Fixes label wrong blending and improves performance while enabling outline. (#16717)

This commit is contained in:
James Chen 2016-10-19 10:19:14 +08:00 committed by minggo
parent 90db0eb6bf
commit a5fdc07fca
1 changed files with 21 additions and 6 deletions

View File

@ -15,13 +15,28 @@ uniform vec4 u_textColor;
void main() void main()
{ {
vec4 sample = texture2D(CC_Texture0, v_texCoord); vec4 sample = texture2D(CC_Texture0, v_texCoord);
float fontAlpha = sample.a; float fontAlpha = sample.a; // sample.a == 1 indicates text, a == 0 indicates outline
float outlineAlpha = sample.r; float outlineAlpha = sample.r; // sample.r always > 0
if ((fontAlpha + outlineAlpha) > 0.0){
vec4 color = u_textColor * fontAlpha + u_effectColor * (1.0 - fontAlpha); if (u_effectColor.a > 0.0) // draw outline
gl_FragColor = v_fragmentColor * vec4( color.rgb,max(fontAlpha,outlineAlpha)*color.a); {
if (fontAlpha < 1.0)
{
gl_FragColor = v_fragmentColor * vec4(u_effectColor.rgb, u_effectColor.a * outlineAlpha);
}
else
{
discard; // While drawing outline, text should not be drawn since it will be drawn in next step.
// discard this pixel could improve a little and fix wrong alpha blending if text contains
// alpha channel.
}
} }
else { else if (fontAlpha > 0.0) // draw text
{
gl_FragColor = v_fragmentColor * vec4(u_textColor.rgb, u_textColor.a * fontAlpha);
}
else // discard the pixel in texture rectangle which is transparent
{
discard; discard;
} }
} }