axmol/cocos/renderer/ccShader_Label_df.frag

27 lines
825 B
GLSL

const char* ccLabelDistanceFieldNormal_frag = STRINGIFY(
\n#ifdef GL_ES\n
precision lowp float;
\n#endif\n
varying vec4 v_fragmentColor;
varying vec2 v_texCoord;
uniform vec4 u_textColor;
void main()
{
vec4 color = texture2D(CC_Texture0, v_texCoord);
//the texture use dual channel 16-bit output for distance_map \n
//float dist = color.b+color.g/256.0; \n
// the texture use single channel 8-bit output for distance_map \n
float dist = color.a;
//todo:Implementation 'fwidth' for glsl 1.0 \n
//float width = fwidth(dist); \n
//assign width for constant will lead to a little bit fuzzy,it's temporary measure.\n
float width = 0.04;
float alpha = smoothstep(0.5-width, 0.5+width, dist) * u_textColor.a;
gl_FragColor = v_fragmentColor * vec4(u_textColor.rgb,alpha);
}
);