Added passes for premultiplied alpha, fixed alpha blending for native transparency

shaders/circle.glsl

@@ -1,7 +1,7 @@
 /* center radius (pixels) */
 #define C_RADIUS 128
 /* center line thickness (pixels) */
-#define C_LINE 2
+#define C_LINE 1.5
 /* outline color */
 #define OUTLINE #333333
 /* Amplify magnitude of the results each bar displays */

shaders/circle/3.frag

@@ -0,0 +1 @@
+#include ":util/premultiply.frag"

shaders/radial/1.frag

@@ -29,10 +29,10 @@ out vec4 fragment;
 #define PI 3.14159265359
 
 void main() {
-
+    
     #if USE_ALPHA > 0
-    #define APPLY_FRAG(f, c) f = vec4(f.rgb * f.a + c.rgb * (1 - f.a), max(c.a, f.a))
-    fragment.a;
+    #define APPLY_FRAG(f, c) f = vec4(f.rgb * f.a + c.rgb * (1 - clamp(f.a, 0, 1)), max(c.a, f.a))
+    fragment = #00000000;
     #else
     #define APPLY_FRAG(f, c) f = c
     #endif

shaders/radial/2.frag

@@ -0,0 +1 @@
+#include ":util/premultiply.frag"

shaders/rc.glsl

@@ -28,10 +28,9 @@
 
 /* Set window background opacity mode. Possible values are:
    
-   "native" - True transparency provided by the compositor.
-              Requires GLFW 3.3+ and an active compositor. Can
-              reduce performance on some systems, and will not
-              blend with the visualizer's alpha layer.
+   "native" - True transparency provided by the compositor. Can
+              reduce performance on some systems, depending on
+              the compositor used.
    
    "xroot"  - Maintain a copy of the root window's pixmap
               (usually the desktop background) to provide a
@@ -54,8 +53,8 @@
 #request setgeometry 0 0 800 600
 
 /* Window background color (RGB format).
-   Only works with `setopacity "none"` */
-#request setbg 000000
+   Does not work with `setopacity "xroot"` */
+#request setbg 00000000
 
 /* (X11 only) EWMH Window type. Possible values are:
    
@@ -68,7 +67,7 @@
    
    https://standards.freedesktop.org/wm-spec/wm-spec-1.3.html#idm140130317606816
 */
-#request setxwintype "desktop"
+#request setxwintype "normal"
 
 /* (X11 only) EWMH Window state atoms (multiple can be specified).
    Possible values are:

shaders/util/premultiply.frag

@@ -0,0 +1,15 @@
+
+#request nativeonly true
+
+#request uniform "prev" tex
+uniform sampler2D tex;
+
+out vec4 fragment;
+in vec4 gl_FragCoord;
+
+void main() {
+    fragment = texelFetch(tex, ivec2(gl_FragCoord.x, gl_FragCoord.y), 0);
+    #if PREMULTIPLY_ALPHA > 0
+    fragment.rgb *= fragment.a;
+    #endif
+}