21 lines
1.6 KiB
GLSL
21 lines
1.6 KiB
GLSL
mediump vec3 blend_normal(mediump vec4 base, mediump vec4 stroke, mediump float alpha_tot)
|
|
{ return mix(base.rgb, stroke.rgb, stroke.a/alpha_tot); }
|
|
mediump vec3 blend_multiply(mediump vec4 base, mediump vec4 stroke, mediump float alpha_tot)
|
|
{ return mix(stroke.rgb, mix(base.rgb, base.rgb*stroke.rgb, stroke.a/alpha_tot), base.a/alpha_tot); }
|
|
mediump vec3 blend_screen(mediump vec4 base, mediump vec4 stroke, mediump float alpha_tot)
|
|
{ return mix(stroke.rgb, mix(base.rgb, 1.0-(1.0-base.rgb)*(1.0-stroke.rgb), stroke.a/alpha_tot), base.a/alpha_tot); }
|
|
mediump vec3 blend_colorDodge(mediump vec4 base, mediump vec4 stroke, mediump float alpha_tot)
|
|
{ return mix(stroke.rgb, mix(base.rgb, base.rgb/(1.0-stroke.rgb), stroke.a/alpha_tot), base.a/alpha_tot); }
|
|
mediump vec3 blend_overlay(mediump vec4 base, mediump vec4 stroke, mediump float alpha_tot)
|
|
{ return mix(stroke.rgb, mix(base.rgb, mix(2.0*base.rgb*stroke.rgb, 1.0-2.0*(1.0-base.rgb)*(1.0-stroke.rgb), floor(base.rgb*2.0)), stroke.a/alpha_tot), base.a/alpha_tot); }
|
|
mediump vec4 blend(mediump vec4 base, mediump vec4 stroke, int mode) {
|
|
mediump float contribution = (1.0 - base.a) * stroke.a;
|
|
mediump float alpha_tot = base.a + contribution;
|
|
if (mode == 0) return vec4(blend_normal(base, stroke, alpha_tot), alpha_tot);
|
|
else if (mode == 1) return vec4(blend_multiply(base, stroke, alpha_tot), alpha_tot);
|
|
else if (mode == 2) return vec4(blend_screen(base, stroke, alpha_tot), alpha_tot);
|
|
else if (mode == 3) return vec4(blend_colorDodge(base, stroke, alpha_tot), alpha_tot);
|
|
else if (mode == 4) return vec4(blend_overlay(base, stroke, alpha_tot), alpha_tot);
|
|
else return vec4(1.0, 0.0, 0.0, 1.0);
|
|
}
|