41 lines
1021 B
GLSL
41 lines
1021 B
GLSL
in vec2 TexCoords;
|
|
flat in vec4 fg;
|
|
flat in vec4 bg;
|
|
uniform int backgroundPass;
|
|
|
|
layout(location = 0, index = 0) out vec4 color;
|
|
layout(location = 0, index = 1) out vec4 alphaMask;
|
|
|
|
uniform sampler2D mask;
|
|
|
|
#define COLORED 2
|
|
|
|
void main() {
|
|
if (backgroundPass != 0) {
|
|
if (bg.a == 0.0) {
|
|
discard;
|
|
}
|
|
|
|
alphaMask = vec4(1.0);
|
|
|
|
// Premultiply background color by alpha.
|
|
color = vec4(bg.rgb * bg.a, bg.a);
|
|
} else if ((int(fg.a) & COLORED) != 0) {
|
|
// Color glyphs, like emojis.
|
|
vec4 glyphColor = texture(mask, TexCoords);
|
|
alphaMask = vec4(glyphColor.a);
|
|
|
|
// Revert alpha premultiplication.
|
|
if (glyphColor.a != 0) {
|
|
glyphColor.rgb = vec3(glyphColor.rgb / glyphColor.a);
|
|
}
|
|
|
|
color = vec4(glyphColor.rgb, 1.0);
|
|
} else {
|
|
// Regular text glyphs.
|
|
vec3 textColor = texture(mask, TexCoords).rgb;
|
|
alphaMask = vec4(textColor, textColor.r);
|
|
color = vec4(fg.rgb, 1.0);
|
|
}
|
|
}
|