axmol/core/renderer/shaders/label_sdf.frag

33 lines
923 B
GLSL

#version 310 es
precision highp float;
precision highp int;
layout(location = 0) in vec4 v_fragmentColor;
layout(location = 1) in vec2 v_texCoord;
layout(binding = 0) uniform sampler2D u_tex0;
layout(std140) uniform fs_ub {
vec4 u_textColor;
};
layout(location = 0) out vec4 FragColor;
void main()
{
vec4 color = texture(u_tex0, v_texCoord);
//the texture use dual channel 16-bit output for distance_map
//float dist = color.b+color.g/256.0;
// the texture use single channel 8-bit output for distance_map
float dist = color.a;
//TODO: Implementation 'fwidth' for glsl 1.0
float width = fwidth(dist);
//assign width for constant will lead to a little bit fuzzy,it's temporary measure.
//float width = 0.04;
//float width = 1.0/16.0;
float alpha = smoothstep(0.5-width, 0.5+width, dist) * u_textColor.a;
FragColor = v_fragmentColor * vec4(u_textColor.rgb,alpha);
}