69 lines
2.2 KiB
GLSL
69 lines
2.2 KiB
GLSL
shader_type canvas_item;
|
|
render_mode blend_premul_alpha;
|
|
|
|
const float TAU = 6.283185307;
|
|
const float PI = 3.1415926536;
|
|
|
|
uniform int num_receptors = 8;
|
|
uniform float receptor_offset = 0.0;
|
|
uniform vec4 line_color : hint_color = vec4(0.0, 0.0, 1.0, 1.0);
|
|
uniform vec4 dot_color : hint_color = vec4(0.0, 0.0, 1.0, 1.0);
|
|
uniform vec4 shadow_color : hint_color = vec4(0.0, 0.0, 0.0, 1.0);
|
|
//uniform float bps = 1.0;
|
|
uniform float line_thickness = 0.006;
|
|
uniform float dot_radius = 0.033;
|
|
uniform float shadow_thickness = 0.01;
|
|
uniform float shadow_thickness_taper = 0.33;
|
|
uniform float px = 0.002; // Represents 1px in UV space, for AA purposes
|
|
|
|
//void vertex() {
|
|
//}
|
|
|
|
float angle_diff(float a, float b) {
|
|
float d = mod((a - b), TAU);
|
|
if (d > PI) d = TAU - d;
|
|
return d;
|
|
}
|
|
|
|
void fragment() {
|
|
if (COLOR.rgba != vec4(1.0, 0.0, 0.0, 1.0)) {
|
|
COLOR.rgba = vec4(0.0);
|
|
lowp float dist = distance(UV, vec2(0.0));
|
|
lowp float angle = atan(-UV.y, UV.x);
|
|
float line_alpha = 0.0;
|
|
float dot_alpha = 0.0;
|
|
float shadow_alpha = 0.0;
|
|
float px2 = px/2.0;
|
|
|
|
float diff = abs(dist - 1.0);
|
|
float d2 = diff - line_thickness;
|
|
if (d2 < -px2){
|
|
line_alpha = 1.0;
|
|
} else if (d2 < shadow_thickness){
|
|
if (d2 < px2)
|
|
line_alpha = 1.0 - (d2 + px2)/px;
|
|
shadow_alpha = 1.0 - min((d2 - shadow_thickness*shadow_thickness_taper)/(shadow_thickness*(1.0-shadow_thickness_taper)), 1.0);
|
|
}
|
|
|
|
// Iterate over all the receptors and check distance to them
|
|
float receptor_spacing = TAU/float(num_receptors);
|
|
for (float rads=receptor_offset; rads<TAU; rads+=receptor_spacing){
|
|
// Check for dot distance
|
|
vec2 uv = vec2(cos(rads), -sin(rads));
|
|
float dist2 = distance(UV, uv);
|
|
float diff2 = dist2 - dot_radius;
|
|
if (diff2 < -px2){
|
|
dot_alpha = 1.0;
|
|
} else if (diff2 < shadow_thickness){
|
|
if (diff2 < px2)
|
|
dot_alpha = 1.0 - (diff2 + px2)/px;
|
|
shadow_alpha = max(shadow_alpha, 1.0-min((diff2 - shadow_thickness*shadow_thickness_taper)/(shadow_thickness*(1.0-shadow_thickness_taper)), 1.0));
|
|
}
|
|
}
|
|
line_alpha = max(line_alpha - dot_alpha, 0.0);
|
|
|
|
COLOR.rgb = (dot_color.rgb*dot_alpha) + (line_color.rgb*line_alpha) + (shadow_color.rgb*shadow_alpha);
|
|
COLOR.a = dot_alpha + line_alpha*(1.0-dot_alpha);
|
|
COLOR.a = COLOR.a + shadow_alpha*(1.0-COLOR.a);
|
|
COLOR.a = clamp(COLOR.a, 0.0, 1.0); }
|
|
} |