axmol/cocos/renderer/shaders/label_outline.frag

50 lines
1.4 KiB
GLSL

/*
* LICENSE ???
*/
const char* labelOutline_frag = R"(
#ifdef GL_ES
precision lowp float;
#endif
varying vec4 v_fragmentColor;
varying vec2 v_texCoord;
uniform vec4 u_effectColor;
uniform vec4 u_textColor;
uniform sampler2D u_texture;
#ifdef GL_ES
uniform lowp int u_effectType; // 0: None (Draw text), 1: Outline, 2: Shadow
#else
uniform int u_effectType;
#endif
void main()
{
vec4 sample = texture2D(u_texture, v_texCoord);
// fontAlpha == 1 means the area of solid text (without edge)
// fontAlpha == 0 means the area outside text, including outline area
// fontAlpha == (0, 1) means the edge of text
float fontAlpha = sample.a;
// outlineAlpha == 1 means the area of 'solid text' and 'solid outline'
// outlineAlpha == 0 means the transparent area outside text and outline
// outlineAlpha == (0, 1) means the edge of outline
float outlineAlpha = sample.r;
if (u_effectType == 0) // draw text
{
gl_FragColor = v_fragmentColor * vec4(u_textColor.rgb, u_textColor.a * fontAlpha);
}
else if (u_effectType == 1) // draw outline
{
// multipy (1.0 - fontAlpha) to make the inner edge of outline smoother and make the text itself transparent.
gl_FragColor = v_fragmentColor * vec4(u_effectColor.rgb, u_effectColor.a * outlineAlpha * (1.0 - fontAlpha));
}
else // draw shadow
{
gl_FragColor = v_fragmentColor * vec4(u_effectColor.rgb, u_effectColor.a * outlineAlpha);
}
}
)";