Split shell, settings, and compositor into focused modules

compositor/src/render/shaders/rounded_border_shader.frag

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+
+precision highp float;
+
+uniform float alpha;
+uniform vec4 clip_rect;
+uniform float radius;
+uniform float border_width;
+uniform vec4 border_color;
+uniform vec4 border_color_to;
+uniform vec4 gradient_line;
+uniform vec4 focus_color;
+uniform vec4 focus_color_to;
+uniform vec4 focus_gradient_line;
+uniform float focus_mix;
+varying vec2 v_coords;
+
+#if defined(DEBUG_FLAGS)
+uniform float tint;
+#endif
+
+void main() {
+    vec2 point = gl_FragCoord.xy - clip_rect.xy;
+    vec2 half_size = clip_rect.zw * 0.5;
+    vec2 distance = abs(point - half_size) - (half_size - vec2(radius));
+    float signed_distance = length(max(distance, 0.0))
+        + min(max(distance.x, distance.y), 0.0)
+        - radius;
+    float outer_coverage = 1.0 - smoothstep(-0.5, 0.5, signed_distance);
+
+    vec2 inner_half_size = max(half_size - vec2(border_width), vec2(0.0));
+    float inner_radius = max(radius - border_width, 0.0);
+    vec2 inner_distance = abs(point - half_size)
+        - (inner_half_size - vec2(inner_radius));
+    float inner_signed_distance = length(max(inner_distance, 0.0))
+        + min(max(inner_distance.x, inner_distance.y), 0.0)
+        - inner_radius;
+    float inner_coverage = 1.0 - smoothstep(-0.5, 0.5, inner_signed_distance);
+    float coverage = max(outer_coverage - inner_coverage, 0.0);
+    float progress = clamp(dot(gl_FragCoord.xy - gradient_line.xy, gradient_line.zw), 0.0, 1.0);
+    // Interpolate premultiplied endpoints: a transparent endpoint must not
+    // leak its RGB into the visible border or create a dark halo.
+    vec4 from = vec4(border_color.rgb * border_color.a, border_color.a);
+    vec4 to = vec4(border_color_to.rgb * border_color_to.a, border_color_to.a);
+    float focus_progress = clamp(dot(gl_FragCoord.xy - focus_gradient_line.xy, focus_gradient_line.zw), 0.0, 1.0);
+    vec4 focus_from = vec4(focus_color.rgb * focus_color.a, focus_color.a);
+    vec4 focus_to = vec4(focus_color_to.rgb * focus_color_to.a, focus_color_to.a);
+    vec4 color = mix(mix(from, to, progress), mix(focus_from, focus_to, focus_progress), focus_mix) * coverage * alpha;
+
+#if defined(DEBUG_FLAGS)
+    if (tint == 1.0)
+        color = vec4(0.0, 0.2, 0.0, 0.2) + color * 0.8;
+#endif
+
+    gl_FragColor = color;
+}