgb;
float sigDist = median(sample.r, sample.g, sample.b) - 0.5;
float opacity = clamp(sigDist/fwidth(sigDist) + 0.5, 0.0, 1.0);
gl_FragColor = mix(bgColor, fgColor, opacity);
}